Evaluation of the Effect of Topical Pistachio Hull Hydroalcoholic Extract Ointment on Wound Healing in Rat: A Histologic and Planimetric Study

Pistachio nut and hull have anti-inflammatory, antimicrobial and antioxidant effects. The aim of this study was to investigate the effects of pistachio hull hydroalcoholic extract ointment on wound healing process.

For wound planimetric assessment, 20 healthy rats were randomly divided into 5 groups of 4, including control group (open wound without any intervention and treatment), positive control group (open wound with basic ointment without extract), and the 3 other groups receiving 1%, 2% and 4% ointments respectively. On the 7th and 14th days, biopsies from wound tissues were taken and after Mason Trichrome staining we evaluated collagen. H&E staining was done for histopathological assessments.

The results showed that wound treatment with pistachio hull ointment in the experimental groups showed a significant increase (P<0.05) in the percentage of wound healing rate. Also, there was a significant difference in the thickness of skin and collagen diameter, and reduction of edema between experimental and control groups (P<0.05). Also we found significant decrease in inflammatory cell count on the 14th day in the groups treated with pistachio hull extract compared to those in the control group (P<0.05), which was indicative of accelerated wound healing in the experimental groups.

According to the results of this study, pistachio hull hydroalcoholic extract ointment potentially possesses healing effects on the wound created in the skin of the rat.