Antimicrobial activities of the crude methanol extract of Acorus calamus Linn.

A partially-purified fraction obtained from column chromatographic preparation of the crude methanol extract of Acorus calamus Linn. rhizomes was investigated for its antimicrobial activities on various microorganisms including bacteria, yeasts and filamentous fungi. It exhibited high activity againstfilamentous fungi: Trichophyton rubrum, Microsporum gypseum, and Penicillium marneffei with IC50 values of 0.2, 0.2 and 0.4 mg/ml, respectively. However, it showed moderate activity against yeasts: Candida albicans, Cryptococcus neoformans and Saccharomyces cerevisiae (MIC 0.1-1 mg/ml) and low activity against bacteria (MIC 5->10 mg/ml). Scanning electron microscopic observation revealed that hyphae and conidia treated with this fraction were shrunken and collapsed, which might be due to cell fluid leakage.