Antimicrobial activity of Mentha piperita and Saturenja hortensis in a murine model of cutaneous protothecosis

Background: To date there is no defined pharmacologic treatment protocol available against cutaneous protothecosis, which is difficult to combat using conventional drugs.

Objectives: Our experiment aimed to comparatively investigate the effect of two essential oils (Mentha piperita and Saturenja hortensis) against cutaneous protothecosis experimentally induced by Prototheca zopfii in mice.

Materials and methods: Immunosuppressed BALB/c female mice, were divided into six experimental groups, infected with P. zopfii, and then treated for 21 days against the infection. The effectiveness of the different treatments was assessed clinically and histologically by quantifying the degree of inflammation (immunohistochemical quantification of macrophages, T lymphocytes and neutrophils) and fibrosis.

Results: Skin lesions in experimental protothecosis from non-treated mice were more severe as compared to the four groups of treated animals. Both M. piperita and S. hortensis have proved to be efficient in vivo in the treatment of cutaneous protothecosis by reducing the clinical signs and significantly reducing the degree of inflammation (P<0.05 for the number of macrophages, T lymphocytes and neutrophils) and fibrosis as compared to untreated animals.

Conclusion: Interestingly, our study shows that M. piperita and S. hortensis could represent a potential source of natural antimicrobial products in the treatment of cutaneous protothecosis.