ABSTRACT
Starvation is a global challenge. Nutritional status of an organism may influence its psychosocial behavior and other nervous system processes like motor responses and its ability to learn and memorize. This study determined the impact of starvation-induced stress on memory sensitization, habituation and psychosomatic responses in an experimental animal design. 25 wistar rats were randomly sampled and grouped into 1-control, 2-feed after 6 hours deprivation, 3-feed after12 hours deprivation, 4-feed after 18 hours deprivation and 5-feed after 24 hours deprivation. Behavioral tests carried out included the multiple maze tests and elevated plus maze test. Grip strength test was performed to determine neuromuscular response and endurance in all groups. Biochemical investigation of brain stress markers was done on the last day of the study. There was a significant (P≤0.05) enhancement in memory processes and anxiolytic behavior after 6 hours feed deprivation. An increase in antioxidants after 6 hours feed deprivation was suspected to be a compensatory response. A progressive decrease in memory facilitation, anxiolytic behavior and muscular strength was reported after 12, 18 and 24 hours feed deprivation. The increase in habituation and decrease in psychosomatic response was observed and appreciated as the duration of feed deprivation was increased. This study provided evidence about a possible link between memory processes and stress-related alterations in calcium, magnesium and nitric oxide. Starvation may impairlearning, memory and motor responses, but this tendency is dependent on the extent of feed deprivation and nutrient depletion.
ABSTRACT
Aims: The present study investigated the effects of the methanolic extract of the rind of Citrullus lanatus on lead acetate induced toxicity on semen parameters, reproductive hormone assay and testicular histology in male albino Wistar rats. Study Design: Controlled experimental study using randomly assigned laboratory animals. Place and Duration of Study: Department of Human Physiology, College of Health Sciences, University of Port Harcourt, PMB 5323, Port Harcourt, Nigeria and Department of Physiology, Madonna University, Elele Campus, Rivers State, Nigeria between January 2013 and February 2014. Methodology: Twenty male rats were assigned into four groups: Group A to D of five rats each. Group A served as control and received 2ml/kg bw of 10% extract vehicle; Group B received 200mg/kg bw of the methanolic extract of the rind of Citrullus lanatus; Group C received 2.25mg/kg bw of lead acetate; and Group Dwere co-administered with 2.25 mg/kg bw lead acetate and 200 mg/kg bw of the methanolic extract of the rind of Citrullus lanatus. The drugs and extracts were administered orally to the rats for 35days. On day 36, blood samples were collected from anaesthetized rats by cardiac puncture for reproductive hormone assay and the testes harvested for determination of semen parameters and histological studies. Semen parameters: count, motility, viability, and morphology were determined and assay for plasma levels of Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH) and testosterone done. Results: Results obtained showed that, compared to control rats, administration of the methanolic extract of the rind Citrullus lanatus significantly enhanced sperm count and all reproductive hormone levels (P<0.05); and also caused non-significant increases in sperm motility, percentage of spermatocytes with normal morphology and percentage of live spermatocytes, but decreased percentage of dead spermatocytes (P>0.05). Treatment with lead acetate caused a significant reduction in levels of all reproductive hormones and significant diminution of sperm motility, morphology, viability; with increases in percentage of dead spermatocytes (P<0.05). Expectedly, co-administration of the methanolic extract of the rind of Citrullus lanatus with lead acetate ameliorated the deleterious effects of lead acetate resulting in significant increases in sperm count and all reproductive hormones (P<0.05) and non-significant increases in motility, morphology and live spermatocytes (P>0.05): however, the percentage of spermatocytes with abnormal heads were significantly increased. The results suggest that the methanolic extract of the rind of Citrullus lanatus exerts a possible ameliorative effect on lead acetate induced toxicity on some reproductive parameters in male albino Wistar rats. Conclusion: The findings suggest that the methanolic extract of the rind of Citrullus lanatus exerts a possible beneficial effect on male reproductive parameters in albino Wistar rats and validates anecdotal reports of the beneficial effect of watermelon consumption from our environment. We however, recommend further studies in this regard.