Antioxidant Activity of Bark Extracts from Erythrophleum Couminga Baill. (FABACEAE)

The bark of Erythrophleum couminga is used by the population of northwestern of Madagascar to treat promptly infected or fresh wounds. The objective of this study was therefore to verify whether rapid wound healing is linked to the antioxidant activity of this plant. To do this, crude ethyl acetate (AcOEt), methanol (MeOH), and aqueous (H2O) extracts from the plant's bark were used to determine their antioxidant activity using a spectrophotometric method involving free radical scavenging by diphenyl-picrylhydrazil (DPPH). Preliminary phytochemical screening showed that the AcOEt and MeOH extracts are very rich in saponins, triterpenoids, flavonoids, tannins, and steroids. The IC50 values represent the concentration of extracts that inhibit 50% of free radicals. The IC50 values of the AcOEt, MeOH, and H2O extracts were 6.92 µg/ml, 10.35 µg/ml, and 10.99 µg/ml, respectively. The IC50 value of ascorbic acid (reference product) was 3.78 µg/ml. All IC50 values obtained were below 30 µg/ml, indicating strong antioxidant activity in these extracts. This activity could be due to the various chemical families present in the bark of Erythropleum couminga, which are known to have powerful antioxidant properties. Further studies will be conducted to isolate and identify the active molecule(s).