Nitric oxide inhibitory activity of herbal extract formulae for anti-inflammation

Abstract

Introduction: The objective of this research was to investigate anti-inflammatory activity of herbal extracts formulaefrom four plants, Zingiber cassumunar (ZC), Centella asiatica (CA), Zingiber officinale (ZO) and Piper nigrum(PN) by variable proportion of each plant. The active compound(s) contributing to its anti-inflammatoryactivity of best formula was verified using high performance liquid chromatography (HPLC) method.

Method: Inhibitory activity against lipopolysaccharide (LPS) induced nitric oxide production in RAW 264.7cell lines was used as assay for anti-inflammation. Each plant and five formulae (CF1-CF5) wereextracted by maceration in 95% ethanol.

Result: The ethanolic extract of CF2 and CF4 showed the highest nitric oxide inhibitory activities with IC₅₀ value of 7.83 and 7.87 μg/ml, respectively. Three plant extracts, PN, ZO and ZC also exhibited highnitric oxide inhibitory activities with IC₅₀ value of 10.52, 11.93 and 21.33 μg/ml, respectively.The studies on chemical constituents using high performance liquid chromatography (HPLC) showedthat piperine and (E)-1-(3,4-dimethoxyphenyl) butadiene (DMPBD) were a major compound in thecombine formula 2 and 4 extracts. Terpinine-4-ol, 6-gingerol and asiatic acid were a minor compoundin the extracts.

Discussion and Conclusion: Combination of herbal extract such as CF2 and CF4 formulae possessed good nitric oxide inhibitory activity which was higher than single plant extract.

Key words: Anti-inflammatory, Nitric oxide, Herbal extract formulae, Zingiber cassumunar, Centella asiatica, Zingiber officinale, Piper nigrum