Fifty adults male Wistar rats (10 weeks old; 160–180 g) obtained from the Department of Biochemistry, Faculty of Science, University of Port Harcourt, Nigeria were used for the present study. The animals were housed in plastic cages placed in a well-ventilated vivarium and subjected to natural photoperiod of 12-h light:12-h dark cycle. They were fed with rat chow and given drinking water ad libitum for two weeks before the commencement of the experiment. All the animals received humane care according to the conditions stated in the ‘Guide for the Care and Use of Laboratory Animals’ prepared by the National Academy of Science (NAS) and published by the National Institute of Health. The experimental protocols were performed after approval by the University of Port Harcourt Ethical Committee.