Experimental animals

Healthy, adult male and female Wistar rats (180–230 g of weight) purchased from the Medical Research Institute, Colombo, Sri Lanka were used in this study. All animals received humane care. They were housed in plastic cages in the animal house of the Department of Zoology and Environment Sciences, University of Colombo under standard animal house conditions (temperature; 28–31 °C, photoperiod; approximately 12 h natural light per day, relative humidity: 50–55%). The animals were fed with pelleted food (VET HOUSE Ltd. Colombo, Sri Lanka) and clear drinking water ad libitum. Ethical approval for the laboratory animal study was obtained from the Institute of Biology, Sri Lanka (Ethical approval number -IOBSL 111 05 29). Hence, all experiments conducted were in compliance with the Organization for Economic Co-operation and Development (OECD) guidelines.