We aimed to investigate the effect of bromelain, the extract from stems of pineapples on the high-fat diet (HFD)-induced deregulation of hepatic lipid metabolism and non-alcoholic fatty liver disease (NAFLD), and its underlying mechanism in mice. Mice were daily administrated with HFD with or without bromelain (20 mg/kg) for 12 weeks, and we found that bromelain decreased the HFD-induced increase in body weight by ~30%, organ weight by ~20% in liver weight and ~40% in white adipose tissue weight. Additionally, bromelain attenuated HFD-induced hyperlipidemia by decreasing the serum level of total cholesterol by ~15% and triglycerides level by ~25% in mice. Moreover, hepatic lipid accumulation, particularly that of total cholesterol, free cholesterol, triglycerides, fatty acids, and glycerol, was decreased by 15–30% with bromelain treatment. Mechanistically, these beneficial effects of bromelain on HFD-induced hyperlipidemia and hepatic lipid accumulation may be attributed to the decreased fatty acid uptake and cholesteryl ester synthesis and the increased lipoprotein internalization, bile acid metabolism, cholesterol clearance, the assembly and secretion of very low-density lipoprotein, and the β-oxidation of fatty acids by regulating the protein expression involved in the above mentioned hepatic metabolic pathways. Collectively, these findings suggest that bromelain has therapeutic value for treating NAFLD and metabolic diseases.

Bromelain, an enzyme extracted from the stems of pineapples, exerts anticoagulant effects; however, the regulatory mechanisms are not fully understood. Here, we aimed to investigate the effects of bromelain on non-alcoholic fatty liver disease (NAFLD)-induced deregulation of blood coagulation and the underlying molecular mechanisms. C57BL/6 mice were fed a high-fat diet (HFD), with or without bromelain (20 mg/kg/day) administration, for 12 weeks. Treatment with bromelain decreased thrombus formation in the liver and prolonged HFD-induced shortened prothrombin, activated partial thromboplastin, and fibrinogen times. Moreover, liquid chromatography-mass spectrometry/mass spectrometry and Western blot analysis showed that bromelain inhibited NAFLD-induced activation of the intrinsic, extrinsic, and common pathways by upregulating the protein expression of antithrombin III, serpin family G member 1, and α1-antitrypsin, and downregulating the protein expression of fibrinogen in the liver and plasma. Bromelain also upregulated the level of plasminogen and downregulating factor XIII expression in the liver and plasma. Collectively, these findings suggest that bromelain exerts anticoagulant effects on NAFLD-induced deregulation of coagulation by inhibiting the activation of the coagulation cascade, decreasing the stability of clots, and promoting fibrinolytic activity. The present study provides new insights into the potential therapeutic value of bromelain for the prevention and treatment of thrombosis-related diseases.

Torenia concolor Lindley var. formosama Yamazaki ethanolic extract (TCEE) is reported to have anti-inflammatory and anti-obesity properties. However, the effects of TCEE and its underlying mechanisms in the activation of endothelial nitric oxide synthase (eNOS) have not yet been investigated. Increasing the endothelium-derived nitric oxide (NO) production has been known to be beneficial against the development of cardiovascular diseases. In this study, we investigated the effect of TCEE on eNOS activation and NO-related endothelial function and inflammation by using an in vitro system. In endothelial cells (ECs), TCEE increased NO production in a concentration-dependent manner without affecting the expression of eNOS. In addition, TCEE increased the phosphorylation of eNOS at serine 635 residue (Ser635) and Ser1179, Akt at Ser473, calmodulin kinase II (CaMKII) at threonine residue 286 (Thr286), and AMP-activated protein kinase (AMPK) at Thr172. Moreover, TCEE-induced NO production, and EC proliferation, migration, and tube formation were diminished by pretreatment with LY294002 (an Akt inhibitor), KN62 (a CaMKII inhibitor), and compound C (an AMPK inhibitor). Additionally, TCEE attenuated the tumor necrosis factor-α-induced inflammatory response as evidenced by the expression of adhesion molecules in ECs and monocyte adhesion onto ECs. These inflammatory effects of TCEE were abolished by L-NG-nitroarginine methyl ester (an NOS inhibitor). Moreover, chronic treatment with TCEE attenuated hyperlipidemia, systemic and aortic inflammatory response, and the atherosclerotic lesions in apolipoprotein E-deficient mice. Collectively, our findings suggest that TCEE may confer protection from atherosclerosis by preventing endothelial dysfunction.

Dialysis prevents death from uremia in patients with end-stage renal disease (ESRD). Nevertheless, during hemodialysis, circulating levels of di-(2-ethylhexyl) phthalate (DEHP) are increased due to phthalates leaching from medical tubes. Statins are an effective therapy for reducing the risks associated with cardiovascular diseases in patients with chronic kidney disease; however, the mechanism by which statins fail to reduce cardiovascular events in hemodialysis ESRD patients remains unclear. In this study, we investigated whether DEHP and its metabolites interfere with the lipid-lowering effect of statins in hepatocytes. In Huh7 cells, treatment with DEHP and its metabolites abolished the simvastatin-conferred lipid-lowering effect. Mechanistically, DEHP down-regulated the expression of low-density lipoprotein receptor (LDLR) and led to a decrease in LDL binding, which was mediated by the activation of the PPARγ-PCSK9 and LXRα-IDOL signaling pathways. Additionally, the NOX-ROS-TRPA1 pathway is involved in the DEHP-mediated inhibition of LDLR expression and LDL binding activity. Blockage of this pathway abrogated the DEHP-mediated inhibition in the LDLR expression and LDL binding of simvastatin. Collectively, DEHP induces the activation of the NOX-ROS-TRPA1 pathway, which in turn activates PPARγ-PCSK9- and LXRα-IDOL-dependent signaling, and, ultimately, diminishes the statin-mediated lipid-lowering effect in hepatocytes.

HLJ1 (also called DNAJB4) is a member of the DNAJ/Hsp40 family and plays an important role in regulating protein folding and activity. However, there is little information about the role of HLJ1 in the regulation of physiological function. In this study, we investigated the role of HLJ1 in blood coagulation using wild-type C57BL/6 mice and HLJ1-null (HLJ1^-/-) mice. Western blot analysis and immunohistochemistry were used to assess the expression and distribution of HLJ1 protein, respectively. The tail bleeding assay was applied to assess the bleeding time and blood loss. A coagulation test was used for measuring the activity of extrinsic, intrinsic and common coagulation pathways. Thromboelastography was used to measure the coagulation parameters in the progression of blood clot formation. The results showed that HLJ1 was detectable in plasma and bone marrow. The distribution of HLJ1 was co-localized with CD41, the marker of platelets and megakaryocytes. However, genetic deletion of HLJ1 did not alter blood loss and the activity of extrinsic and intrinsic coagulation pathways, as well as blood clot formation, compared to wild-type mice. Collectively, these findings suggest that, although HLJ1 appears in megakaryocytes and platelets, it may not play a role in the function of blood coagulation under normal physiological conditions.