Fungicidal Effect and Oral Acute Toxicity of Cassia spectabilis Leaf Extract

Abstract

The fungicidal activity of Cassia spectabilis leaf extracts was investigated using the disk diffusion technique and the broth dilution method. The extract showed a favorable antimicrobial activity against Candida albicans with a minimum inhibition concentration(MIC)value of 6.25 mg ⁄ ml. Apart from the fungicidal effects, imaging using scanning electron microscopy(SEM)was done to determine the major alterations in the microstructure of the C. albicans. The main abnormalities noted in the SEM studies were the alterations in morphology and complete collapse of the yeast cells after 36 h of exposure to the extract. The in vitro time-kill study performed using the leaf extract at 1 ⁄ 2, 1 or 2 times of the MIC significantly inhibited the yeast growth with a noticeable drop in optical density (OD) of yeast culture, thus confirming the fungicidal effect of the extract on C. albicans. In addition, in vivo antifungal activity studies on candidiasis in mice showed a 5-fold decrease in Candida in kidneys and blood samples in the groups of animals treated with the extract(2.5 g ⁄ kg body weight). In an acute toxicity study using mice, the acute minimum fatal dose of the extract was greater than 2000 mg ⁄ kg, and we found no histopathological changes in macroscopic examination by necropsy of mice treated with extract. We conclude that the extract may be safely used as an anticandidal agent.