Antifungal activity of pH and plant extract active ingredients in feminine intimate cleansers

Abstract

Maria Lidia Guglielminetti, Claudio Benvenuti

Many products for feminine intimate hygiene are available, all with different formulations. These detergents can have microbiological and pharmacological activity, which should be supported by scientific evidence. This study compared the effect on Candida spp. of commercially available cleansers indicated for feminine hygiene, at acid and alkaline pH, with or without active ingredients from plant extracts. The anti-mycological activity of four products was evaluated in 40 strains of Candida spp. isolated from women with vaginitis and in two strains of Candida spp. from the American Type Culture Collection. Three products were formulated at alkaline pH and one at acid pH (SA = Saugella Attiva). Thymol was an ingredient in the acidic cleanser (SA) and in one of the alkaline cleansers. The inhibition halo and the minimum inhibitory concentration (MIC) of the products were determined using a double-blind design. The diameters of the inhibition halos against Candida growth induced by the different cleansers showed an overall statistically significant difference among the products (p < 0.001 on ANOVA), with a significantly higher inhibition of Candida by SA versus the other cleansers. The MIC values observed were highly variable with no significant difference among the four products. Detergents for feminine intimate hygiene should have effective formulations for maintaining genital health and preventing bacterial and fungal contamination. The data here presented suggest that components derived from plant extracts with antimicrobial and anti-inflammatory action, such as thymol, which have been shown to be effective independently of the pH of the detergent, should be preferred. Secondly, the detergents should be formulated at acid pH, which has been proven to be more active than alkaline pH in Candida infections. It is recommended that doctors and pharmacists direct the choice in feminine hygiene towards cleansers with an acid pH and the presence of antimicrobial active ingredients.