Investigation of the chemical composition and anti-inflammatory effects of the crude methanolic extract and fractions of Artocarpus heterophyllus (Fam. Moraceae)

Abstract

Inflammation is a local response of living tissues in mammals towards injury and is normally linked to the pathogenesis of several diseases. In this study, we investigated the anti-inflammatory activity of the methanol extract and the n-hexane, ethyl acetate and butanol fractions of the Jack fruit leaves. Methanolic cold maceration was carried out to get the extract, followed by liquid-liquid fractionation. Two models, viz. xylene-induced ear edema in mice and egg albumin-induced paw edema in rats were used to evaluate them. The anti-inflammatory activity of the extract and fractions was screened for anti-inflammatory activity using xylene-induced ear edema in mice and egg albumin-induced paw edema in rats. The chemical constituents of the extract and fractions were detected by dereplication using HPLC-DAD. Results showed that for the xylene-induced topical edema model, only the 250µg/ear n-butanol fraction exhibited good anti-inflammatory activity at 21.21% when compared with the piroxicam (positive control) at 32.21%. In the egg albumin-induced paw edema both the methanol extract and n-butanol fraction at 250mg/kg and 500mg/kg showed good anti-inflammatory activity after 2hours post-administration, with maximum effect at 6 hours. Specifically, at 6 hours the methanol extract at 250 mg/kg exhibited 41.21% inhibition; the butanol fraction at the same dose exhibited 43.63% inhibition when compared with piroxicam (500 mg/kg) with 38.39% inhibition. The HPLC-DAD analysis of the extract and fractions revealed the presence of six (6) compounds: catechin (1), septicine (2), 5-isoprunetin 8C glucoside (3), naamine (4), protocatechuic acid (5), and vitexin (6). These compounds have been reported to display anti-inflammatory activity. These findings suggest that the leaf extract possess an anti-inflammatory phytocompounds which authenticates their ethno-medicinal usage claim by local people in different parts of Nigeria.