AllantoinvsCentella Asiatica

Allantoin (5-ureidohydantoin) stimulates cell proliferation and tissue regeneration by promoting fibroblast activity, keratinocyte proliferation, and extracellular matrix synthesis including collagen and glycosaminoglycans. It acts as a mild keratolytic by promoting the natural desquamation process—loosening corneocyte adhesion and facilitating shedding—without the irritation, pH disruption, or barrier compromise associated with alpha- or beta-hydroxy acids. Allantoin has anti-inflammatory properties through modulation of prostaglandin synthesis (inhibiting COX-2 and reducing PGE2) and may downregulate pro-inflammatory cytokines. Its moisturizing effect comes from increasing the water-binding capacity of the extracellular matrix and stratum corneum; it is highly soluble and forms hydrogen bonds with water. Allantoin also promotes wound epithelialization. Its safety profile—non-irritating, non-sensitizing, non-comedogenic—makes it suitable for compromised skin, post-procedure care, and infant formulations.

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.