In vitro and in vivo antioxidant potential of the methanolic extract of Cassia singueana Delile (Fabaceae) Lock leaves

The antioxidant activity of Cassia singueana Delile (Fabaceae) Lock methanol leaf extract was investigated in vivo and in vitro using malondialdehyde (MDA) test, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and ferric reducing/antioxidant power (FRAP) photometric assays. The leaves have been of interest to researchers because of its use in the treatment of various disease conditions in Nigerian traditional medicine. C. singueana leaf extract gave a significant (P < 0.05) dose-dependent increase in antioxidant power with the FRAP assay. The DPPH assay showed 66% antioxidant activity at 400 μg/ml of the crude extract but ascorbic acid showed 79% at the same concentration. All doses (0.25, 0.5, and 1.0 g/kg) of the extract exhibited significant (P < 0.05) reduction in MDA value of test rats compared to control from the onset of the investigation up to day 56. Thereafter, the extract showed no protective activity against lipid peroxidation. These findings demonstrate that the extract has antioxidant effects on experimental models and validate its use in Nigerian traditional medicine for the treatment of peptic ulcer. Even in its crude form, the effects were comparable to that of ascorbic acid, a compound with proven antioxidant activity. This finding suggests that the extract could be a potential source of a novel antioxidant.