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ISSN Druckformat: 0731-8898
ISSN Online: 2162-6537
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Black Tea Protects Thymocytes in Tumor-Bearing Animals by Differential Regulation of Intracellular ROS in Tumor Cells and Thymocytes
ABSTRAKT
The accumulated in vitro evidence indicates that many tumors induce T-cell apoptosis as a mechanism of inhibiting antitumor activity. This downregulation of cell-mediated immune functions occurring at the late stages of the disease may be causally related to the thymic involution, because the thymus is the major site of T-cell maturation, extensive proliferation, and differentiation. Our results showed that in Erhlich's ascites carcinoma cell (EAC)-bearing mice, the number of EAC was inversely proportional to the thymocyte count in the host's thymus, which is the primary immune organ. Further studies indicated the presence of tumor-induced thymocyte apoptosis in EAC bearers. Black tea prolonged the survival of the tumor bearer by successfully restricting tumor progression as well as protecting the thymus from tumor insult. In fact, black tea inhibited thymic apoptosis while inducing programmed cell death of EAC. Interestingly, the tea regulated the oxidant status differentially in EAC and thymocytesi.e., it reduced the EAC-induced reactive oxygen species (ROS) generation in the thymus while activating the same in the EAC. A similar effect of black tea was obtained when thymocytes were cultured in the presence of cell-free ascitic fluid, thereby indicating that black tea could directly reduce oxidative stress, an activity independent of its tumoricidal property. As a result, the maturation block in thymocyte subpopulations in tumor bearers was ameliorated significantly in black tea-treated animals. Our results demonstrate that black tea protects thymocytes in the tumor bearer by regulating the intracellular ROS in tumor cells and thymocytes differentially, thereby strengthening its candidacy in future anticancer therapeutic regimens.
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Mandal Debaprasad, Lahiry Lakshmishri, Bhattacharyya Arindam, Bhattacharyya Sankar, Sa Gaurisankar, Das Tanya, Tumor-induced thymic involution via inhibition of IL-7Rα and its JAK-STAT signaling pathway: Protection by black tea, International Immunopharmacology, 6, 3, 2006. Crossref
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Mandal Debaprasad, Bhattacharyya Sankar, Lahiry Lakshmishri, Chattopadhyay Sreya, Sa Gaurisankar, Das Tanya, Black Tea-Induced Decrease in IL-10 and TGF-β of Tumor Cells Promotes Th1/Tc1 Response in Tumor Bearer, Nutrition and Cancer, 58, 2, 2007. Crossref
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SAHA SHILPI, BHATTACHARJEE PUSHPAK, MUKHERJEE SHRAVANTI, MAZUMDAR MINAKSHI, CHAKRABORTY SAMIK, KHURANA ANIL, NAYAK DEBADATTA, MANCHANDA RAJKUMAR, CHAKRABARTY RATHIN, DAS TANYA, SA GAURISANKAR, Contribution of the ROS-p53 feedback loop in thuja-induced apoptosis of mammary epithelial carcinoma cells, Oncology Reports, 31, 4, 2014. Crossref