Scavenging effect of methanol crude extract and fractions of crateva adansonii leaves on 1,1-diphenyl picrylhydrazyl radical

Background: Crateva adansonii leaves have been used for many years traditionally in treating of headaches and inflammation. Objective: To determine the free radical scavenging effect of crude extract and fractions of Crateva adansonii leaves. Methods: The free radical scavenging activities of the methanol crude extract and fractions of the plant leaves were investigated in this study using 1,1-diphenyl picryl hydrazyl (DPPH) photometric assay. Results: The percentage yield of the leaves was 13.87 w/w. 35g of the crude methanol extract was subjected to solvent-solvent partitioning to yield 7.5 g, 2.0 g, and 3.1 g and 8.56 g of n-hexane, chloroform, ethyl acetate and methanol fractions respectively. All fractions showed dose-dependent increases in antioxidant activity. However, ethyl acetate fraction had the highest anti-oxidant activity, with mean percentage antioxidant value of 97.58±0.03 and 98.55±0.12 at 200 and 400 µg/ml respectively which was higher than that of ascorbic acid, 95.62±0.22 and 96.67±0.07 at 200 and 400 µg/ml respectively. Conclusions: The high anti-oxidant activities of the crude extract and fractions of the plant could be responsible for its wide use as an anti-inflammatory therapy in ethno-medicine.