Thyroid hormone-induced haemoglobin changes and antioxidant enzymes response in erythrocytes

Thyroid hormones modulate haemoglobin and reactive oxygen species (ROS) production, leading to antioxidant changes. This study evaluated the antioxidant response to ROS in erythrocytes in hypothyroid and hyperthyroid rats. Wistar rats were divided into four groups: control; hyperthyroid (T4-12 mg 1(-1) in drinking water); sham operated (simulation of thyroidectomy); and hypothyroid (thyroidectomized). Four weeks after, blood was collected and haemoglobin and T(4) levels, lipid peroxidation (LPO), protein oxidation, superoxide dismutase (SOD), catalase (CAT) , glutathione S-transferase (GST) and glutathione peroxidase (GPx) activities, and total radical antioxidant potential (TRAP) were measured. SOD, CAT and GST immunocontent was evaluated. Haemoglobin levels were increased in hyperthyroid erythrocytes. LPO and carbonyls were augmented (65% and 55%, respectively) in hyperthyroid and reduced (31% and 56%, respectively) in hypothyroid group. SOD and CAT activities have not changed, as well as CAT immunocontent. TRAP was diminished in both hyperthyroid and hypothyroid groups (36% and 37%, respectively). GST activity and immunocontent, as well as GPx activity, were increased in hyper and hypothyroid rats. The data suggest that thyroid hormone changes determine ROS concentration changes and decrease of some antioxidant defences that would lead to a compensatory answer of the GST and GPx enzymes, which could be consider as credible biomarkers.     

Effect of vitamin E and selenium on antioxidant enzymes in brain,kidney and liver of cigarette smoke-exposed mice

The present study was conducted to evaluate the protective effects of vitamin E and selenium (Se) application on alteration of antioxidant enzyme activities against cigarette smoking induced oxidative damage in brains, kidneys and liver of mice. Male mice (balb/c) were exposed to cigarette smoke and treated with Se and/or vitamin E. Glutathione transferase (GST), glutathione peroxidase (GPX), glutathione reductase (GRX), superoxide dismutase (SOD) and catalase (CAT) enzyme activities in mice brain, kidney and liver were measured spectrophotometrically. GST, GPX, GRX, SOD and CAT enzyme activities in the brains of smoke-exposed mice were found lower than the enzymes activities of control mice and Se-and vitamin E-treated mice at the end of the three and five months. Opposite to brain, enzyme activities in kidneys and livers of smoke-exposed mice were found higher than the enzymes activities of control mice and Se-and vitamin E-treated mice at the end of the three and five months. Activities of GST, GPX, GRX SOD and CAT in the livers, kidneys and brains of smoke-exposed mice were found statistically different (p < 0.01) compared to control mice and Se-and vitamin E-treated mice. Combined application of vitamin E and Se had an additive protective effect against changing enzymes activities in smoke-exposed mice livers, kidneys and brains at the end of the both application periods. These results suggest that cigarette smoke exposure enhances the oxidative stress, thereby disturbing the tissue antioxidant defense system and combined application of vitamin E and Se protects the brain, kidney and liver from oxidative damage through their antioxidant potential.     

Fenugreek seeds modulate 1,2-dimethylhydrazine-induced hepatic oxidative stress during colon carcinogenesis

1,2-dimethylhydrazine (DMH) is a colon carcinogen which undergoes oxidative metabolism in the liver. We have investigated the modulatory effect of fenugreek seeds (a spice) on colon tumor incidence as well as hepatic lipid peroxidation (LPO) and antioxidant status during DMH-induced colon carcinogenesis in male Wistar rats. In DMH treated rats, 100% colon tumor incidence was accompanied by enhanced LPO and a decrease in reduced glutathione (GSH) content as well as a fall in glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) activities. Inclusion of fenugreek seed powder in the diet of DMH treated rats reduced the colon tumor incidence to 16.6%, decreased the LPO and increased the activities of GPx, GST, SOD and CAT in the liver. We report that fenugreek modulates DMH-induced hepatic oxidative stressduring colon cancer     

Effects of Flaxseed Oil on Lead Acetate-Induced Neurotoxicity in Rats

It is well known that chronic exposure to lead (Pb(+2)) alters a variety of behavioral tasks in rats and mice. Here, we investigated the effect of flaxseed oil (1,000?mg/kg) on lead acetate (20?mg/kg)-induced brain oxidative stress and neurotoxicity in rats. The levels of Pb(+2), lipid peroxidation, nitric oxide (NO), and reduced glutathione (GSH) and the activity of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), glutathione-S-transferase (GST), and glutathione peroxidase (GPx) were determined in adult male albino rats. The level of Pb(+2) was markedly elevated in brain and blood of rats. This leads to enhancement of lipid peroxidation and NO production in brain with concomitant reduction in GSH, CAT, SOD, GR, GST, and GPx activities. These findings were associated with DNA fragmentation. In addition, lead acetate induced brain injury as indicated by histopathological changes of the brain. Treatment of rats with flaxseed oil resulted in marked improvement in most of the studied parameters as well as histopathological features. These findings suggest to the conclusion that flaxseed oil significantly decreased the adverse harmful effects of lead acetate exposure on the brain as well as Pb(+2)-induced oxidative stress.     

Chemopreventive potential of luteolin during colon carcinogenesis induced by 1,2-dimethylhydrazine

We investigated the chemopreventive potential of luteolin on hepatic and circulatory lipid peroxidation and antioxidant status during 1,2-dimethylhydrazine induced colon carcinogenesis in rats. Rats were given a weekly subcutaneous injection of DMH at a dose of 20 mg/kg body weight for 15 weeks. Luteolin (0.2 mg/kg body weight/everyday p.o.) was given at the initiation and also at the postinitiation stages of carcinogenesis to DMH treated rats. The animals were sacrificed at the end of 30 weeks. Enhanced lipid peroxidation in the liver and circulation of tumor bearing rats was accompanied by a significant decrease in the levels of plasma and hepatic reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), vitamin C, vitamin E and beta-carotene in DMH treated rats as compared to the control rats. Intragastric administration of luteolin (0.2mg/kg body weight) to DMH-treated rats significantly reduced the incidence and size of tumor in the colon, reduced lipid peroxidation levels and enhanced the plasma and hepatic activities of GSH, GPx, GST, GR, SOD, CAT, vitamin C, vitamin E and beta-carotene. Thus the chemopreventive efficacy of luteolin against colon carcinogenesis is evidenced by our preliminary studies which showed decreased incidence of tumors and the antiperoxidative and antioxidant effect of luteolin. Further study on the exact mechanism of action of luteolin in preventing colon carcinogenesis is yet to be elucidated.     

Antioxidant response and oxidative stress levels in Macrobrachium borellii (Crustacea: Palaemonidae) exposed to the water-soluble fraction of petroleum

The aim of the present work was to evaluate the effect of the water soluble fraction of hydrocarbons (WSF) on the antioxidant status of the freshwater prawn Macrobrachium borellii. First, seasonal variations were studied in a non-polluted area. Hepatopancreas and gills showed season-related fluctuations in catalase (CAT), glutathione-S-transferase (GST) activities and in lipid peroxidation levels (LPO), but not in superoxide dismutase (SOD). Then, adults were exposed semi-statically to sublethal doses for 7days. CAT, SOD, GST, and glutathione peroxidase (GPx) activities and LPO, reduced glutathione (GSH) and protein oxidation (PO) levels were determined. Exposed individuals showed significant increases in CAT, SOD, and GST activities in hepatopancreas and CAT activity in gills. GPx activity did not vary in either tissues. While LPO levels increased, GSH levels decreased significantly in hepatopancreas of exposed animals, but PO levels showed no variation. Induction of SOD was also assessed by Real-time PCR mRNA expression in hepatopancreas. The non-enzymatic antioxidant activity was also tested; ABTS 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid) was higher in hemolymph of treated-prawns compared to controls, but ferric reducing activity of plasma assay (FRAP) values did not change. Taken together, the present results indicated that the antioxidant defenses of M. borellii, mainly in hepatopancreas, were significantly affected by aquatic hydrocarbon contamination, regardless of the season.     

Protective effect of glycine supplementation on the levels of lipid peroxidation and antioxidant enzymes in the erythrocyte of rats with alcohol-induced liver injury

We studied the effect of glycine supplementation on lipid peroxidation and antioxidants in the erythrocyte membrane, plasma and hepatocytes of rats with alcohol-induced hepatotoxicity. Administering ethanol (20%) for 60 days to male Wistar rats resulted in significantly elevated levels of erythrocyte membrane, plasma and hepatocyte thiobarbituric acid reactive substances (TBARS) as compared with those of the experimental control rats. Decreased activities of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione reductase (GR) were also observed on alcohol supplementation as compared with those of the experimental control rats. Glycine was administered at a dose of 0.6 g kg(-1) body weight to rats with alcohol-induced liver injury, which significantly decreased the levels of TBARS and significantly elevated the activities of SOD, CAT, GSH, GPx and GR in the erythrocyte membrane, plasma and hepatocytes as compared to that of untreated alcohol supplemented rats. Thus, our data indicate that supplementation with glycine offers protection against free radical-mediated oxidative stress in the erythrocyte membrane, plasma and hepatocytes of animals with alcohol-induced liver injury.     

Antioxidant efficacy of black pepper (Piper nigrum L.) and piperine in rats with high fat diet induced oxidative stress

The present study was aimed to explore the effect of black pepper (Piper nigrum L.) on tissue lipid peroxidation, enzymic and non-enzymic antioxidants in rats fed a high-fat diet. Thirty male Wistar rats (95-115 g) were divided into 5 groups. They were fed standard pellet diet, high-fat diet (20% coconut oil, 2% cholesterol and 0.125% bile salts), high-fat diet plus black pepper (0.25 g or 0.5 g/kg body weight), high-fat diet plus piperine (0.02 g/kg body weight) for a period of 10 weeks. Significantly elevated levels of thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and significantly lowered activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and reduced glutathione (GSH) in the liver, heart, kidney, intestine and aorta were observed in rats fed the high fat diet as compared to the control rats. Simultaneous supplementation with black pepper or piperine lowered TBARS and CD levels and maintained SOD, CAT, GPx, GST, and GSH levels to near those of control rats. The data indicate that supplementation with black pepper or the active principle of black pepper, piperine, can reduce high-fat diet induced oxidative stress to the cells.     

Temperature increase results in oxidative stress in goldfish tissues. 2. Antioxidant and associated enzymes

Activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione-S-transferase (GST), glutathione reductase (GR), and glucose-6-phophate dehydrogenase (G6PDH) were measured in four tissues of goldfish, Carassius auratus L., over 1-12 h of high temperature (35 degrees C) exposure followed by 4 or 24 h of lower temperature (21 degrees C) recovery. SOD activity was strongly affected by heat shock, increasing 4-fold in brain, liver, and kidney, but was mainly reversed at recovery. In some tissues, activities of SOD, catalase, GPx, and G6PDH decreased significantly after 1 h heat shock exposure suggesting that thermal inactivation possibly occurred, but were renewed at further exposure. In many cases, 4 h of return to the initial temperature decreased enzyme activities. High correlation coefficients between SOD activities and levels of lipid peroxidation products suggest that these products might be involved in up-regulation of antioxidant defense. Several enzymes (SOD, GST, GR) responded to stress in coordinated manner.     

The effect of one year's swimming exercise on oxidant stress and antioxidant capacity in aged rats

The effect of exercise on oxidant stress and on alterations in antioxidant defense in elderly has been investigated extensively. However, the impact of regularly performed long-term physical activity starting from adulthood and prolonged up to the old age is not yet clear. We have investigated the changes in the activities of antioxidant enzymes - superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) - and lipid peroxidation in various tissues of rats which had performed (old-trained) or had not performed (old-control) regular swimming exercise for one year. These animals were compared with young-sedentary rats. Increased lipid peroxidation was observed with ageing in all tissues (heart, liver, kidney, striated muscle) and swimming had no additional effect on this elevation of lipid peroxidation. Heart and striated muscle SOD activites, and striated muscle CAT activity increased as a consequence of ageing, whereas kidney and liver CAT activities, as well as GPx activities in kidney, liver, lung and heart were significantly decreased compared to young controls. Lung and heart SOD, liver CAT activities as well as GPx activities in liver, lung and heart were increased significantly in rats which performed exercise during ageing, compared to the old-control group. These findings suggest that lifelong exercise can improve the antioxidant defense in many tissues without constituting any additional oxidant stress.     

Protective effect of black tea extract on the levels of lipid peroxidation and antioxidant enzymes in liver of mice with pesticide-induced liver injury

Sub-acute hepatotoxicity was induced in mice by exposure to pesticides. The effect of pretreatment with aqueous black tea extract on lipid peroxidation and antioxidants in the liver was investigated. Administering a combination dose of chlorpyriphos and cypermethrin (20 mg kg(-1) each) on alternate days over a 15-day period to male mice resulted in induction of sub-acute toxicity as reflected by elevated levels of liver damage marker enzymes alkaline phosphatase(ALP), aspartate transaminase(AST) and alanine transaminase(ALT). Significantly elevated levels of lipid peroxidation were observed in the experimental group (group III) as compared with control mice. Decreased activities of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), total thiol, glutathione peroxidase (GPx), glutathione reductase(GR) and glutathione-S-transferase (GST) were also observed in pesticide-treated as compared to control mice. Aqueous black tea extract was given as a pretreatment to group IV mice at a dose of 200 mg ml(-1) polyphenols before the pesticide dose, which significantly decreased the levels of lipid peroxidation and significantly elevated the activities of SOD, CAT, GSH, total thiol, GPx, GR and GST in liver to levels similar to the controls. Thus, the data offer support for the claim that the central mechanism of pesticide action occurs via changes in cellular oxidative status and shows conclusively that supplementation with black tea extract protects against the free radical-mediated oxidative stress in hepatocytes of animals with pesticide-induced liver injury.     

Temporal variations of lipid peroxidation products, antioxidants and liver marker enzymes in experimental hyperammonemic rats

Circadian variations of lipid peroxidation products: thiobarbituric acid and reactive substances (TBARS), antioxidants: reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and liver marker enzymes such as transaminases (aspartate transaminase (AST) and alanine transaminase (ALT), alkaline phosphatase (ALP) and γ-Glutamyl transpeptidase (GGT) in circulation were analysed in control and ammonium chloride (AC) induced (100 mg/kg bodyweight) hyperammonemic rats. Elevated lipid peroxidation and liver marker enzymes (increased mesor of TBARS, AST, ALT, ALP and GGT) associated with decreased activities of antioxidants (decreased mesor of GPx, GSH, SOD and CAT) were found in hyperammonemic rats. Variations in acrophase, amplitude and r values were also found in between the control and hyperammonemic rats. These alterations clearly indicate that temporal liver marker enzymes and redox status are modulated during hyperammonemic conditions, which may also play a crucial role in disease development.     

Modulatory effect of Urtica dioica L. (Urticaceae) leaf extract on biotransformation enzyme systems, antioxidant enzymes, lactate dehydrogenase and lipid peroxidation in mice.

The effects of two doses (50 and 100 mg/kg body wt given orally for 14 days) of an ethanol-water (80%-20%) extract of Urtica dioica L. and butylated hydroxyanisole (BHA) were investigated, for phase I and phase II enzymes, antioxidant enzymes, lactate dehydrogenase, lipid peroxidation and sulfhydryl groups in the liver of Swiss albino mice (8-9 weeks old). A modulatory effect of two doses and BHA was also observed for the activities of glutathione S-transferase, DT-diaphorase, superoxide dismutase and catalase in the kidney, lung and forestomach, as compared with the control group. The activities of cytochrome b5 (cyt b5), NADH-cytochrome b5 reductase (cyt b5 R), glutathione S-transferase (GST), DT-diaphorase (DTD), glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD) and catalase (CAT) showed a significant increase in the liver at both dose levels of extract. Both extract-treated showed significantly lower activity of cytochrome P450 (cyt P450), lactate dehydrogenase (LDH), NADPH-cytochrome P450 reductase (cyt P450 R), total sulfhydryl groups (T-SH), nonprotein sulfhydryl groups (NP-SH) and protein-bound sulfhydryl groups (PB-SH). BHA-treated Swiss albino mice showed a notable increase in levels of cyt b5, DTD, T-SH, PB-SH, GPx, GR, and SOD in the liver while, LDH, cyt P450, cyt P450 R, Cyt b5 R, GST, NP-SH, and CAT levels were reduced significantly as compared to control values. The extract was effective in inducing GST, DTD, SOD and CAT activity in the forestomach and SOD and CAT activity in the lung at both dose levels. BHA-treated Swiss albino mice induced DTD, GST and all antioxidative parameters in the kidney, lung and forestomach.     

24-hour rhythms in oxidative stress during hepatocarcinogenesis in rats: effect of melatonin or alpha-ketoglutarate

To compare the effects of alpha-ketoglutarate (alpha-KG) and melatonin on 24-h rhythmicity of oxidative stress in N-nitrosodiethylamine (NDEA)-injected Wistar male rats, melatonin (5 mg/kg i.p.) or alpha-KG (2 g/kg through an intragastric tube) was given daily for 20 weeks. In blood collected at 6 time points during a 24-h period, serum activity of aspartate transaminase (AST) and alanine transaminase (ALT) and the levels of alpha-fetoprotein (alpha-FP) were measured as markers of liver function. To assess lipid peroxidation and the antioxidant status, plasma levels of thiobarbituric acid reactive substances (TBARS) and of reduced glutathione (GSH) were measured, together with the activity of erythrocyte superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST). NDEA augmented mesor and amplitude of rhythms in AST and ALT activity and plasma alpha-FP levels and mesor values of plasma TBARS, while decreasing mesor values of plasma GSH and erythrocyte SOD, CAT, GPx and GST. Acrophases were delayed by NDEA in all cases except for alpha-FP rhythm, which became phase-advanced. Co-administration of melatonin or alpha-KG partially counteracted the effects of NDEA. Melatonin decreased mesor of plasma TBARS and augmented mesor of SOD activity. The results indicate that melatonin and alpha-KG are effective in protecting from NDEA-induced perturbation of 24-h rhythms in oxidative stress. Melatonin augmented antioxidant defense in rats.     

Combined effects of 2,4-D and azinphosmethyl on antioxidant enzymes and lipid peroxidation in liver of Oreochromis niloticus

This study aims to investigate the effects of the herbicide 2,4-D and the insecticide azinphosmethyl on hepatic antioxidant enzyme activities and lipid peroxidation in tilapia. Fish were exposed to 27 ppm 2,4-D, 0.03 ppm azinphosmethyl and to a mixture of both for 24, 48, 72 and 96 h. Activities of catalase (EC 1.11.1.6), glutathione-S-transferase (GST, EC 2.5.1.18) and the level of malondialdehyde (MDA) in the liver of Oreochromis niloticus exposed to 2,4-D and azinphosmethyl, both individually and in combination, were not affected by the pesticide exposures. However, glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) and glutathione reductase (GR, EC 1.6.4.2) activities in individual and combined treatments, increased significantly compared to controls. Furthermore, glutathione peroxidase (GPx, EC 1.11.1.9) activity increased in individual treatment, while the same enzyme activity decreased in combination. 2,4-D did not affect the activity of superoxide dismutase (SOD, EC 1.15.1.1), but the activity of this enzyme in azinphosmethyl treatment decreased, while its activity increased in combination. Combined treatment of the pesticides exerted synergistic effects in the activity of SOD, while antagonistic effects were found in the activities of G6PD, GPx, GR. The results indicate that O. niloticus resisted oxidative stress by antioxidant mechanisms and prevented increases in lipid peroxidation.     

Parameters related to oxygen free radicals in erythrocytes,plasma and epidermis of the hairless rat

The following parameters related to oxygen free radicals (OFR) were determined in erythrocytes and the epidermis of hairless rats: catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced (GSH) and oxidized (GSSG) glutathione, glutathione S-transferase (GST), superoxide dismutase (SOD) and thiobarbituric acid reactive substances (TBARS). GSH, GSSG and TBARS were also analyzed in plasma. In erythrocytes, the Pearson correlation coefficients (r) were significant (p < 0.001) between glutathione and other parameters as follows: GSH correlated negatively with GSSG (r = -0.665) and TBARS (r = -0.669); GSSG correlated positively with SOD (r = 0.709) and TBARS (r = 0.752). Plasma GSSG correlated negatively with erythrocytic thermostable GST activity (r = -0.608; p=0.001) and with erythrocytic total GST activity (r = -0.677; p < 0.001). In epidermis (p < 0.001 in all cases), GSH content correlated with GSSG (r = 0.682) and with GPx (r = 0.663); GSSG correlated with GPx (r = 0.731) and with GR (r = 0.794). By multiple linear regression analysis some predictor variables (R(2)) were found: in erythrocytes, thermostable GST was predicted by total GST activity and GSSG, GSSG content was predicted by GSH and by the GSH/GSSG ratio and GPx activity was predicted by GST, CAT and SOD activities; in epidermis, GSSG was predicted by GR and SOD activities and GR was predicted by GSSG, TBARS and GPx. It is concluded that the hairless rat is a good model for studying OFR-related parameters simultaneously in blood and skin, and that it may provide valuable information about other animals under oxidative stress.     

Oxidative stress biomarkers in the freshwater characid fish, Brycon cephalus, exposed to organophosphorus insecticide Folisuper 600 (methyl parathion)

Methyl parathion (MP) is an organophosphorus insecticide used worldwide in agriculture and aquaculture due to its high activity against a broad spectrum of insect pests. The effect of a single exposure to 2 mg L(- 1) of a commercial formulation of MP (MPc: Folisuper 600(R), MP 600 g L(- 1)) on catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione S-transferase (GST), reduced glutathione (GSH) and lipid peroxidation (LPO) of the liver, white muscle and gills of Brycon cephalus was evaluated after 96 h of treatment. MPc exposure resulted in a significant induction of SOD, CAT and GST activity in all tissues. However, the GPx activity decreased significantly in white muscle and gills, whereas no alterations were observed in hepatic GPx activity. MPc also induced a significant increase in LPO values in the white muscle and gills, while hepatic LPO levels did not show any significant alteration. The current data suggest that MPc has oxidative-stress-inducing potential in fish, and that gills and white muscle are the most sensitive organs of B. cephalus, with poor antioxidant potentials. The various parameters studied in this investigation can also be used as biomarkers of exposure to MPc.     

The effects of boric acid-induced oxidative stress on antioxidant enzymes and survivorship in Galleria mellonella

Larvae of the wax moth, Galleria mellonella (L.), were reared from first instar on a diet supplemented with 156, 620, 1,250, or 2,500 ppm boric acid (BA). The content of malondialdehyde (MDA, an oxidative stress indicator), and activities of the antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx)] were determined in the fat body and hemolymph in the 7th instar larvae and newly emerged pupae. Relative to control larvae, MDA was significantly increased in larval hemolymph, larval and pupal fat body, but decreased in the pupal hemolymph. Insects reared on diets with 156- and 620-ppm BA doses yielded increased SOD activity but 1,250- and 2,500-ppm doses resulted in decreased SOD activity in larval hemolymph. SOD activity was significantly increased but CAT was decreased in the larval fat body. High dietary BA treatments led to significantly decreased GST activity. However, they increased GPx activity in larval hemolymph. Dietary BA also affected larval survival. The 1,250- and 2,500-ppm concentrations led to significantly increased larval and pupal mortality and prolonged development. In contrast, the lowest BA concentration increased longevity and shortened development. We infer that BA toxicity is related, at least in part, to oxidative stress management.