In Vivo Assay of Wound Healing Activities of Silymarin Extract on Cutaneous Wounds Caused by Leishmania major

Cutaneous leishmaniasis (CL), caused by the intracellular protozoa Leishmania, causes full-thickness skin wounds and scar formation afterwards, which may bring about some complications such as scar formation, secondary infection, and wound expansion. This investigation was conducted to determine the effect of hydroalcoholic extract of silymarin, as an anti-oxidant, anti-inflammatory, and anti-scar, for treatment of CL caused by Leishmania major. A total of 28 female BALB/C mice were injected with amastigotes of Leishmania major and after the wounds came up on their tail-base they were randomly divided into four groups (n = 7): E1 and E2, which received silymarin 5% and 10% gel, respectively, and C1 and C2 were treated with normal saline and vehicle gel, respectively, every 24 hours for 20 days. Wound size was measured every three days. Finally, the mice were sacrificed with high dose of ether, and full-thickness skin samples from the wound site was obtained for stereological estimation of collagen and vessel volume densities, fibroblasts population, vascular length density, and mean diameter of the vessels. Silymarin gel in either concentration of 5% and 10% accelerates wound closure (P < 0.05) and also improves collagen synthesis and revascularization by means of increasing length density, volume density, and mean diameter of blood vessels (P < 0.05). Topical administration of silymarin extract in both doses of 5% and 10% showed promising effects on the healing process of CL-induced wounds.