Novel substituted pyrazolone derivatives as AMP-activated protein kinase activators to inhibit lipid synthesis and reduce lipid accumulation in ob/ob mice.

Non-alcoholic fatty liver disease (NAFLD) is a clinical syndrome characterized by hepatic steatosis. NAFLD is closely linked to obesity, insulin resistance and dyslipidemia. AMP-activated protein kinase (AMPK) functions as an energy sensor and plays a central role in regulating lipid metabolism. In this study, we identified a series of novel pyrazolone AMPK activators using a homogeneous time-resolved fluorescence assay (HTRF) based on the AMPKα2ß1γ1 complex. Compound 29 (C29) is a candidate compound that directly activated the kinase domain of AMPK with an EC50 value of 2.1-0.2 µmol/L and acted as a non-selective activator of AMPK complexes. Treatment of HepG2 cells with C29 (20, 40 µmol/L) dose-dependently inhibited triglyceride accumulation. Chronic administration of C29 (10, 30 mg/kg every day, po, for 5 weeks) significantly improved lipid metabolism in both the liver and the plasma of ob/ob mice. These results demonstrate that the AMPK activators could be part of a novel treatment approach for NAFLD and associated metabolic disorders.

Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice.

AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK α subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome.

[Intervening effect of naoxintong on anti-platelet treatment with aspirin].

OBJECTIVE: To investigate the effect of small dosage aspirin on platelet biochemical indexes in patients with cardio-cerebrovascular diseases and the intervening action of Naoxintong (NXT). METHODS: The blood levels of P-selectin (P), thrombin B2 (TXB2), and platelet aggregation (PAG) induced by arachidonic acid (AA) and adenosine diphosphate (ADP) were determined in 145 patients with cardio-cerebrovascular diseases (diabetes mellitus, hypertension, coronary heart disease and cerebral infarction), after they were medicated with aspirin 100 mg per day for 7 days. Then they were randomly assigned to the aspirin group and the NXT group Both groups took aspirin 100 mg per day continually, but to patients in the NXT group, NXT 9 tablets per day was given additionally. The blood levels of above-mentioned biochemical indexes were re-examined 1 month after medication. RESULTS: The first determination showed the plasma level of P-selectin and TXB2 concentration were positively correlated with PAG, either induced by AA (r = 0.449, P < 0.01 and r = 0.576, P < 0.01) or by ADP (r = 0.525, P < 0.01; r = 0.501, P < 0.01). Positive correlation also showed between plasma level of P-selectin and TXB2 (r = 0.610, P < 0.01). There was no significant difference of all the three indexes between the two groups (P > 0.05). Re-examination showed that levels of the 3 indexes significantly decreased in both groups (P < 0.01), and all were lower in the NXT group than in the aspirin group respectively (P < 0.05). There was no significant difference in the incidence of adverse reaction between two groups (P > 0.05). CONCLUSION: The anti-platelet effect of one-week administration of aspirin for patients with cardio-cerebrovascular diseases can not be optimal, the combination with NXT could enhance the effect without increase of adverse reaction.