Various preclinical studies suggest mitigating effect of quercetin against cancer, a dietary flavonoid. Quercetin suffers from poor metabolic stability, which appears to offset its pharmacological efficacy. Recently, we isolated quercetin-6-C-β-D-glucopyranoside (QCG) from Ulmus wallichiana planchon that has greater stability profile over quercetin. In the present study, the cytotoxic and apoptotic effects of QCG on prostate cancer cells were assessed. QCG inhibited prostate cancer cell proliferation by arresting cells at G0/G1 phase of cell cycle and induces apoptosis as evident from cytochrome c release, cleavage of caspase 3 and poly (ADP-ribose) polymerase. Mechanistic studies revealed that QCG inhibited reactive oxygen species (ROS) generation and Akt/mTOR cell survival pathways. Aryl hydrocarbon receptor (AhR) was a critical mediator of QCG action as knockdown of AhR attenuated QCG-induced cell cycle arrest, apoptosis and inhibition of Akt/mTOR pathway in prostate cancer cells. Taken together, our results suggest that QCG exhibits anti-cancer activity against prostate cancer cells via AhR-mediated down regulation of Akt/mTOR pathway in PC-3 cells.
Biochimie. 2015 Oct 14 [Epub ahead of print]
Rajeev Kumar, Karan Singh Saini, Amit Kumar, Sudhir Kumar, E Ramakrishna, Rakesh Maurya, Rituraj Konwar, Naibedya Chattopadhyay
Endocrinology Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India. , Endocrinology Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India. , Endocrinology Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India. , Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031, India. , Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031, India. , Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110001, India. , Endocrinology Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110001, India. Electronic address: r_konwar@cdri. res. in. , Endocrinology Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India; Academy of Scientific and Innovative Research (AcSIR), New Delhi 110001, India.