Acute and subacute toxicity evaluation of aqueous extracts of Carpobrotus edulis in Sprague Dawley rats

Abstract

Carpobrotus edulis is a common medicinal plant used in Southern Africa. Despite its extensive use in herbal medicine, there is no documented scientific evidence corroborating its safety. This study aims to evaluate the acute and subacute toxic effects of the aqueous extracts of Carpobrotus edulis in Sprague Dawley rats. In acute toxicity testing, three healthy female Sprague Dawley rats were exposed to Carpobrotus edulis aqueous extract per step at any of the four fixed dose levels of 300, 600, 1200 and 2000mg/Kg body weight. The Sprague Dawley rats were observed clinically for any signs of toxicity. A 28-day subacute toxicity testing was carried out on thirty-two Sprague Dawley rats grouped in four experimental groups of eight animals each. Group A received 100mg//kg of the extract, Group B received 300mg/kg while Group C received 1000mg/kg. Group D was a negative control group and received distilled water. Bodyweight, feed and water intake were measured at weekly intervals. Blood for biochemical analysis was collected on the last day of the study period. Gross pathological and histopathological examination was done on all experimental rats. There were no clinical signs suggestive of toxicity on all doses used in acute toxicity testing. The LD50 of the aqueous extract of Carpobrotus edulis was estimated to be above 2000mg/kg. On subacute toxicity testing, there were no significance differences (P<0.05) on body weight changes, feed and water intake in all experimental groups. The serum biochemical results also did not show any significant variation among all the experimental groups. Gross pathology and histopathology examination of the selected organ tissues revealed no differences between control and treated Sprague Dawley Rats. It is concluded from the study that the aqueous extracts of Carpobrotus edulis are potentially safe.