Gotu Kola (Centella asiatica)

Gotu Kola (Centella asiatica) is a low‑lying, herbaceous plant native to tropical Asia and the Pacific. Its aerial parts have been used for centuries as a culinary herb and in traditional medicine, primarily to support skin health, cognition, and circulatory function. Modern research focuses on its rich array of triterpenoid saponins, which appear to mediate many of its therapeutic actions.

• Asiatic acid: The principal bioactive, asiatic acid (C₃₀H₄₈O₅; IUPAC: (3S,5R,6R,8S,9R,10R,13R,14R,15S,16R,17R)-3,5,6,8,9,10,13,14,15,16,17‑undecahydro‑2‑(2‑hydroxy‑2‑methyl‑propyl)-17‑(hydroxy‑methyl)‑2‑(2‑hydroxy‑3‑methyl‑but-1‑enyl)‑3,5,6,8,9,10,13,14,15,16,17‑decahydro‑1‑H‑cyclopenta[a]phenanthrene‑3‑carboxylic acid, is a pentacyclic triterpenoid.
• Other compounds: The plant also contains madecassic acid, centellosides, flavonoids (e.g., quercetin), and a range of phenolic acids.
• Asiatic acid properties: Molecular weight of asiatic acid: 488.71 g·mol⁻¹, with a logP ≈ 3.5, indicating moderate lipophilicity that facilitates membrane penetration.
• Saponin glycosides: The saponin glycosides (e.g., asiaticoside) are more polar (logP ≈ −1) and require hydrolysis (by intestinal microbiota or hepatic enzymes) to release the active aglycones.

• Cultivation: Gotu Kola is cultivated primarily in India, Sri Lanka, Indonesia, and the Philippines, where the climate (high humidity, warm temperatures) supports optimal phytochemical content.
• Supplement source: Commercial supplements are typically derived from aerial parts (leaves, stems) harvested at the vegetative stage, then dried and milled.
• Extraction methods: Extraction commonly employs ethanol‑water (70 %–80 % ethanol) or super‑critical CO₂ to preserve triterpenoids; water extracts retain higher flavonoid content.
• Quality standards: High‑quality extracts are standardized to 10 %–20 % triterpenoid content and certified free of heavy metals (lead, cadmium, arsenic) and pesticide residues.
• Quality assurance: Good Manufacturing Practice (GMP) and third‑party testing (e.g., USP, NSF) are essential quality markers, as plant‑derived raw material can vary widely in active‑compound concentration.