Centella AsiaticavsResveratrol

The four key triterpenoid saponins—madecassoside, asiaticoside, madecassic acid, and asiatic acid—exert distinct but complementary mechanisms. Madecassoside and asiaticoside are anti-inflammatory: they inhibit NF-κB nuclear translocation and IκB kinase activity, reducing TNF-α, IL-6, and IL-1β production in keratinocytes and dermal cells. Madecassic acid and asiatic acid (the aglycone forms) stimulate type I and III collagen synthesis in fibroblasts by upregulating collagen gene expression and procollagen production. All four compounds promote wound healing by stimulating angiogenesis via VEGF (vascular endothelial growth factor) upregulation, fibroblast proliferation and migration, and extracellular matrix remodeling. Centella extracts also increase superoxide dismutase (SOD) and catalase activity in skin cells, enhancing endogenous antioxidant defense. The triterpenes may modulate TGF-β and Smad signaling. TECA (Titrated Extract of Centella Asiatica) standardizes these actives for consistent clinical efficacy.

Resveratrol activates SIRT1 (sirtuin 1), a NAD+-dependent deacetylase that deacetylates histones and non-histone targets including p53, FOXO transcription factors, and NF-κB, regulating cellular stress response, DNA repair, autophagy, and inflammatory pathways in keratinocytes and fibroblasts. It scavenges superoxide anion, hydroxyl radical, and metal-induced free radicals through its phenolic hydroxyl groups. Resveratrol inhibits NF-κB nuclear translocation and downstream cytokine production (TNF-α, IL-1β, IL-6), reducing UV-induced inflammation. It inhibits tyrosinase (mild brightening), matrix metalloproteinase-9 (MMP-9, gelatinase B) to prevent collagen and elastin breakdown, and AP-1 (c-Fos/c-Jun) to reduce photoaging-related gene expression. It may also activate Nrf2, upregulating antioxidant enzymes (HO-1, NQO1). Topical application achieves higher skin tissue concentrations than oral supplementation due to first-pass metabolism. Stability is improved in anhydrous or encapsulated formulations.