RESEARCH ARTICLES CURRENT SCIENCE, VOL. 110, NO. 2, 25 JANUARY 2016 187 *For correspondence. (e-mail: sam19narayan@yahoo.co.in) Potent antitumour activity of (–)epigallocatechin gallate: indications from in vitro, in vivo and in silico studies Samarendra Narayanan 1, *, Balaji Ramchandran 2 , Satheesh Rajendiran 2 , Sarbani Chandra 2 , Atul Tiwari 2 , Ravisankar Rajarethinam 3 and Ramesh Kureeckal Vasudev 1 1 Department of Biotechnology, Center for Post-graduate Studies, Jain University, Bengaluru 560 011, India 2 Department of Biology, Syngene International Limited, Jigani Link Road, Bengaluru 560 011, India 3 Institute of Molecular and Cell Biology, Biopolis, Singapore Antitumour efficacy of (–)epigallocatechin-3-gallate (EGCG) was evaluated in vitro against the cancer cell lines BxPC-3 (pancreatic cancer), A549 (lung cancer), SH-SY5Y (neuroblastoma), MDA-MB-231 and MCF-7 (breast cancer); in vivo in nude mice by tumour growth inhibition of pancreatic cancers (BxPC-3, MIAPaCa-2), breast cancer (MDA-MB-231) and in silico by docking studies. EGCG significantly inhi- bited these cancer cell lines in vitro and showed signi- ficant tumour reduction in vivo. EGCG docked on to the Her-2 receptor (1N8Y) and the tubulin dimer re- ceptor at a site other than the existing docetaxel ligand. Overall our results suggest that EGCG has potent antineoplastic activity. Keywords: Antitumour efficacy, breast cancer, dock- ing, epigallocatechin gallate, lung cancer. CANCER is the deadliest of all diseases known to mankind. Despite significant advances in cancer therapy in recent years, the mean survival time, even after aggressive ther- apy, remains low. According to the Global Cancer Report (GLOBOCAN), in 2012 there were 14.1 million new cases worldwide 1 . Presently various anticancer drugs are administered in combination with radiation therapy. Not only is the treatment for cancer expensive, but it also has severe side effects. Pancreatic cancers, a group of extremely aggressive human cancers, have been reported to cause 330,391 deaths worldwide annually 1 , while the overall 5-year sur- vival rate remains less than 5% (ref. 2). Conventional treatments have little impact on the progression of pan- creatic cancers 3 . Breast cancer is the leading type of can- cer in women, accounting for 25% of all cases, and causing 522,000 deaths worldwide annually 1 . Treatment is often accompanied by severe side effects. Prostate can- cer, one of the most aggressive cancers in men with a 5-year survival rate of less than 5%, is resistant to con- ventional chemotherapeutic agents. It has high morbidity and an estimated annual mortality of more than 307,481 deaths 1 . Small-cell lung cancer is a highly malignant can- cer that most commonly arises within the lung and occa- sionally in the cervix, prostrate and gastrointestinal tract. Relapse is common with a median survival time of only 12–18 months 1 . Epigallocatechin gallate (EGCG), a green tea poly- phenol, is known to inhibit cell proliferation and induce apoptosis in a variety of human neoplasms 4–6 . Recently, some compounds from natural products targeting tubulin have been discovered such as epothi- lone, paclitaxel, colchicines and vindesine 7–9 . Previous studies on EGCG have attempted to examine the anti- tumour activity employing in vitro or in vivo methods 6,10 . We report here, the anticancer activity of EGCG in ad- dition to the in vitro, in vivo and immunohistochemical (IHC) studies conducted, and the in silico aspects of inhi- bition of HER 2 tyrosin kinase receptor and tubulin dimer receptor 1 TUB (already containing docetaxel ligand) with the help of docking studies. Besides studying the docking of EGCG with Her2 receptor (1N8Y), we also examine the in silico aspect of microtubule polymeriza- tion for the inhibition of tumour cell growth. In the mitotic phase of the cell cycle, microtubules maintain dynamic equilibrium with tubulin dimers by assembling the tubu- lin into microtubules or, conversely, disassembling microtubules to tubulin 7 . Disruption of the dynamic equi- librium can induce cell-cycle arrest and ultimately lead to apoptosis. Materials and methods EGCG (Carbosynth, Berkshire, UK) was dissolved in ste- rile 1 mM phosphate buffered saline (PBS) to obtain a clear solution.