Inhibition of phospholipase A2, platelet aggregation and egg albumin induced rat paw oedema as anti-inflammatory effect of Peltophorun pterocarpus stem-bark

Abstract

Abstract Background Most medicinal plants presently employed in traditional medicine are used without scientific evidence, thereby suggesting a need to explore efficient and reliable investigations of their potential. We, therefore, conducted the present study to ascertain the efficacy of flavonoid-rich extract of Peltophorum pterocarpum sterm-bark in the treatment and management of inflammatory disorders as employed in folk medicine. Materials and methods Flavonoid-rich extract of Peltophorum pterocarpum sterm-bark and a total of fifty-five (55) Wistar rats were used for this study. Eighteen (18) mice were used for toxicity testing, and the phytochemical analysis was done using the Trease and Evans method, while the acute toxicity was done using Lorke’s method. In vivo anti-inflammatory study was done using the egg albumin-induced paw oedema method, while the in vitro anti-inflammatory studies were performed for the extract using phospholipase A2 inhibition and calcium chloride-induced platelet aggregation assays. Results The phytochemical analysis revealed that the extract of Peltophorum pterocarpum sterm-bark contains tannins, terpenoids, steroids, phenols, alkaloids, flavonoids, glycosides, and saponins ranging from 0.307 ± 0.02 to 1279.567 ± 149.868. The acute toxicity test of the extract showed no toxicity up to 5000 mg/kg body weight. In the systemic oedema of the rat paw, scalar doses of the extract significantly (p < 0.05) suppressed the development of paw oedema induced by egg albumin, particularly with the Indomethacin (1.77 ± 0.41) when compared with the control (5.50 ± 0.26). However, varying doses of the extract significantly (p < 0.05) inhibited phospholipase A2 activity and CaCl2-Induced platelet aggregation in a concentration, dose, and time-dependent manner, in comparison to prednisolone. Conclusion These results indicate that the extract exhibited anti-inflammatory potential, and the mechanism of this activity has a promising ability to inhibit phospholipase A2 activity and platelet aggregation in rats inflicted with paw oedema.