Assessment of antidermatophytic activities of Urtica dioica L. against Microsporum canis in a guinea pig model

Abstract

Purpose: To investigate the antidermatophytic effects of Urtica dioica L. against Microsporum canis in vitro and in a guinea pig model. Methods: The in vitro antifungal activity of the extracts was measured by disc diffusion method and assessment of minimum inhibitory concentration (MIC). The dorsum of the guinea pigs was infected with M. canis and topically treated as follows: negative control (NC) received no treatment; positive control (PC) received terbinafine 1 %; DMSO group (negative control) received 10 % DMSO (vehicle); while three other groups, viz, SN10%, SN20% and SN30% received 10, 20 and 30 % hydroalcohol extract dissolved in 10 % DMSO, respectively. Results: Both extracts did not show considerable antifungal activity against M. canis compared with terbinafine. The MICs of aqueous and hydroalcoholic extracts were 30 and 20 mg.ml-1, respectively. PC and SN30% groups showed normal hair growth on day 15 while their skin looked healthy on day 30 post-inoculation. Lesion severity and clinical scores declined in SN30% and PC groups in comparison to NC group, on day 30 post-inoculation. Also, on day 30 post-inoculation, the clinical efficacy of the test formulations increased to 11.76, 23.52, 76.47, 5.88, and 94.11 % for SN10%, SN20%, SN30%, DMSO10%, and PC groups, respectively. Conclusions: The hydroalcoholic extract of this plant could be further developed, with a view to its possibe use as an adjunct remedy for topical treatment of tinea corporis. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, 300001 Nigeria. All rights reserved.