Advancements on centelloside biosynthesis in tissue cultures of Centella asiatica (L.) Urban

Centella asiatica (L.) Urban is a medicinal herb widely valued for its bioactive triterpenoid saponins, collectively known as centellosides, which include asiaticoside (ASI), madecassoside (MAD), asiatic acid (ASA), and madecassic acid (MDA). These compounds exhibit diverse pharmacological properties, including neuroprotective, wound healing, and antioxidant activities, driving their demand in the pharmaceutical, nutraceutical, and cosmetic industries. However, overreliance on wild harvesting and the absence of standardized cultivation practices result in inconsistent quality, ecological strain, and scalability challenges. Wild populations exhibit 5- to 10-fold variation in centelloside content depending on geographic origin, environmental conditions, and harvest time, underscoring the need for standardized production systems. In vitro culture systems such as callus, shoot, and hairy root cultures present sustainable alternatives to produce metabolite-rich biomass. This review analyses recent biotechnological interventions such as elicitation, precursor feeding, and cell permeability enhancers and genetic engineering, employed for enhancement of centellosides. Furthermore, it reviews the status and future potential of emerging approaches, including metabolic engineering through CRISPR/Cas9 genome editing and extracellular vesicle-based production to boost centelloside yields. Finally, key research gaps are identified to support the development of scalable production systems and a reliable supply chain. While previous reviews have covered tissue culture establishment and general biotechnological strategies, the present review is the first to systematically compare elicitor efficacy across culture systems, critically evaluate the gap between genomic discoveries and functional validation and assess scalability from shake-flask to bioreactor systems.