Utilizing meta-topolin for the micropropagation of high-yielding natural clones of Centella asiatica (L.) Urban and evaluation of their anti-uropathogenic activity.

Centella asiatica (L.) Urb., also known as Indian pennywort, is an important ethnomedicinal herb valued for its bioactive compounds, including asiaticoside, madecassoside, asiatic acid, and madecassic acid, collectively termed centellosides, which possess neuroprotective, wound-healing, and antioxidant properties. In the present study, 87 accessions of C. asiatica were collected from six agro-climatic zones of West Bengal, India, and evaluated for centelloside content and bioactivity. The chemotype C20 was identified as a high-yielding chemotype, exhibiting maximum accumulation of secondary metabolites: 31.02 ± 0.29 mg/g asiaticoside, 37.53 ± 0.11 mg/g madecassoside, 16.84 ± 0.06 mg/g asiatic acid, and 14.16 ± 0.12 mg/g madecassic acid, as quantified by high-performance thin layer chromatography. This chemotype also demonstrated the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl assay, 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid assay, and ferric reducing antioxidant power assay. This chemotype has also shown significant antimicrobial potential, with a maximum inhibition zone of 18.33 ± 0.26 mm against the human pathogen Staphylococcus aureus. Due to the optimum efficiency of C20 in all aspects studied in the present findings, among the 87 accessions, it is considered an elite chemotype. Micropropagation of elite chemotype using MS medium supplemented with meta-topolin (1.5 mg/L) and indole-3-acetic acid (0.5 mg/L) yielded maximum (28.39 ± 0.06) shoots per explant, while optimal rooting was achieved on half-strength MS medium with 0.5 mg/L indole-3-butyric acid. Genetic and phytochemical fidelity between wild and regenerated plants was confirmed through SCoT marker profiling and high-performance liquid chromatography. This reproducible method for elite plant selection and their mass production has the potential to revolutionise the pharmaceutical and herbal medicine industries.