INVESTIGATION OF CHEMICAL AND ANTIFUNGAL PROPERTIES OF TRADITIONALLY USED MEDICINAL PLANTS FOR SKIN DISEASES IN SRI LANKA

Abstract

The antifungal and antioxidant properties of various extracts of plants are of great interest in food and beverage, cosmetic and pharmaceutical industries. Present study was carried out to investigate antioxidant and antifungal properties. Extracts from different parts of six medicinal plants; Delinia retusa, Elaeocarpus serratus, Cassia alata, Alpinia malaccensis, Indigofera tinctoria and Alstonia scholaris were selected. According to the literature, there is no proper scientific evidence to prove the traditional usage of above plant for skin diseases in Sri Lanka. Therefore, the main objective of the study is to evaluate antifungal and antioxidant properties of above medicinal plants and to investigate active fractions coming from activity directed fractionation. Antifungal activity was tested for five dermatophytes T. mentagrophytes, T. rubrum, E. floccosum, M canis and M gypseum where the P. variotti ATCC 22319 was used as quality control organism. The agar well diffusion assay was used and the antifungal activity was evaluated by measuring the inhibition zone diameter (Medical Research Institute, Colombo). DPPH scavenging assay was used to determine the antioxidant properties. Fruit extract of D. retusa was active against all the dermatophytes used in the study and the highest inhibition zone observed (14 mm) for M. gypseum. FlowTr extract of D. retusa appeared to be positivec results against all the dermatophytes except P. variotti and showed highest inhibition zone for M canis (15 mm). For DPPH assay, IC 50 value of D. retusa flower, leaf and fruit showed 17.75 ± 0.70 ligm1-1, 24.5 + 0.77 pgml-land 37.00 ± 3.71 tigm1-1. Since, D. retusa is endemic to Sri Lanka as well as not being studied was selected for further studies. Ethyl acetate and n-butanol fractions were active against all dermatophytes used in the study except P. variotti. Ethyl acetate fraction appeared highest inhibition zone diameter (14 mm) for M gypseum where as the n-butanol fraction obtained 14 mm for T. mentagrophytes. The ethyl acetate fraction (6.60 ± 0.30 ligm1-1) was appeared to contain most active antioxidant substances followed by the n-butanol fraction (14.50 ± 0.95 vigml-1). In conclusion, to author's knowledge present study can be considered as the only systematic report of initial screening of active extracts in order to isolate antifungal principles through activity directed separations.