Total phenolic, flavonoid contents and in-vitro anti-inflammation evaluation of ethanol extracts of Hibiscus sabdariffa calyx, Malus domestica and their 1:1 extracts blend on protein denaturation

Hibiscus sabdarifa and Malus domestica are well known and widely used herbs, which contains several interesting bioactive constituents and possesses health promoting properties. The aim of this study is to determine the total phenolic and flavonoid contents, evaluate and compare the anti-inflammatory effects of ethanol extracts of the two extracts and a 1:1 blend of the extracts against the denaturation of proteins in vitro. The respective extracts were analyzed for their contents of polyphenols and flavonoids. The test extracts and reference drug (Ibuprofen) of varying concentrations were also incubated with egg albumin under controlled experimental conditions and subjected to determination of absorbance to assess the anti-inflammatory property. The results obtained exhibited a concentration-dependent inhibition of protein denaturation by both extracts, the 1:1 blend as well as the reference drug. The EC₅₀ for extracts as well as those for the blend and the reference drug were determined by the dose-response curve using Graphpad Prism 5.0 software.