Centella Asiatica

Centella asiatica found fame in skincare long before dentistry caught up. The cosmetics industry markets it as "CICA" — a calming ingredient for compromised skin. But behind that label sits 2,000 years of Ayurvedic wound-healing tradition and a biochemical mechanism that translates directly into oral care, particularly for gum tissue regeneration.

What it is

Centella asiatica (family Apiaceae) is a creeping perennial herb native to the wet tropics of Asia, Africa, and Oceania. In Ayurvedic medicine it is called "mandukaparni" and has been used for wound healing and mucosal inflammation for millennia. In traditional Chinese medicine it is known as 积雪草 (jī xuě cǎo).

The biological activity comes from three primary triterpenoids:

| Compound | Type | Primary action | |---|---|---| | Asiaticoside | glycoside | stimulates type I collagen synthesis | | Asiatic acid | aglycone | anti-inflammatory, antioxidant | | Madecassic acid | aglycone | anti-fibrotic, regenerative |

A fourth component — madecassoside (glycoside of madecassic acid) — adds to the healing effect. Quality extracts are standardized to 30–40% total triterpenoids. This is the specification to verify when sourcing raw material.

INCI designation: Centella Asiatica Extract. Some cosmetic formulations list individual fractions: Asiaticoside, Asiatic Acid, Madecassic Acid.

How it works

Centella's mechanism is a cascade, not a single reaction — which explains why it works across wound healing, inflammation control, and microbial biofilm management.

Collagen synthesis. The key molecule is asiaticoside. A 2012 Korean study (Kim et al., PMID 22628285) was the first to demonstrate its action directly on human periodontal ligament cells (HPDLCs). Asiaticoside at 25–100 µg/mL significantly increased mRNA expression of type I collagen, osteocalcin, and alkaline phosphatase. Immunocytochemistry confirmed protein-level synthesis. The authors concluded that asiaticoside has potential for enhancing periodontal tissue healing.

Anti-inflammatory pathway. Asiatic acid and madecassic acid inhibit NF-κB signaling — the central transcription factor of the inflammatory response — reducing output of IL-1β, TNF-α, and prostaglandin E2. In the 2024 study by Chonsut et al. (PMID 39296309), centella ethanol extract significantly suppressed nitric oxide (NO) secretion in RAW264.7 macrophages, a standard readout for pro-inflammatory activation.

Anti-biofilm activity. The same 2024 experiment showed that at ½ × MIC concentration, the extract inhibited S. mutans biofilm formation comparably to 0.2% chlorhexidine. Molecular docking revealed that asiatic acid, madecassic acid, and madasiatic acid bind glucosyltransferase C (GtfC) of S. mutans with superior affinity versus chlorhexidine and acarbose controls.

Wound healing. The 2022 systematic review by Arribas-López et al. (PMC 8956065) analyzed 4 clinical trials and multiple preclinical studies. Identified mechanisms: angiogenesis stimulation, increased FGF and VEGF production, accelerated collagen deposition. Centella acts on the proliferative phase of healing, not only the inflammatory phase.

Clinical evidence in dentistry

The most direct periodontal study is Sombat et al. (2005, PMID 16022023). Fifteen patients in supportive periodontal therapy with residual pockets of 5–8 mm received biodegradable chips with centella and pomegranate extract delivered subgingivally. Result: statistically significant improvement in periodontal clinical parameters and reduction in IL-1β in gingival crevicular fluid versus control. Both antibacterial and anti-inflammatory actions were implicated.

Two registered clinical trials tested centella directly in toothpaste and rinse formats. Trial NCT02616042 used a randomized crossover design for a toothpaste with centella and bamboo salt, measuring plaque index and gingival index. Trial NCT02827305 evaluated a gotu kola mouthwash as an adjunct to mechanical plaque control.

What does not work: centella is not a potent antiseptic in the classical sense. Its MIC against major periodontopathogens is moderate. It does not replace chlorhexidine or CPC for acute infections. Its strength is in chronic anti-inflammatory and regenerative action, not rapid antibacterial kill.

Concentration below 0.1% is unlikely to produce clinically meaningful effects. Non-standardized extracts with low triterpenoid content are the most common reason for inconsistent results in cosmetic products.

Safety

Regulatory status: centella extract is listed in COSING (EU cosmetics database) without concentration restrictions. The European Medicines Agency (EMA/HMPC) recognizes its traditional use for minor wounds. No FDA safety objections for topical use.

Adverse reactions. Contact dermatitis has been documented at concentrations above 1% with prolonged use. At 0.1–0.5%, adverse reactions in humans are rare. No mucosal irritation was reported in available dental clinical trials.

Photosensitization: not observed at concentrations up to 1%.

Pregnancy: systemic high-dose data are insufficient. At standard concentrations in oral care products, systemic absorption is minimal. No formal clinical data exist for pregnant populations.

Compatibility with QDRO actives. Chemically compatible with nano-hydroxyapatite, xylitol, zinc citrate, CPC, and mild surfactants (cocamphoacetate, cocamidopropyl betaine).

---

Sources:

• Sombat S et al. Adjunctive periodontal treatment with Centella asiatica and Punica granatum extracts in supportive periodontal therapy. J Int Acad Periodontol. 2005;7(3):70-9. PMID 16022023
• Kim SH et al. Asiaticoside induces type I collagen synthesis and osteogenic differentiation in human periodontal ligament cells. J Periodontal Res. 2012;47(3):336-43. PMID 22628285
• Chonsut P et al. Potential Activities of Centella asiatica Leaf Extract against Pathogenic Bacteria-Associated Biofilms and Its Anti-Inflammatory Effects. Adv Pharmacol Pharm Sci. 2024. PMID 39296309
• Arribas-López E et al. A Systematic Review of the Effect of Centella asiatica on Wound Healing. Int J Environ Res Public Health. 2022;19(6):3266. PMC 8956065
• Sombat S et al. Adjunctive periodontal treatment with Centella asiatica and Punica granatum extracts. A preliminary study. J Int Acad Periodontol. 2003;5(4):106-15. PMID 14604059