Free Radical Scavenging and In Vitro Anti-inflammatory Activities of the n-Hexane Fraction of Rhizophora mucronata Leaves from South Kalimantan, Indonesia

Abstract

Free radicals can cause tissue damage that can be prevented by antioxidant compounds. An anti-inflammatory is a compound that can suppress inflammation caused by oxidative stress. One of the wetland plants from South Kalimantan that has the potential as an antioxidant and anti-inflammatory is mangrove (Rhizophora mucronata). This study aims to determine the radical-capturing and anti-inflammatory activities of the n-hexane fraction of the ethanol extract of R. mucronata leaves. Extraction was performed by the maceration method, and fractionation by the liquid-liquid method. Qualitative test of radical scavenging using the thin layer chromatography method, while a quantitative test using UV-Vis spectrophotometry. Anti-inflammatory test using the protein denaturation inhibition method. Extraction of 750 g of R. mucronata leaf powder with 96% ethanol yielded 51.72 g (6.9%), and from 10 g of the 96% ethanol extract, the n-hexane fraction was 12.65 g (63.3%).  The n-hexane fraction test showed the presence of several compounds with potential as free-radical scavengers qualitatively, and quantitatively yielded an IC₅₀ of 77.0925 ppm, which falls in the strong category. The anti-inflammatory test results showed an IC₅₀ value of 64.902 ppm, which falls within the strong category. This study demonstrated that the n-hexane fraction of R. mucronata leaves exhibited promising preliminary in vitro free-radical-scavenging and anti-inflammatory activities.