Pyridostigmine attenuates hypertension by inhibiting activation of the renin-angiotensin system in the hypothalamic paraventricular nucleus.

Activation of the renin-angiotensin system (RAS) triggers oxidative stress and an inflammatory response in the hypothalamic paraventricular nucleus (PVN), in turn increasing the sympathetic hyperactivity that is a major cause of hypertension. Pyridostigmine has cardioprotective effects by suppressing the RAS of myocardial tissue. However, whether pyridostigmine attenuates hypertension by inhibiting the RAS of the PVN remains unclear. We thus investigated the effect and mechanism of pyridostigmine on two-kidney one-clip (2K1C)-induced hypertension. 2K1C rats received pyridostigmine, or not, for 8 weeks. Cardiovascular function, hemodynamic parameters, and autonomic activity were measured. The PVN levels of pro-/anti-inflammatory cytokines, oxidative stress, and RAS signaling molecules were evaluated. Our results showed that hypertension was accompanied by cardiovascular dysfunction and an autonomic imbalance characterized by enhanced sympathetic but diminished vagal activity. The PVN levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS), NOX-2, and malondialdehyde (MDA) increased; those of IL-10 and superoxide dismutase (SOD) decreased. Moreover, the RAS signaling pathway was activated, as evidenced by increased levels of the angiotensin-converting enzyme (ACE), angiotensin II (Ang II), and the Ang II type 1 receptor (AT1R) and a decreased AT2R level. Pyridostigmine lowered blood pressure and improved cardiovascular function, associated with restoration of the autonomic balance. Meanwhile, pyridostigmine decreased PVN IL-6, TNF-α, ROS, NOX-2, and MDA levels and increased IL-10 and SOD levels. Additionally, pyridostigmine suppressed PVN ACE, Ang II, and AT1R levels and increased AT2R expression. Pyridostigmine attenuated hypertension by inhibiting PVN oxidative stress and inflammation induced by the RAS.

Dihydrotriazine derivatives display high anticancer activity and inducing apoptosis, ROS, and autophagy.

A series of dihydrotriazine derivatives bearing 5-aryloxypyrazole moieties were designed, and their anticancer activities against three human cancer cell lines (SGC-7901, HepG-2 and MCF-7) and one non-cancer cell line (LO2) were explored using the MTT assay in vitro. Most of the compounds exhibited potent antiproliferative activities against the three cancer cell lines, with compound 10e (IC50 = 2.12 µM) exhibiting the most potent antiproliferative activity against HepG-2 cells. Interestingly, autophagy was observed in the 10e-treated HepG-2 cells. Compound 10e also increased reactive oxygen species (ROS) levels and resulted in marked HepG-2 cells apoptosis. Further studies revealed that compound 10e could enhance the expression of Cl-PARP, Cl-caspase-3, and Cl-caspase-9. In addition, 10e triggered the formation of autophagosomes by promoting LC3-II and Beclin-1 expression. These results might be useful for exploring and developing dihydrotriazine derivatives as novel anticancer agents.