98-457: Arctia plantaginis , the wood tiger , is a moth of the family Erebidae . Several subspecies are found in the Holarctic ecozone south to Anatolia , Transcaucasus , northern Iran, Kazakhstan, Mongolia, China , Korea and Japan. One subspecies is endemic to North America. This species was formerly a member of the genus Parasemia , but was moved to Arctia along with the other species of
196-642: A chemical reaction that can produce free radicals . Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants are frequently added to industrial products, such as polymers , fuels , and lubricants , to extend their usable lifetimes. Foods are also treated with antioxidants to forestall spoilage , in particular the rancidification of oils and fats . In cells , antioxidants such as glutathione , mycothiol , or bacillithiol , and enzyme systems like superoxide dismutase , can prevent damage from oxidative stress . Known dietary antioxidants are vitamins A , C , and E , but
294-416: A class of closely related enzymes that catalyze the breakdown of the superoxide anion into oxygen and hydrogen peroxide. SOD enzymes are present in almost all aerobic cells and in extracellular fluids. Superoxide dismutase enzymes contain metal ion cofactors that, depending on the isozyme, can be copper, zinc, manganese or iron. In humans, the copper/zinc SOD is present in the cytosol , while manganese SOD
392-401: A few organisms, and can be pathogens or virulence factors . The interactions between these different antioxidants may be synergistic and interdependent. The action of one antioxidant may therefore depend on the proper function of other members of the antioxidant system. The amount of protection provided by any one antioxidant will also depend on its concentration, its reactivity towards
490-406: A frequent phenotype in many populations, suggesting there are other selection pressures favoring white morphs. A possible explanation for the persistence of white morphs despite their higher predation rates is selection heterogeneity; in other words, due to the wide geographic distribution of the wood tiger moth, different populations experience vastly different selective pressures. One consideration
588-549: A group of insects that includes all members of the order Lepidoptera that are not butterflies . They were previously classified as suborder Heterocera, but the group is paraphyletic with respect to butterflies (suborder Rhopalocera) and neither subordinate taxon is used in modern classifications. Moths make up the vast majority of the order. There are approximately 160,000 species of moth, many of which have yet to be described. Most species of moth are nocturnal , although there are also crepuscular and diurnal species. While
686-404: A laboratory study showed that yellow males had lower mating success compared to white males. This trade-off between reproductive success and predator avoidance could explain why two polymorphisms exist. Females tend to attract males during the day, and they group together at dusk. It has been observed that once attracted to a group of females, male P. plantaginis will readily mate with females of
784-837: A poisonous, toxic, or otherwise unpalatable or unprofitable effect to predators. Typically, aposematic species experience strong selection favoring monomorphic populations. As a specific warning signal phenotype becomes more common in an environment, more and more predators learn to avoid individuals bearing such signals. In P. plantaginis , a distinct hindwing pattern of bands and splotches of white or yellow on black warns predators of its chemical defenses. Populations of P. plantaginis , are, however, almost always polymorphic, with males exhibiting varying degrees of either yellow or white melanized banding patterns. Yellow morphs show stronger warning signals and experience lower predation rates and longer predator-hesitation. White morphs are preyed upon significantly more by birds than yellow morphs, but persist as
882-638: A related species Arctica villa , most likely due to their similar sex pheromones. Similarly, female P. plantaginis are also attracted to male Artica villa s. Flight behavior in populations of P. plantaginis vary between color morphs and are under frequency dependent selection. In outdoor cage experiments of populations with various frequencies of yellow and white male morphs, researches found that white morphs were significantly more active and had longer periods of sustained activity than yellow morphs across all treatment groups. In groups with higher frequencies of yellow morphs, overall flying activity for both morphs
980-592: A single morphological phenotype, the differential selective pressures experienced by various populations of the species likely leads to the maintenance of its widespread polymorphism. Wood tiger moths are polyphagous , meaning their diet can vary significantly. Eating different host plants can result in different immune function and overall life history traits; one example of this is shown by wood tiger moth caterpillars that feed on ribwort plantain. These plant contain high levels of iridoid glycosides, which help caterpillars produce defensive chemicals. A 2015 study showed that
1078-421: A vitamin by oxidizing polypeptides, appears to have a mostly antioxidant action in the human body. As with the chemical antioxidants, cells are protected against oxidative stress by an interacting network of antioxidant enzymes. Here, the superoxide released by processes such as oxidative phosphorylation is first converted to hydrogen peroxide and then further reduced to give water. This detoxification pathway
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#17327973435791176-445: A warning signal comes at the expense of immune function. Basically, there is a trade off between immune function and predatory defense. Thus predation is an import factor when considering the evolution of pathogen virulence and host immunity. Aposematism is common in many Lepidoptera species; it is an adaptive mechanism in which prey produce conspicuous warning signals. In the wood tiger moth, conspicuous coloration patterns communicate
1274-440: Is glutathione , which is made from amino acids. As any glutathione in the gut is broken down to free cysteine, glycine and glutamic acid before being absorbed, even large oral intake has little effect on the concentration of glutathione in the body. Although large amounts of sulfur-containing amino acids such as acetylcysteine can increase glutathione, no evidence exists that eating high levels of these glutathione precursors
1372-769: Is a significant food resource in southern Africa . Another saturniid used as food is the cavorting emperor ( Usta terpsichore ). In one country alone, Congo , more than 30 species of moth larvae are harvested. Some are sold not only in the local village markets, but are shipped by the ton from one country to another. Nocturnal insectivores often feed on moths; these include some bats , some species of owls and other species of birds . Moths also are eaten by some species of lizards , amphibians , cats , dogs , rodents , and some bears . Moth larvae are vulnerable to being parasitized by Ichneumonidae . Baculoviruses are parasite double-stranded DNA insect viruses that are used mostly as biological control agents. They are members of
1470-439: Is also a substrate for the redox enzyme ascorbate peroxidase , a function that is used in stress resistance in plants. Ascorbic acid is present at high levels in all parts of plants and can reach concentrations of 20 millimolar in chloroplasts . Glutathione has antioxidant properties since the thiol group in its cysteine moiety is a reducing agent and can be reversibly oxidized and reduced. In cells, glutathione
1568-532: Is an important part of their physiology, especially in the cooler climates of North America and Eurasia. As latitude increases, populations of P. plantaginis show higher melanization (conversion of resources into melanin). This melanin confers thermoregulatory advantages by increasing a male moth's ability to absorb radiation. This increased melanization comes at a cost, however, as it is costly to produce, and thus male moths with more melanization suffer increased predation as their warning signals are weaker. Thus it
1666-434: Is an important, innate immune response that occurs in invertebrates to protect against a variety of parasites and pathogens. The antioxidants serve to protect cells from damage incurred by the creation of free radicals resulting from the encapsulation reaction. In environments where the pathogen load is likely to be high, the food ingested by an individual moth is important in building its defense mechanisms. Birds and ants are
1764-548: Is an unusual enzyme since, although hydrogen peroxide is its only substrate, it follows a ping-pong mechanism . Here, its cofactor is oxidised by one molecule of hydrogen peroxide and then regenerated by transferring the bound oxygen to a second molecule of substrate. Despite its apparent importance in hydrogen peroxide removal, humans with genetic deficiency of catalase — " acatalasemia " — or mice genetically engineered to lack catalase completely, experience few ill effects. Peroxiredoxins are peroxidases that catalyze
1862-426: Is associated with increased mortality, but saw no significant effect from vitamin C. No health risk was seen when all the randomized controlled studies were examined together, but an increase in mortality was detected when only high-quality and low-bias risk trials were examined separately. As the majority of these low-bias trials dealt with either elderly people , or people with disease, these results may not apply to
1960-459: Is beneficial for healthy adults. Measurement of polyphenol and carotenoid content in food is not a straightforward process, as antioxidants collectively are a diverse group of compounds with different reactivities to various reactive oxygen species. In food science analyses in vitro, the oxygen radical absorbance capacity (ORAC) was once an industry standard for estimating antioxidant strength of whole foods, juices and food additives, mainly from
2058-464: Is capable of producing target-specific chemical defense fluids in response to predation threats. Warning signals show no phenotypic plasticity in adult wood tiger moths. The shapes and patterning of adult warning signals are entirely determined during resource allocation of the larval stage. Once an adult metamorphoses, their warning signal phenotype can no longer change. Yellow morphs are able to avoid predation more readily than white morphs; however,
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#17327973435792156-429: Is commonly used in the production of commercial, industrial lubricants and rubber products and it also acts as a supplement for automotive engine oils. The vast majority of complex life on Earth requires oxygen for its metabolism, but this same oxygen is a highly reactive element that can damage living organisms. Organisms contain chemicals and enzymes that minimize this oxidative damage without interfering with
2254-540: Is considered more effective, but there are concerns over its effects on human health. Despite being commonly thought to be undertaken by all moths, only the larvae of several moth species eat animal fibres, creating holes in articles of clothing, in particular those made of wool. Most species do not eat fabrics, and some moth adults do not even eat at all. Some, like the Luna , Polyphemus , Atlas , Promethea , cecropia , and other large moths do not have mouth parts. This
2352-400: Is currently unknown. One hypothesis is called celestial or transverse orientation. By maintaining a constant angular relationship to a bright celestial light, such as the moon, they can fly in a straight line. Celestial objects are so far away that, even after travelling great distances, the change in angle between the moth and the light source is negligible; further, the moon will always be in
2450-406: Is extraordinarily variable. The wingspan is 32–38 mm. Normally, it has a black forewing in both sexes, with moderately broad, ivory yellow bands. In the male, the hindwing is yellow or white with an irregular marginal band, which is often interrupted, and two or three submarginal spots. The basal portion of the hindwing bears black streaks at the margin of the cell and before the anal margin. In
2548-446: Is immune variation. A 2013 study demonstrated that male yellow and white larvae saw different survival rates when reared in aggregations; yellow male survived to pupate better in aggregations than white males did, which may reflect different immune investments. In aggregations, white males saw better ability to encapsulate pathogens, while yellow males had higher hemolymph (equivalent to insect 'blood') lytic activity (virus attacking). Thus
2646-401: Is itself readily oxidized. Research into how vitamin E prevents the process of lipid peroxidation led to the identification of antioxidants as reducing agents that prevent oxidative reactions, often by scavenging reactive oxygen species before they can damage cells. Antioxidants are used as food additives to help guard against food deterioration . Exposure to oxygen and sunlight are
2744-462: Is maintained in the reduced form by the enzyme glutathione reductase and in turn reduces other metabolites and enzyme systems, such as ascorbate in the glutathione-ascorbate cycle , glutathione peroxidases and glutaredoxins , as well as reacting directly with oxidants. Due to its high concentration and its central role in maintaining the cell's redox state, glutathione is one of the most important cellular antioxidants. In some organisms glutathione
2842-546: Is only 0.5% per year with an increase to 4.5% per year at UA supersaturation levels (535+ μmol/L). Many of these aforementioned studies determined UA's antioxidant actions within normal physiological levels, and some found antioxidant activity at levels as high as 285 μmol/L. Ascorbic acid or vitamin C , an oxidation-reduction ( redox ) catalyst found in both animals and plants, can reduce, and thereby neutralize, reactive oxygen species such as hydrogen peroxide. In addition to its direct antioxidant effects, ascorbic acid
2940-541: Is partly offset by the involvement of carotenoids in photoinhibition , and in algae and cyanobacteria, by large amount of iodide and selenium , which involves these antioxidants reacting with over-reduced forms of the photosynthetic reaction centres to prevent the production of reactive oxygen species. Physiological antioxidants are classified into two broad divisions, depending on whether they are soluble in water ( hydrophilic ) or in lipids ( lipophilic ). In general, water-soluble antioxidants react with oxidants in
3038-470: Is possible because they live off the food stores from when they were a caterpillar, and only live a short time as an adult (roughly a week for some species). Many species of adult moths do however eat: for instance, many will drink nectar . Items of fabric infested by clothes moth larvae may be treated by freezing them for several days at a temperature below −8 °C (18 °F). Some moths are farmed for their economic value. The most notable of these
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3136-460: Is present in the mitochondrion . There also exists a third form of SOD in extracellular fluids , which contains copper and zinc in its active sites. The mitochondrial isozyme seems to be the most biologically important of these three, since mice lacking this enzyme die soon after birth. In contrast, the mice lacking copper/zinc SOD (Sod1) are viable but have numerous pathologies and a reduced lifespan (see article on superoxide ), while mice without
3234-553: Is replaced by other thiols, such as by mycothiol in the Actinomycetes , bacillithiol in some gram-positive bacteria , or by trypanothione in the Kinetoplastids . Vitamin E is the collective name for a set of eight related tocopherols and tocotrienols , which are fat-soluble vitamins with antioxidant properties. Of these, α-tocopherol has been most studied as it has the highest bioavailability , with
3332-413: Is the silkworm , the larva of the domesticated moth Bombyx mori . It is farmed for the silk with which it builds its cocoon . As of 2002 , the silk industry produces more than 130 million kilograms of raw silk, worth about 250 million U.S. dollars , each year. Not all silk is produced by Bombyx mori . There are several species of Saturniidae that also are farmed for their silk, such as
3430-426: Is the result of multiple enzymes, with superoxide dismutases catalysing the first step and then catalases and various peroxidases removing hydrogen peroxide. As with antioxidant metabolites, the contributions of these enzymes to antioxidant defenses can be hard to separate from one another, but the generation of transgenic mice lacking just one antioxidant enzyme can be informative. Superoxide dismutases (SODs) are
3528-471: Is thought that due to the various climatic conditions of populations of wood tiger moth, there are different costs and benefits to produces more melanin, which serves to maintain the global diversity of warning signals that we see throughout the species. In both yellow and white male phenotypes, individuals with more melanin had a heightened ability to trap heat but an increased predation rate due to its weaker and less effective signal. Moth Moths are
3626-422: Is when a pattern creates an illusion that makes discerning the edges of an object difficult. It essentially destroys the appearance of any outline the object may have. Though the idea of disruptive coloration, which is clearly a camouflage technique, seems counterintuitive in aposematism, it has been demonstrated that the same coloration pattern on a moth can act as either a warning signal or a camouflage depending on
3724-592: The Baculoviridae , a family that is restricted to insects. Most baculovirus isolates have been obtained from insects, in particular from Lepidoptera. There is evidence that ultrasound in the range emitted by bats causes flying moths to make evasive maneuvers. Ultrasonic frequencies trigger a reflex action in the noctuid moth that causes it to drop a few centimeters or inches in its flight to evade attack, and tiger moths can emit clicks to foil bats' echolocation. The fungus Ophiocordyceps sinensis infects
3822-522: The Carboniferous period, but only evolved their characteristic proboscis alongside the rise of angiosperms in the Cretaceous period. The modern English word moth comes from Old English moððe ( cf. Northumbrian mohðe ) from Common Germanic (compare Old Norse motti , Dutch mot , and German Motte all meaning 'moth'). Its origins are possibly related to
3920-546: The Fenton reaction . While ascorbic acid is effective antioxidant, it can also oxidatively change the flavor and color of food. With the presence of transition metals, there are low concentrations of ascorbic acid that can act as a radical scavenger in the Fenton reaction. The relative importance of the antioxidant and pro-oxidant activities of antioxidants is an area of current research, but vitamin C, which exerts its effects as
4018-430: The bioavailability of antioxidants, such as some carotenoids in vegetables. Processed food contains fewer antioxidant vitamins than fresh and uncooked foods, as preparation exposes food to heat and oxygen. Other antioxidants are not obtained from the diet, but instead are made in the body. For example, ubiquinol (coenzyme Q) is poorly absorbed from the gut and is made through the mevalonate pathway . Another example
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4116-470: The butterflies form a monophyletic group, the moths, comprising the rest of the Lepidoptera, do not. Many attempts have been made to group the superfamilies of the Lepidoptera into natural groups, most of which fail because one of the two groups is not monophyletic: Microlepidoptera and Macrolepidoptera , Heterocera and Rhopalocera , Jugatae and Frenatae, Monotrysia , and Ditrysia . Although
4214-440: The endocrine system and may increase tumor development rates due to 1,1-dimethylhydrazine . BHT-Q can cause DNA damage and mismatches through the cleavage process, generating superoxide radicals. DBP is toxic to marine life if exposed long-term. Phenolic antioxidants have low biodegradability, but they do not have severe toxicity toward aquatic organisms at low concentrations. Another type of antioxidant, diphenylamine (DPA) ,
4312-464: The gastrointestinal tract and preventing them from being absorbed. Examples are oxalic acid , tannins and phytic acid , which are high in plant-based diets. Calcium and iron deficiencies are not uncommon in diets in developing countries where less meat is eaten and there is high consumption of phytic acid from beans and unleavened whole grain bread. However, germination, soaking, or microbial fermentation are all household strategies that reduce
4410-673: The hydroxyl radical (·OH), and the superoxide anion (O 2 ). The hydroxyl radical is particularly unstable and will react rapidly and non-specifically with most biological molecules. This species is produced from hydrogen peroxide in metal-catalyzed redox reactions such as the Fenton reaction . These oxidants can damage cells by starting chemical chain reactions such as lipid peroxidation , or by oxidizing DNA or proteins. Damage to DNA can cause mutations and possibly cancer , if not reversed by DNA repair mechanisms, while damage to proteins causes enzyme inhibition, denaturation , and protein degradation . The use of oxygen as part of
4508-629: The 12-k Da protein thioredoxin and its companion thioredoxin reductase . Proteins related to thioredoxin are present in all sequenced organisms. Plants, such as Arabidopsis thaliana , have a particularly great diversity of isoforms. The active site of thioredoxin consists of two neighboring cysteines, as part of a highly conserved CXXC motif , that can cycle between an active dithiol form (reduced) and an oxidized disulfide form. In its active state, thioredoxin acts as an efficient reducing agent, scavenging reactive oxygen species and maintaining other proteins in their reduced state. After being oxidized,
4606-528: The Alpine regions of Italy, Austria and Switzerland indicated a single whole population. Pairwise Fst values, AMOVA and COl results showed little to no differentiation between populations during the two sampling years of 2009 and 2010. This overall high genetic diversity and low differentiation between populations suggests much gene flow and high population density in P. plantaginis populations. Though this extreme gene flow would be thought to lead to fixation of
4704-754: The Old English maða meaning ' maggot ' or from the root of midge which until the 16th century was used mostly to indicate the larva , usually in reference to devouring clothes. Moth larvae, or caterpillars , make cocoons from which they emerge as fully grown moths with wings. Some moth caterpillars dig holes in the ground, where they live until they are ready to turn into adult moths. Moths evolved long before butterflies; moth fossils have been found that may be 190 million years old. Both types of Lepidoptera are thought to have co-evolved with flowering plants , mainly because most modern species, both as adults and larvae, feed on flowering plants. One of
4802-848: The Rocky Mountain region to southern New Mexico, with isolated populations occurring in Arizona and the Sierra Nevada mountains of California and Nevada. P. plantaginis prefer slightly moist areas, like meadows with nearby streams. Adults like to spend time close to lupine stands, which are meadows of plants from the genus Lupinus . It is estimated that over 250 annual and perennial species of this genus Lupinus are distributed throughout both montane and lowland habitats, with hugely diverse regions found in North and South America. A two-year study of populations of P. plantaginis throughout
4900-414: The ability of P. plantaginis to secrete two different chemical fluids as defense mechanisms in response to two different types of predators. Along with its colorful, conspicuous hindwing color patterns, these moths secrete defense fluids from their abdomen and thoracic glands. The abdominal fluids deterred ants and not birds, while thoracic fluids deterred birds but not ants, suggesting that a single species
4998-404: The active reduced form through reduction by other antioxidants, such as ascorbate, retinol or ubiquinol. This is in line with findings showing that α-tocopherol, but not water-soluble antioxidants, efficiently protects glutathione peroxidase 4 ( GPX4 )-deficient cells from cell death. GPx4 is the only known enzyme that efficiently reduces lipid-hydroperoxides within biological membranes. However,
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#17327973435795096-406: The active thioredoxin is regenerated by the action of thioredoxin reductase, using NADPH as an electron donor . The glutathione system includes glutathione, glutathione reductase , glutathione peroxidases , and glutathione S -transferases . This system is found in animals, plants and microorganisms. Glutathione peroxidase is an enzyme containing four selenium - cofactors that catalyzes
5194-739: The activity of antioxidant enzymes, such as glutathione reductase and superoxide dismutase . (See also selenium in biology and zinc in biology .) retinol (vitamin A): 1–3 Uric acid has the highest concentration of any blood antioxidant and provides over half of the total antioxidant capacity of human serum. Uric acid's antioxidant activities are also complex, given that it does not react with some oxidants, such as superoxide , but does act against peroxynitrite , peroxides , and hypochlorous acid . Concerns over elevated UA's contribution to gout must be considered one of many risk factors. By itself, UA-related risk of gout at high levels (415–530 μmol/L)
5292-631: The ailanthus moth ( Samia cynthia group of species), the Chinese oak silkmoth ( Antheraea pernyi ), the Assam silkmoth ( Antheraea assamensis ), and the Japanese silk moth ( Antheraea yamamai ). The larvae of many species are used as food , particularly in Africa, where they are an important source of nutrition. The mopane worm, the caterpillar of Gonimbrasia belina , from the family Saturniidae,
5390-459: The backdrop. Wood tiger moths exhibit a behavior where they essentially 'feign death' by dropping suddenly on to the ground in the presence of a predator and taking on a specific, rigid posture with folded legs. Once on the ground, the moths are much more difficult to detect. This suggests that the hindwing pattern of the wood tiger moth can switch instantly from conspicuous to camouflage, which has obvious adaptive advantages. A 2017 study highlighted
5488-521: The beneficial effect of oxygen. In general, antioxidant systems either prevent these reactive species from being formed, or remove them, thus minimizing their damage. Reactive oxygen species can have useful cellular functions, such as redox signaling . Thus, ideally, antioxidant systems do not remove oxidants entirely, but maintain them at some optimum concentration. Reactive oxygen species produced in cells include hydrogen peroxide (H 2 O 2 ), hypochlorous acid (HClO), and free radicals such as
5586-476: The body preferentially absorbing and metabolising this form. It has been claimed that the α-tocopherol form is the most important lipid-soluble antioxidant, and that it protects membranes from oxidation by reacting with lipid radicals produced in the lipid peroxidation chain reaction. This removes the free radical intermediates and prevents the propagation reaction from continuing. This reaction produces oxidised α-tocopheroxyl radicals that can be recycled back to
5684-496: The breakdown of hydrogen peroxide and organic hydroperoxides. There are at least four different glutathione peroxidase isozymes in animals. Glutathione peroxidase 1 is the most abundant and is a very efficient scavenger of hydrogen peroxide, while glutathione peroxidase 4 is most active with lipid hydroperoxides. Surprisingly, glutathione peroxidase 1 is dispensable, as mice lacking this enzyme have normal lifespans, but they are hypersensitive to induced oxidative stress. In addition,
5782-505: The cell cytosol and the blood plasma , while lipid-soluble antioxidants protect cell membranes from lipid peroxidation . These compounds may be synthesized in the body or obtained from the diet. The different antioxidants are present at a wide range of concentrations in body fluids and tissues, with some such as glutathione or ubiquinone mostly present within cells, while others such as uric acid are more systemically distributed (see table below). Some antioxidants are only found in
5880-505: The development of many antioxidant pigments – particularly during the Jurassic period – as chemical defences against reactive oxygen species that are byproducts of photosynthesis . Originally, the term antioxidant specifically referred to a chemical that prevented the consumption of oxygen. In the late 19th and early 20th centuries, extensive study concentrated on the use of antioxidants in important industrial processes, such as
5978-440: The earliest known species that is thought to be an ancestor of moths is Archaeolepis mane . Its fossil fragments show scaled wings that are similar to caddisflies in their veining. Some moths, particularly their caterpillars , can be major agricultural pests in many parts of the world. Examples include corn borers and bollworms . The caterpillar of the spongy moth ( Lymantria dispar ) causes severe damage to forests in
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#17327973435796076-512: The efficacy of certain anticancer medication and radiation therapy . Pharmaceuticals and supplements that have antioxidant properties suppress the formation of free radicals by inhibiting oxidation processes. Radiation therapy induce oxidative stress that damages essential components of cancer cells, such as proteins, nucleic acids, and lipids that comprise cell membranes. Relatively strong reducing acids can have antinutrient effects by binding to dietary minerals such as iron and zinc in
6174-454: The extracellular SOD have minimal defects (sensitive to hyperoxia ). In plants, SOD isozymes are present in the cytosol and mitochondria, with an iron SOD found in chloroplasts that is absent from vertebrates and yeast . Catalases are enzymes that catalyse the conversion of hydrogen peroxide to water and oxygen, using either an iron or manganese cofactor. This protein is localized to peroxisomes in most eukaryotic cells. Catalase
6272-733: The families Erebidae and Sphingidae , may be the key pollinators for some flowering plants in the Himalayan ecosystem. The roles of moths as pollinators have been studied less frequently than those of diurnal pollinators, but recent studies have established that moths are important, but often overlooked, nocturnal pollinators of a wide range of plants. Some researchers say it is likely that many plants thought to be dependent on bees for pollination also rely on moths, which have historically been less observed because they pollinate mainly at night. Moths frequently appear to circle artificial lights. The reason for this behavior (positive phototaxis )
6370-515: The family Tineidae are commonly regarded as pests because their larvae eat fabric such as clothes and blankets made from natural proteinaceous fibers such as wool or silk . They are less likely to eat mixed materials containing some artificial fibers. There are some reports that they may be repelled by the scent of wood from juniper and cedar , by lavender , or by other natural oils; however, many consider this unlikely to prevent infestation. Naphthalene (the chemical used in mothballs )
6468-435: The female, the hindwing is red above with the base strongly black. Numerous aberrations have been found and named, which often occur predominantly, and only exceptionally among typical specimens. Major aberrations are listed by Seitz, 1913. There are populations throughout the globe, but most common in northern latitudes of North America and Eurasia. The North American populations range from Alaska to Manitoba, and south through
6566-665: The formation of engine-fouling residues. Antioxidant polymer stabilizers are widely used to prevent the degradation of polymers , such as rubbers, plastics and adhesives , that causes a loss of strength and flexibility in these materials. Polymers containing double bonds in their main chains, such as natural rubber and polybutadiene , are especially susceptible to oxidation and ozonolysis . They can be protected by antiozonants . Oxidation can be accelerated by UV radiation in natural sunlight to cause photo-oxidation . Various specialised light stabilisers, such as HALS may be added to plastics to prevent this. An overview of some of
6664-406: The genera Acerbia , Pararctia , Parasemia , Platarctia , and Platyprepia . P. plantaginis males occur predominantly in two distinct color phenotypes: yellow and white. They are aposematic , meaning their colorations serve to deter predators from attacking. In populations of aposematic species, it is common to have a single coloration phenotype dominate, because predators better learn to avoid
6762-406: The general population. This meta-analysis was later repeated and extended by the same authors, confirming the previous results. These two publications are consistent with some previous meta-analyses that also suggested that vitamin E supplementation increased mortality, and that antioxidant supplements increased the risk of colon cancer . Beta-carotene may also increase lung cancer . Overall,
6860-662: The glutathione S -transferases show high activity with lipid peroxides. These enzymes are at particularly high levels in the liver and also serve in detoxification metabolism. The dietary antioxidant vitamins A, C, and E are essential and required in specific daily amounts to prevent diseases. Polyphenols , which have antioxidant properties in vitro due to their free hydroxy groups , are extensively metabolized by catechol-O-methyltransferase which methylates free hydroxyl groups, and thereby prevents them from acting as antioxidants in vivo. Common pharmaceuticals (and supplements) with antioxidant properties may interfere with
6958-702: The iridoid glycosides present in plantain-eating larvae is sufficient to deter both ants and parasitoids. Though it may benefit caterpillars to intake more plant compounds that can help produce defensive chemicals (depending on the plant), this process can be costly and energy intensive for caterpillars. As polyphagous larvae, this process of detoxification and toxin sequestration can be especially costly if their physiology has to support detoxification processes for different types of plants and compounds. Investing more in detoxification as larvae results in lower reproductive output as adults. P. plantaginis are capital breeders, which means that they do not feed as adults, and thus
7056-664: The large number of clinical trials carried out on antioxidant supplements suggest that either these products have no effect on health, or that they cause a small increase in mortality in elderly or vulnerable populations. A 2017 review showed that taking antioxidant dietary supplements before or after exercise is unlikely to produce a noticeable reduction in muscle soreness after a person exercises. Antioxidant vitamins are found in vegetables, fruits, eggs, legumes and nuts. Vitamins A, C, and E can be destroyed by long-term storage or prolonged cooking. The effects of cooking and food processing are complex, as these processes can also increase
7154-644: The larvae of many different species of moths. Moths, like butterflies, bees and other more popularly recognized pollinating insects, serve an essential role as pollinators for many flowering plants, including species that bees do not visit. Nocturnal moths fly from flower to flower to feed on nectar during the night much as their diurnal relatives do during the day. A study conducted in the UK found moths dusted with pollen from 47 different plant species, including seven species largely ignored by bees. Some studies indicate that certain species of moths, such as those belonging to
7252-562: The larval diet is incredibly important component in adult fitness. Males are, on average, smaller than females but experience a relatively similar rate of development. Generally a longer development time correlates with a larger pupal mass, and in females, pupal mass correlates with total lifetime eggs produced. As a polyphagous species, the life history traits of P. plantaginis depend on its habitat and diet. In P. plantaginis , high anti-oxidant intake from their diet significantly increases their ability to encapsulate pathogens. Encapsulation
7350-424: The light source. Studies have found that light pollution caused by increasing use of artificial lights has either led to a severe decline in moth population in some parts of the world or has severely disrupted nocturnal pollination. [REDACTED] Quotations related to Moths at Wikiquote Anti-oxidant Antioxidants are compounds that inhibit oxidation (usually occurring as autoxidation ),
7448-484: The more common phenotype and rare phenotypes suffer higher predation. Rare phenotypes are often selected against because predators are less familiar with their aposematic signal. Thus, other selective pressures exist to perpetuate weaker aposematic signals in exchange for other adaptive benefits. P. plantaginis has become a common model for studying the counteracting selective pressures of predation , mate choice , immune function , thermoregulation , and more. This moth
7546-614: The most applied antioxidants for polymer materials is shown below: (Hindered) Phenolic Antioxidants : Act by scavenging free radicals formed during the thermal oxidation process, thus preventing chain reactions that lead to polymer degradation. Examples: butylated hydroxytoluene , 2,4-dimethyl-6- tert -butylphenol , para tertiary butyl phenol , 2,6-di-tert-butylphenol , 1,3,5-Tris(4-(tert-butyl)-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazinane-2,4,6-trione Phosphites : Act by decomposing peroxides into non-radical products, thus preventing further generation of free radicals, and contributing to
7644-541: The most common predators of P. plantaginis , to which the moth has both general and specialized defense mechanisms. The blue tit ( Cyanistes caeruleus ) is a well known predator. Selection by predation can impact host immune defense, as demonstrated by an experiment measuring the virulence of a pathogen Serrate marcescens in Arctia plantaginis larvae. Larvae with smaller warning signals had higher survival rates than those with larger warning signals, suggesting that developing
7742-492: The northeastern United States, where it is an invasive species . In temperate climates, the codling moth causes extensive damage, especially to fruit farms. In tropical and subtropical climates, the diamondback moth ( Plutella xylostella ) is perhaps the most serious pest of brassicaceous crops. Also in sub-Saharan Africa , the African sugarcane borer is a major pest of sugarcane, maize , and sorghum . Several moths in
7840-467: The overall oxidate stability of the polymer. Phosphites are often used in combination with phenolic antioxidants for syngeristic effects. Example: tris(2,4-di-tert-butylphenyl)phosphite Thioesters : Act by decomposing peroxides into non-radical products. Thioesters are also used as co-stabilisers with primary antioxidants. Hindered Amine Light Stabilizers (HALS) : HALS act by scavenging free radicals generated during photo-oxidation, thus preventing
7938-649: The oxidation processes. Antioxidant stabilizers are also added to fat-based cosmetics such as lipstick and moisturizers to prevent rancidity. Antioxidants in cosmetic products prevent oxidation of active ingredients and lipid content. For example, phenolic antioxidants such as stilbenes , flavonoids , and hydroxycinnamic acid strongly absorb UV radiation due to the presence of chromophores . They reduce oxidative stress from sun exposure by absorbing UV light. Antioxidants may be added to industrial products, such as stabilizers in fuels and additives in lubricants , to prevent oxidation and polymerization that leads to
8036-575: The particular reactive oxygen species being considered, and the status of the antioxidants with which it interacts. Some compounds contribute to antioxidant defense by chelating transition metals and preventing them from catalyzing the production of free radicals in the cell. The ability to sequester iron for iron-binding proteins , such as transferrin and ferritin , is one such function. Selenium and zinc are commonly referred to as antioxidant minerals , but these chemical elements have no antioxidant action themselves, but rather are required for
8134-452: The peroxide substrate. Over-oxidation of this cysteine residue in peroxiredoxins inactivates these enzymes, but this can be reversed by the action of sulfiredoxin . Peroxiredoxins seem to be important in antioxidant metabolism, as mice lacking peroxiredoxin 1 or 2 have shortened lifespans and develop hemolytic anaemia , while plants use peroxiredoxins to remove hydrogen peroxide generated in chloroplasts. The thioredoxin system contains
8232-768: The phytate and polyphenol content of unrefined cereal. Increases in Fe, Zn and Ca absorption have been reported in adults fed dephytinized cereals compared with cereals containing their native phytate. High doses of some antioxidants may have harmful long-term effects. The Beta-Carotene and Retinol Efficacy Trial (CARET) study of lung cancer patients found that smokers given supplements containing beta-carotene and vitamin A had increased rates of lung cancer. Subsequent studies confirmed these adverse effects. These harmful effects may also be seen in non-smokers, as one meta-analysis including data from approximately 230,000 patients showed that β-carotene, vitamin A or vitamin E supplementation
8330-766: The polymer material from UV radiation. Vitamins : Naturally occurring antioxidants like Vitamin C and Vitamin E are used for specific applications. Blends : Blends of different types of antioxidants are commonly applied, as they can serve various and multiple purposes. Synthetic phenolic antioxidants (SPAs) and aminic antioxidants have potential human and environmental health hazards. SPAs are common in indoor dust, small air particles, sediment, sewage, river water and wastewater. They are synthesized from phenolic compounds and include 2,6-di-tert-butyl-4-methylphenol (BHT) , 2,6-di-tert-butyl-p-benzoquinone (BHT-Q), 2,4-di-tert-butyl-phenol (DBP) and 3- tert -butyl-4-hydroxyanisole (BHA) . BHT can cause hepatotoxicity and damage to
8428-650: The presence of polyphenols . Earlier measurements and ratings by the United States Department of Agriculture were withdrawn in 2012 as biologically irrelevant to human health, referring to an absence of physiological evidence for polyphenols having antioxidant properties in vivo . Consequently, the ORAC method, derived only from in vitro experiments, is no longer considered relevant to human diets or biology , as of 2010. Alternative in vitro measurements of antioxidant content in foods – also based on
8526-430: The prevention of metal corrosion , the vulcanization of rubber, and the polymerization of fuels in the fouling of internal combustion engines . Early research on the role of antioxidants in biology focused on their use in preventing the oxidation of unsaturated fats , which is the cause of rancidity . Antioxidant activity could be measured simply by placing the fat in a closed container with oxygen and measuring
8624-455: The process for generating metabolic energy produces reactive oxygen species. In this process, the superoxide anion is produced as a by-product of several steps in the electron transport chain . Particularly important is the reduction of coenzyme Q in complex III , since a highly reactive free radical is formed as an intermediate (Q · ). This unstable intermediate can lead to electron "leakage", when electrons jump directly to oxygen and form
8722-408: The rate of oxygen consumption. However, it was the identification of vitamins C and E as antioxidants that revolutionized the field and led to the realization of the importance of antioxidants in the biochemistry of living organisms . The possible mechanisms of action of antioxidants were first explored when it was recognized that a substance with anti-oxidative activity is likely to be one that
8820-403: The reduction of hydrogen peroxide, organic hydroperoxides , as well as peroxynitrite . They are divided into three classes: typical 2-cysteine peroxiredoxins; atypical 2-cysteine peroxiredoxins; and 1-cysteine peroxiredoxins. These enzymes share the same basic catalytic mechanism, in which a redox-active cysteine (the peroxidatic cysteine) in the active site is oxidized to a sulfenic acid by
8918-789: The roles and importance of the various forms of vitamin E are presently unclear, and it has even been suggested that the most important function of α-tocopherol is as a signaling molecule , with this molecule having no significant role in antioxidant metabolism. The functions of the other forms of vitamin E are even less well understood, although γ-tocopherol is a nucleophile that may react with electrophilic mutagens, and tocotrienols may be important in protecting neurons from damage. Antioxidants that are reducing agents can also act as pro-oxidants. For example, vitamin C has antioxidant activity when it reduces oxidizing substances such as hydrogen peroxide; however, it will also reduce metal ions such as iron and copper that generate free radicals through
9016-458: The rules for distinguishing moths from butterflies are not well established, one very good guiding principle is that butterflies have thin antennae and (with the exception of the family Hedylidae ) have small balls or clubs at the end of their antennae. Moth antennae are usually feathery with no ball on the end. The divisions are named by this principle: "club-antennae" (Rhopalocera) or "varied-antennae" (Heterocera). Lepidoptera first evolved during
9114-567: The superoxide anion, instead of moving through the normal series of well-controlled reactions of the electron transport chain. Peroxide is also produced from the oxidation of reduced flavoproteins , such as complex I . However, although these enzymes can produce oxidants, the relative importance of the electron transfer chain to other processes that generate peroxide is unclear. In plants, algae , and cyanobacteria , reactive oxygen species are also produced during photosynthesis , particularly under conditions of high light intensity . This effect
9212-574: The term antioxidant has also been applied to numerous other dietary compounds that only have antioxidant properties in vitro , with little evidence for antioxidant properties in vivo . Dietary supplements marketed as antioxidants have not been shown to maintain health or prevent disease in humans. As part of their adaptation from marine life, terrestrial plants began producing non-marine antioxidants such as ascorbic acid ( vitamin C ), polyphenols , and tocopherols . The evolution of angiosperm plants between 50 and 200 million years ago resulted in
9310-1788: The two main factors in the oxidation of food, so food is preserved by keeping in the dark and sealing it in containers or even coating it in wax, as with cucumbers. However, as oxygen is also important for plant respiration , storing plant materials in anaerobic conditions produces unpleasant flavors and unappealing colors. Consequently, packaging of fresh fruits and vegetables contains an ≈8% oxygen atmosphere. Antioxidants are an especially important class of preservatives as, unlike bacterial or fungal spoilage, oxidation reactions still occur relatively rapidly in frozen or refrigerated food. These preservatives include natural antioxidants such as ascorbic acid (AA, E300) and tocopherols (E306), as well as synthetic antioxidants such as propyl gallate (PG, E310), tertiary butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA, E320) and butylated hydroxytoluene (BHT, E321). Unsaturated fats can be highly susceptible to oxidation, causing rancidification . Oxidized lipids are often discolored and can impart unpleasant tastes and flavors. Thus, these foods are rarely preserved by drying; instead, they are preserved by smoking , salting , or fermenting . Even less fatty foods such as fruits are sprayed with sulfurous antioxidants prior to air drying. Metals catalyse oxidation. Some fatty foods such as olive oil are partially protected from oxidation by their natural content of antioxidants. Fatty foods are sensitive to photooxidation, which forms hydroperoxides by oxidizing unsaturated fatty acids and ester . Exposure to ultraviolet (UV) radiation can cause direct photooxidation and decompose peroxides and carbonyl molecules. These molecules undergo free radical chain reactions, but antioxidants inhibit them by preventing
9408-421: The two types of wood tiger moth may be maintained in populations because they have different immune investments. This is advantageous in thriving in heterogeneous environments with differential risk factors for immune challenges. Though the aposematic signal of a wood tiger moth is highly conspicuous against vegetative scenery, its patterning is less easy to detect when it drops to the ground. Disruptive coloration
9506-441: The upper part of the visual field, or on the horizon. When a moth encounters a much closer artificial light and uses it for navigation, the angle changes noticeably after only a short distance, in addition to being often below the horizon. The moth instinctively attempts to correct by turning toward the light, thereby causing airborne moths to come plummeting downward, and resulting in a spiral flight path that gets closer and closer to
9604-508: Was considerably lower. The data suggest that white male morphs invest less in producing costly warning signals and thus have more energy to invest in flight for both avoiding predation and finding mates. Yellow males, which in previous studies have been shown to be less sexually favored by females than whites, tend to be most active at peak female-calling periods. Wood tiger moths have a limited amount of resources to allocate to different life history traits and adaptive strategies; thermoregulation
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