In-vitro scavenging activity and acute toxicity study of methanol leaves extract and fractions of Lophira lanceolata Tiegh. Ex Keay(Ochnaceae) in rats

Petroleum ether, dichloromethane, ethyl acetate, butanol and water fractions were prepared from the methanol extract of the plant. The scavenging activity of DPPH (2,2-Diphenyl-1-picrylhydrazyl), the total phenolic (TPC) and total flavonoid (TFC)contents of the extract and fractions were determined by spectrophotometrical methods using gallic acid (GA) and quercetin (Qu) as reference antioxidant. The fifty percent inhibitory concentration (IC₅₀),fifty percent effective concentration (EC₅₀) and the antiradical power (ARP) were determined for all extract and fractions. An acute toxicity study using a single oral dose of 5000 mg/kg of the ethyl acetate fraction of the plant was conducted in female Albino rats following the OECD(420) Guidelines. Blood samples were collected for hematological and biochemical analysis. Histopathological examinations of the heart, kidney and liver were performed. The results showed that the ethylacetate fraction of L lanceolata had the highest free radical scavenging activity of DPPH (IC₅₀=1,43;EC₅₀= 0.07 and ARP= 14,28)and also contain the highest amount of total phenols (14,4±0,02mg of GA equivalent/g of plant fraction) and total flavonoids (93,3±0,04mg of Qu equivalent/g of plant fraction)as compared to other fractions and ascorbic acid (IC₅₀=5,82;EC₅₀= 3.44; ARP=3,44). The hematological parameters and the lipid profile didn’t show any major change compared to the control group. However, a significant increase of aspartate aminotransferase (AST, p<0.001) and alanine aminotransferase (ALT, p<0.001) showed that the ethyl acetate fraction of the methanol extract of L. lanceolata leaves might not totally be safe for consumption, in the conditions of our experiment.