Prospects of Plumbago rosea L. hairy root culture in traditional preparations: a phytochemical comparison with tuberous roots

Agrobacterium rhizogenes mediated hairy root culture of Plumbago rosea L. is an attractive alternative for the production of plumbagin which is the major bioactive compound in P. rosea tuberous roots. The traditional industries form the major consumer of the tuberous roots as these are used in many ayurvedic preparations. The present work investigates the prospects of utilizing hairy roots in the place of tuberous roots based on bacterial survival test of hairy roots and comparison through phytochemical analyses (TLC, Spectrophotometry, HPLC and LC-MS). Since the traditional system of medicine follows stringent curing procedure before incorporation of the roots in medicinal preparations, cured tuberous and hairy roots were also compared. The phytochemical profile of hairy roots was remarkably similar to that of tuberous roots. Curing caused no change in the phytotchemical composition of the roots but only a reduction in the amount of plumbagin and other molecules. Plumbagin was reduced to 0.372 ± 0.026% dry weight (DW) in cured tuberous roots (1.15 ± 0.08% DW in uncured) and 0.061± 0.0043% DW in cured hairy roots (1.32 ± 0.09% DW in uncured). An 11.3 fold increase in root biomass with 1.56% DW plumbagin obtained in bioreactor as against 5.39 fold in shake-flasks (with 1% w/v inoculum over 3 weeks period), adds to the prospects of its applicability in traditional systems. The results suggest a refurbishment of conventional high quantity cured roots in traditional preparations with low quantity uncured roots, irrespective of root types.