Massive lindane overdose with toxicokinetics analysis.

BACKGROUND: Lindane is a possible carcinogen with known teratogenicity and immunologic and neurotoxic properties. Despite reports of seizures, coma, and death associated with its use as well as banning of its environmental use by the Environmental Protection Agency (EPA), the US Food and Drug Administration (FDA) still allows treatment with lindane as a second-line scabicide and pediculicide. We present a case of a massive suicidal ingestion of lindane in which the patient survived the ingestion, though he did expire shortly thereafter from an unrelated cause pre-discharge. METHODS: Pharmacokinetic analysis of serum lindane concentrations was performed with Phoenix® WinNONLIN®. The estimated distribution half-life for lindane was 10.3 h, and the terminal half-life was 162.9 h, much longer than the previously reported terminal half-life of 25-36 h. Because of this long half-life, repeated lindane exposures may lead to accumulation of lindane in the tissues. RESULT: After overdose, toxicity may be delayed and full recovery may be prolonged.

Alleviation of lindane induced toxicity in testis of Swiss mice (Mus musculus) by combined treatment with vitamin C, vitamin E and alpha-lipoic acid.

Mitigation of lindane induced toxicity in testis of Swiss mice by combined treatment with vitamin C, vitamin E and alpha-lipoic acid has been evaluated. Male healthy mice (40), 8-10 weeks old were randomly selected and divided into 4 groups, control (C); lindane (L); antioxidant (A) and antioxidant plus lindane (A+L). Group C animals were administered only the vehicle (olive oil); in group L lindane was administered orally at a dose of 40 mg/kg body wt.; in group A combination of antioxidants at a dose of 125 mg/kg body wt.(vitamin C: 50 mg/kg body wt., vitamin E: 50 mg/kg body wt. and alpha-lipoic acid: 25 mg/kg body wt.) was administered orally; in group A+L both antioxidants (125 mg/kg body wt.) and lindane (40 mg/kg body wt.) were administered at their respective doses. In group A+L antioxidants were administered 1 h prior to lindane administration. All treatments were continuously given for 60 days. Histopathological changes due to lindane intoxication indicated shrunken and distorted seminiferous tubules, sparse Leydig cells and blood vessels and atrophy in the tissue. The testis weight also decreased significantly. Lindane treated group showed increased lipid peroxidation, whereas glutathione, glutathione peroxidase, superoxide dismutase, catalase and protein were significantly decreased compared to control. Lindane induced damage was minimized by administration of antioxidants. Results suggest that combined pretreatment with antioxidants can alleviate the damage caused to testis by lindane.

Protective effect of gallic acid against lindane induced toxicity in experimental rats.

Lindane is an organochlorine pesticide that persists in the environment, bioaccumulate through food chain and has a risk of causing adverse effects to human health and the environment. It induces cell damage by producing free radicals and reactive oxygen species. The aim of the present study is to investigate the protective effect of gallic acid (a plant derived polyphenol) against lindane induced hepatic and renal toxicity in rats. Liver damage was assessed by hepatic serum marker enzymes like SGOT, SGPT and ALP and histopathological observation. Renal damage was observed by histopathological examination and serum markers like creatinine and urea. Treatment with lindane increased the levels of lipid peroxidation, serum marker enzyme activity with a concomitant decrease in GSH, CAT, SOD, GPx and GST. Histological alterations were also observed in kidney and liver tissue with lindane treatment. Co-treatment of gallic acid significantly prevented the lindane induced alterations in kidney and liver tissues with a decrease in LPO, serum marker enzyme activity and a significant increase in antioxidant levels. These results suggest that gallic acid has protective effect over lindane induced oxidative damage in rat liver and kidney.

Augmentation of cholinesterases and ATPase activities in the cerebellum and pons-medulla oblongata, by a combination of antioxidants (resveratrol, ascorbic acid, alpha-lipoic acid and vitamin E), in acutely lindane intoxicated mice.

In the present investigation neurotoxic effects of lindane and the protective potential of a combination of antioxidants against lindane-induced toxicity were evaluated in Swiss mice. The investigation was carried out on acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and adenosine triphosphatase (ATPase) activities of the cerebellum and pons-medulla oblongata. Healthy mice, 7-8 weeks old were administered acute dose of lindane (40 mg/kg b.w.), antioxidants, both lindane and antioxidants, and vehicle in four separate groups, subcutaneously. Resveratrol (Res), ascorbic acid (C), alpha-lipoic acid (ALA) and vitamin E (E) were used in the combination for neuroprotection at the concentration of 5 mg/kg b.w., 50 mg/kg b.w., 20 mg/kg b.w. and 50 mg/kg b.w. respectively. Enzymatic activities were used as biochemical marker for manifestation of lindane-induced acute toxicity. Protective effects of antioxidants were also evaluated using the same parameters. Treatment of lindane to normal control animals resulted in a significant decrease in AChE, BChE and ATPase levels in crude homogenates of cerebellum and pons-medulla. Antioxidants treatment significantly increased the levels of enzymes. Critical difference (CD) of AChE, BChE and ATPase levels in various groups was found significant at 1% in cerebellum and pons-medulla both (i.e. P<0.01).

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.

Organochlorine pesticides dieldrin and lindane induce cooperative toxicity in dopaminergic neurons: role of oxidative stress.

Elevated environmental exposure to pesticides has been implicated as a contributing factor in the pathogenesis of Parkinson's disease (PD), a progressive movement disorder resulted from degeneration of the nigrostriatal dopaminergic (DA) pathway. Organochlorine pesticides (OCPs) including dieldrin and lindane remain ubiquitous in the environment and food supply due to their resistance to degradation and bioaccumulation along the food chain. While prior studies have gained insight into the neurotoxic effects of individual OCPs such as dieldrin, the effect of combinations of coexisting OCPs is lacking. In this study, we determined the combined effect of dieldrin and lindane on DA neurons and potential mechanism of action. Combinations of dieldrin and lindane (5-25 microM) were more effective in causing toxicity in immortalized rat N27 DA neurons than when used alone. Mechanistically, dieldrin and lindane combination induced a rapid increase in the levels of intracellular reactive oxygen species, a decrease in mitochondrial membrane potential and activation of caspase 3/7. Pretreatment with antioxidant N-acetyl cysteine blocked the effect of dieldrin and lindane on ROS generation and mitochondrial membrane potential and protected against dieldrin- and lindane-induced neurotoxicity. These results demonstrate that dieldrin and lindane work cooperatively to induce DA neurotoxicity through the induction of oxidative stress and mitochondrial dysfunction. These findings may advance understanding of the role of pesticides in the multi-factorial etiology of PD.

Protective effects of dietary ginger (Zingiber officinales Rosc.) on lindane-induced oxidative stress in rats.

The protective effect of dietary feeding of Zingiber officinales Rosc. (ginger) against lindane-induced oxidative stress was investigated in male albino rats. Oxidative stress was monitored by estimating the extent of lipid peroxidation, activities of the oxygen free radical (OFR) scavenging enzymes superoxide dismutase (SOD) and catalase (CAT) and the status of the glutathione redox cycle antioxidants. Lindane administration (30 mg/kg bw orally for 4 weeks) was associated with enhanced lipid peroxidation and compromised antioxidant defenses in rats fed a normal diet. Concomitant dietary feeding of ginger (1%w/w) significantly attenuated lindane-induced lipid peroxidation, accompanied by modulation of OFR scavenging enzymes as well as reduced glutathione (GSH) and the GSH dependent enzymes glutathione peroxidase (Gpx), glutathione reductase (GR) and glutathione-S-transferase (GST) in these rats. These findings suggest that a diet containing naturally occurring compounds is effective in exerting protective effects by modulating oxidative stress.

PolicosanolPlus and Neuroprevin ameliorate pesticide-mediated inhibition of neurite outgrowth and neurite degeneration.

BACKGROUND: Pesticide exposure is a recognized risk factor for neurodegenerative diseases. Recently, bifenthrin, a pyrethroid pesticide, was shown to inhibit the formation of neurites and cause neurite retraction, raising concern that these newer and less toxic pesticides may also contribute to neurodegenerative diseases. PolicosanolPlus and Neuroprevin are nutraceutical supplements which promote the survival of neurites in neuronal cell cultures. Here we determine if PolicosanolPlus and Neuroprevin can ameliorate the neurodegenerative effects of bifenthrin. MATERIAL/METHODS: PC12 cells were treated with NGF, bifenthrin, PolicosanolPlus and Neuroprevin in various combinations and the formation of neurites was assessed microscopically at times ranging from 12 to 72 hours post treatment. Bifenthrin was also withheld at the time of NGF, PolicosanolPlus and Neuroprevin treatment and added after neurite formed to assess neurite retraction. RESULTS: Bifenthrin (1 x 10(-6) M) inhibits neurite outgrowth, in the absence of cell death, by more than 50% at 12 hours and by more than 80% at 72 hours. With addition of PolicosanolPlus and/or Neuroprevin at the time of cell seeding, bifenthrin does not inhibit neurite outgrowth. Addition of bifenthrin to differentiated cells results in a retraction of 90% of neurites, while those with PolicosanolPlus and Neuroprevin show no significant retraction of neurites. CONCLUSIONS: The pesticide, bifenthrin, inhibits neurite formation and causes neurite retraction. PolicosanolPlus and Neuroprevin are nutraceutical supplements which ameliorate the effects of bifenthrin on neurite outgrowth and retraction. Dietary supplementation with PolicosanolPlus and Neuroprevin may protect against developmental and long-term neurodegenerative events that result from exposure to pesticides.

Antioxidants prevent gamma-hexachlorocyclohexane-induced inhibition of rat myometrial gap junctions and contractions.

Lindane (gamma-hexachlorocyclohexane) is a commonly used pesticide that bioaccumulates in mammalian adipose tissue. Lindane inhibits gap junctional intercellular communication and oscillatory contractions of pregnant rat myometrium in vitro. The present study investigated the role of oxidative stress in lindane's inhibition of myometrial function in mid-gestation pregnant rat uteri. Lucifer yellow dye was microinjected into cultured myocytes to assess gap junctional intercellular communication. Lindane exposure (100 microM) resulted in a time-dependent, biphasic inhibition of dye transfer. This pattern of inhibition was also seen upon cell exposure to the pro-oxidant, tert-butyl hydroperoxide (100 microM). Lindane's initial and secondary-onset dye transfer inhibitions were reversed by cotreatment and pretreatment with the antioxidants, alpha-tocopherol (25-100 microM), diphenyl-1,4-phenylene diamine (10-30 microM), and superoxide dismutase (100-400 U/ml). D-mannitol (100-300 mM) also reversed lindane's initial dye transfer inhibition. Nitro blue tetrazolium reduction to formazan (measured spectrophotometrically) was elevated upon exposure of cultured cells to lindane or tert-butyl hydroperoxide, indicating the presence of reducing agents. Lipid peroxidation, assessed as thiobarbituric acid-reactive substances, was also elevated in lindane-exposed cell cultures. alpha-Tocopherol reversed this elevation. Finally, uterine contractility was assessed by measuring isometric contractions of uterine strips hung in standard muscle baths. Pretreatment with alpha-tocopherol prevented lindane's abolishment of uterine contractions in vitro. These data support the hypothesis that lindane inhibits uterine contractility and myometrial gap junctions by establishing an oxidative stress environment.

Prolonged phenobarbital pretreatment abolishes the early oxidative stress component induced in the liver by acute lindane intoxication.

Lindane administration to rats (60 mg/kg b.w.) led to an enhancement in the oxidative stress status of the liver at 4 h after treatment, characterized by increases in hepatic thiobarbituric acid reactants (TBARS) formation and chemiluminescence, reduced glutathione (GSH) depletion, and diminution in the biliary content and release of GSH. These changes were observed in the absence of changes in either microsomal functions (cytochrome P450 content, NADPH-dependent superoxide radical production, and NADPH-cytochrome P450 reductase or NADPH oxidase activities) or in oxidative stress-related enzymatic activities (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and glutathione-S-transferases), over control values. Phenobarbital (PB) administration (0.1% in drinking water; 15 days) elicited an enhancement in liver microsomal functions, lipid peroxidation, and GSH content, without changes in oxidative stress-related enzymatic activities, except for the elevation in those of glutathione reductase and glutathione-S-transferase, compared to control rats. Lindane given to PB-pretreated rats did not alter liver microsomal functions, lipid peroxidation, glutathione status, or oxidative stress-related enzymatic activities, as compared to PB-pretreated animals. In addition, lindane induced periportal necrosis with hemorrhagic foci in untreated rats, but not in PB-pretreated animals. It is concluded that the early oxidative stress response of the liver to lindane and hepatic injury are suppressed by PB pretreatment via induction of microsomal enzymes in all zones of the hepatic acinus. reserved.

Lindane-induced inhibition of spontaneous contractions of pregnant rat uterus.

Hexachlorocyclohexanes (HCHs) are prevalent insecticides. Lindane (gamma-HCH) inhibits uterine gap junctions but beta-HCH does not. Because gap junctions promote coordination of oscillatory uterine contractions, we hypothesized that lindane, but not beta-HCH, would inhibit uterine contractions. Uterine strips from midgestation rats were suspended in standard muscle baths and exposed to HCHs in a cumulative manner. Lindane induced concentration-dependent decreases in contraction force (ED50 of 9.2 microM) and complete uterine quiescence at 30 microM. In contrast, beta-HCH had no effect on contraction force, but 20 to 200 microM beta-HCH increased contraction frequency in a concentration-dependent manner. Isomer-specific differences in uterine responses were observed at similar HCH isomer tissue concentrations. Additionally, the phospholipase A2 inhibitor and antioxidant quinacrine increased the ED50 for contraction force inhibition to 84.5 microM lindane. Lindane also increased cAMP concentrations. Lindane and beta-HCH have distinctly different actions in the uterus. Lindane's inhibitory action may involve cAMP, arachidonic acid, or oxidative stress.

Effect of tetrandrine on proto-oncogene c-fos expression in rat cerebrum.

AIM: To detect the effect of tetrandrine (Tet) on c-fos gene expression in cerebrum induced by lindane, a neurotoxicant which activates Ca2+ channels. METHODS: Northern and dot blotting, dual wavelength thin layer chromatography scanner, were used in this study. RESULTS: Lindane 30 mg.kg-1 given by intragastric gavage (i.g.) increased the expression of c-fos gene to 146 mm2 in rat cerebrum 1 h after treatment. Tet 1, 2, and 4 mg.kg-1 given by i.g. 30 min prior to lindane reduced c-fos gene expression in a concentration-dependent manner. Expressed genes reached only 86, 40, and 39 mm2, respectively. CONCLUSION: Tet inhibited c-fos gene expression in rat cerebrum induced by Ca2+ agonist-lindane.

Lindane cytotoxicity in cultured neocortical neurons is ameliorated by GABA and flunitrazepam.

The effect of lindane (gamma-hexachlorocyclohexane) on [35S]t-butylbicyclophosphorothionate ([35S]TBPS) binding and GABA-stimulated 36Cl- influx was investigated in cultured cerebral cortical neurons. In addition, the cytotoxic action of lindane as well as a protection by GABA and flunitrazepam were studied together with the ability of lindane to increase the intracellular concentration of free Ca2+. Lindane was found to be toxic to the neurons, an effect that could be completely prevented by the simultaneous presence of GABA (0.1 microM) and flunitrazepam (100 microM) and reduced by GABA alone. An interaction with the GABA receptor-gated chloride channel was demonstrated by an inhibitory action of lindane on [35S]TBPS binding (IC50 188 +/- 51 nM) and on GABA-stimulated 36Cl- influx in the neurons. Lindane only marginally increased the intracellular Ca2+ concentration in the neurons. It is concluded that the cytotoxic action of lindane is mediated through interaction with GABA receptors in a manner essentially independent of changes in intracellular Ca2+ homeostasis.

Effects of lindane exposure on rainbow trout (Oncorhynchus mykiss) immunity. II. In vitro restoration of antibody-secreting cells and lymphocyte proliferation activity by nitrogranulogen after in vivo immunosuppression due to lindane.

A dose-dependent immunomodulatory effect of Nitrogranulogen (NGG) was observed in vitro on antibody-secreting cells and lymphocyte proliferation in rainbow trout. Because different doses of lindane (10, 50 and 100 mg/kg, injected intraperitoneally) had a depressing effect on the same immune functions, the authors restored them using NGG in vitro.

Anticonvulsant activity of delta-HCH, calcium channel blockers and calmodulin antagonists in seizures induced by lindane and other convulsant drugs.

The anticonvulsant activity of delta-HCH and of a calmodulin antagonist, W-7 were investigated on convulsions induced in mice by lindane (ED100 100 mg/kg), by GABAergic antagonists PTZ (ED100 60 mg/kg) and PTX(ED100 4 mg/kg), by calcium channel agonist BAY-K-8644 (ED100 5 mg/kg), by two agonists of excitatory amino acid receptors, kainic acid (ED100 80 mg/kg) and NMDA (ED100 160 mg/kg and by the atypical benzodiazepine Ro 5-4864 (ED100 40 mg/kg). The anticonvulsant activity of a voltage-dependent calcium channel antagonist, nifedipine was also investigated on convulsions induced by Ro 5-4864, BAY-K-8644, kainic acid and NMDA. delta-HCH antagonized lindane- and BAY-K-8644-induced convulsions (ED50 231 (172-309) mg/kg and 148 (142-154) mg/kg, respectively) and at concentrations up to 300 mg/kg failed to antagonize Ro 5-4864, kainic acid and NMDA convulsions. In contrast delta-HCH potentiated PTX-induced seizures. Nifedipine antagonized BAY-K-8644- and kainic acid-induced convulsions (ED50 6.5 (4.3-9.7) mg/kg and 30 (13-70) mg/kg but at concentrations up to 20 mg/kg failed to antagonize Ro 5-4864 and 25% of protection was observed on NMDA-induced convulsions at the highest dose (20 mg/kg). The ED50 of W-7 to antagonize convulsions induced by lindane and BAY-K-8644 were 12 (8-19) mg/kg and 49 (29-85) mg/kg, respectively. Some anticonvulsant effect was observed against PTZ and NMDA but without any dose-dependent anticonvulsant activity. W-7 did not protect against PTX and kainic acid convulsions and 30% of protection was observed against convulsions at the highest dose of W-7 (75 mg/kg).(ABSTRACT TRUNCATED AT 250 WORDS)

Lindane-induced convulsions in NMRI and OF1 mice: antagonism with (+)MK-801 and voltage-dependent calcium channel blockers.

The convulsant profile of lindane was investigated in OF1 and NMRI mice lines in relation to other convulsants acting at the GABAA and NMDA receptor complexes. Thus, a specific GABA-gated chloride channel blocker, PTX, a GABAA receptor antagonist, PTZ, and an excitatory amino acid receptor agonist, NMDA, were used. Antagonism of the convulsant effects of each of these drugs was investigated with (+)MK-801, a blocker of the NMDA-operated cation channel, and with nifedipine, a voltage-dependent calcium channel antagonist. While no differences in potency for PTX or PTZ to induce seizures were observed between OF1 and NMRI mice, lindane was approximately 80 and 90% more potent in its ability to induce seizures and lethality, respectively, in OF1 than in NMRI mice. Brain lindane concentrations at the moment of convulsion, measured after ED100 doses of lindane (400 and 200 mg/kg for NMRI and OF1 mice, respectively), did not differ between OF1 and NMRI mice, suggesting that the different potency of lindane between these mouse lines is a consequence of pharmacokinetic factors. Furthermore, (+)MK-801 antagonized seizures induced by either lindane, PTX or PTZ with similar potencies in both mouse lines. These results, coupled with the different pharmacokinetics of lindane in OF1 and NMRI mice, suggest that the distinct effects of lindane in these mice are not mediated by different activities at either NMDA or GABAA receptor complexes. Nonetheless, nifedipine antagonized lindane-induced seizures with a three-fold higher potency in NMRI than in OF1 mice. In contrast, nifedipine failed to antagonize PTX and PTZ convulsions in both OF1 and NMRI mice. These results suggest that besides the GABAA receptor complex other mechanisms related to calcium mobilization may be involved in the convulsant action of lindane.

Vitamin E protects human leucocytes against toxic effects of lindan in vitro.

Vitamin E (15 micrograms/ml and 60 micrograms/ml) was used for protection of human leucocytes against toxic effects of lindan (150 microM and 200 microM) in vitro. The protective effect of vitamin E manifested itself as maintenance of the phagocytic activity of granulocytes, the value of nucleologram in lymphocytes, and the proportion of euchrysin-negative lymphocytes near the values in controls.

Protective role of vitamin A in the male reproductive toxicity of hexachlorocyclohexane (HCH) in the rat.

The reproductive toxicity of the organochlorine insecticide, hexachlorocyclohexane (HCH), was investigated in male albino rats fed a diet free of vitamin A or containing vitamin A at 2000 or 100,000 IU/kg diet. Diets containing 1000 ppm HCH for 7 weeks did not cause testicular toxicity in the vitamin-A-deficient and supplemented rats. However, reproductive toxicity was clearly manifested 2 weeks after withdrawing HCH from the diets and was more pronounced in the vitamin A deficient rats compared to their vitamin A supplemented counterparts. Reduction in the testicular weights was accompanied by atrophy of epididymides and seminal vesicles in the vitamin A deficient rats alone. Inhibition of spermatogenesis was further confirmed by decreased sperm count in the epididymis. Biochemically, the activities of the steroidogenic enzymes were drastically reduced. Supplementation of vitamin A after withdrawal of HCH accelerated the recovery and restored spermatogenesis and enzyme activities in the deficient rats. These results demonstrate the greater susceptibility of the male reproductive system to HCH toxicity during vitamin A deficiency and also the protective effect of vitamin A supplementation.

GABAergic modulation of lindane (gamma-hexachlorocyclohexane)-induced seizures.

The main objective of this work was to study the role of the GABAergic system on the convulsions elicited by the organochlorine insecticide lindane. The concentration of lindane in rat brain at the onset of the first tonic convulsion was taken as the endpoint for the neurotoxic action of the insecticide administered by intravenous infusion. Pretreatment with the GABA agonists muscimol and progabide, the GABA uptake blocker SK&F 89976-A, the GABA transaminase inhibitor gamma-acetylenic GABA, and the GABA indirect agonist phenobarbital significantly increased the threshold concentration of lindane in brain required to induce convulsions. The GABA agonist THIP, the GABA competitive antagonist bicuculline, and the prodrug cetyl-GABA had no effect on the brain level of lindane required to induce seizures. The noncompetitive GABA antagonists, picrotoxinin and pentylenetetrazol, significantly decreased the brain concentration of lindane needed to elicit convulsions. The concentration of GABA in the brain of lindane-treated rats was only modified by the significant increase produced after gamma-acetylenic GABA pretreatment. These results show that the convulsions elicited by lindane can be facilitated by some GABA antagonists and antagonized by GABA mimetics, especially those that enhance GABA functionality. The present data are consistent with the proposed in vitro competition of lindane for the picrotoxinin binding site associated with the Cl- ionophore of the GABAA receptor, and suggest that lindane may also interact in vivo with this site.