Das Laxmidhar, Vinayak Manjula
Biochemistry and Molecular Biology Laboratory, Department of Zoology (Centre of Advanced Study), Banaras Hindu University, Varanasi-221005, India.
PLoS One. 2015 Apr 10;10(4):e0124000. doi: 10.1371/journal.pone.0124000. eCollection 2015.
Inhibition of carcinogenesis may be a consequence of attenuation of oxidative stress via activation of antioxidant defence system, restoration and stabilization of tumour suppressor proteins along with modulation of inflammatory mediators. Previously we have delineated significant role of curcumin during its long term effect in regulation of glycolytic pathway and angiogenesis, which in turn results in prevention of cancer via modulation of stress activated genes. Present study was designed to investigate long term effect of curcumin in regulation of Nrf2 mediated phase-II antioxidant enzymes, tumour suppressor p53 and inflammation under oxidative tumour microenvironment in liver of T-cell lymphoma bearing mice. Inhibition of Nrf2 signalling observed during lymphoma progression, resulted in down regulation of phase II antioxidant enzymes, p53 as well as activation of inflammatory signals. Curcumin potentiated significant increase in Nrf2 activation. It restored activity of phase-II antioxidant enzymes like GST, GR, NQO1, and tumour suppressor p53 level. In addition, curcumin modulated inflammation via upregulation of TGF-β and reciprocal regulation of iNOS and COX2. The study suggests that during long term effect, curcumin leads to prevention of cancer by inducing phase-II antioxidant enzymes via activation of Nrf2 signalling, restoration of tumour suppressor p53 and modulation of inflammatory mediators like iNOS and COX2 in liver of lymphoma bearing mice.
抑制致癌作用可能是通过激活抗氧化防御系统减轻氧化应激、恢复和稳定肿瘤抑制蛋白以及调节炎症介质的结果。此前我们已经阐述了姜黄素在其长期作用中对糖酵解途径和血管生成的调节作用,这反过来又通过调节应激激活基因来预防癌症。本研究旨在探讨姜黄素在T细胞淋巴瘤荷瘤小鼠肝脏氧化肿瘤微环境下对Nrf2介导的II期抗氧化酶、肿瘤抑制因子p53和炎症的长期调节作用。在淋巴瘤进展过程中观察到的Nrf2信号抑制导致II期抗氧化酶、p53下调以及炎症信号激活。姜黄素显著增强了Nrf2的激活。它恢复了GST、GR、NQO1等II期抗氧化酶的活性以及肿瘤抑制因子p53的水平。此外,姜黄素通过上调TGF-β以及对iNOS和COX2的相互调节来调节炎症。该研究表明,在长期作用中,姜黄素通过激活Nrf2信号诱导II期抗氧化酶、恢复肿瘤抑制因子p53以及调节淋巴瘤荷瘤小鼠肝脏中iNOS和COX2等炎症介质,从而预防癌症。