Effects of topical application of combined phyllanthus emblica linn. and simvastatin on diabetic wound in mice

Abstract

Non-healing diabetic foot ulcers are the most common cause of lower extremity amputation. Drug combination treatment is the most recent emerging strategy in local treatment of diabetic wound. This study aimed to find out the combined effects and underlying mechanisms of combined Phyllanthus emblica Linn. (PE) and simvastatin (SIM) on diabetic wound in mice. Male BALB/C mice were divided into five groups: control group (CON+Vehicle), diabetic wounded group (DM+Vehicle, streptozotocin 45 mg/kg. i.p. daily for 5 days), diabetic wounded groups with daily treatment of 100%PE cream, 5%SIM cream, and 100%PE+5%SIM combined cream, w/v, for 4 days, 7 days and 14 days. Mice bilateral full thickness wound excision was made after diabetic mice model establishment. Wound tissue malondialdehyde (MDA) level, IL-6 protein level, number of infiltrated neutrophils, percentages of wound closure (%WC), percentage of capillary vascularity (%CV) and percentage of re-epithelialization (%RE) were analyzed. The results showed that PE and simvastatin combination treatment increased %WC significantly on day 14. PE and simvastatin combination treatment increased %CV significantly both on day 7 and day 14. PE and simvastatin combination treatment downregulated number of infiltrated neutrophils significantly on both day 4 and day 7. PE and simvastatin combination treatment has tendency to reduce IL-6 protein level in diabetic wound both on day 4 and day 7. Further, PE and simvastatin combination treatment reduced MDA content significantly on day 4. Moreover, increasement of %CV had a strong positive correlation (r=0.7136, p=0.0019) with %WC on day 7. These findings showed that topical application of PE and simvastatin combination treatment could enhance wound healing by upregulating VEGF protein level, angiogenesis, and wound closure based on the combined effects on inhibiting oxidative stress and inflammation in diabetic mice.