Wound Healing Activity of Tanzanian-Sourced Centella asiatica on Second-Degree Burn Wounds in Wistar Rats

Abstract

Introduction: Burn wounds heal slowly, often with complications. Centella asiatica (L.) Urb. (Apiaceae) has traditional uses in wound management, but region-specific evidence from Tanzania is lacking. The study aimed to evaluate the burn wound healing effect of topically applied C. asiatica leaf extract in a rat model of second-degree thermal injury, using complete epithelialization time as the primary outcome. This study was designed as a pilot/exploratory investigation to generate preliminary data on locally sourced plant material.

Methods: Fifteen male Wistar rats were randomly assigned to four groups: negative control (no treatment), positive control (1.0% silver sulfadiazine cream), 0.5% w/v C. asiatica ethanol extract dispersed in distilled water, and 1.0% w/v C. asiatica ethanol extract dispersed in distilled water. Standardized second-degree burns were induced on the dorsal skin under diethyl ether anesthesia. Treatments were applied once daily. Two rats died from inter-animal aggression during acclimatization and were excluded from analysis, leaving final group sizes of n=3 for three groups and n=4 for one group. Epithelialization time was recorded daily. Group comparisons used one-way ANOVA with Tukey's HSD post hoc test (significance at                            p-value < 0.05).  

Results: The 1.0% w/v C. asiatica group showed the shortest mean epithelialization time (12.7 ± 0.6 days), followed by 0.5% w/v (14.0 ± 0.8 days), silver sulfadiazine (16.0 ± 0.8 days), and negative control (23.0 ± 1.0 days). ANOVA revealed significant differences among groups (F(3,9) = 68.67, p-value < 0.001). Post hoc analysis confirmed faster healing with both C. asiatica concentrations compared to silver sulfadiazine (p-value < 0.001) and untreated controls (p-value < 0.001). The difference between 0.5% and 1.0% C. asiatica was not statistically significant (p-value = 0.065), representing a non-significant trend rather than confirmed dose-dependence.

Conclusion: Topical C. asiatica ethanol extract (aqueous dispersion) significantly accelerates burn wound epithelialization in rats, with the higher concentration showing the fastest healing. These preliminary findings support further investigation of locally sourced C. asiatica as a potential low-cost intervention for burn care. However, due to substantial methodological limitations including small sample size, lack of vehicle control, unblinded assessment, and suboptimal anesthesia/analgesia protocols these results should be interpreted as hypothesis generating. Histological and phytochemical studies are needed before clinical translation.