Phytochemical Composition and Anti-Inflammatory Potential of Flavonoid-Rich Fraction of Erythrina senegalensis DC (Fabaceae) Leaf

Erythrina senegalensis (leaves, root, and bark) has been used in folkloric medicine in West Africa to manage inflammation for centuries, although this has not been scientifically validated. Herein, we investigated the anti-inflammatory properties of flavonoid-rich fraction of ethanol extract of Erythrina senegalensis leaves. In vitro anti-inflammatory parameters were assayed using human red blood cell (HRBC) methods. Also, acute toxicity study was performed in adult mice (between 3 to 4 months), while in vivo anti-inflammatory activity was evaluated using egg albumin paw oedema adult (between 3 to 4 months) rat model. Phytochemical examination revealed high levels of flavonoids, tannins, terpenoids, and phenolics. No mortality in mice was recorded up to 5000 mg/kg. At the various concentrations (0.2-1.0 mg/ml), the extract was potent in stabilizing the HRBC membrane, and significantly (p < 0.05) suppressed albumin denaturation, platelet aggregation, phospholipase A2 and protease activity in a concentration-dependent trend in a similar way with the reference drug. Also, the in vivo study showed that the extract significantly (p < 0.05) decreased rat paw oedema formation in a time-dependent (0.5-5 hrs) manner. The extract at 100 mg/kg elicited the greatest Inhibition (68.30 %) and competes favourably with the standard group (65.70 %). These, thus, affirm the anti-inflammatory potency of the extract.