Induction of Manganese-Superoxide Dismutase by YS 51, a Synthetic 1-(β-Naphtylmethyl)6,7-Dihydroxy- 1,2,3,4-Tetrahydroisoquinoline Alkaloid

(S)YS-51, a novel isoquinoline alkaloid, attenuates obesity-associated non-alcoholic fatty liver disease in mice by suppressing lipogenesis, inflammation and coagulation

Obesity-associated non-alcoholic fatty liver disease (NAFLD) increases coagulation and inflammation. We hypothesized that (S)YS-51, an agent found to be beneficial in animal models of sepsis, may reduce NAFLD in high-fat diet (HFD) mice by reducing coagulation and inflammation. C57BL/6 mice were fed either a chow diet or HFD and each was supplemented with or without (S)YS-51 (10mg/kg, daily, i.p.) for 16 weeks. The results showed that HFD caused significant increases in lipogenesis [CD36, fatty acid synthase (FAS) and sterol response element binding protein (SREBP)-1c mRNA and protein], inflammation [monocyte chemotactic protein (MCP)-1, tumor necrosis factor (TNF)-α, intercellular cell adhesion molecule-1 (ICAM-1), TGF-β, and procollagen type 1 mRNA, macrophage infiltration] and coagulation [tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) mRNA and thrombin antithrombin complex (TAT)] in the liver, adipose tissue and serum, which were significantly reduced by (S)YS-51. These results of (S)YS-51 were accompanied by significant reduction of weight gain, liver size, hepatic steatosis and fibrosis, blood cholesterol, hepatic triglyceride, and macrophage infiltration and inflammatory cytokines in adipose tissue without affecting food intake in HFD mice. Interestingly, (S)YS-51 increased SIRT1 mRNA and protein and AMPK expression in the liver of HFD mice by increasing both NAD(+)/NADH ratio and LKB1 phosphorylation. In HepG2 cells, (S)YS-51 activated SIRT1 followed by AMPK. Finally, (S)YS-51 improved glucose tolerance and insulin resistance in HFD mice. We concluded that (S)YS-51 attenuates NAFLD and insulin resistance in HFD mice by, at least, activation of SIRT1/AMPK signals. Thus, (S)YS-51 may be beneficial in NAFLD treatment.

Heme oxygenase-1 induction by (S)-enantiomer of YS-51 (YS-51S), a synthetic isoquinoline alkaloid, inhibits nitric oxide production and nuclear factor-kappaB translocation in ROS 17/2.8 cells activated with inflammatory stimulants

Activation of the inducible nitric oxide synthase (iNOS) pathway contributes to inflammation-induced osteoporosis by suppressing bone formation and causing osteoblast apoptosis. We investigated the mechanism of action by which YS-51S, a synthetic isoquinoline alkaloid, inhibits iNOS expression and nitric oxide (NO) production in ROS 17/28 osteoblast cells activated with the mixture of TNF-alpha, IFN-gamma and LPS (MIX). YS-51S, concentration- and time-dependently, increased heme oxygenase (HO-1) expression. Treatment with YS-51S 1 h prior to MIX significantly reduced MIX-induced NO production and iNOS expression with the IC50 to NO production of 47+/-3.3 microM. Electrophoretic mobility shift assay (EMSA) and western blot analysis showed that YS-51S inhibited MIX-mediated activation and translocation of NF-kappaB to nucleus by suppressing the degradation of its inhibitory protein IkappaBalpha in cytoplasm. YS-51S also reduced NF-kappaB-luciferase activity. In addition, an HO-1 inhibitor ZnPPIX, antagonized the inhibitory effect of YS-51S on iNOS expression and DNA strand break induced by MIX, indicating prevention of NO production by YS-51S is associated with HO-1 activity. Moreover, YS-51S inhibited the oxidation of cytochrome c(2+) by peroxynitrite (PN). Our results indicated that YS-51S may be beneficial in NO-mediated inflammatory conditions such as rheumatoid arthritis by alleviating iNOS expression and NO-mediated cell death of osteoblast with 1) inducing HO-1 expression, 2) interfering the activation of NF-kappaB and 3) quenching of PN.

YS 51, 1-(beta-naphtylmethyl)-6,7-dihydroxy-1,2,3,4,-tetrahydroisoquinoline, protects endothelial cells against hydrogen peroxide-induced injury via carbon monoxide derived from heme oxygenase-1

Oxidative stress plays an important role in the pathophysiology of several vascular diseases such as atherosclerosis, and great attention has been placed on the protective role of heme oxygenase-1 (HO-1) for vasculature against oxidant-induced injury. We tested whether the protective effects of YS 51, 1-(beta-naphtyl-methyl)-6,7-dihydroxy-1,2,3,4,-tetrahydroisoquinoline, against hydrogen peroxide (H2O2)-induced cell injury is associated with HO-1 activity in bovine aortic endothelial cells (BAEC). YS 51 increased HO-1 expression and activity in concentration-dependent manners (10-100 microM) and time-dependent manners (1, 3, 6, 18 h), which were correlated well with its protective effect against H2O2-induced injury. Zinc protoporphyrin IX (ZnPP IX), a HO inhibitor, significantly inhibited the effect of YS 51 (50 microM). In contrast, [Ru(CO)3(Cl)2]2 (CORM-2, a CO releasing molecule) but not bilirubin protected against H2O2-induced injury. Oxyhemoglobin (HbO2) used as a CO scavenger significantly inhibited the protective effect of both YS 51 and CORM-2. Furthermore, both YS 51 and CORM-2 significantly reduced H2O2-induced intracellular reactive oxygen species (ROS) production; however, this was counteracted by ZnPP IX, HbO2 and deferoxamine. We found evidence for the involvement of PI3/Akt kinase and ERK1/2 pathways in HO-1 induction by YS-51. Taken together, we conclude that CO is, at least, responsible for the YS 51-mediated protective action of endothelial cells against oxidant stress via HO-1 gene induction, involving the activation of the PI3/Akt and ERK1/2 kinase pathways. Thus, YS 51 may be useful in oxidative stress-induced vascular disorders.