Six polyherbal ointments containing methanol leaf extracts of Ageratum conyzoides Linn. (Asteraceae), Argemone mexicana Linn. (Papaveraceae), Heliotropium indicum Linn. (Boraginaceae) and bark extract of Alstonia scholaris (L.) R. Brown. (Apocynaceae) were formulated and tested for wound healing activity in rats using excision and incision wound models and skin irritation study. The effects of test samples on the rate of wound healing were assessed by the rate of wound closure, period of epithelialisation, wound breaking strength and determination of hydroxyproline. Nitrofurazone (0.2% w/w) in respective ointment bases was used as reference standard for the activity comparison. All the groups of animals treated with various formulations exhibited significant (P<0.01) increase in the percentage of wound contraction as compared to the respective control group of animals on different days of the study commencing from Day 8. The hydroxyproline content in the treatment groups were found to be significantly higher compared to the respective control group of animals. The skin breaking strength in the animals of all formulation treatment groups was significantly greater than that of the animals of the corresponding control group, thus showing enhanced collagen synthesis. The tested ointments did not show any severe type of irritation and there was no evidence of any noticeable inflammation on the skin. Our study indicates that a combination of 2.5% w/w each of the methanol extracts of A. conyzoides, A. mexicana, A. scholaris and H. indicum can be useful in wound contraction, improvement of tensile strength and augmentation in hydroxyproline content or collagen content. These properties together make this combination a potential candidate for wound healing activities. The present work justifies the use of these plant materials for wound healing as claimed in the folklore literature.
