Endothelin-1 (ET-1) has been implicated in the pathogenesis of cardiac fibrosis. Stimulation of endothelin receptors (ETR) with ET-1 leads to fibroblast activation and myofibroblast differentiation, which is mainly characterized by an overexpression of α-smooth muscle actin (α-SMA) and collagens. Although ET-1 is a potent profibrotic mediator, the signal transductions and subtype specificity of ETR contributing to cell proliferation, as well as α-SMA and collagen I synthesis in human cardiac fibroblasts are not well clarified. This study aimed to evaluate the subtype specificity and signal transduction of ETR on fibroblast activation and myofibroblast differentiation. Treatment with ET-1 induced fibroblast proliferation, and synthesis of myofibroblast markers, α-SMA, and collagen I through the ET_AR subtype. Inhibition of G_αq protein, not G_αi or G_βγ, inhibited these effects of ET-1, indicating the essential role of G_αq protein-mediated ET_AR signaling. In addition, ERK1/2 was required for ET_AR/G_αq axis-induced proliferative capacity and overexpression of these myofibroblast markers. Antagonism of ETR with ETR antagonists (ERAs), ambrisentan and bosentan, inhibited ET-1-induced cell proliferation and synthesis of α-SMA and collagen I. Furthermore, ambrisentan and bosentan promoted the reversal of myofibroblasts after day 3 of treatment, with loss of proliferative ability and a reduction in α-SMA synthesis, confirming the restorative effects of ERAs. This novel work reports on the ET_AR/G_αq/ERK signaling pathway for ET-1 actions and blockade of ETR signaling with ERAs, representing a promising therapeutic strategy for prevention and restoration of ET-1-induced cardiac fibrosis.

Infrapatellar fat pad (IFP)/ synovial fibrosis is closely associated with the clinical symptoms of joint pain and stiffness, which contribute to locomotor restriction in osteoarthritis (OA) patients. Hence, this study was designed to gain insight on whether losartan, a selective angiotensin II type 1 receptor (AT1R) antagonist, has therapeutic benefit to reverse IFP/synovial fibrosis and secondarily to attenuate pain behavior. In male Wistar rats with monoiodoacetic acid (MIA)-induced IFP/synovial fibrosis, a possible role for increased AT1R expression in the pathogenesis of IFP/synovial fibrosis was assessed over an 8-week period. Pain behavior comprised static weight bearing and von Frey paw withdrawal thresholds (PWTs), which were assessed once or twice weekly, respectively. Groups of MIA-rats received oral losartan (30-mg/kg; n = 8 or 100-mg/kg; n = 9) or vehicle (n = 9) for 28-days according to a prevention protocol. Animals were euthanized on day 28 and various tissues (IFP/synovium, cartilage and lumbar dorsal root ganglia (DRGs)) were collected for histological, immunohistochemical and western blot analyses. Administration of once-daily losartan for 28-days dose-dependently attenuated the development of static weight bearing. This was accompanied by reduced IFP/synovial fibrosis and suppression of TGF-β1 expression. Chronic treatment of MIA-rats with losartan had an anti-fibrotic effect and it attenuated pain behavior in this animal model.

Introduction: Non-alcoholic fatty liver disease (NAFLD) is one of the metabolic disorders related to the pathophysiology of type 2 diabetes mellitus (T2DM). Therapeutic strategies are focused on the improvement of energy balance and lifestyle modification. Additionally, the derivative of the bioactive fungal metabolite is of interest to provide health benefits, especially in obese and pre-diabetic conditions. In our screening of anti-diabetic compounds from fungal metabolites and semisynthetic derivatives, a depsidone derivative, namely pyridylnidulin (PN), showed potent glucose uptake-inducing activity. The present study aimed to investigate the liver lipid metabolism and anti-diabetic properties of PN in diet-induced obesity mice.Methods: Male C57BL/6 mice were induced obesity and pre-diabetic conditions by dietary intervention with a high-fat diet (HFD) for 6 weeks. These obese mice were orally administered with PN (40 or 120 mg/kg), metformin (150 mg/kg), or vehicle for 4 weeks. Glucose tolerance, plasma adipocytokines, hepatic gene and protein expressions were assessed after treatment.Results: Improved glucose tolerance and reduced fasting blood glucose levels were found in the PN and metformin-treated mice. Additionally, hepatic triglyceride levels were consistent with the histopathological steatosis score regarding hepatocellular hypertrophy in the PN and metformin groups. The levels of plasma adipocytokines such as tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) were reduced in the PN (120 mg/kg) and metformin-treated mice. In addition, hepatic gene expression involved in lipid metabolism, including lipogenic enzymes was significantly reduced in the PN (120 mg/kg) and metformin-treated mice. The increased protein expression levels of phosphorylated AMP-activated protein kinase (p-AMPK) was also found in PN and metformin-treated mice.Discussion: Considering the increased p-AMPK protein expression levels in PN and metformin-treated mice were revealed as the underlying mechanisms to improve metabolic parameters. These results suggested that PN provided the health benefit to slow the progression of NAFLD and T2DM in obese and pre-diabetic conditions.

Type 2 diabetes mellitus (T2DM) is a global health issue associated with oxidative stress, inflammation, and insulin resistance. Even though α-glucosidase inhibitors such as acarbose are used in treatment, their efficacy is limited by gastrointestinal side effects. In this study, we evaluated the antioxidant properties and α-glucosidase inhibition of C-12 dithiocarbamate andrographolide analogues compared to the parent compound, andrographolide. Among all analogues, compound 3f exhibited strong antioxidant activity, achieving 84% DPPH inhibition and a reducing antioxidant power activity of 254 μM ascorbic acid equivalent (AAE) at 500 μM. Additionally, molecular docking suggested a favorable binding to both yeast and human α-glucosidase at a comparable level as andrographolide, verified by the surface plasmon resonance (SPR) detection system, indicating a strong binding affinity with a dissociation constant ( K _D ) of 12.86 μM. It also retains favorable physicochemical properties that align with drug-likeness based on Lipinski’s Rule. Functional assay confirmed its inhibitory activity with an IC ₅₀ of 411 μM against the yeast α-glucosidase enzyme model, which was greater than both andrographolide and acarbose. Further molecular dynamics (MD) simulation analysis revealed that compound 3f exhibited stable and thermodynamically favorable binding to human α-glucosidase as well as interacting with key amino acids similar to those of andrographolide, providing a preliminary understanding of its potential relevance in a human enzyme context. Altogether, these findings highlight the significant potential of compound 3f as a novel α-glucosidase inhibitor, offering a potential therapeutic alternative and paving the way for further anti-diabetic drug development.

Obesity has been linked to metabolic syndrome, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). Obesity causes a decrease in growth hormone (GH) levels and an increase in insulin levels. Long-term GH treatment increased lipolytic activity as opposed to decreasing insulin sensitivity. Nonetheless, it is possible that short-term GH administration had no impact on insulin sensitivity. In this study, the effect of short-term GH administration on liver lipid metabolism and the effector molecules of GH and insulin receptors were investigated in diet-induced obesity (DIO) rats. Recombinant human GH (1 mg/kg) was then administered for 3 days. Livers were collected to determine the hepatic mRNA expression and protein levels involved in lipid metabolism. The expression of GH and insulin receptor effector proteins was investigated. In DIO rats, short-term GH administration significantly reduced hepatic fatty acid synthase (FASN) and cluster of differentiation 36 (CD36) mRNA expression while increasing carnitine palmitoyltransferase 1A (CPT1A) mRNA expression. Short-term GH administration reduced hepatic FAS protein levels and downregulated gene transcription of hepatic fatty acid uptake and lipogenesis, while increasing fatty acid oxidation in DIO rats. DIO rats had lower hepatic JAK2 protein levels but higher IRS-1 levels than control rats due to hyperinsulinemia. Our findings suggest that short-term GH supplementation improves liver lipid metabolism and may slow the progression of NAFLD, where GH acts as the transcriptional regulator of related genes.

Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer, with a high incidence of metastasis and chemoresistance. Epithelial-mesenchymal transition (EMT) is one of the molecular mechanisms that has been linked to the promotion of metastasis, and it can be promoted by several activators including the NF-κB signaling pathway. As a result, targeting EMT may be a potential strategy for treating TNBC. Pinostrobin is one of the important flavonoids found in the rhizome and rootlet of Boesenbergia rotunda (L.) Mansf. (fingerroot) that exhibits anticancer activities. However, the precise mechanism underlying the anticancer effect of pinostrobin on breast cancer remains unclear, and additional evidence is needed. In this study, the MCF-7 and MDA-MB-231 breast cancer cells were treated with various concentrations of pinostrobin. To determine the effect of pinostrobin on cell viability, an MTT assay was performed. Wound healing and Transwell chamber assays were conducted to examine the effect of pinostrobin on migration ability. RT-PCR was used to detect the expression of mRNA involved in NF-κB and EMT signaling pathways. The results revealed that low concentrations of pinostrobin did not affect cell viability, while higher concentrations produced an inhibitory effect on the viability of both cell lines. Pinostrobin also impeded migration and suppressed the expression of N-cadherin, a mesenchymal marker. Molecular docking analysis also suggested that the pinostrobin may target N-cadherin with higher binding affinity than IKK complex and NF-κB p65. These findings indicate that pinostrobin may serve as a potential treatment for TNBC.