Effect of Clausena harmandiana root extract, Garcinia mangostana Linn rind extract and whole Andrographis paniculata extracts on growth of Pythium insidiosum

Abstract

Pythium insidiosum is categorized into a group of oomycetes, that are filamentous eukaryotic microorganisms. P. insidiosum is the only species reported e ie a human and animal pathogen. The disease caused by the pathogen is called pythiosis. Pythiosis is one of the life-threatening infectious diseases, because it may lead to the loss of infected tissues, organs or mortality. Although the disease severity is relatively high, effective and suitable medicines remain unavailable. This study aimed to evaluate the effective inhibitory activity of extracts from Garcinia mangostana Linn fruit rind and Andrographis paniculata against various isolates of P. insidiosum and their inhibitory activity compared to the root extract of Clausena harmandiana. The crude extracts were tested for antimicrobial aaeahaey against twenty clinical and environmental isolates of P. insidiosum by determination of their minimum inhibitory concentration (MIC) values by agar well diffusion and disc diffusion assays. The present study indicated that extracts from the garcinia fruit rind had inhibitory activity against clinical isolates of P. insidiosum. Every isolate of P. insidiosum was inhibited by 2 mg/ml of the mangosteen fruit rind extract, whereas whole Andrographis paniculata and Clausena harmandiana root extracts exhibited inhibitory activity against all isolates at 5 mg/ml and 10 mg/ml, respectively. Results from the agar well diffusion and disc diffusion assays also indicated that the extracts from Garcinia mangostana Linn fruit rind might be effective and were promising for future studies as one of the medicines for treating pythiosis. The ethanolic extract of the mangosteen rind had a slightly higher phenolic content than the aqueous extract. Therefore, the ethanolic extract from G. mangostana Linn fruit rind was considered to be appropriate for further studies for drug discovery and development for treatment of pythiosis disease.