Humulus japonicus Extract Ameliorates Hepatic Steatosis Through the PPARα-Mediated Suppression of Alcohol-Induced Oxidative Stress

Humulus japonicus has been used to treat obesity, hypertension, and nonalcoholic fatty liver and to alleviate inflammation and oxidative stress. In the present study, we aimed to investigate the effects of H. japonicus ethanol extracts (HE) and luteolin 7-O-β-d-glucoside (LU), which is identified as a major active component of H. japonicus, on ethanol-induced oxidative stress and lipid accumulation in primary hepatocytes. Mouse primary hepatocytes were treated with HE and stimulated with ethanol. The MTT test was used to determine cell viability. By using Western blotting, the effects of HE on the expression of different proteins were investigated. Experimental mice were given a 5% alcohol liquid Lieber-DeCarli diet to induce alcoholic fatty liver. We found that both HE and LU individually attenuated ethanol-induced lipid accumulation, lipogenic protein expression, and cellular oxidative stress in hepatocytes. Treatment with HE or LU increased PPARα and SOD1 expression and catalase activity in a dose-dependent manner. Small interfering RNA of PPARα reduced the effects of HE on oxidative stress, lipid metabolism, and levels of antioxidants. We also observed that orally administered HE treatment alleviated hepatic steatosis in a diet containing ethanol-fed mice. This study suggests HE as a functional food that can improve hepatic steatosis, thereby preventing hepatic injury caused by alcohol consumption.

The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications

Ischaemia–reperfusion (I–R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I–R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.

Discovery of 4-benzyloxy and 4-(2-phenylethoxy) chalcone fibrate hybrids as novel PPARα agonists with anti-hyperlipidemic and antioxidant activities: Design, synthesis and in vitro/in vivo biological evaluation

In the current work, a series of novel 4-benzyloxy and 4-(2-phenylethoxy) chalcone fibrate hybrids (10a-o) and (11a-e) were synthesized and evaluated as new PPARα agonists in order to find new agents with higher activity and fewer side effects. The 2-propanoic acid derivative 10a and the 2-butanoic acid congener 10i showed the best overall PPARα agonistic activity showing E_max% values of 50.80 and 90.55%, respectively, and EC₅₀ values of 8.9 and 25.0 μM, respectively, compared to fenofibric acid with E_max = 100% and EC₅₀ = 23.22 μM, respectively. These two compounds also stimulated carnitine palmitoyltransferase 1A gene transcription in HepG2 cells and PPARα protein expression. Molecular docking simulations were performed for the newly synthesized compounds to study their predicted binding pattern and energies in PPARα active site to rationalize their promising activity. In vivo, compounds 10a and 10i elicited a significant hypolipidemic activity improving the lipid profile in triton WR-1339-induced hyperlipidemic rats, including serum triglycerides, total cholesterol, LDL, HDL and VLDL levels. Compound 10i possessed better anti-hyperlipidemic activity than 10a. At a dose of 200 mg/kg, it demonstrated significantly lower TC, TG, LDL and VLDL levels than that of fenofibrate at the same dose with similar HDL levels. Compounds 10i and 10a possessed atherogenic indices (CRR, AC, AI, CRI-II) like that of fenofibrate. Additionally, a promising antioxidant activity indicated by the increased tissue reduced glutathione and plasma total antioxidant capacity with decreased plasma malondialdehyde levels was demonstrated by compounds 10a and 10i. No histopathological alterations were recorded in the hepatic tissue of compound 10i (200 mg/kg).

Fenofibrate Ameliorates Hepatic Ischemia/Reperfusion Injury in Mice: Involvements of Apoptosis, Autophagy, and PPAR-α Activation

Hepatic ischemia and reperfusion injury is characterized by hepatocyte apoptosis, impaired autophagy, and oxidative stress. Fenofibrate, a commonly used antilipidemic drug, has been verified to exert hepatic protective effects in other cells and animal models. The purpose of this study was to identify the function of fenofibrate on mouse hepatic IR injury and discuss the possible mechanisms. A segmental (70%) hepatic warm ischemia model was established in Balb/c mice. Serum and liver tissue samples were collected for detecting pathological changes at 2, 8, and 24 h after reperfusion, while fenofibrate (50 mg/kg, 100 mg/kg) was injected intraperitoneally 1 hour prior to surgery. Compared to the IR group, pretreatment of FF could reduce the inflammatory response and inhibit apoptosis and autophagy. Furthermore, fenofibrate can activate PPAR-α, which is associated with the phosphorylation of AMPK.

Fenofibrate Protects Cardiomyocytes from Hypoxia/Reperfusion- and High Glucose-Induced Detrimental Effects

Lesions caused by high glucose (HG), hypoxia/reperfusion (H/R), and the coexistence of both conditions in cardiomyocytes are linked to an overproduction of reactive oxygen species (ROS), causing irreversible damage to macromolecules in the cardiomyocyte as well as its ultrastructure. Fenofibrate, a peroxisome proliferator-activated receptor alpha (PPARα) agonist, promotes beneficial activities counteracting cardiac injury. Therefore, the objective of this work was to determine the potential protective effect of fenofibrate in cardiomyocytes exposed to HG, H/R, and HG+H/R. Cardiomyocyte cultures were divided into four main groups: (1) control (CT), (2) HG (25 mM), (3) H/R, and (4) HG+H/R. Our results indicate that cell viability decreases in cardiomyocytes undergoing HG, H/R, and both conditions, while fenofibrate improves cell viability in every case. Fenofibrate also decreases ROS production as well as nicotinamide adenine dinucleotide phosphate oxidase (NADPH) subunit expression. Regarding the antioxidant defense, superoxide dismutase (SOD Cu²⁺/Zn²⁺ and SOD Mn²⁺), catalase, and the antioxidant capacity were decreased in HG, H/R, and HG+H/R-exposed cardiomyocytes, while fenofibrate increased those parameters. The expression of nuclear factor erythroid 2-related factor 2 (Nrf2) increased significantly in treated cells, while pathologies increased the expression of its inhibitor Keap1. Oxidative stress-induced mitochondrial damage was lower in fenofibrate-exposed cardiomyocytes. Endothelial nitric oxide synthase was also favored in cardiomyocytes treated with fenofibrate. Our results suggest that fenofibrate preserves the antioxidant status and the ultrastructure in cardiomyocytes undergoing HG, H/R, and HG+H/R preventing damage to essential macromolecules involved in the proper functioning of the cardiomyocyte.

The protective effect of fenofibrate, triptorelin, and their combination against premature ovarian failure in rats

Cyclophosphamide (CP) is a chemotherapy alkylating agent that causes a lot of side effects including premature ovarian failure (POF). This study aimed to evaluate the possible protective effect of fenofibrate (FEN) in CP-induced POF. Rats were randomly divided into five groups as follows: negative control, CP, triptorelin (TRI)-treated, FEN (FEN)-treated, and FEN + TRI-treated. Histological study, collagen area fraction, and immunoexpression of proliferating cell nuclear antigen (PCNA) were evaluated. Also, estrogen, anti-mullerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and ovarian malondialdehyde (MDA), nitric oxide (NOx), reduced glutathione (GSH), superoxide dismutase (SOD), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and vascular endothelial growth factor (VEGF) were measured. CP significantly reduced ovarian follicle count, as compared with the control group (1.00 ± 0.76 versus 7.75 ± 1.83, respectively). Meanwhile, FEN, either solely or in combination with TRI, significantly increased ovarian follicle count, as compared with the CP group (3.88 ± 0.83 and 5.75 ± 1.39, respectively). As compared with the control group, CP increased the levels of MDA, NOx, IL-10, TNF-α, FSH, LH, and collagen area fraction; however, levels of GSH, SOD, VEGF, AMH, estrogen, and PCNA immunoexpression were reduced with CP. Administration of FEN either solely or in combination with TRI showed significant improvement in all the parameters previously mentioned. FEN can protect the ovary from CP-induced side effects possibly through antioxidant and anti-inflammatory actions.

Bisoprolol, a β1 antagonist, protects myocardial cells from ischemia-reperfusion injury via PI3K/AKT/GSK3β pathway

The aim of this work was to explore whether bisoprolol plays a protective role in cardiomyocytes against ischemia-reperfusion injury via PI3K/AKT/ GSK3β pathway. We pretreated male Sprague Dawley (SD) rats with bisoprolol by oral administration prior to 0.5 h ischemia/4 h reperfusion. Myocardial infarct size and serum levels of cTnI and CK-MB were measured. In vitro, H9c2 cells were treated with hypoxia and reoxygenation, followed by measurement of cell viability, apoptosis, ROS production, cytometry, activities of AKT, GSK3β, and p-38 in the presence and absence of GSK3β siRNA. We found that bisoprolol reduced infarct size from 44% in I/R group to 31% in treated group (P < 0.05). The levels of cTnI and CK-MB were decreased from 286 ± 7 pg/mL and 32.2 ± 2 ng/mL in I/R group to 196 ± 2 pg/mL and 19.6 ± 0.9 ng/mL in the treated group, respectively (P < 0.05). Bisoprolol also increased cell viability while decreased apoptosis and ROS production in the treatment of hypoxia/ reoxygenation. Furthermore, bisoprolol increased AKT and GSK3β phosphorylation, an effect that was immediately eliminated by LY294002. GSK3β-specific siRNA experiment further confirmed that bisoprolol protected the myocardium against hypoxia/reoxygenation-induced injury via suppressing GSK3β activity. In conclusion, bisoprolol protected myocardium against ischemia-reperfusion injury via the PI3K/AKT/ GSK3β pathway.

ArrhythmoGenoPharmacoTherapy

This review is focusing on the understanding of various factors and components governing and controlling the occurrence of ventricular arrhythmias including (i) the role of various ion channel-related changes in the action potential (AP), (ii) electrocardiograms (ECGs), (iii) some important arrhythmogenic mediators of reperfusion, and pharmacological approaches to their attenuation. The transmembrane potential in myocardial cells is depending on the cellular concentrations of several ions including sodium, calcium, and potassium on both sides of the cell membrane and active or inactive stages of ion channels. The movements of Na+, K+, and Ca2+ via cell membranes produce various currents that provoke AP, determining the cardiac cycle and heart function. A specific channel has its own type of gate, and it is opening and closing under specific transmembrane voltage, ionic, or metabolic conditions. APs of sinoatrial (SA) node, atrioventricular (AV) node, and Purkinje cells determine the pacemaker activity (depolarization phase 4) of the heart, leading to the surface manifestation, registration, and evaluation of ECG waves in both animal models and humans. AP and ECG changes are key factors in arrhythmogenesis, and the analysis of these changes serve for the clarification of the mechanisms of antiarrhythmic drugs. The classification of antiarrhythmic drugs may be based on their electrophysiological properties emphasizing the connection between basic electrophysiological activities and antiarrhythmic properties. The review also summarizes some important mechanisms of ventricular arrhythmias in the ischemic/reperfused myocardium and permits an assessment of antiarrhythmic potential of drugs used for pharmacotherapy under experimental and clinical conditions.

Cardioprotective Effect of Olive Oil Against Ischemia Reperfusion-induced Cardiac Arrhythmia in Isolated Diabetic Rat Heart

Background

Olive oil is rich in monounsaturated fatty acids and has been reported for a variety of beneficial cardiovascular effects, including blood pressure lowering, anti-platelet, anti-diabetic, and anti-inflammatory effects. Diabetes is a major risk factor for cardiac dysfunctions, and olive oil prevents diabetes-induced adverse myocardial remodeling.

Objective

The study aimed to evaluate the effects of olive oil against streptozotocin-induced cardiac dysfunction in animal models of diabetes and ischemia and reperfusion (I/R)-induced cardiac arrhythmias.

Methods

Diabetes was induced in male rats with a single intraperitoneal injection of streptozotocin (60 mg/kg i.p), rats were treated for five, 15, or 56 days with olive oil (1 ml/kg p.o). Control animals received saline. Blood glucose and body weight were monitored every two weeks. At the end of the treatment, rats were sacrificed and hearts were isolated for mounting on Langedorff’s apparatus. The effect of olive oil on oxidative stress and histopathological changes in the cardiac tissues were studied.

Results

The initial blood glucose and body weight were not significantly different in the control and olive-treated animals. Streptozotocin (60 mg/kg i.p) caused a significant increase in the blood glucose of animals as compared to saline-treated animals. The control, saline-treated diabetic animals exhibited a 100% incidence of I/R-induced ventricular fibrillation, which was reduced to 0% with olive oil treatment. The protective effects of olive oil were evident after 15 and 56 days of treatment. Diltiazem, a calcium channel blocker (1 µm/L) showed similar results and protected the I/R-induced cardiac disorders. The cardiac tissues isolated from diabetic rats exhibited marked pathological changes in the cardiomyocytes, including decreased glutathione (GSH) and increased oxidative stress (malondialdehyde; MDA). Pretreatment of animals with olive oil (1 ml/kg p.o) increased GSH and decreased MDA levels. Olive oil also improved the diabetic-induced histopathological changes in the cardiomyocytes.

Conclusion

Olive oil possesses cardiac protective properties against I/R-induced cardiac arrhythmias in rats. It attenuated oxidative stress and diabetes-induced histopathological changes in cardiac tissues. The observed cardiac protectiveness of olive oil in the present investigation may be related to its antioxidant potential.

Mechanisms underlying direct actions of hyperlipidemia on myocardium: an updated review

Hyperlipidemia is a common metabolic disorder and one of risk factors for cardiovascular disease. Clinical studies have shown that hyperlipidemia increases the risk of non-ischemic heart failure, while decreasing serum lipids can reverse heart dysfunction. Apart from indirectly affecting the function of the heart by promoting the development of atherosclerosis, hyperlipidemia also affects the systolic function and cardiac electrophysiological response of the heart directly, which may be related to gradual accumulation of cardiac lipids and consequent systemic oxidative stress, proinflammatory state and mitochondrial dysfunction. However, the mechanism underlying direct effects of hyperlipidemia on the heart are not fully understood. In this review, we provide an updated summary of recent experimental and clinical studies that focus on elucidating the mechanisms of the action of hyperlipidemia on cardiac function, the relationship between heart failure and serum lipids, and protective effects of lipid-lowering drugs on the heart. The exciting progress in this field supports the prospect of guiding early protection of the heart to benefit the patients with chronic hyperlipidemia and familial hyperlipidemia.

Peroxisome Proliferator-Activated Receptor α Agonist and Its Target Nanog Cooperate to Induce Pluripotency

The pharmaceutical compounds that modulate pluripotent stem cell (PSC) identity and function are increasingly adopted to generate qualified PSCs and their derivatives, which have promising potential in regenerative medicine, in pursuit of more accuracy and safety and less cost. Here, we demonstrate the peroxisome proliferator-activated receptor α (PPARα) agonist as a novel enhancer of pluripotency acquisition and induced pluripotent stem cell (iPSC) generation. We found that PPARα agonist, examined and selected Food and Drug Administration (FDA) -approved compound libraries, increase the expression of pluripotency-associated genes, such as Nanog, Nr5A2, Oct4, and Rex1, during the reprogramming process and facilitate iPSC generation by enhancing their reprogramming efficiency. A reprogramming-promoting effect of PPARα occurred via the upregulation of Nanog, which is essential for the induction and maintenance of pluripotency. Through bioinformatic analysis, we identified putative peroxisome proliferator responsive elements (PPREs) located within the promoter region of the Nanog gene. We also determined that PPARα can activate Nanog transcription by specific binding to putative PPREs. Taken together, our findings suggest that PPARα is an important regulator of PSC pluripotency and reprogramming, and PPARα agonists can be used to improve PSC technology and regenerative medicine.

Protective role of fenofibrate in sepsis-induced acute kidney injury in BALB/c mice

Acute kidney injury (AKI) is a severe complication of sepsis, which largely contributes to the associated high mortality rate. Fenofibrate, a peroxisome proliferator activated receptor α (PPARα) agonist, has received considerable attention because of its effects related to renal damage-related energy metabolism and inflammation. The present study investigated the effects of fenofibrate on sepsis-associated AKI in BALB/c mice subjected to caecal ligation and puncture (CLP). Eight-week-old male BALB/c mice were divided into four groups: control group, fenofibrate group, caecal ligation and puncture (CLP) group, and fenofibrate + CLP group. CLP was performed after mice were gavaged with fenofibrate for 2 weeks. After 48 hours, we measured the histopathological alterations of the kidney tissue and plasma levels of serum creatinine (CRE), neutrophil gelatinase-associated lipocalin (NGAL), reactive oxygen species (ROS), ATP, and ADP. We evaluated PPARα and P53 protein levels as well as interleukin (IL)-1β, IL-6, and tumour necrosis factor-α mRNA levels. Our results showed that administering fenofibrate significantly reduced kidney histological alterations caused by CLP. Fenofibrate inhibited the plasma levels of ROS, CRE, NGAL, and increased the ATP/ADP ratio. Fenofibrate significantly inhibited elevations in P53, IL-1β, IL-6, and tumour necrosis factor-α expression. The results suggest that fenofibrate administration effectively modulates energy metabolism and may be a novel approach to treat sepsis-induced renal damage.

Role of PPAR-α agonist fenofibrate in the treatment of induced benign prostatic hyperplasia with dysplastic changes in rats

Nearly all men who reach average life expectancy have prostate disease. The most common is benign prostatic hyperplasia (BPH). Peroxisome proliferator-activated receptor alpha (PPARα) had protective effect in different models, but still, there are no studies explain its role in BPH. So that we investigated the effect of fenofibrate (FEN) on induced BPH by testosterone propionate (TP) (3 mg/kg/day for 4 weeks) subcutaneous injection followed by FEN (300 mg/kg/day) was given orally for 4 weeks. We measured prostate weights changes, prostatic tissue superoxide dismutase (SOD), and malondialdehyde (MDA) levels. Prostate-specific antigen (PSA), dihydrotestosterone (DHT), and total antioxidant capacity (TAC) in serum were determined. The mRNA gene expressions of proliferating cell nuclear antigen (PCNA), PPARα, and glutathione peroxidase (GPx) in prostatic tissue were also measured by quantitative real-time polymerase chain reaction. In addition, the histopathological changes and activated caspase3 immunoexpression were evaluated. Our results showed that TP succeeded in induction of BPH, which was detected by significant increase in prostate weights, prostatic tissue MDA, serum levels of DHT, PSA, and mRNA gene expression of PCNA but significant decrease in PPARα and GPx gene expression. Moreover, TAC in serum and SOD level in prostate tissue decreased. The histopathological examination showed typical changes of BPH with dysplastic changes with marked decrease in activated caspase3 immunoexpression indicating marked suppression of the apoptotic process. FEN significantly improved all disturbed parameters of BPH model. Moreover, there are no dysplastic changes with co-administration of FEN to BPH induced group.