The anti-amoebic activity of some medicinal plants used by AIDS patients in southern Thailand

Abstract

The anti-amoebic activities of chloroform, methanol and water extracts from 12 Thai medicinal plants (39 extracts) commonly used by AIDS patients in southern Thailand were screened, at a concentration of 1,000 μg/ml, against Entamoeba histolytica strain HTH-56:MUTM and strain HM1:IMSS growing in vitro. The extracts were incubated with 2×105E. histolytica trophozoites/ml of medium at 37°C under anaerobic conditions for 24 h. The cultures were examined with an inverted microscope and scored (1-4) according to the appearance and numbers of the trophozoites. The extracts that caused inhibition were selected and retested using the same conditions but with concentrations that ranged from 31.25 to 1,000 μg/ml using E. histolytica strain HM1:IMSS, and the IC50values for each extract were calculated. The chloroform extracts from Alpinia galanga (IC5055.2 μg/ml), Barleria lupulina (IC5078.5 μg/ml), Boesenbergia pandurata (IC5045.8 μg/ml), Piper betle (IC5091.1 μg/ml) and Piper chaba (IC5071.4 μg/ ml) and the methanol extract from B. pandurata (IC5057.6 μg/ml) were all classified as "active", i.e. with an IC50of less than 100 μg/ml, whereas those from Murraya paniculata (IC50116.5 μg/ml) and Zingiber zerumbet (IC50196.9 μg/ml) were classified as being "moderately active". The IC50of a standard drug, metronidazole, was 1.1 μg/ml. © Springer-Verlag 2006.