Acute toxicity and 28-day oral administration of euclea natalensis extract in Swiss albino mice

Abstract

Euclea natalensis is a medicinal plant indigenous to South Africa that has been used for ages in the management of different diseases including pulmonary-related diseases. The present study was undertaken to investigate the toxicity effects of the medicinal plant in Swiss albino mice. Acute and 28-day repeated oral toxicity studies were performed following the Organization for Economic Cooperation and Development (OECD) test guidelines 423 and 407, respectively. For acute oral toxicity, euclea natalensis was administered at 500 mg/kg body weight repeatedly for seven days and the mice were observed for signs of toxicity for seven days. The gross pathological observation was performed at the end of the study. Haematology, clinical chemistry and histopathology examinations were performed for the acute study. No treatment-related deaths or toxic signs were observed with euclea natalensis in the acute toxicity experiments. For the 28-day oral toxicity study, the plant was administered at 500 mg/kg body weight, 250 mg/kg body weight and 125 mg/kg body weight. The animals were monitored and observed clinically every day after dosing, and body weight changes and feed consumption were monitored weekly. In the main study, no significant differences in body weight and feed consumption were observed between the controls and treated animals. Additionally, no gross pathological findings in relative organ weights and histopathological abnormalities were observed in either control mice or treated mice. Lesions observed were age- related and not dose-dependent. The blood results did not show any significant difference between the treated animals and the control animals. In conclusion, euclea natalensis has been found to be non-toxic and, therefore, the no observed adverse effects level (NOAEL) is 500 mg/kg body weight.