The With-No-Lysine (K) (WNK) kinases play a critical role in blood pressure regulation and body fluid and electrolyte homeostasis. Herein, we introduce the first orally bioavailable pan-WNK-kinase inhibitor, WNK463, that exploits unique structural features of the WNK kinases for both affinity and kinase selectivity. In rodent models of hypertension, WNK463 affects blood pressure and body fluid and electro-lyte homeostasis, consistent with WNK-kinase-associated physiology and pathophysiology.

Sesamin (Ses), one of the major lignans in sesame seeds and oil, has been reported to have many benefits and medicinal properties. However, its protective effects against nickel (Ni)-induced injury in liver have not been clarified. The aim of the present study was to investigate the effects of sesamin on hepatic oxidative DNA injury and apoptosis in mice exposed to nickel. Kunming mice were exposed to nickel sulfate with or without sesamin coadministration for 20 days. The data showed that sesamin significantly prevented nickel-induced hepatotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of liver damage (serum aminotransferase activities) and histopathological analysis. Moreover, nickel-induced profound elevation of reactive oxygen species (ROS) production and oxidative stress, as evidenced by an increase of the lipid peroxidation level and depletion of the intracellular reduced glutathione (GSH) level in liver, were suppressed by treatment with sesamin. Sesamin also restored the activities of antioxidant enzymes (T-SOD, CAT, and GPx) and decreased 8-hydroxy-2-deoxyguanosine (8-OHdG) levels in nickel-treated mice. Furthermore, a TUNEL assay showed that nickel-induced apoptosis in mouse liver was significantly inhibited by sesamin. Exploration of the underlying mechanisms of sesamin action revealed that activities of caspase-3 were markedly inhibited by the treatment of sesamin in the liver of nickel-treated mice. Sesamin increased expression levels of phosphoinositide-3-kinase (PI3K) and phosphorylated protein kinase B (PBK/Akt) in liver, which in turn inactivated pro-apoptotic signaling events, restoring the balance between pro- and anti-apoptotic Bcl-2 proteins in the liver of nickel-treated mice. In conclusion, these results suggested that the inhibition of nickel-induced apoptosis by sesamin is due at least in part to its antioxidant activity and its ability to modulate the PI3K-Akt signaling pathway.

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Lead (Pb), a well-known environmental toxin, is one of the major hazards for human health. Quercetin (QE), a natural flavonoid, has been reported to have many benefits and medicinal properties. However, its protective effects against Pb-induced endoplasmic reticulum (ER) stress in liver have not been clarified. The aim of the present study was to investigate the effects of quercetin on hepatic ER stress in rats exposed to Pb. Wistar rats were exposed to lead acetate in the drinking water with or without quercetin co-administration for 75 days. Our data showed that quercetin significantly prevented Pb-induced hepatotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of liver damage and histopathological analysis. Quercetin markedly decreased Pb contents in blood and liver. Western blot analysis showed that Pb-induced ER stress in rat liver was significantly inhibited by quercetin. In exploring the underlying mechanisms of quercetin action, we found quercetin markedly suppressed Pb-induced oxidative stress. Quercetin decreased reactive oxygen species (ROS) production and increased the total antioxidant capacity in rat livers. Additionally, quercetin dramatically increased Phosphoinositide-3-kinase (PI3K) and phosphorylated protein kinase B (PKB/Akt) levels in liver rats. In the examined unfolded protein response (UPR) pathways, quercetin markedly inhibited the Pb-induced increase of the phosphorylated inositol-requiring enzyme 1 (IRE1) and c-jun N-terminal kinase (JNK) in rat liver. Taken together, these results suggested that the inhibition of Pb-induced ER stress by quercetin is due at least in part to its anti-oxidant stress activity and its ability to modulate the PI3K/Akt and IRE1/JNK signaling pathway.

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