The Effect of Dietary Polyunsaturated Fatty Acid on Skin Wound Healing in Chronic Diabetic Rat

The potential role of omega – 3 (ω-3) and omega - 6(ω-6) fatty acids on wound healing is of interest and controversial. In the present study, the effect of dietary intake of fish oil (ω-3 diet ) and corn oil (ω-6 diet) on skin wound healing has been investigated in rat. This experimental study was performed on four groups of male rats (one normal group and three diabetic groups). Diabetes was induced by subcutaneous injection of 50 mg/kg streptozotocin. In diabetic groups, one group was control and received STZ alone, and the other two diabetic groups were respectively fed with oral Fish oil (Fo group) and corn oil (co group) from 4 weeks after the induction of diabetes till complete wound healing. All animals were wounded by a 4 cm vertical incision in the midline of dorsum 8 weeks after diabetes induction. Wound surface area, percentage of wound healing, vessels density, and epidermal growth were measured at various post-operated periods. The results showed that, surface area of wound in co group was less than that of FOtreated rats and control group at the 7th post – operative day. Moreover the percentage of wound healing in co group was 97% at the 20th day, while this parameter in FO group and control group were 66% and 71.3% respectively. Although vessels density and epidermal growth in control group were significantly less than those of normal group, no significant difference was found between both FO and CO groups with control group in this regard. Moreover, FO diet and CO diet had an inhibitory effect on increased plasma glucose in diabetic rats by 46.8% and 40.7% respectively. Diabetic rats demonstrated increased plasma total cholesterol, triglyceride and LDLC levels, but this change was significantly decreased by both diets at the end of 7th week. FO and CO diets also caused an increase in plasma HDL level comparing to the control group. We concluded that, corn oil (ω-6 diet) supplementation can result in an acceleration of skin wound healing in chronic diabetic rats, but fish oil have no effect. These actions of corn oil may be mediated through changes in inflammatory or fibroplasias stages of wound response.