Anti-inflammatory properties and gas chromatography-mass spectrometry analysis of ethyl acetate fraction of Crateva adansonii DC leaves

Abstract

Chineye C. Umeti, Funmilayo D. Onajobi, Efere M. Obuotor, Godâ??swill N. Anyasor, Edward B. Esan

Aim: This study was designed to determine the most active anti-inflammatory fraction of Crateva adansonii leaves and characterize the bioactive compounds. Methods: Dried and pulverized C. adansonii leaves (CAL) were extracted with 70% methanol, followed by successive solvent partitioning into hexane, ethyl acetate (CALE), butanol, and aqueous leaf fractions. In vitro antioxidant assays carried out on the extract/ fractions were 1,1-diphenyl 2-picryl hydrazyl (DPPH), hydrogen peroxide, ferric reducing antioxidant power (FRAP), nitric oxide scavenging, total antioxidant capacity (TAC), total phenol, and flavonoid (TF) assays. In vitro anti-inflammatory assays investigated were heat-induced bovine serum albumin (BSA) denaturation and human red blood cell (HRBC) membrane stabilization against hypotonicity-induced hemolysis. Formaldehydeinduced inflammation model in rats was carried out, followed by paw edema measurement, as well as serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities assays. The CALE fraction was subjected to gas chromatography-mass spectrophotometry (GC-MS) analytical method. Results: CAL extract and fractions substantially inhibited BSA denaturation and stabilized HRBC membrane against hypotonicity-induced hemolysis; however, CALE exhibited the highest activity. CALE also suppressed formaldehyde-induced rat paw edema and significantly (p < 0.001) reduced serum ALT and AST activities. In addition, CALE demonstrated significantly high (p < 0.05) antioxidant activities in DPPH and nitric oxide scavenging activities when compared with the other test samples. CALE also exhibited an appreciable amount in FRAP, TAC, and TF. GC-MS analysis of CALE indicated the presence of 19 tentatively identified compounds with anti-inflammatory and/or antioxidant properties. Conclusion: Ethyl acetate fraction of C. adansonii leaves exhibited anti-inflammatory activities which could be through antioxidant effect and perhaps through suppression of pro-inflammatory mediators. Hence, ethyl acetate fraction of C. adansonii leaf could serve as an important source of a lead drug candidate for pharmaceutical drug development in the management of inflammation.

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