Faculty of Medicine, Department of Skin and Venereal Diseases, School of Health Sciences, University of Ioannina, Ioannina, Greece.
Faculty of Pharmacy, Department of Pharmacognosy and Natural Products Chemistry, National and Kapodistrian University of Athens, Athens, Greece.
Mycoses. 2019 Jul;62(7):597-603. doi: 10.1111/myc.12893. Epub 2019 May 8.
Malassezia yeasts produce bioactive indolic substances when grown on L-tryptophan agar. A panel of these substances was tested against commensal and opportunistic fungi, the Minimum Inhibitory Concentration (MIC) was determined and the potential for in loco antifungal activity on the skin was assessed.
Eight indoles were included (malassezin, pityriacitrin, indirubin, indolo[3,2-b]carbazole, 6-formylindolo[3,2-b]carbazole, tryptanthrin, 6-hydroxymethylindolo[3,2-b]carbazole and 6-methylindolo[3,2-b]carbazole) and were tested against 40 fungal strains [yeasts: Malassezia spp.(N = 9); Cryptococcus spp.(N = 10); Candida spp.(N = 7); Yarrowia lipolytica(N = 1); Exophialla dermatitidis (N = 2); moulds: Aspergillus spp.(N = 7); Fusarium spp.(N = 2); Rhizopus oryzae(N = 2)]. The concentration of 5/8 of the tested indoles on diseased skin was calculated from published data. Kruskal-Wallis and Mann-Whitney U tests were employed for group susceptibility evaluation in 33 strains.
The MIC range was 0.125-32 μg/mL, and the median log MIC was four. Indirubin was the most potent antifungal agent and differed significantly from the others. The highest median MIC was found for FICZ. Malassezia with Candida strains were more susceptible compared to Cryptococcus and Aspergillus, and this inhibitory activity was predicted to be valid also on human skin.
Malassezia yeasts produce indolic species that inhibit an array of clinically significant yeasts and moulds.
当马拉色菌在 L-色氨酸琼脂上生长时，会产生生物活性吲哚物质。对这些物质进行了测试，以评估它们对共生真菌和机会性真菌的最低抑菌浓度 (MIC)，并评估其在皮肤中的潜在抗真菌活性。
包括 8 种吲哚（马色拉嗪、糠疹酸、靛蓝、吲哚并[3,2-b]咔唑、6-甲酰基吲哚并[3,2-b]咔唑、色胺酮、6-羟甲基吲哚并[3,2-b]咔唑和 6-甲基吲哚并[3,2-b]咔唑），并对 40 株真菌菌株进行了测试（酵母：马拉色菌属（N=9）；隐球菌属（N=10）；念珠菌属（N=7）；解脂耶氏酵母（N=1）；皮炎外瓶霉（N=2）；霉菌：曲霉属（N=7）；镰刀菌属（N=2）；根霉属（N=2））。根据已发表的数据，计算出 5/8 种测试吲哚在患病皮肤上的浓度。对 33 株菌进行了 Kruskal-Wallis 和 Mann-Whitney U 检验，以评估群体易感性。
MIC 范围为 0.125-32μg/mL，中位数 log MIC 为 4。靛蓝是最有效的抗真菌剂，与其他物质有显著差异。FICZ 的 MIC 中位数最高。与隐球菌和曲霉相比，马拉色菌和念珠菌对这些物质更敏感，这种抑制活性也有望在人体皮肤上发挥作用。
马拉色菌产生的吲哚类物质抑制了一系列临床上重要的酵母和霉菌。
