Telmisartan attenuates N-nitrosodiethylamine-induced hepatocellular carcinoma in mice by modulating the NF-κB-TAK1-ERK1/2 axis in the context of PPARγ agonistic activity.

Hepatocellular carcinoma (HCC) is characterized by bad prognosis and is the second most common reason for cancer-linked mortality. Treatment with sorafenib (SRF) alone increases patient survival by only a few months. A causal link has been determined between angiotensin II (Ang-II) and HCC. However, the mechanisms underlying the tumorigenic effects of Ang-II remain to be elucidated. N-Nitrosodiethylamine was utilized to examine the effects of telmisartan (TEL) (15 mg/kg), SRF (30 mg/kg), and a combination of these two agents on HCC mice. Downregulation of NF-кBP65 mRNA expression and inhibition of the phosphorylation-induced activation of both ERK1/2 and NF-кB P65 were implicated in the anti-tumor effects of TEL and SRF. Consequent regression of malignant changes and improvements in liver function associated with reduced levels of AFP, TNF-α, and TGF-ß1 were also confirmed. Anti-proliferative, anti-metastatic, and anti-angiogenic effects of treatment were indicated by reduced hepatic cyclin D1 mRNA expression, reduced MMP-2 levels, and reduced VEGF levels, respectively. TEL, but not SRF, demonstrated agonistic activity for PPARγ receptors, as evidenced by increased PPARγ DNA binding activity, upregulation of CD36, and HO-1 mRNA expression followed by increased liver antioxidant capacity. Both TEL and SRF inhibited TAK1 phosphorylation-induced activation, indicating that TAK1 might act as a central mediator in the interaction between ERK1/2 and NF-кB. TEL, by modulating the ERK1/2, TAK1, and NF-кB signaling axis in the context of PPARγ agonistic activity, exerted anti-tumor effects and increased tumor sensitivity to SRF. Therefore, TEL is an encouraging agent for further clinical trials regarding the management of HCC.

Telmisartan ameliorates dextran sodium sulfate-induced colitis in rats by modulating NF-κB signalling in the context of PPARγ agonistic activity.

Variations in Nrf-2 and NF-κB expression profiles have been reported in ulcerative colitis (UC), in which an interplay between these two critical pathways has been identified. The therapeutic potential of angiotensin receptor blockers (ARBs) for oxidative damage and inflammation has recently received considerable attention. Dextran sodium sulfate (DSS)-induced colitis in rats closely resembles human UC and is associated with oxidative damage and the production of pro-inflammatory mediators. Therefore, we aimed to investigate the effect of orally administered telmisartan (TEL) (1.75, 3.5 and 7 mg/kg) in a rat model of DSS-induced colitis. Our study revealed that TEL, particularly at 7 mg/kg, alleviated tissue injury and inflammatory signs upon histological analysis and enhanced survival and recovery during DSS-induced colitis. The levels of colonic IL-1ß, IL-6, TNF-α and serum C-reactive protein (CRP) were downregulated, while the level of colonic IL-10 was upregulated. TEL repressed DSS-induced neutrophil infiltration and improved the colonic antioxidant defence machinery. TEL inhibited apoptotic signalling as indicated by lower caspase 3 expression, increased CD36 gene expression and exhibited PPARγ agonistic activity. In addition, TEL downregulated gene expression and inhibited phosphorylation of the NF-κB p65 subunit. On the other hand, TEL upregulated the gene expression of Nrf-2 and HO-1. We concluded that TEL, besides its PPARγ agonistic activity, acted as a modulator of Nrf-2/NF-κB interactions and exhibited anti-apoptotic activity after tissue damage and that PPARγ and CD36 might play a critical role in the pathogenesis of murine colitis. Therefore, our findings suggest that further investigations on human IBDs are warranted.