Antifungal activity in plants from Chinese traditional and folk medicine

Ethnopharmacological relevance: From over 100 Chinese clinical trial publications, we retrieved 22 commercial preparations and 17 clinical prescriptions used as Traditional Chinese Medicine (TCM) for treating mycotic vaginitis, typically caused by Candida albicans. The 8 most frequently used plants as well as another 7 TCM and 18 folk medicinal plants used in the South of China for antifungal therapy were investigated for in vitro antifungal activity. Materials and methods: For each plant we tested 4 extracts prepared with different solvents (water, ethanol, acetone, and n-hexane) for inhibition of Candida albicans and Saccharomyces cerevisiae growth in liquid culture. Results: Some plants have quite strong antifungal activity, such as Tujinpi (Pseudolarix kaempferi Cord.), of which each extract could significantly inhibit the growth of both tested fungi. In addition, the acetone extract of Kushen (Sophora flavescens Ait.), the ethanol, acetone, and hexane extracts of Guanghuoxiang (Pogostemon cablin (Blanco) Benth.) and Gaoliangjiang (Alpinia officinarum Hance), the hexane extract of Dingxiang (Eugenia caryophyllata Thunb.), and the ethanol and acetone extracts of Kulianpi (Melia toosendan Sieb. et Zucc.) and Laliao (Polygonum hydropiper L), all inhibited Candida albicans growth by more than 50%. In some cases growth inhibition was even comparable to that by the clinically used antifungal miconazole, which we used as our positive control. Conclusions: The majority of plants, whose clinical use for antifungal treatment is well supported within TCM or Chinese folk medicine, show in vitro antifungal activity against Candida albicans. Since Candida species represent the most common fungal pathogen of humans, these results provide more scientific evidence supporting the clinical application of these plants, and can serve as a starting point for new drug discovery from TCM and Chinese folk medicine. (C) 2012 Published by Elsevier Ireland Ltd.