Stem Bark Extract of Sterculia setigera Delile Exhibits Anti-inflammatory Properties through Membrane Stabilization, Inhibition of Protein Denaturation and Prostaglandin E2 Activity

Abstract

Aims: The stem bark of Sterculia setigera has been used in several African countries for the treatment of many inflammatory conditions. However, there is no scientific report to authenticate this usage. The current study, therefore, aims at assessing the in vitro and in vivo anti-inflammatory activities of the stem bark extract of Sterculia setigera (SSE). Place and Duration of Study: The study was conducted at the Laboratories of Department of Biomedical Sciences, University of Cape Coast, Ghana between October, 2016 and April, 2017. Methodology: In vitro anti-inflammatory activities were assessed using heat and hypotonic solution - induced red blood cell haemolysis assays, as well as egg and bovine serum albumin denaturation assays. In vivo anti-inflammatory effect of SSE (30, 100 and 300 mg/kg, p.o.) and diclofenac (10 mg/kg, p.o.) was assessed using carrageenan as well as prostaglandin E2 -induced paw oedema models in rats. Results: SSE inhibited heat and hypotonic solution-induced haemolysis by a maximum effect of 62.81 ± 1.18% and 76.05 ± 3.08% respectively as compared to diclofenac which was 76.63 ± 3.36% and 76.49 ± 1.67% respectively. Also, egg and bovine serum albumin denaturation were markedly inhibited by SSE with a maximum inhibitory effect of 74.84 ± 64% and 45.73 ± 8.41% respectively. Diclofenac had a maximum inhibitory effect of 72.23 ± 3.14% and 52.02 ± 0.72% respectively for egg and bovine serum albumin denaturation assays. Also, SSE (30, 100 and 300 mg/kg, p.o.) and diclofenac (10 mg/kg, p.o.) significantly and dose-dependently reduced rats’ paw oedema in the carrageenan and prostaglandin E2 – induced inflammation tests. Conclusion: SSE exhibited anti-inflammatory effects in both in vitro and in vivo models and this gives credence to its folkloric usage.