Chemopreventive principles from Pueararia lobata flowers: In Vitro Evaluation of the Inhibition of the NF kappa B activating signaling pathway

Research over the last years has revealed that transcription factor NF kappa B has a pivotal function in the regulation of genes from which the resulting products are involved in the processes of cell proliferation and differentiation, apoptosis and inflammation. The activation of this nuclear factor has been linked with the promotion of tumorigenesis, angiogenesis and metastasis since NF kappa B is activated by carcinogens, inflammatory cytokines and chemotherapeutic agents. Consequently, its activation is inhibited by many agents which are known to have chemopreventive potency.

The aim of the present work is to search molecular evidence for the chemopreventive activity shown by the flowers of Pueraria lobata (Willd.) Ohwi (Fabaceae). Pueraria is a medicinal plant widely used in the traditional Chinese medicine and it is known to produce large amounts of isoflavones. The main constituents of the 80% ethanol extract were identified as the isoflavones tectorigenin-7-O-[β-D-xylopyranosyl-(1–6)-β-D-glucopyranoside], tectorigenin-7-O-β-D- glucopyranoside and tectorigenin and quantified using a validated HPLC-UV method [1]. The total extract, subfractions and pure compounds isolated from these flowers were evaluated for their effect on the NF kappa B activating signaling pathway (Luciferase luciferase reporter gene assay and Electrophoretic electrophoretic mobility shift assay). The results revealed that the extract of the flowers of this medicinal plant exhibit moderate inhibitory activity, which is mainly due to the aglycon tectorigenin showing the highest activity in comparison to the other evaluated pure compounds and fractions.

References: [1] Bebrevska, L. et al. (submitted) Planta Medica