Sapium ellipticum (Hochst.) Pax Leaf Extract: In-vitro Antioxidant Activities and Lethal Dose (LD50) Determination in Wistar Rats

Abstract

Prior to this investigation, the LD50 and antioxidant activities of Sapium ellipticum leaf extract have not been reported, hence; the focus of this study. The LD50 of the extract was determined through three routes of administration using the method of Lorke. The Intraperitoneal (i.p) and intramuscular (i.m) LD50 values were determined as 979.80 and 1,341.60 mg/kg body weight (BW) respectively. Oral administration of the extract (to a dose of 45,000 mg/kg BW) did not cause any negative behavioral changes in the animals, and no mortality was recorded within and after 24h of the experiment. The antioxidant properties of the extract was assessed in vitro in terms of its free radical scavenging, metal chelating and reducing power activities as well as its ability to inhibit the formation of malondialdehyde (MDA), an index of lipid peroxidation. The total phenolic content of the extract was determined as 74.23±3.12 mg GAE/g. Data obtained indicate that the extract exhibited appreciable free radical scavenging activity (IC50 = 0.128 mgmL-1) and strong reducing power in comparison with butylated hydroxyl toluene (BHT, IC50 = 0.118 mgmL-1) and ascorbic acid (IC50 = 0.120 mgmL-1) used as reference antioxidants. The inhibition of linoleic acid induced-lipid peroxidation by the extract was comparable to that of BHT and greater than that elicited by ascorbic acid. In terms of metal chelating activity, ethylene diamine tetraacetic acid (EDTA) used as positive control elicited a significantly (p≤0.05) higher activity than the extract at all concentrations used. Findings from this study credit Sapium ellipticum ethanol leaf extract with significant antioxidant properties. The plant material may therefore be of immense relevance in combating oxidative stress and its related ailments.