Clinical Microbiology Division Indian Institute of Integrative Medicine, Canal Road, Jammu-180 001, India.
Ann Clin Microbiol Antimicrob. 2010 Feb 3;9:7. doi: 10.1186/1476-0711-9-7.
Hydroxychavicol, isolated from the chloroform extraction of the aqueous leaf extract of Piper betle L., (Piperaceae) was investigated for its antifungal activity against 124 strains of selected fungi. The leaves of this plant have been long in use tropical countries for the preparation of traditional herbal remedies.
The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of hydroxychavicol were determined by using broth microdilution method following CLSI guidelines. Time kill curve studies, post-antifungal effects and mutation prevention concentrations were determined against Candida species and Aspergillus species "respectively". Hydroxychavicol was also tested for its potential to inhibit and reduce the formation of Candida albicans biofilms. The membrane permeability was measured by the uptake of propidium iodide.
Hydroxychavicol exhibited inhibitory effect on fungal species of clinical significance, with the MICs ranging from 15.62 to 500 microg/ml for yeasts, 125 to 500 microg/ml for Aspergillus species, and 7.81 to 62.5 microg/ml for dermatophytes where as the MFCs were found to be similar or two fold greater than the MICs. There was concentration-dependent killing of Candida albicans and Candida glabrata up to 8 x MIC. Hydroxychavicol also exhibited an extended post antifungal effect of 6.25 to 8.70 h at 4 x MIC for Candida species and suppressed the emergence of mutants of the fungal species tested at 2 x to 8 x MIC concentration. Furthermore, it also inhibited the growth of biofilm generated by C. albicans and reduced the preformed biofilms. There was increased uptake of propidium iodide by C. albicans cells when exposed to hydroxychavicol thus indicating that the membrane disruption could be the probable mode of action of hydroxychavicol.
The antifungal activity exhibited by this compound warrants its use as an antifungal agent particularly for treating topical infections, as well as gargle mouthwash against oral Candida infections.
从胡椒（Piperaceae）水提氯仿萃取物中分离得到的 5-羟基胡椒酚，对 124 株选定真菌进行了抗真菌活性研究。这种植物的叶子在热带国家长期用于制备传统草药。
采用 CLSI 指南规定的肉汤微量稀释法测定 5-羟基胡椒酚的最低抑菌浓度（MIC）和最低杀菌浓度（MFC）。分别针对念珠菌属和曲霉属进行时间杀菌曲线研究、抗真菌后效应和突变预防浓度测定。还测试了 5-羟基胡椒酚抑制和减少白色念珠菌生物膜形成的潜力。通过摄取碘化丙啶来测量膜通透性。
5-羟基胡椒酚对具有临床意义的真菌种属表现出抑制作用，其 MIC 范围为酵母菌 15.62-500μg/ml、曲霉属 125-500μg/ml 和皮肤真菌 7.81-62.5μg/ml，而 MFC 与 MIC 相似或为其两倍。在 8×MIC 时，白色念珠菌和光滑念珠菌的浓度依赖性杀灭率高达 8×MIC。5-羟基胡椒酚对念珠菌属的抗真菌后效应也延长了 6.25-8.70 h，在 4×MIC 时，抑制了测试真菌种属的突变体的出现，在 2×-8×MIC 浓度下抑制了真菌的生长。此外，它还抑制了白色念珠菌生物膜的形成并减少了已形成的生物膜。当暴露于 5-羟基胡椒酚时，白色念珠菌细胞对碘化丙啶的摄取增加，这表明膜破坏可能是 5-羟基胡椒酚的作用模式。
该化合物表现出的抗真菌活性使其可用作抗真菌剂，特别是用于治疗局部感染，以及作为治疗口腔念珠菌感染的漱口液。
