The Journal of Steroid Biochemistry and Molecular Biology, 2021
Phytoecdysteroids are molecules derived from sterol metabolism and found in many plants. They dis... more Phytoecdysteroids are molecules derived from sterol metabolism and found in many plants. They display a wide array of pharmacological effects on mammals (e.g. anabolic, anti-diabetic). Although these effects have been long established, the molecular targets involved remain to be identified. Like endogenous steroid hormones and bile acids, which are biochemically related, ingested or injected phytoecdysteroids undergo a set of reactions in mammals leading to the formation of numerous metabolites, only some of which have been so far identified, and it is presently unknown whether they represent active metabolites or inactivation products. In the large intestine, ecdysteroids undergo efficient 14-dehydroxylation. Other changes (reductions, epimerization, side-chain cleavage) are also observed, but whether these occur in the liver and/or large intestine is not known. The purpose of this study was to investigate the pharmacokinetics of 20-hydroxyecdysone (20E), the most common phytoecdysteroid, when administered to mice and rats, using, when required, tritium-labelled molecules to permit metabolic tracking. Bioavailability, the distribution of radioactivity and the kinetics of formation of metabolites were followed for 24-48 hours after ingestion and qualitative and quantitative analyses of circulating and excreted compounds were performed. In mice, the digestive tract always contains the majority of the ingested 20E. Within 30 minutes after ingestion, 20E reaches the large intestine, where microorganisms firstly remove the 14-hydroxyl group and reduce the 6-one. Then a very complex set of metabolites (not all of which have yet been identified) appears, which correspond to poststerone derivatives formed in the liver. We have observed that these compounds (like bile acids) undergo an entero-hepatic cycle, involving glucuronide conjugation in the liver and subsequent deconjugation in the intestine. Despite the very short half-life of ecdysteroids in mammals, this entero-hepatic cycle helps to maintain their plasma levels at values which, albeit low (≤0.2 µM), would be sufficient to evoke several pharmacological effects. Similar 20E metabolites were observed in mice and rats; they include in particular 14-deoxy-20E, poststerone and 14-deoxypoststerone and their diverse reduction products; the major products of this metabolism have been unambiguously identified. The major sites of metabolism of exogenous ecdysteroids in mammals are the large intestine and the liver. The entero-hepatic cycle contributes to the metabolism and to maintaining a low, but pharmacologically significant, concentration of ecdysteroids in the blood for ca. 24 hours after ingestion. These data, together with parallel in vitro experiments provide a basis for the identification of 20E metabolite(s) possibly involved in the physiological effects associated with ecdysteroids in mammals.
Les phytoecdysteroides (PEs) sont des analogues des hormones de mue des insectes impliques dans l... more Les phytoecdysteroides (PEs) sont des analogues des hormones de mue des insectes impliques dans la defense des plantes contre les phytophages. Notre travail a pour but de mieux comprendre la voie de biosynthese des PEs et sa regulation chez l’epinard. La 20-hydroxyecdysone (20E) est le PE majoritaire, metaboliquement stable, dont la redistribution au sein de la plante se fait continuellement au profit des feuilles les plus jeunes et aux depens des feuilles âgees. L’etude de la biosynthese de la 20E a partir d’acide mevalonique ainsi que de plusieurs intermediaires putatifs a montre que seules les feuilles âgees sont aptes a realiser la biosynthese dans sa totalite ; la localisation subcellulaire des enzymes et leur specificite de substrat different des insectes et resulte en une sequence differente de la biosynthese. La biosynthese des PEs est etroitement controlee : l’exportation de la 20E produite dans les feuilles âgees est necessaire pour que la synthese y soit continue, et l’ac...
20-hydroxyecdysone (20E) is the major phytoecdysteroid of about 6% of plants. Its role in plant p... more 20-hydroxyecdysone (20E) is the major phytoecdysteroid of about 6% of plants. Its role in plant physiology has not been fully elucidated. In this work we studied the effects of 20E application on some morphological and biochemical parameters of tomato, Lycopersicum esculentum, seed during germination and seedling development (5 d). We compared the 20E effects with the action of phytohormones: gibberellic acid (GA 3), naftalen acetic acid (NAA), benzyl amino purine (BAP). NAA treatment resulted in marked reduction in shoot length. GA 3 treatment promoted maximal shoot elongation. BAP affected negatively shoot length only at late stages, while 20E application stimulated shoot elongation at early stages and reduced it on the fifth day; NAA inhibited root elongation all along the test period. GA 3 treatment had no effect on root length, whereas BAP showed strong inhibition on root elongation. On the other hand, 20E showed a weak inhibition of root elongation on the fifth day. As compared to control and to other treatments, NAA and 20E provoked a drastic decrease in protein contents during seedling growth, whereas a high increase was observed under BAP treatment. Electrophoresis revealed that protein bands were not degraded and mobilized after NAA treatment while in control or after 20E and others phytohormones applications, protein patters displayed weak band intensities and some of them were not detected. NAA, GA 3 and BAP provoked a decrease in proline content during seedlings, while the effect of 20E on proline levels varied during germination and plantlet development. This work showed that 20E like phytohormones fulfil some bioactive actions during germination and seedlings growth in tomato.
20-Hydroxyecdysone (20E) is the most abundant phytoecdysteroid (PE) produced by plants, where it ... more 20-Hydroxyecdysone (20E) is the most abundant phytoecdysteroid (PE) produced by plants, where it represents a protective molecule against insect attack. The aim of the present study was to assess the effects of 20E on the growth, metabolic enzymes and antioxidant systems of wheat seedlings under lead stress induced by Pb(NO3)2 (3 mM). Pre-treatment concentrations (0, 1, 3 and 5 μM) of 20E were applied for two days, then wheat seedlings were transferred for 5 days to a treatment solution containing lead nitrate. When plants were grown without pre-treatment, germination and growth were impaired, while signs of oxidative stress were observed. 20E pre-treatment (3 or 5 μM) was able to efficiently protect seedlings from Pb toxicity by reducing Pb uptake and Pb-induced oxidative stress, as well by enhancing Pb excretion. Thus, 20E pre-treatment maintains normal germination, elongation, biomass, and metabolism in spite of the presence of Pb. Our results show that 20E protects oxidative balance and enhances the anti-oxidative systems, and more specifically the ascorbate-glutathione system. To our knowledge, this study shows for the first time that 20E treatment induces metabolic changes that allow the plants to resist heavy metal stress.
Phytoecdysteroids are plant analogues of insect moulting hormones and are used by plants to repel... more Phytoecdysteroids are plant analogues of insect moulting hormones and are used by plants to repel or disturb phytophagous insects. They are also active on mammals and present in many plants used in traditional medicine. The Ajuga genus contains several such species, which occur in various pharmacopoeias. We report the isolation and identification of major and minor ecdysteroids present in two Ajuga species, A. iva and A. remota, both of which are used as medicinal plants in Africa. Three minor ecdysteroids (abutasterone, ponasterone A and sidisterone) have been found for the first time in the Ajuga genus.
Environmental science and pollution research international, 2013
Spinach extracts contain powerful natural antioxidants and have been used to improve the response... more Spinach extracts contain powerful natural antioxidants and have been used to improve the response of animal cells to various stress factors. The aim of the present study was to assess the effects of a methanolic extract of spinach (SE) used at two concentrations (21.7 and 217 ppm) on the growth, certain enzymes and antioxidant systems in wheat seedlings under lead stress. When wheat seedlings were grown for 7 days in a solution containing Pb(NO3)2 (3 mM), germination and growth were impaired, while signs of oxidative stress were observed. SE (217 ppm) pretreatment was able to protect seedlings from Pb toxicity by both reducing Pb uptake and Pb-induced oxidative stress. As a consequence, almost normal germination, elongation, biomass and α-amylase activity were restored by SE (217 ppm) pretreatment of wheat seedlings, in spite of the presence of Pb. Our results support the protective role and the antioxidant effect of SE against Pb. These results show an amazing similarity to the effects of SE in animals, which suggests that providing “nutraceuticals” to plants could improve their “health” status.
Lead (Pb) is the most common heavy metal contaminant in the environment. Pb is not an essential e... more Lead (Pb) is the most common heavy metal contaminant in the environment. Pb is not an essential element for plants, but they absorb it when it is present in their environment, especially in rural areas when the soil is polluted by automotive exhaust and in fields contaminated with fertilizers containing heavy metal impurities. To investigate lead effects on nutrient uptake and metabolism, two plant species, spinach (Spinacia oleracea) and wheat (Triticum aestivum), were grown under hydroponic conditions and stressed with lead nitrate, Pb(NO 3 ) 2 , at three concentrations (1.5, 3, and 15 mM).
A B S T R A C T Lead (Pb) is an environmental pollutant extremely toxic to plants and other livin... more A B S T R A C T Lead (Pb) is an environmental pollutant extremely toxic to plants and other living organisms including humans. To assess Pb phytotoxicity, experiments focusing on germination of wheat seeds were germinated in a solution containing Pb (NO 3 ) 2 (0.05; 0.1; 0.5; 1 g/L) during 6 days. Lead accumulation in seedlings was positively correlated with the external concentrations, and negatively correlated with morphological parameters of plant growth. Lead increased lipid peroxidation, enhanced soluble protein concentrations and induced a significant accumulation of proline in roots. Esterase activity was enhanced in the presence of lead, whereas a-amylase activity was significantly inhibited. Antioxidant enzymes activities, such as, ascorbate peroxidase, peroxidase, superoxide dismutase, catalase and glutathione S-transferase were generally significantly increased in the presence of lead in a dose-dependent manner. The present results thus provide a model system to screen for natural compounds able to counteract the deleterious effects of lead. ß 2010 Acadé mie des sciences. Published by Elsevier Masson SAS. All rights reserved. R É S U M É Le Plomb (Pb) est un polluant environnemental extrêmement toxique pour les plantes et les autres organismes vivants dont l'Homme. La toxicité du Pb a é té testé e sur la germination du blé . Les grains sont mises à germer pendant six jours dans des solutions de nitrate de Pb (0,05 ; 0,1 ; 0,5 ; 1 g/L). L'accumulation de Pb dans les jeunes plantes est corré lé e avec l'augmentation de sa concentration dans la solution aqueuse et une croissance ré duite des plantes. La peroxydation des lipides, la concentration des proté ines solubles et de la proline sont accrues par le traitement. L'activité esté rasique est stimulé e, celle de l'a-amylase significativement inhibé e, et les activité s des enzymes antioxydantes -ascorbate peroxydase, peroxydase, superoxyde dismutase, catalase et glutathion Stransfé rase -augmentent significativement et d'une maniè re dose-dé pendante. Nos travaux fournissent un modè le qui sera utilisé pour rechercher des substances susceptibles de proté ger contre les effets dé lé tè res du Pb.
Many plant species produce phytoecdysteroids (PEs: i.e. analogues of insect steroid hormones). Th... more Many plant species produce phytoecdysteroids (PEs: i.e. analogues of insect steroid hormones). There is increasing evidence that PEs are used as a chemical defence by plants against non-adapted insects and nematodes. PEs are good candidates for the development of an environmentally safe approach to crop protection. Most crop species do not accumulate PEs. However, many arguments support the idea that most, if not all, plant species have the genetic ability to produce PEs, but the biosynthetic pathway is not active. A better understanding of the PE biosynthetic pathway and its regulation is consequently necessary. Spinach is one of the very few crop plants which produce large amounts of PEs, of which 20-hydroxyecdysone is the major component. Labeling experiments with radiolabeled precursor (mevalonic acid), putative ecdysteroid intermediates and 20-hydroxyecdysone itself have allowed investigation of PE biosynthesis and transport during spinach development. Biosynthesis takes place in older leaf sets ("sources"), but not in the young developing ones, which in contrast accumulate (acting as "sinks") the PEs produced by the older leaves. PEs are thus continuously redistributed within the developing plant, as its leaf set number increases. The biosynthetic pathway has been analyzed using excised leaves and various labeled precursors, and a preferential sequence of the last steps has been established. Although they do not produce PEs, apical leaf sets are nevertheless able to perform several putative terminal steps of PE biosynthesis. The regulatory mechanisms of PE synthesis appear to involve a direct negative feedback of 20-hydroxyecdysone (the major PE in spinach) on its own synthesis; thus, a sustained synthesis in older leaves requires that they can export the PE they produce.
We have investigated the effects of harmaline, a plant secondary metabolic compound belonging to ... more We have investigated the effects of harmaline, a plant secondary metabolic compound belonging to β-carboline alkaloids, on the 4th instar larvae of Plodia interpunctella (Lepidoptera). When incorporated into the diet, harmaline caused weight loss of larvae with a reduction in ...
The Journal of Steroid Biochemistry and Molecular Biology, 2021
Phytoecdysteroids are molecules derived from sterol metabolism and found in many plants. They dis... more Phytoecdysteroids are molecules derived from sterol metabolism and found in many plants. They display a wide array of pharmacological effects on mammals (e.g. anabolic, anti-diabetic). Although these effects have been long established, the molecular targets involved remain to be identified. Like endogenous steroid hormones and bile acids, which are biochemically related, ingested or injected phytoecdysteroids undergo a set of reactions in mammals leading to the formation of numerous metabolites, only some of which have been so far identified, and it is presently unknown whether they represent active metabolites or inactivation products. In the large intestine, ecdysteroids undergo efficient 14-dehydroxylation. Other changes (reductions, epimerization, side-chain cleavage) are also observed, but whether these occur in the liver and/or large intestine is not known. The purpose of this study was to investigate the pharmacokinetics of 20-hydroxyecdysone (20E), the most common phytoecdysteroid, when administered to mice and rats, using, when required, tritium-labelled molecules to permit metabolic tracking. Bioavailability, the distribution of radioactivity and the kinetics of formation of metabolites were followed for 24-48 hours after ingestion and qualitative and quantitative analyses of circulating and excreted compounds were performed. In mice, the digestive tract always contains the majority of the ingested 20E. Within 30 minutes after ingestion, 20E reaches the large intestine, where microorganisms firstly remove the 14-hydroxyl group and reduce the 6-one. Then a very complex set of metabolites (not all of which have yet been identified) appears, which correspond to poststerone derivatives formed in the liver. We have observed that these compounds (like bile acids) undergo an entero-hepatic cycle, involving glucuronide conjugation in the liver and subsequent deconjugation in the intestine. Despite the very short half-life of ecdysteroids in mammals, this entero-hepatic cycle helps to maintain their plasma levels at values which, albeit low (≤0.2 µM), would be sufficient to evoke several pharmacological effects. Similar 20E metabolites were observed in mice and rats; they include in particular 14-deoxy-20E, poststerone and 14-deoxypoststerone and their diverse reduction products; the major products of this metabolism have been unambiguously identified. The major sites of metabolism of exogenous ecdysteroids in mammals are the large intestine and the liver. The entero-hepatic cycle contributes to the metabolism and to maintaining a low, but pharmacologically significant, concentration of ecdysteroids in the blood for ca. 24 hours after ingestion. These data, together with parallel in vitro experiments provide a basis for the identification of 20E metabolite(s) possibly involved in the physiological effects associated with ecdysteroids in mammals.
Les phytoecdysteroides (PEs) sont des analogues des hormones de mue des insectes impliques dans l... more Les phytoecdysteroides (PEs) sont des analogues des hormones de mue des insectes impliques dans la defense des plantes contre les phytophages. Notre travail a pour but de mieux comprendre la voie de biosynthese des PEs et sa regulation chez l’epinard. La 20-hydroxyecdysone (20E) est le PE majoritaire, metaboliquement stable, dont la redistribution au sein de la plante se fait continuellement au profit des feuilles les plus jeunes et aux depens des feuilles âgees. L’etude de la biosynthese de la 20E a partir d’acide mevalonique ainsi que de plusieurs intermediaires putatifs a montre que seules les feuilles âgees sont aptes a realiser la biosynthese dans sa totalite ; la localisation subcellulaire des enzymes et leur specificite de substrat different des insectes et resulte en une sequence differente de la biosynthese. La biosynthese des PEs est etroitement controlee : l’exportation de la 20E produite dans les feuilles âgees est necessaire pour que la synthese y soit continue, et l’ac...
20-hydroxyecdysone (20E) is the major phytoecdysteroid of about 6% of plants. Its role in plant p... more 20-hydroxyecdysone (20E) is the major phytoecdysteroid of about 6% of plants. Its role in plant physiology has not been fully elucidated. In this work we studied the effects of 20E application on some morphological and biochemical parameters of tomato, Lycopersicum esculentum, seed during germination and seedling development (5 d). We compared the 20E effects with the action of phytohormones: gibberellic acid (GA 3), naftalen acetic acid (NAA), benzyl amino purine (BAP). NAA treatment resulted in marked reduction in shoot length. GA 3 treatment promoted maximal shoot elongation. BAP affected negatively shoot length only at late stages, while 20E application stimulated shoot elongation at early stages and reduced it on the fifth day; NAA inhibited root elongation all along the test period. GA 3 treatment had no effect on root length, whereas BAP showed strong inhibition on root elongation. On the other hand, 20E showed a weak inhibition of root elongation on the fifth day. As compared to control and to other treatments, NAA and 20E provoked a drastic decrease in protein contents during seedling growth, whereas a high increase was observed under BAP treatment. Electrophoresis revealed that protein bands were not degraded and mobilized after NAA treatment while in control or after 20E and others phytohormones applications, protein patters displayed weak band intensities and some of them were not detected. NAA, GA 3 and BAP provoked a decrease in proline content during seedlings, while the effect of 20E on proline levels varied during germination and plantlet development. This work showed that 20E like phytohormones fulfil some bioactive actions during germination and seedlings growth in tomato.
20-Hydroxyecdysone (20E) is the most abundant phytoecdysteroid (PE) produced by plants, where it ... more 20-Hydroxyecdysone (20E) is the most abundant phytoecdysteroid (PE) produced by plants, where it represents a protective molecule against insect attack. The aim of the present study was to assess the effects of 20E on the growth, metabolic enzymes and antioxidant systems of wheat seedlings under lead stress induced by Pb(NO3)2 (3 mM). Pre-treatment concentrations (0, 1, 3 and 5 μM) of 20E were applied for two days, then wheat seedlings were transferred for 5 days to a treatment solution containing lead nitrate. When plants were grown without pre-treatment, germination and growth were impaired, while signs of oxidative stress were observed. 20E pre-treatment (3 or 5 μM) was able to efficiently protect seedlings from Pb toxicity by reducing Pb uptake and Pb-induced oxidative stress, as well by enhancing Pb excretion. Thus, 20E pre-treatment maintains normal germination, elongation, biomass, and metabolism in spite of the presence of Pb. Our results show that 20E protects oxidative balance and enhances the anti-oxidative systems, and more specifically the ascorbate-glutathione system. To our knowledge, this study shows for the first time that 20E treatment induces metabolic changes that allow the plants to resist heavy metal stress.
Phytoecdysteroids are plant analogues of insect moulting hormones and are used by plants to repel... more Phytoecdysteroids are plant analogues of insect moulting hormones and are used by plants to repel or disturb phytophagous insects. They are also active on mammals and present in many plants used in traditional medicine. The Ajuga genus contains several such species, which occur in various pharmacopoeias. We report the isolation and identification of major and minor ecdysteroids present in two Ajuga species, A. iva and A. remota, both of which are used as medicinal plants in Africa. Three minor ecdysteroids (abutasterone, ponasterone A and sidisterone) have been found for the first time in the Ajuga genus.
Environmental science and pollution research international, 2013
Spinach extracts contain powerful natural antioxidants and have been used to improve the response... more Spinach extracts contain powerful natural antioxidants and have been used to improve the response of animal cells to various stress factors. The aim of the present study was to assess the effects of a methanolic extract of spinach (SE) used at two concentrations (21.7 and 217 ppm) on the growth, certain enzymes and antioxidant systems in wheat seedlings under lead stress. When wheat seedlings were grown for 7 days in a solution containing Pb(NO3)2 (3 mM), germination and growth were impaired, while signs of oxidative stress were observed. SE (217 ppm) pretreatment was able to protect seedlings from Pb toxicity by both reducing Pb uptake and Pb-induced oxidative stress. As a consequence, almost normal germination, elongation, biomass and α-amylase activity were restored by SE (217 ppm) pretreatment of wheat seedlings, in spite of the presence of Pb. Our results support the protective role and the antioxidant effect of SE against Pb. These results show an amazing similarity to the effects of SE in animals, which suggests that providing “nutraceuticals” to plants could improve their “health” status.
Lead (Pb) is the most common heavy metal contaminant in the environment. Pb is not an essential e... more Lead (Pb) is the most common heavy metal contaminant in the environment. Pb is not an essential element for plants, but they absorb it when it is present in their environment, especially in rural areas when the soil is polluted by automotive exhaust and in fields contaminated with fertilizers containing heavy metal impurities. To investigate lead effects on nutrient uptake and metabolism, two plant species, spinach (Spinacia oleracea) and wheat (Triticum aestivum), were grown under hydroponic conditions and stressed with lead nitrate, Pb(NO 3 ) 2 , at three concentrations (1.5, 3, and 15 mM).
A B S T R A C T Lead (Pb) is an environmental pollutant extremely toxic to plants and other livin... more A B S T R A C T Lead (Pb) is an environmental pollutant extremely toxic to plants and other living organisms including humans. To assess Pb phytotoxicity, experiments focusing on germination of wheat seeds were germinated in a solution containing Pb (NO 3 ) 2 (0.05; 0.1; 0.5; 1 g/L) during 6 days. Lead accumulation in seedlings was positively correlated with the external concentrations, and negatively correlated with morphological parameters of plant growth. Lead increased lipid peroxidation, enhanced soluble protein concentrations and induced a significant accumulation of proline in roots. Esterase activity was enhanced in the presence of lead, whereas a-amylase activity was significantly inhibited. Antioxidant enzymes activities, such as, ascorbate peroxidase, peroxidase, superoxide dismutase, catalase and glutathione S-transferase were generally significantly increased in the presence of lead in a dose-dependent manner. The present results thus provide a model system to screen for natural compounds able to counteract the deleterious effects of lead. ß 2010 Acadé mie des sciences. Published by Elsevier Masson SAS. All rights reserved. R É S U M É Le Plomb (Pb) est un polluant environnemental extrêmement toxique pour les plantes et les autres organismes vivants dont l'Homme. La toxicité du Pb a é té testé e sur la germination du blé . Les grains sont mises à germer pendant six jours dans des solutions de nitrate de Pb (0,05 ; 0,1 ; 0,5 ; 1 g/L). L'accumulation de Pb dans les jeunes plantes est corré lé e avec l'augmentation de sa concentration dans la solution aqueuse et une croissance ré duite des plantes. La peroxydation des lipides, la concentration des proté ines solubles et de la proline sont accrues par le traitement. L'activité esté rasique est stimulé e, celle de l'a-amylase significativement inhibé e, et les activité s des enzymes antioxydantes -ascorbate peroxydase, peroxydase, superoxyde dismutase, catalase et glutathion Stransfé rase -augmentent significativement et d'une maniè re dose-dé pendante. Nos travaux fournissent un modè le qui sera utilisé pour rechercher des substances susceptibles de proté ger contre les effets dé lé tè res du Pb.
Many plant species produce phytoecdysteroids (PEs: i.e. analogues of insect steroid hormones). Th... more Many plant species produce phytoecdysteroids (PEs: i.e. analogues of insect steroid hormones). There is increasing evidence that PEs are used as a chemical defence by plants against non-adapted insects and nematodes. PEs are good candidates for the development of an environmentally safe approach to crop protection. Most crop species do not accumulate PEs. However, many arguments support the idea that most, if not all, plant species have the genetic ability to produce PEs, but the biosynthetic pathway is not active. A better understanding of the PE biosynthetic pathway and its regulation is consequently necessary. Spinach is one of the very few crop plants which produce large amounts of PEs, of which 20-hydroxyecdysone is the major component. Labeling experiments with radiolabeled precursor (mevalonic acid), putative ecdysteroid intermediates and 20-hydroxyecdysone itself have allowed investigation of PE biosynthesis and transport during spinach development. Biosynthesis takes place in older leaf sets ("sources"), but not in the young developing ones, which in contrast accumulate (acting as "sinks") the PEs produced by the older leaves. PEs are thus continuously redistributed within the developing plant, as its leaf set number increases. The biosynthetic pathway has been analyzed using excised leaves and various labeled precursors, and a preferential sequence of the last steps has been established. Although they do not produce PEs, apical leaf sets are nevertheless able to perform several putative terminal steps of PE biosynthesis. The regulatory mechanisms of PE synthesis appear to involve a direct negative feedback of 20-hydroxyecdysone (the major PE in spinach) on its own synthesis; thus, a sustained synthesis in older leaves requires that they can export the PE they produce.
We have investigated the effects of harmaline, a plant secondary metabolic compound belonging to ... more We have investigated the effects of harmaline, a plant secondary metabolic compound belonging to β-carboline alkaloids, on the 4th instar larvae of Plodia interpunctella (Lepidoptera). When incorporated into the diet, harmaline caused weight loss of larvae with a reduction in ...
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