Enhancement of isoflavonoid production and release in Pueraria candollei cell suspension culture using elicitors for improving pharmacological activities

Plant tissue culture is controllable and sustainable production system of functional ingredients. Pueraria candollei is used as an herbal medicine to alleviate postmenopausal symptoms. However, conventional sources are limited by prolonged cultivation periods and inconsistent quality. Cell suspension culture of P. candollei was aimed at enhancing and controlling the production of isoflavonoids and deoxymiroestrol. This was achieved by employing 2-hydroxypropyl-beta-cyclodextrin (HPBCD) and cellulase as elicitors. The effect of elicitation on estrogenic and anti-inflammatory properties of P. candollei cell extracts was assessed. HPBCD elicitation increases three times the total isoflavonoid accumulation, while cellulase elicitation resulted in 2.5-fold increase in deoxymiroestrol production compared with controls, observed at day 20. Furthermore, HPBCD results in the release of isoflavonoids particularly daidzein (61.30 +/- 0.26 mu g/mL) into the medium. In both the elicitation groups, the upregulation of genes associated with isoflavonoid and deoxymiroestrol biosynthetic pathways was observed. Specifically, CHS gene transcription was induced within six days. On days 12 and 20, IFS and HID, which convert chalcones to isoflavonoids, were significantly upregulated. Additionally, the upregulation of CYP81E, IFR, and PT-1, which are involved in chromene production, was observed on day 3. HPBCD treatment exhibited a more potent effect on the expression of all the examined genes than cellulase. HPBCD treated extract led to increased estrogenic and anti-inflammatory activities, as evidenced by modulation of gene expression related to these pathways. In summary, HPBCD and elicitation techniques can be strategically employed to improve both quality and productivity of P. candollei cells as a source of functional ingredients.