Evaluation of Anti-Inflammatory and Antibacterial Activity of Horsfieldia iryaghedhi (RUK) of Sri Lanka

Abstract

The development of anti-inflammatory and antibacterial drugs is mainly dependent on the discovery of novel compounds from natural sources. This study aims to assess the in vitro anti-inflammatory and antibacterial activity of methanol and aqueous extracts of leaf, bark and combination (leaf and bark) extracts of the plant Horsfieldia iryaghedhi (RUK). RUK is a plant with variety of therapeutic uses and is mainly used to treat stomach ulcers and indigestion. Both extracts were tested for in vitro anti-inflammatory activity by the heat-induced egg albumin denaturation method using Diclofenac Sodium as the positive control. The methanol bark, leaf and combination extracts of Horsfieldia iryaghedhi exhibited the highest percentage inhibition in its highest concentration (1000μg/ml) as 97.0±5.67%, 79.1±1.64% and 81.4±3.30% respectively while the percentage inhibition of Diclofenac Sodium was 85.0±3.37%. The aqueous bark, leaf and combination extracts of RUK also exhibited the highest percentage inhibition in its highest concentration (1000μg/ml) as 67.6±5.53%, 80.4±2.55% and 77.0±2.49% respectively. All extracts were tested for antibacterial activity against gram-negative bacteria Escherichia coli (ATCC®25922) and gram-positive bacteria Staphylococcus aureus (ATCC®25923) by agar well diffusion method using Gentamicin as the positive control. None of the extracts were found to possess antibacterial activity against E.coli, but methanol leaf and combination extracts at the highest concentration (100μg/ml) were observed antibacterial activity against S.aureus with the zone of inhibition 19.6mm and 13.25mm respectively. This study concludes that the H.iryaghedhi extracts have significant anti-inflammatory activity. Furthermore, methanol bark extract demonstrated potent anti-inflammatory activity compared to other extracts.