Regeneration of Centella asiatica plants from non-embryogenic cell lines and evaluation of antibacterial and antifungal properties of regenerated calli and plants

BACKGROUND The threatened plant Centella asiatica L. is traditionallyused for a number of remedies. In vitro plant propagation and enhanced metabolite production of active metabolites through biotechnological approaches has gained attention in recent years. RESULTS Present study reveals that 6-benzyladenine (BA) either alone or in combination with 1-naphthalene acetic acid (NAA) supplemented in Murashige and Skoog (MS) medium at different concentrations produced good quality callus from leaf explants of C. asiatica. The calli produced on different plant growth regulators at different concentrations were mostly embryogenic and green. Highest shoot regeneration efficiency; 10 shoots per callus explant, from non-embryogenic callus was observed on 4.42 μM BA with 5.37 μM NAA. Best rooting response was observed at 5.37 and 10.74 μM NAA with 20 average number of roots per explant. Calli and regenerated plants extracts inhibited bacterial growth with mean zone of inhibition 9-13 mm diameter when tested against six bacterial strains using agar well diffusion method. Agar tube dilution method for antifungal assay showed 3.2-76% growth inhibition of Mucor species, Aspergillus fumigatus and Fusarium moliniformes. CONCLUSIONS The present investigation reveals that non-embryogenic callus can be turned into embryos and plantlets if cultured on appropriate medium. Furthermore, callus from leaf explant of C. asiatica can be a good source for production of antimicrobial compounds through bioreactor.