We investigated the effects of melatonin on sperm parameters and some biochemical markers in lead-exposed male Wistar rats. Lead (50 mg/kg bw/day) and/or melatonin (4 mg/kg or 10 mg/kg bw/day) was administered for 4 weeks, while 2-week lead exposure was preceded by or followed by 2-week treatment with both doses of melatonin in other groups. Lead reduced glutathione, catalase, adjusted testes weight, semen parameters but did not change malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase, and total antioxidant capacity. Though independent of prolactin, lead-induced gonadotoxicity was both centrally and peripherally mediated, as it reduced gonadotropin-releasing hormone and testosterone levels, while gonadotropin levels did not change significantly probably due to negative feedback by elevated estradiol. However, pre-, simultaneous, or posttreatment of lead-exposed rats with melatonin reduced MDA, SOD, and estradiol but dose-dependently increased other parameters. Conclusively, lead causes male gonadotoxicity through oxidative stress and endocrine mechanisms, and these could be dose-dependently prevented and ameliorated by melatonin.

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Introduction: Lead is the most used nonphysiological neurotoxic heavy metal in the world that has been indicated to interfere with the cognitive and noncognitive processes via numerous mechanisms. The neuroprotective effect of melatonin is well known, but the effect of its interaction with lead in the brain remains inconclusive.Objective: To assess the therapeutic role of melatonin on cognitive deficit, anxiety and depressive-like symptoms in matured male Wistar rats exposed to a subchronic lead chloride (PbCl 2 ). Methods: Twenty male Wistar rats were blindly randomized into four groups (n = 5/group): group 1 to 4 underwent intragastric administration of physiological saline (10 ml/kg; vehicle), PbCl 2 (50 mg/kg), melatonin (10 mg/kg) and PbCl 2 + melatonin respectively for a period of 4 weeks during which neurobehavioral data were extracted, followed by neurochemical and histopathological evaluations. Results: Exposure to PbCl 2 reduced cognitive performance by increasing the escape latency and average proximity to the platform zone border, decreasing average path length in the platform zone, cognitive score, and time spent in probing. It raised the thigmotaxis percentage, time spent in rearing, number of pellet-like feces, and time spent in the dark compartment of a bright/dark box which are predictors of anxiety. It also induced depressive-like behavior as immobility time was enhanced. PbCl 2 deranged neurochemicals; malondialdehyde, interlukin-1β, and tumor necrotic factor-α were increased while superoxide dismutase and acetylcholinesterase were decreased without remarkable alteration in reduced glutathione and nitric oxide. Administration of PbCl 2 further disrupted neuronal settings of hippocampal proper and dentate gyrus. In contrast, the supplementation of melatonin reversed all the neurological consequences of PbCl 2 neurotoxicity by eliciting its properties against oxidative and nonoxidative action of PbCl 2 .This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Background Nigerian Cannabis sativa (hemp) causes male gonadotoxicity by inducing hyperprolactinemia, down-regulation of hypothalamic-pituitary-testicular axis, and oxidative stress. Benin republic hemp has been preferred by illicit users in Nigeria but its effect on male fertility is not understood. This study determined and compared the compositions of Benin republic hemp ethanol extract (BHE) and Nigerian hemp. The effects of BHE on semen parameters, reproductive hormones, and anti-oxidant status, and the possibility of bromocriptine (prolactin inhibitor) to abolish hemp-induced toxicities in rats were also investigated. Methods Thirty-six male Wistar rats were blindly randomized into 6 oral treatment groups ( n = 6 each). Groups I (control) and II received normal saline and bromocriptine (3 mg/kg) respectively. Groups III and IV received 2 mg/kg of BHE alone and in combination with bromocriptine respectively, while groups V and VI received 10 mg/kg BHE alone and in combination with bromocriptine respectively. Comparisons among the groups were done by one-way analysis of variance, followed by post-hoc Tukey multiple comparison test. Statistical significance was considered at p < 0.05. Results The BHE has no cannabichromene and tetrahydrocannabinol but a very small quantity of cannabinol and higher quantity of fatty acids when compared to Nigerian hemp. Both doses of BHE increased sperm count, morphology and viability but not motility. Co-administration of BHE with bromocriptine lowered sperm count but increased sperm morphology and viability. Bromocriptine and/or BHE caused reduction in the plasma prolactin level, increase in the plasma superoxide dismutase activity, but no significant change in the plasma gonadotropin releasing hormone, follicle stimulating hormone (except for the increase in rats that received bromocriptine+ 10 mg/kg BHE), luteinizing hormone, estradiol, malondialdehyde and glutathione peroxidase. The 10 mg/kg BHE or bromocriptine+BHE (both doses) increased total anti-oxidant capacity and catalase. Conclusions The BHE improves semen parameters by reducing plasma prolactin and enhancing plasma anti-oxidant status. Its pro-fertility potential might be associated with its deficiency in the widely known gonadotoxic phytocannabinoids.

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