IgM antibody and colony fungal load impacts of orally administered ethanol extract of Plectranthus scutellarioides on mice with systemic candidiasis

Abstract

Context: Candida albicans is a pathogenic fungus that causes vulvovaginal candidiasis (VVC), which presents significant clinical problems in immunocompromised patients. There are no studies that correlate IgM antibody responses and fungal loads following the use of ethanol leaf extract of Plectranthus scutellarioides (L.) R.Br. (ELEP) on VVC. Aims: To examine colony fungi loads, IgM antibody responses, and their correlation in Balb/c mice infected with C. albicans treated with orally administered ELEP. Methods: Twenty-five female Balb/c mice were randomly divided into five groups (five mice in each group): normal group (oral ELEP + not infected), VVC control (VCC) group (infected + oral 0.2 mL saline), ketoconazole-treated in VCC group (infected + oral antifungal agents), and two treatment groups (infected + oral ELEP with 500 and 750 mg/kg b.w.). Treatments were administered for 14 days after infection with C. albicans. Colony fungal loads and IgM antibodies were measured by counting colony forming units and flow cytometry using anti-C. albicans antibody kits, respectively. Results: Ingestion of the ELEP significantly affected fungal load clearance and decreased IgM antibody levels compared to that in the VCC group (p<0.001). Furthermore, ingestion of the ELEP was associated with significantly lower concentrations of IgM antibodies and colony forming units (p<0.001). Conclusions: These data strongly suggest that IgM antibody response is involved in of the mechanism by which ELEP decreases C. albicans infection. Furthermore, these results provide important information for the potential application of ELEP in the treatment of Balb/C mice with systemic candidiasis.