Effects of standardized extract of centella asiatica ECa 233 on second degree burn wound healing in normal and diabetic rats

The purpose of this study was to investigate the effects of standardized extract of Centella asiatica ECa 233 on second degree burn wound healing induced by 90º C hot plate for 10 seconds on the selected area of the back. Male Wistar rats weighing 250-300 g were used and divided into two groups for normal and diabetic rats. In each group, the animals were subdivided into six subgroups as follows : no burn, burn with no treatment (untreated), burn treated with gel base, burn treated with 0.05, 0.1 and 0.5% ECa 233 gel. The wounds were daily treated with 100 mg of the test substances topically. Evaluation of wound healing including a visual observation, an estimation of rate of wound healing, measurement of cutaneous blood flow, lipid peroxidation assay and histopathological observation was made at day 3, 7 and 14 post burning. The result revealed that rate of wound healing in both normal and diabetic rats treated with ECa 233 was significantly different from those observed in their respective untreated and gel base-treated groups. In comparison to their respective control groups, cutaneous blood flow was significantly increased in ECa 233-treated groups at all three time points in diabetic rats whereas it was observed only at day 3 and 7 in normal group. In normal, burn injury significantly increased oxidative stress which was counteracted by ECa 233 throughout experimental period. However, in diabetic, antioxidant property of ECa 233 was evident only on day 14. Visual and histopathological observation, application of ECa 233 seemed to reduce inflammatory cell in normal and diabetic rats though with a lesser extent in the latter group. In addition, the number of hair follicles in ECa 233-treated groups, both in normal and diabetic rats were found to increase on day 3 and 7 post burning. In conclusion topical application of standardized extract of Centella asiatica ECa 233 clearly facilitated burn wound healing in normal and diabetic rats. Shortening of inflammatory process by its anti-inflammatory, increased rate of re-epithelialization and might explain the results observed. Increased of cutaneous blood flow, increased number of hair follicles and anti-oxidation could play role as well. Some other mechanisms await further investigation.