Effect of exogenous epidermal growth factor (EGF) on nonenzymatic antioxidant capacities and MPO activity of wound tissue

Vascular Endothelial Growth Factor Supplementation Enhance Skin Antioxidant Capacity in Hyperglycemic Rats

The fundamental reasons for delayed wound healing in diabetic animals include inadequate production of growth factors or their increased devastation. Vascular Growth Factor (VEGF) has a biological role in the healing process of mucosal and skin wounds, especially in the process of new vessel formation. We planned to examine the oxidant-antioxidant events that occur during healing with topical VEGF application in diabetic rats. Experiments were performed 36 adults female Wistar albino rat diabetes induced by streptozotocin. The incisional wounds were made on the dorsal region in the rats. Rats were separated to 3 groups: the untreated (negative control) group (n=12), the chitosan group (n=12), the chitosan + VEGF group (n=12). The treatments were continued for 3 and 7 days, excluding the control and negative control groups. Then, the animals were sacrificed on the 3rd and 7th days of wound healing. Antioxidant and oxidant parameters in skin tissue were measured using biochemical methods. Topical VEGF application was decreased the NOx levels on the 3rd day compared to other groups. Moreover, it increased wound tissue GSH and AA levels, subsequently contributing to the enhance tissue antioxidant capacity. In conclusion, VEGF application increases the antioxidant capacity of the tissue and simultaneously reduces the oxidative stress and thus gives a positive acceleration to the wound healing process.

Oxidant and antioxidant events during epidermal growth factor therapy to cutaneous wound healing in rats

Cutaneous wound healing is a highly complex process, which includes inflammation, cell proliferation, matrix deposition and remodelling phases. Various growth factors, like epidermal growth factor (EGF), play an important role during wound healing. However, little is known about relationship between EGF and oxidant-antioxidant events in cutaneous wound healing models. Thus we planned to evaluate the connection between EGF therapy and oxidative stress in dermal tissue followed by wounding. Fifty-four adult male Wistar-albino rats were randomly divided into three groups: control, untreated and topical EGF administrated group. A linear full-thickness excision of 40 mm in length on both sides of spinal cord was made on the back of each rat and sutured under anaesthesia and sterile conditions. Excision was closed with 4/0 atraumatic silk suture. EGF solution was freshly prepared at 10 ng/ml dose in thilotears gel under aseptic conditions. Following the surgery, 1 ml of EGF solution was administered to wound strips one time in everyday. The animals were euthanised and wound tissues were collected on days 1, 5, 7 and 14. Thiobarbituric acid reactive substans (TBARS), glutathione (GSH), reactive nitrogen oxide species (NOx), ascorbic acid levels and superoxide dismutase activity were measured spectrophotometrically. TBARS levels decreased and NOx levels increased on day 5 after operation, and GSH levels were increased on day 14 in EGF administered group compared with untreated group. Our data showed that EGF may act like an antioxidant by scavenging toxic oxidation products in wound tissue. In addition, it may contribute healing of the wound tissue in earlier stages and suggest a potential effective role for antioxidant therapies, especially until day 5.