Exogenous NADPH exerts a positive inotropic effect and enhances energy metabolism via SIRT3 in pathological cardiac hypertrophy and heart failure.

BACKGROUND: Therapies are urgently required to ameliorate pathological cardiac hypertrophy and enhance cardiac function in heart failure. Our preliminary experiments have demonstrated that exogenous NADPH exhibits a positive inotropic effect on isolated heart. This study aims to investigate the positive inotropic effects of NADPH in pathological cardiac hypertrophy and heart failure, as well as the underlying mechanisms involved. METHODS: Endogenous plasma NADPH contents were determined in patients with chronic heart failure and control adults. The positive inotropic effects of NADPH were investigated in isolated toad heart or rat heart. The effects of NADPH were investigated in isoproterenol (ISO)-induced cardiac hypertrophy or transverse aortic constriction (TAC)-induced heart failure. The underlying mechanisms of NADPH were studied using SIRT3 knockout mice, echocardiography, Western blotting, transmission electron microscopy, and immunoprecipitation. FINDINGS: The endogenous NADPH content in the blood of patients and animals with pathological cardiac hypertrophy or heart failure was significantly reduced compared with age-sex matched control subjects. Exogenous NADPH showed positive inotropic effects on the isolated normal and failing hearts, while antagonism of ATP receptor partially abolished the positive inotropic effect of NADPH. Exogenous NADPH administration significantly reduced heart weight indices, and improved cardiac function in the mice with pathological cardiac hypertrophy or heart failure. NADPH increased SIRT3 expression and activity, deacetylated target proteins, improved mitochondrial function and facilitated ATP production in the hypertrophic myocardium. Importantly, inhibition of SIRT3 abolished the positive inotropic effect of NADPH, and the anti-heart failure effect of NADPH was significantly reduced in the SIRT3 Knockout mice. INTERPRETATION: Exogenous NADPH shows positive inotropic effect and improves energy metabolism via SIRT3 in pathological cardiac hypertrophy and heart failure. NADPH thus may be one of the potential candidates for the treatment of pathological cardiac hypertrophy or heart failure. FUNDING: This work was supported by grants from the National Natural Science Foundation of China (No. 81973315, 82173811, 81730092), Natural Science Foundation of Jiangsu Higher Education (20KJA310008), Jiangsu Key Laboratory of Neuropsychiatric Diseases (BM2013003) and the Priority Academic Program Development of the Jiangsu Higher Education Institutes (PAPD).

Inhibitory effects of Qushuanling Capsule () on thrombus formation and platelet aggregation in rats.

OBJECTIVE: To investigate the effects of Qushuanling Capsule ( QSLC) on thrombus formation and platelet aggregation in rats. METHODS: Arteriovenous bypass, venous thrombosis, and middle cerebral artery thrombosis models were used in rats to investigate the anti-thrombotic effects of QSLC, a compound of nine Chinese herbs. The platelet aggregation induced by adenosine diphosphate (ADP), thrombin or arachidonic acid (AA), as well as the contents of thromboxane B(2) (TXB(2)) and 6-keto-prostaglandin F1α (6-keto-PGF1α) in rat plasma and aortic walls, were determined to investigate the possible mechanisms of the anti-thrombotic effects of QSLC. RESULTS: After oral administration with QSLC for 7 days, arteriovenous bypass thrombosis was obviously suppressed compared with the model group, venous thrombosis was also obviously suppressed, rat behaviors were obviously improved, and brain infarct size as well as water content were also reduced. The platelet aggregation induced by ADP or thrombin was inhibited by QSLC, but the drug had no effect on AA-induced platelet aggregation and content of TXB(2) and 6-keto-PGF1α in plasma and the aortic wall. CONCLUSION: These results suggest that QSLC can be used in the prevention and treatment of thrombotic diseases, and that its mechanism of action may be related to inhibition of platelet aggregation.

Therapeutic potential of Naja naja atra venom in a rat model of diabetic nephropathy.

OBJECTIVE: To study the protective effects of naja naja atra venom (NNAV) in a rat model of diabetic nephropathy (DN). METHODS: The rat diabetes model was induced by intraperitoneal injection of streptozotocin (STZ). Thirty-two model rats were randomly divided into one DN group (n=8) and three treatment groups (n=8 each) that received NNAV at doses of 30, 90, or 270 µg/(kg·day) via oral gavage, another eight rats as normal controls. After 12 weeks, all rats were sacrificed and the changes in serum and urine biological index levels were determined by colorimetric assay. Microalbumin (mALB), N-acetyl-ß- glucosaminidase (NAG) and cystatin C (CysC) concentrations were measured by ELISA. Renal tissues were sliced for pathological and immunohistochemical observations. RESULTS: Comparied with the DN group, serum glucose was decreased by 31.04%, total cholesterol 21.96%, triglyceride 23.78%, serum creatinine 19.83%, blood urea nitrogen 31.28%, urinary protein excretion 45.42%, mALB 10.42%, NAG 20.65%, CysC 19.57%, whereas albumin increased by 5.55%, high-density lipoprotein-cholesterol 59.09%, creatinine clearance 19.05% in the treatment group by NNAV administration at dose of 90 µg/(kg·day). NNAV also reduced the levels of malondialdehyde in serum (22.56%) and kidney tissue (9.79%), and increased superoxide dismutase concentration in serum (15%) and decreased it in renal tissue (8.85%). In addition, under light microscopy kidney structure was improved and glomerular hypertrophy decreased by 8.29%. As shown by immunohistochemistry, NNAV inhibited transforming growth factor-ß1 by 6.70% and nuclear actor-κB by 5.15%. CONCLUSION: NNAV improves biological indexes in DN, and it may exert renoprotective effects in rats with STZ-induced diabetes.

Therapeutic effect of osthole on hyperlipidemic fatty liver in rats.

AIM: To study the effects of osthole on hyperlipidemic fatty liver and investigate the possible mechanisms. METHODS: A rat model with hyperlipidemic fatty liver was successfully established by feeding fatty milk for 6 weeks. The experimental rats were then treated with 5-20 mg/kg osthole for 6 weeks. The mouse hyperlipidemic model was induced by feeding fatty milk when they were treated with 10-20 mg/kg osthole for 3 weeks. RESULTS: After treatment with osthole, the levels of rat serum total cholesterol (TC), triglyceride (TG) and low density lipoprotein-cholesterol significantly decreased as compared with the fatty liver model group (P< 0.05 or P< 0.01). Hepatic weight and its coefficient, the hepatic tissue contents of TC, TG, and malondialdehyde, also significantly decreased (P< 0.05 or P< 0.01). In fatty milk-induced hyperlipidemic mice, the post-heparin plasma activities of lipoprotein lipase (LPL), hepatic lipase (HL), and total lipase (TL) significantly increased after treatment with 10-20 mg/kg osthole for 3 weeks (P< 0.05 or P< 0.01). Importantly, the histological evaluation of rat liver demonstrated that osthole dramatically decreased lipid accumulation (P< 0.01). CONCLUSION: Osthole was found to have therapeutic effects on fatty milk-induced rat fatty liver; the mechanisms might be associated with its anti-oxidation and the elevation of the activities of LPL and HL.

Experimental study of osthole on treatment of hyperlipidemic and alcoholic fatty liver in animals.

AIM: To evaluate the effects of osthole on fatty liver, and investigate the possible mechanism. METHODS: A quail model with hyperlipidemic fatty liver and rat model with alcoholic fatty liver were set up by feeding high fat diet and alcohol, respectively. These experimental animals were then treated with osthole 5-20 mg/kg for 6 wk, respectively. Whereafter, the lipid in serum and hepatic tissue, and coefficient of hepatic weight were measured. RESULTS: After treatment with osthole the levels of serum total cholesterol (TC), triglyceride (TG), lower density lipoprotein-cholesterol (LDL-C), coefficient of hepatic weight, and the hepatic tissue contents of TC and TG were significantly decreased. The activity of superoxide dismutase (SOD) in liver was improved. In alcohol-induced fatty liver rats, the level of malondialdehyde (MDA) in liver was decreased. In high fat-induced fatty liver quails, glutathione peroxidase (GSH-PX) in liver was significantly improved. The histological evaluation of liver specimens demonstrated that the osthole dramatically decreased lipid accumulation. CONCLUSION: These results suggested that osthole had therapeutic effects on both alcohol and high fat-induced fatty liver. The mechanism might be associated with its antioxidation.