Acute lindane intoxication: a study on lindane tissue concentration and oxidative stress-related parameters in liver and erythrocytes

Grape seed alleviates lindane-induced oxidative stress and improves growth performance, caecal fermentation and antioxidant capacity in growing rabbits

This study evaluated the protective effect of grape seed on performance, caecal characteristics, blood metabolites and liver antioxidant status in lindane-treated rabbits. Four-week-old New Zealand White rabbits (n = 96) with an initial body weight of 0.750 ± 0.23 g were randomly divided into four groups (n = 24). One group was the control received only corn oil orally, while group L were received lindane daily via gavage in corn oil (4 mg/kg BW; 1/50 LD₅₀ for oral dose), group GS was treated with 50 g grape seed /kg diet, and group LGS treated with a combination of both L and GS for 98 days. Results revealed that final body weight (FBW), average daily gain (ADG), dry matter intake and feed efficiency (FE) were similar between GS and control groups, and achieved the highest FBW and ADG, and the best FE. Caecum pH of the L group increased, while the caecum pH of the GS group decreased sharply. There was a significant increase in the concentration of total VFA, acetic acid, propionic acid and NH₃ -N in the GS group, but butyric acid level decreased. GS treatment resulted in a significant increase in the concentrations of total protein, albumin and AChE. GPx, GST, CAT and SOD activity decreased, but TBARS activity significantly increased in the group L, while GS caused a significant elevation of antioxidant activity in the liver. These results confirm that the antioxidant compounds present in grape seed can alleviate the oxidative stress caused by lindane-induced hepatotoxicity and could be a useful supplement to maintain health and improve performance in rabbits.

Endosulfan-induced hepatotoxicity is route of exposure independent in rats

Endosulfan is an important hepatotoxic agent that generates free oxygen radicals in liver. With the widespread use of endosulfan in agriculture, human beings are most likely to be exposed to it by eating food contaminated with endosulfan, exposure to its low levels by skin contact with contaminated soil, smoking cigarettes made from tobacco that has endosulfan residues on it, or by nose and whole body inhalation exposure in the farms during its application. Since endosulfan is a frequently used pesticide, and the incidence of toxic injury to the liver tissue in relation to its widespread use reported in the literature, we considered it necessary to investigate whether endosulfan-induced liver injury could be route of exposure dependent. Eighteen mature male albino Wistar rats, weighing between 180 and 220 g, were used in this study. The hepatotoxic effects of oral administration of endosulfan (5 mg/kg body weight) daily for 30 days, and 30 days whole body inhalation exposure to ungraded concentration of endosulfan were investigated in rats using serum liver enzymes and histopathological assay. At the end of the experimental period, serum alanine aminotransferase, aspartate amino transferase, alkaline phosphatase, and creatine kinase activities obtained for the group of rats exposed orally to endosulfan were not significantly different (p ≥ 0.05) from the activities obtained for rats exposed by whole body inhalation. However, the activity of these enzymes obtained for the rats exposed to endosulfan by both oral and inhalation routes were significantly increased (p ≤ 0.05) compared, respectively, to the control. Also, on microscopic examination, the liver tissues of experimental groups exhibited severe damage histopathologically. The results of the enzyme and histological analyses showed that both oral and whole body inhalation exposure to endosulfan may cause liver tissue damage in rats. The exposure to endosulfan in rats caused liver tissue damage independent of the route of exposure.

The effect of ascorbic acid supplementation on endosulfan toxicity in rabbits

We investigated the endosulfan-induced alterations and the effect of vitamin C supplementation on endosulfan-induced alterations in serum biochemical markers of oxidative stress and antioxidant capacity in rabbits. Basal, 4th and 6th week serum levels of total oxidant status (TOS), thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), total antioxidant capacity (TAC), total protein sulfhydryl (T-SH) and glutathione-S-transferase (GST) were measured in rabbits administered endosulfan (1 mg/kg) alone or in combination with vitamin C (20 mg/kg) for 6 weeks. Control rabbits received either vehicles or vitamin C. Serum TOS, TBARS and AOPP levels at 4th and 6th week were significantly higher whereas T-SH levels were significantly lower than basal values in endosulfan-administered rabbits. GST increased significantly at 4th week but decreased below basal value at 6th week. Similarly, TAC decreased significantly at 6th week. Vitamin C supplementation increased TAC at 4th and 6th weeks in controls and increased T-SH and GST and decreased TOS, TBARS and AOPP at 4th week in endosulfan-administered rabbits. TAC increased significantly at 6th week by vitamin C supplementation in endosulfan-administered rabbits. There were significant increments in TBARS and decrements in TAC and GST levels at 6th week compared to 4th week in endosulfan-administered rabbits. Present findings indicated to an increased and progressively uncompensated oxidant stress in endosulfan-administered rabbits that was substantially ameliorated by vitamin C supplementation through an improvement in antioxidant capacity. It was suggested that vitamin C supplementation might be helpful in preventing the detrimental effects of increased oxidative stress caused by endosulfan exposure.

Protective role of curcumin on lindane induced reproductive toxicity in male Wistar rats

The aim of this study was to explore the adverse effects of lindane pesticide on testes and epididymus weight, sperm head counts, sperm motility, abnormal changes in sperm morphology, biochemical changes in endogenous antioxidants and oxidative enzymes in male wistar rats as well as to assess ameliorating role of 'curcumin'. Rats were exposed daily to lindane (30 mg/kg bw) for 14 and 28 days and administered with curcumin (100 mg/kg bw) in pretreatment, post treatment and combination groups. We observed decrease (p < 0.001) in testes and cauda epididymus weight, decrease (p < 0.001) in testicular sperm head count, increase (p < 0.001) in abnormal tail morphology (headless tail, multiple tail, broken tail, coiled tail and bent tail), abnormal head morphology (excessive hook, amorphous head, pin head, short head, blunt hook and detached hook) and decrease (p < 0.001) in sperm motility after lindane exposure, as compared to control. There was (p < 0.01) decline in superoxide dismutase, catalase and glutathione-s-transferase activity on lindane exposure, however, no change (p > 0.05) was observed in glutathione level. Lipid peroxidation was (p < 0.01) enhanced on lindane exposure as compared to control. Curcumin administration was able to ameliorate lindane induced reproductive toxicity in pretreatment, post treatment and combination groups. The study indicated that even after 14 days of metabolism, toxic effects of lindane were evident.

Oxidative stress in liver and red blood cells in acute lindane toxicity in rats

The aim of our study was to determine the role and dynamics of oxidative and nitrosative stress, as well as superoxide dismutase (SOD) and catalase activity in the hepatocytes and erythrocytes in early phase of acute lindane intoxication. Male Wistar rats were divided into groups: control, dimethylsulfoxide and lindane-treated groups (L, 8 mg/kg, intraperitoneally). Animals were sacrificed 0.5 and 4 hours after treatment (L(0.5) and L(4) groups, respectively). Oxidative and nitrosative stress parameters and antioxidant enzymes were determined spectrophotometrically. Liver and plasma thiobarbituric acid reactive substances (TBARS) concentration were significantly increased 0.5 after lindane administration (p < .01), with subsequent additional rise within 4 hours (p < .01), while plasma nitrite + nitrate level was significantly higher only 4 hours after lindane treatment. Total liver SOD activity was significantly increased in L(4) group in comparison with control group (p < .01). In conclusion, oxidative and nitrosative stress play an important role in early phase of acute lindane hepatotoxicity. Antioxidant capacity of hepatocytes is partly increased, due to an adaptive increase in SOD activity.

Hexachlorocyclohexane differentially alters the antioxidant status of the brain regions in rat

Hexachlorocyclohexane (HCH), a highly persistent organochlorine insecticide, is neurotoxic at acute doses and causes degenerative effects on chronic exposure. HCH has been reported to induce oxidative stress in cells and tissues. Mammalian brain is sensitive to oxidative stress which is implicated in neurodegenerative diseases. Effect of HCH on the brain regions, cortex, cerebellum, midbrain and brainstem, has been investigated by studying the response of antioxidant enzymes in rats treated orally with HCH at 25 and 100mg/kg b.w. for 2 weeks. Lipid peroxidation and glutathione depletion was seen in all the brain regions of HCH treated rats. The brain regions showed distinct variation in the antioxidant enzyme activities. Activities of glutathione peroxidase, glutathione reductase, glutathione-S-transferase and catalase were markedly induced whereas superoxide dismutase was inhibited at higher dose in all the brain regions. Marked induction and inhibition of the antioxidant enzymes, especially in the cortex and to varying degrees in other brain regions, was seen in HCH treated rats. These biochemical changes suggest vulnerability to oxidative stress in the brain is region-specific. Whether these changes are adaptive or compromise the capacity of the brain to deal with the HCH-induced oxidative stress that could lead to degenerative neurotoxic manifestations remain to be understood.

Effect of lindane on hepatic and brain cytochrome P450s and influence of P450 modulation in lindane induced neurotoxicity

Oral administration of lindane (2.5, 5, 10 and 15 mg/kg, body weight) for 5 days was found to produce a dose-dependent increase in the activity of P450 dependent 7-ethoxyresorufin-O-deethylase (EROD), 7-pentoxyresorufin-O-dealkylase (PROD) and N-nitrosodimethylamine demethylase (NDMA-d) in rat brain and liver. A significant increase in the hepatic and brain P450 monooxygenases was also observed when the duration of exposure of low dose (2.5 mg/kg) of lindane was increased from 5 days to 15 or 21 days. As observed with different doses, the magnitude of induction in the activity of P450 monooxygenases was several fold higher in liver microsomes when compared with the brain. Western blotting studies have indicated that the increase in the P450 enzymes could be due to the increase in the expression of P450 1A1/1A2, 2B1/2B2 and 2E1 isoenzymes. In vitro studies using organic inhibitors specific for individual P450 isoenzymes and antibody inhibition experiments have further demonstrated that the increase in the activity of PROD, EROD and NDMA-d are due to the increase in the levels of P450 2B1/2B2, 1A1/1A2 and 2E1 isoenzymes, respectively. Induction studies have further shown that while pretreatment of 3-methylcholanthrene (MC), an inducer of P4501A1/1A2, did not produce any significant effect in the incidence of lindane induced convulsions, pretreatment with phenobarbital (PB), an inducer of P450 2B1/2B2 or ethanol, an inducer of P450 2E1 catalysed reactions, significantly increased the incidence of lindane induced convulsions. Similarly, when the P450-mediated metabolism of lindane was blocked by cobalt chloride incidence of convulsions was increased in animals treated with lindane indicating that lindane per se or its metabolites formed by PB or ethanol inducible P450 isoenzymes are involved in its neurobehavioral toxicity.

Oxidative stress and loss of cortisol secretion in adrenocortical cells of rainbow trout (Oncorhynchus mykiss) exposed in vitro to endosulfan, an organochlorine pesticide

The effects of endosulfan, a widely used organochlorine pesticide, on cortisol secretion, cell viability, antioxidants and lipid peroxidation were investigated in enzymatically dispersed head kidney cells of rainbow trout (Oncorhynchus mykiss). ACTH- and dbcAMP-stimulated cortisol secretion, and cell viability were impaired in a dose-related manner following acute in vitro exposure to endosulfan (EC(50) 19 microM, LC(50) 366 microM) and the loss of cortisol secretion was detected even at concentrations of endosulfan that did not decrease cell viability. Stimulation with dbcAMP did not restore cortisol secretion in endosulfan exposed cells while stimulation with pregnenolone maintained cortisol secretion until viability of cells was affected. Thus endosulfan may disrupt processes between the step generating cAMP and the step where pregnenolone is used. Activity of catalase increased at concentrations of endosulfan that did not impair cortisol secretion, and decreased at higher doses. Glutathione peroxidase (GPx) activity was significantly reduced at doses of endosulfan that also reduced levels of glutathione, an essential cofactor of GPx. Exposure up to 1 x 10(-7) M endosulfan increased the activity of glutathione transferase. The present in vitro study identified endosulfan as a chemical inducing a loss of secretory responses in teleost adrenocortical steroidogenic cells and alterations in the activity of enzymes known to be involved in oxidative stress pathways. Moreover, the significant increase in lipid hydroperoxides levels provided further evidence for endosulfan-induced oxidative stress.

Changes in glutathione-redox balance induced by hexachlorocyclohexane and lindane in CHO-K1 cells

1. The basal cytotoxic effect of the organochlorine pesticides hexachlorocyclohexane and lindane on CHO-K1 cultures was assessed at fractions of their lethal doses as determined by the neutral red incorporation (NRI) assay (NRI(6.25), NRI(12.5) and NRI(25)). The sulphur-redox cycle enzymes glutathione peroxidase, glutathione reductase and glutathione S-transferase, and total and oxidized glutathione were evaluated at several points during the standard growth curve of the cultures. 2. After incubation with each compound for 24 h, both glutathione peroxidase and reductase showed a substantial increase at the lowest exposure doses (NRI(6.25))--more significantly for lindane than for 1,2,3,4,5,6-hexachlorocyclohexane (HCH)--and dropped at higher doses of both compounds. The reduced and oxidized glutathione content was greatly diminished at the lower exposures, whereas the total glutathione content was higher at NRI(12.5) values. 3. Changes in cell membrane integrity were assessed for a wide range of pesticide concentrations with the lactate dehydrogenase release assay and lipid peroxidation. Membrane leakage and peroxide production were significantly enhanced at concentrations of HCH 50 microg ml(-1), although this effect was not significant at lindane concentrations < 200 microg ml(-1). 4. Lipid peroxidation increased with exposure to HCH at concentrations as low as NRI(6.25), whereas in the case of lindane, this increase was only significant at doses of NRI(25) and above.

Hexachlorocyclohexane-induced behavioural and neurochemical changes in rat

Effect of chronic oral exposure (10 and 20 mg kg(-1) body wt. for 7, 15 and 30 days) to hexachlorocyclohexane (HCH) on open-field behaviour and activities of cerebral Na+,K+-ATPase, Mg2+-ATPase and acetylcholinesterase (AChE) of rat was evaluated. Motor and grooming activities were altered, whereas vertical exploratory activity was unaffected by HCH. Activities of Na+,K+-ATPase, Mg2+-ATPase and AChE were inhibited significantly by the pesticide. The results suggest that HCH induces impairment of the enzymes involved in synaptic activity, resulting in behavioural alterations.

Acute hexachlorocyclohexane-induced oxidative stress in rat cerebral hemisphere

Hexachlorocyclohexane (HCH) is reported to induce oxidative stress in liver and testis of rat. With an objective to examine its effect on brain tissue acute toxicity of HCH (10 and 20 mg/kg body wt, i.p.) on the antioxidant defense system of cerebral hemisphere of rat was evaluated. Lipid peroxidation (LPX) was elevated after 24 h in the crude homogenate and sub-cellular fractions (nuclear and mitochondrial) except the microsomal fraction in which LPX was induced after 6 h and remained elevated till 24 h. The pesticide elicited decrease in the activities of cytosolic total, CN(-)-sensitive (not at 24 h) and CN-resistant superoxide dismutases; total, Se-dependent and Se-independent glutathione peroxidases; and catalase throughout the measurement period. In contrast, glutathione reductase activity was elevated till 24 h after a fall at 6 h of pesticide exposure. Cerebral contents of glutathione and ascorbic acid were decreased in response to HCH. The results suggest the possible involvement of reactive oxygen species in the mechanism of HCH-induced neurotoxicity in rat.

Differences in hepatic drug metabolizing enzymes and their response to lindane in rat, rabbit and monkey

Untreated rabbit liver microsomes demonstrated the highest content of cytochrome P450 and activity of NADPH cytochrome c reductase compared to rat and monkey. The sodium dodecyl sulfate polyacrylamide gel electrophoresis of microsomes from untreated rabbit demonstrated a greater quantity of 50 KDa polypeptide than in rat and monkey. The activity of glutathione-S-transferase towards 1-chloro-2,4-dinitrobenzene and the band intensity of 26 KDa polypeptide was found to be at maximum in untreated rabbits, while rat liver demonstrated the highest activity of glutathione-S-transferase towards ethacrynic acid. The extent of hepatic microsomal lipid peroxidation was at maximum in untreated rats. The activity of catalase was higher in untreated monkeys compared to untreated rats and rabbits. Lindane at a dose of 10 mg kg-1 body weight for a period of six days increased the hepatic content of cytochrome P450 and the activities of NADPH cytochrome c reductase, aminopyrine N-demethylase, glutathione-S-transferases, haem oxygenase and lipid peroxidation, decreased non-protein thiols and concomitantly intensified the 50 and 26 KDa polypeptides in the microsomes and 100,000 x g supernatants respectively, in the rat but not in the rabbit or monkey. The results demonstrate that lindane is a bifunctional inducer in the rat and non-functional in rabbit and monkey. It also increased the activities of hepatic drug metabolizing enzymes with concomitant production of oxidative stress in the rat, whereas in rabbit and monkey it did not alter the drug metabolizing enzymes nor produced any oxidative stress.

Brain and liver lipid peroxidation levels following acute and short-term lindane administration in the rat

Oxidative stress-related parameters in rat brain and liver were evaluated following acute (60 mg/kg i.p., 2 and 24 h after dosing) or short-term (1000 ppm in the diet for 90 days) lindane administration. Both treatments elicited a significant accumulation of lindane in brain and liver, with convulsions observed in short-term and 24-h lindane-treated rats. In these conditions, lindane exposure did not alter brain lipid peroxidation, assessed as thiobarbituric acid reactants formation and spontaneous chemiluminescence, parameters that were enhanced in the liver. The activities of antioxidant enzymes in the brain (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose 6-phosphate dehydrogenase) were not modified by acute lindane treatment, while brain glutathione content was significantly reduced by 13%. It is concluded that lindane does not alter the oxidative stress status of the brain as occurs in liver, regardless of the time of exposure of rats to either acute or short-term administration of the insecticide.