Wound healing and anti-inflammatory activities of bee venom-chitosan blend films

Abstract

Bee venom (BV) therapy is the therapeutic application of honey bee venom for the treatment of various diseases. In order to apply BV to the skin, as a topical formulation, chitosan (Chit) films were fabricated. Bee venom could be loaded at 6% w/w of polymer in the films. The morphology and mechanical properties, including bioadhesive properties, surface pH, primary skin irritation test, microbial penetration, tensile strength, percentage of elongation and swelling ratio, were evaluated. According to the mechanical properties of the films, 6% bee venom-chitosan (6% BV-Chit) films were superior to both chitosan free film (Chit-F) and other films containing lower concentrations of BV. Accordingly, chitosan films containing 6% BV were the subject of further pharmacological and biological tests. The wound healing activities of Chit-F and 6% BV-Chit films were evaluated using excision, round section, full thickness skin wound model in rats. In addition, the anti-inflammatory effects of Chit-F and 6% BV-Chit films were studied in rats using the rat paw edema thickness method. Furthermore, serum prostaglandin E2 (PGE2) was determined to investigate the possible mechanism for the anti-inflammatory activity of this topical formulation. The results show that both Chit-F and 6% BV- Chit films accelerated the wound healing compared to untreated rats. As for the anti-inflammatory effects, 6% BV-Chit films had greater potency compared to that of Chit-F and this effect was comparable to that of the standard NSAI, indomethacin. Moreover, the elevated serum PGE2 was significantly reduced in a descending order as follows: indomethacin > 6% BV-Chit > Chit-F. These results suggest that the combination of wound healing ability of chitosan together with the anti-inflammatory activity of BV in one topical formulation provide a promising therapy for rapid complete sterile wound healing, in addition to an anti-inflammatory activity for topical inflammatory lesions.