Identification of Major Active Ingredients Responsible for Burn Wound Healing ofCentella asiaticaHerbs

Centella asiaticaherbs have been prescribed as a traditional medicine for wound healing in China and Southeast Asia for a long time. They contain many kinds of triterpenoid compounds, mainly including glycosides (asiaticoside and madecassoside) and corresponding aglycones (asiatic acid and madecassic acid). To identify which is the major active constituent, a comprehensive and comparative study of these compounds was performed.In vitro, primary human skin fibroblasts, originating from healthy human foreskin samples, were treated with various concentrations of asiaticoside, madecassoside, asiatic acid, and madecassic acid, respectively. Cell proliferation, collagen synthesis, MMP-1/TIMP-1 balance, and TGF-β/Smad signaling pathway were investigated.In vivo, mice were orally administered with the four compounds mentioned above for two weeks after burn injury. The speed and quality of wound healing, as well as TGF-β₁levels in skin tissues, were examined. Interestingly, in contrast to prevalent postulations, asiaticoside and madecassoside themselves, rather than their corresponding metabolites asiatic acid and madecassic acid, are recognized as the main active constituents ofC. asiaticaherbs responsible for burn wound healing. Furthermore, madecassoside is more effective than asiaticoside (P=0.0446for procollagen type III synthesisin vitro,P=0.0057for wound healing speed, andP=0.0491for wound healing patternin vivo, correspondingly).