Theaflavins Induce Autophagy in Ehrlich’s Ascites Carcinoma Cells both In vivo and In vitro

Abstract

To investigate the efficacy of Theaflavins to induce autophagy and its tumoricidal activity towards Ehrlich’s Ascites Carcinoma cells. The apoptosis-inducing role of Theaflavins against cancer is reported. Autophagy, a cellular mechanism under stress, occurs either as a survival process or Type-II programmed-cell death in the presence/absence of apoptosis. The report of Theaflavins inducing autophagy against cancer is poor. Here, for the first time, the investigation for the anti-tumor efficacy of Theaflavins via autophagy in EAC was attempted. EAC-bearing mice were treated orally with Theaflavins (10 mg/kg b.w.) every alternate day with a total of 27 doses. Body weight, tumor volume and survivability were recorded. Tumoricidal and cellular dehydrogenase activity, in vivo and in vitro, were studied using Trypan-blue exclusion and MTT assay respectively. Theaflavins-treated EAC cells were subjected to Monodansylcadaverine- staining. LC3II turnover and LC3I conversion were detected by western blotting. Apoptosis up to 12 h TF-treatment was estimated by AnnexinV binding. This is the first report of Theaflavins inducing autophagy in EAC cells in vivo and in vitro. Oral Theaflavins treatment restricted excessive body-weight increase due to tumors, reduced tumor volume, and increased survivability of tumor-bearing mice. Theaflavins caused EAC cell death (~8% in vitro, ~30% in vivo), significantly reduced metabolic activity, and created conspicuous vacuolization in surviving cells. Resultant vacuoles (in vitro, 6 h) were marked as autophagosomes by Monodansylcadaverine-staining. Autophagy was confirmed by LC3II augmentation. No significant apoptosis was observed up to 12 h TF-treatment in vitro. Theaflavins were efficient inducing autophagy and Type-II PCD in EAC cells. Notably, Theaflavins induced autophagy prior to apoptosis in vitro.