ABSTRACT
Aims: Adenium obesum is a known medicinal plant thereby creating the need for the evaluation of its toxicity and histopathological effects on the liver of female Wistar rats orally administered ethanol extract of the plant’s stem bark. Place and Duration of Study: Department of Veterinary Pathology, Ahmadu Bello University, Zaria, Nigeria, between January 2011 and January 2012. Methodology: Ethanol extraction of A. obesum stem bark was performed prior to screening it for its phytochemical constituents. Female rats per group were orally administered by gavage pre-defined doses (300mgkg-1, 2000mgkg-1 and 5000 mgkg-1) of the extract separatively in a stepwise procedure and observed for signs of toxicity. Control rats were administered distilled water placebo. Results: The extract contained some alkaloids, saponins, tannins, flavonoids, glycosides, steroids and triterpens with no anthraquinones. Exposed rats did not show signs of toxicity and neither was there any mortality. Changes in aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase activities were non-significant (p>0.05). Congestion and fatty degenerative changes were seen in the liver of the exposed rats, which were not significantly (p>0.05) different in exposed rats compared to the control. Conclusion: Adenium obesum did not cause major hepatic damage in the exposed rats and therefore, it is a safe oral medicinal plant within the extract dose and exposure period used in the study.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the ameliorative effect of melatonin on sub-chronic chlorpyrifos (CPF) and cypermethrin (CYP)-evoked cognitive changes in male Wistar rats.</p><p><b>METHODS</b>Fifty adult male Wistar rats, divided into five groups of ten rats each, were used for the study. Groups 1 and II were given distilled water and soya oil (2 mL/kg) respectively. Group III was administered with melatonin at 0.5 mg/kg only. Group IV was administered with CPF [7.96 mg/kg (1/10th LD50)] and CYP [29.6 mg/kg (1/10th LD50)], and Group V was administered with CPF [7.96 mg/kg (1/10th LD50)] and CYP [29.6 mg/kg (1/10th LD50)] 30 min after melatonin (0.5 mg/kg). The regimens were administered by gavage once daily for 12 weeks. Thereafter, cognitive performances were determined and the brain was evaluated for malonaldehyde concentration.</p><p><b>RESULTS</b>CPF and CYP induced cognitive deficits and increased brain malonaldehyde concentration, which were all ameliorated by melatonin.</p><p><b>CONCLUSION</b>Cognitive deficits elicited by CPF and CYP was mitigated by melatonin due to its antioxidant property.</p>