Topical application of artesunate on guinea pig allergic contact dermatitis.

Artesunate is derived from the Chinese medicinal herb qinghao. Many animal studies suggest that systemic artesunate has immunoregulatory activity. We investigated the effect of topical artesunate on contact sensitivity in guinea pigs sensitized with DNCB. Female hairless guinea pigs were used and the contact reaction graded by visual (5 point) score and erythema measured with a color analyzer. Topical artesunate inhibited the elicitation reaction of contact hypersensitivity when given at the 1st and 12th h after challenge (p < 0.05), but showed no effect when given from day 3 to day 1 before challenge (p > 0.05). Artesunate had no effect on toxic (irritant) contact dermatitis from 20% croton oil (p > 0.05). The results indicate that topical application of artesunate may offer a novel treatment of allergic contact dermatitis and other cutaneous immune-mediated disorders.