This study was designed to compare the effects of the ethanolic extract of henna and clotrimazole vaginal cream on vaginal candidiasis symptoms. In comparison to clotrimazole, our results showed that the henna cream could significantly reduce the signs and symptoms of vaginal candidiasis. In this regard, burning sensation, itching, discharge, irritation, and dyspareunia decreased in around 90% of the participants in the henna group, while clotrimazole could alleviate these symptoms in only 45%, 5%, 37.5%, 52.5%, and 27.5% of the women, respectively. According to our results, henna was more effective than clotrimazole in decreasing colony formation. Also, the reduction in vaginal pH was more pronounced in the henna group compared to the clotrimazole group. This was the first report on the impact of henna on
C. albicans in humans. We previously investigated the effects of henna on vaginal candidiasis in rats, and our results showed that the effects of 4% henna vaginal cream were similar to that of clotrimazole (
16). Other studies have evaluated the effects of henna on
C. albicans in vitro. For example, Nawasrah et al. combined henna with acrylic resin denture and found that the combination significantly inhibited
C. albicans proliferation (
18). In their study, Singhal et al. compared the effects of pomegranate and henna on
C. albicans and found that the effects of henna were superior to that of pomegranate in terms of controlling candidiasis in vitro (
19). Rahmoun et al. also found that the ethanolic extract of
Algerian L. inermis (150 µg/mL) had antifungal activity (
20). The antifungal activity of the ethanolic extract of henna was also reported by Suleiman and Mohamed in an in vitro study (
15). The results of our study are consistent with those of the above-mentioned studies. It has been shown that the antimicrobial effects of henna leaves result from its 0.5-1.5% lawsone content, a compound showing dyeing properties (
20). The antifungal effects of henna may also be attributed to lawsone in henna leaves (
21). Yoshijima et al. suggested that the hydrophilic materials of henna could reduce
C. albicans adherence to any surface (
22). The antifungal effects of some species of henna, such as Sudanese henna, have been attributed to their naphthoquinone content (
23).
The results of the present study showed that colony formation reduced in both of the study groups (i.e., henna- and clotrimazole-treated); however, the number of colonies reached zero only in the henna group after treatment. Also, vaginal pH reduced, and the mean number of lactobacillus increased significantly in the henna group compared to the clotrimazole group, according to the GEE test. We could not find any study evaluating the effects of henna on lactobacillus colony formation. However, YİĞİT, in his study, found that
Lawsonia inermis had the highest antifungal activity against 68 clinical candida strains, including
C. albicans (
24), which was similar to our observation. Other studies have shown that henna has the ability to disintegrate fungal membranes and enzymes, which can alter the cell membrane arrangement and morphology of fungi (
20,
25).