Fungicidal effect and oral acute toxicity of Psophocarpus tetragonolobus root extract

Abstract

The methanol extract of Psophocarpus tetragonolobus (L.) DC (Leguminosae) root was screened for antimicrobial activity against Candida albicans (Berkhout). The extract showed a favorable antimicrobial activity against C. albicans with a minimum inhibitory concentration (MIC) value of 3.13 mg/mL. Apart from the fungicidal effects, imaging using scanning electron microscopy (SEM) was done to determine the major alterations in the microstructure of C. albicans. The main abnormalities noted via SEM studies were the alterations in morphology and complete collapse of the yeast cells after 36 h of exposure to the extract. The effect of the extract on the growth profile of the yeast was also examined. It changed the normal growth profile of C. albicans, thus confirming the fungicidal effect of the extract on C. albicans. In an acute toxicity study using rats, death was not observed, so the acute minimum fatal dose of the extract was greater than 2000 mg/kg, and we found no pathologic changes in macroscopic examination by necropsy of rats treated with extract. We conclude that the extract may be safely used as an antimicrobial agent. © 2008 Informa Healthcare USA, Inc.