Ultrastructural changes on clinical isolates of Trichophyton rubrum, Trichophyton mentagrophytes, and Microsporum gypseum caused by Solanum chrysotrichum saponin SC-2.

Worldwide, dermatophytoses represent a high percentage of all superficial mycoses. The most frequently isolated dermatophyte is Trichophyton rubrum. Solanum chrysotrichum is a vegetal species widely used in Mexican traditional medicine to treat skin infections; its extract has been used to formulate an herbal medicinal product that is used successfully to treat Tinea pedis. Spirostanic saponin SC-2 from S. Chrysotrichum possesses high activity against dermatophytes. The present study reports the ultrastructural changes observed by means of transmission electron microscopy (TEM) in clinical isolates of T. rubrum, T. mentagrophytes, and Microsporum gypseum induced by saponin SC-2. Strains were grown in RPMI 1640 containing SC-2 (1600 microg/mL). Fungi were harvested at 6, 12, 24, and 48 h; controls without SC-2 were included. T. mentagrophytes was the most susceptible to the SC-2 saponin, followed by M. gypseum, while T. rubrum was the most resistant. The main alterations caused by the SC-2 saponin were as follows: i) loss of cytoplasmic membrane continuity; ii) organelle degradation; iii) to a lesser extent, irreversible damage to the fungal wall; and iv) cellular death.

Effectiveness and tolerability of a standardized phytodrug derived from Solanum chrysotrichum on Tinea pedis: a controlled and randomized clinical trial.

Superficial mycosis such as Tinea pedis affects between 10 and 15% of the population and is amongst the top ten reasons for visiting the doctor in Mexico. The vegetal species Solanum chrysotrichum has been, for many years, widely used in Mexican traditional medicine for the treatment of fungal foot infections. This paper illustrates the results of a controlled and randomized, double-blind clinical trial, which compared the therapeutic effect and the tolerability of a standardized phytodrug from S. chrysotrichum (experimental group) with 2% ketoconazole (control group), applied externally (4 weeks) to 101 patients diagnosed with Tinea pedis. After the treatment, the results showed a clinical effectiveness (> or = 75% improvement of signs and symptoms) of 96.08 % for the group treated with the S. chrysotrichum extract and 91.67% for the ketoconazole group (chi 2, p > 0.38); the mycologic effectiveness (direct examination and negative culture) was 78.43 % and 77.78%, respectively (chi 2, p > 0.94); whilst the tolerability was 100% for both treatments. The therapeutic successes (clinical and mycologic effectiveness plus tolerability) was 74.51% with the experimental treatment and 69.44% with the control (chi 2, p > 0.60). These results support the safety and effectiveness of Solanum chrysotrichum standardized phytodrug for the treatment of Tinea pedis.