Protective effects of Phyllanthus emblica against myocardial ischemia-reperfusion injury: the role of PI3-kinase/glycogen synthase kinase 3β/β-catenin pathway

Study on the white frost formation mechanism during storage of Phyllanthus emblica Linn. fruit based on component analysis and spatial metabolomics

The Phyllanthus emblica Linn. fruit (PEF) is a well-known medicinal and food homologous item in tropical Southeast Asian. During the drying and storing processes, some PEF will grow white frost on its surface, which is typically taken as a sign of greater quality. However, the material basis and formation mechanism of white frost on PEF surfaces are currently unclear, and there is no sufficient evidence to support the correlation between white frost on PEF surfaces and their quality. In this paper, high-performance liquid chromatography (HPLC) was used to study the differences in active ingredient content of PEF medicinal materials with and without frost. The microstructure and elemental composition of white frost were studied using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The Fourier transform infrared spectroscopy (FT-IR) was used to analysis the main functional groups in white frost. The ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) combined with UNIFI database, EDS and FT-IR results, and reference materials were used to identify the chemical composition of white frost. The exocarp of PEF before and after drying and storage was analyzed by spatial metabolomics using desorption electrospray ionization (DESI) mass spectrometry imaging system to reveal the formation mechanism of white frost on the surface of PEF. The results found that the PEF with frost have higher levels of active ingredients than those without frost. EDS and FT-IR results show that white frost is mainly composed of C, O, K elements, and contains a large number of phenolic hydroxyl, carboxyl etc. UPLC-Q-TOF-MS/MS results found that the main components of white frost were organic acids, fatty acids, and tannins, including quality markers such as gallic acid and ellagic acid etc. Spatial metabolomics research found that the white frost formation mechanism mainly involved in the ascorbate and aldarate metabolism, cutin, suberin and wax biosynthesis, citrate cycle (TCA cycle) and biosynthesis of unsaturated fatty acid. This study reveals the material basis, formation mechanism, and relationship between the surface white frost of PEF and the quality of medicinal materials, providing valuable information for the quality evaluation of PEF.

Ischemia-reperfusion injury: molecular mechanisms and therapeutic targets

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-β, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.

lncRNA CCAT2 Protects Against Cardiomyocyte Injury After Myocardial Ischemia/Reperfusion by Regulating BMI1 Expression

Myocardial ischemia/reperfusion (I/R) decreases cardiac function and efficiency. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) have been linked to the cellular processes of myocardial I/R injury. The present investigation elucidated the function of lncRNA colon cancer-associated transcript 2 (CCAT2) in myocardial I/R injury and the related mechanisms.AC16 cardiomyocytes were exposed to hypoxia (16 hours) /reoxygenation (6 hours) (H/R) to mimic myocardial I/R models in vitro. CCAT2 and microRNA (miR) -539-3p expressions in AC16 cardiomyocytes were measured using real-time quantitative polymerase chain reaction. B-cell-specific Moloney murine leukemia virus insertion region 1 (BMI1) protein levels in AC16 cardiomyocytes were determined by western blotting. Cell viability, lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS) levels, mitochondrial membrane potential, and apoptosis were detected using Counting Kit-8, LDH Assay Kit, dihydroethidium assay, 5,5',6,6'-tetrachloro1,1',3,3'-tetramethylbenzimidazolylcarbocyanine iodide staining, flow cytometry, and western blotting, respectively. The interactions between the molecules were confirmed using the dual-luciferase gene reporter. The wingless/integrated/beta-catenin (Wnt/β-catenin) pathway under the H/R condition was detected by western blotting.CCAT2 and BMI1 mRNA expressions were reduced in H/R-exposed AC16 cardiomyocytes. CCAT2 overexpression exerted protective effects against H/R-induced cardiomyocyte injury, as demonstrated by increased cell viability and mitochondrial membrane potential and decreased LDH leakage, ROS levels, and apoptosis. In addition, CCAT2 positively regulated BMI1 expression by binding to miR-539-3p. CCAT2 knockdown or miR-539-3p overexpression restrained the protective effects of BMI1 against H/R-induced cardiomyocyte injury. In addition, miR-539-3p overexpression reversed the protective effects of CCAT2. Furthermore, CCAT2 activated the Wnt/β-catenin pathway under the H/R condition via the miR-539-3p/BMI1 axis.Overall, this investigation showed the protective effects of the CCAT2/miR-539-3p/BMI1/Wnt/β-catenin regulatory axis against cardiomyocyte injury induced by H/R.

Kazinol B protects H9c2 cardiomyocytes from hypoxia/reoxygenation-induced cardiac injury by modulating the AKT/AMPK/Nrf2 signalling pathway

CONTEXT

Kazinol B (KB), an isoprenylated flavan derived from Broussonetia kazinoki Sieb. (Moraceae) root, has long been used in folk medicine.

OBJECTIVE

This study examines the protective effects of KB and its underlying mechanisms in hypoxia and reoxygenation (H/R)-induced cardiac injury in H9c2 rat cardiac myoblasts.

MATERIALS AND METHODS

H9c2 cells were incubated with various concentrations of KB (0, 0.3, 1, 3, 10 and 30 μM) for 2 h and then subjected to H/R insults. The protective effects of KB and its underlying mechanisms were explored.

RESULTS

KB significantly elevated cell viability (1 μM, 1.21-fold; 3 μM, 1.36-fold, and 10 μM, 1.47-fold) and suppressed LDH release (1 μM, 0.77-fold; 3 μM, 0.68-fold, and 10 μM, 0.59-fold) in H/R-induced H9c2 cells. Further, 10 μM KB blocked apoptotic cascades, as shown by the Annexin-V/PI (0.41-fold), DNA fragmentation (0.51-fold), caspase-3 (0.52-fold), PARP activation (0.27-fold) and Bax/Bcl-2 expression (0.28-fold) assays. KB (10 μM) downregulated reactive oxygen species production (0.51-fold) and lipid peroxidation (0.48-fold); it upregulated the activities of GSH-Px (2.08-fold) and SOD (1.72-fold). KB (10 μM) induced Nrf2 nuclear accumulation (1.94-fold) and increased ARE promoter activity (2.15-fold), HO-1 expression (3.07-fold), AKT (3.07-fold) and AMPK (3.07-fold) phosphorylation. Nrf2 knockdown via using Nrf2 siRNA abrogated KB-mediated protective effects against H/R insults. Moreover, pharmacological inhibitors of AKT and AMPK also abrogated KB-induced Nrf2 activation and its protective function.

DISCUSSION AND CONCLUSIONS

KB prevented H/R-induced cardiomyocyte injury via modulating the AKT and AMPK-mediated Nrf2 induction. KB might be a promising drug candidate for managing ischemic cardiac disorders.

Toll-like receptors (TLR2 and TLR4) antagonist mitigates the onset of cerebral small vessel disease through PI3K/Akt/GSK3β pathway in stroke-prone renovascular hypertensive rats

To examine the effect and mechanism of Toll-Like Receptors (TLR2, TLR4) antagonist in CSVD. The rat model of stroke-induced renovascular hypertension (RHRSP) was constructed. TLR2 and TLR4 antagonist was administrated by Intracranial injection. Morris water maze was used to observe the behavioral changes of rat models. HE staining, TUNEL staining and Evens Blue staining were performed to evaluate the permeability of the blood-brain barrier (BBB) and examine the CSVD occurrence and neuronal apoptosis. The inflammation and oxidative stress factors were detected by ELISA. Hypoxia-glucose-deficiency (OGD) ischemia model was constructed in cultured neurons. Western blot and ELISA were used to examine the related protein expression in TLR2/TLR4 signaling pathway and PI3K/Akt/GSK3β signaling pathway. The RHRSP rat model was successfully constructed, and the blood well and BBB permeability were altered. The RHRSP rats showed cogitative impairment and excessive immune response. After TLR2/TLR4 antagonist administration, the behavior of model rats were improved, cerebral white matter injury was reduced, and the expression of several key inflammatory factors including TLR4, TLR2, Myd88 and NF-kB were decreased, as well as the ICAM-1, VCAM-1, inflammation and oxidative stress factors. In vitro experiments showed that TLR4 and TLR2 antagonist increased the cell viability, inhibited the apoptosis, and decreased p-Akt and p-GSK3β expression. Moreover, the PI3K inhibitors resulted in decreased anti-apoptotic and anti-inflammatory effects of TLR4 and TLR2 antagonist. These results suggested that TLR4 and TLR2 antagonist achieved protective effect on the RHRSP through the PI3K/Akt/GSK3β pathway.

An Overview of Cardiotonic Medicinal Plants from the Perspective of Iranian Traditional Medicine

Context: Cardiovascular disorders are a leading cause of mortality and morbidity worldwide, especially in people with diabetes. Due to synthetic drugs’ adverse effects, new medicines are needed. Evidence Acquisition: Iranian traditional medicine (ITM) is one of the oldest medical systems. In this article, we first introduce a list of cardiotonic medicinal plants based on ITM. Then we review the cardio-related effects of these plants based on electronic databases. Results: Among the introduced medicinal plants from ITM, Phyllanthus emblica L., Rosa canina L., Ocimum basilicum L., and Melissa officinalis L. have cardiotonic effects. Also, P. emblica, O. basilicum, M. officinalis, Citrus medica L., Malus domestica Borkh., Elettaria cardamomum (L.) Maton, and R. canina have cardioprotective effects and possess several biological activities that reduce cardiovascular disease risk factors. Conclusions: The cardiotonic medicinal plants based on ITM have excellent value; several pharmacological studies have proved some of their cardioprotective and cardiotonic effects. The other plants’ potential for improving the heart’s contractile power as a cardiotonic drug must be evaluated in further pharmacological and clinical studies.

Current advances on the phytochemical composition, pharmacologic effects, toxicology, and product development of Phyllanthi Fructus

Phyllanthi Fructus (PF), the edible fruits of Phyllanthus emblica L., serves as an important resource for some health products, foods and drugs due to its high safety and sufficient nutritional value. In recent years, in vivo and in vitro experiments have been conducted to reveal the active components of PF. More than 180 compounds have been isolated and identified from the PF so far, primarily including tannins, phenolic acids, flavonoids, terpenoids, polysaccharides, fatty acids and amino acids. In traditional Chinese medicine (TCM), PF is used to cure several diseases such as bronchitis, asthma, diabetes, peptic ulcer, hepatopathy, leprosy, and jaundice. Consistent with ethnopharmacology, numerous modern studies have demonstrated that the extracts or monomeric compounds derived from PF exhibit various pharmacological effects including anti-oxidation, anti-bacteria, anti-inflammation, anti-tumour, anti-virus, immunity improvement, hypoglycemic and hypolipidemic effects, and multiple organ protective protection. Toxicological studies on PF indicated the absence of any adverse effects even at a high dose after oral administration. Due to strict quality control, these pharmacological activities and the safety of PF greatly improve the development and utilization of products. Our comprehensive review aims to summarize the phytochemistry, pharmacological effects, toxicology, and product development of PF to provide theoretical guidance and new insights for further research on PF in the future.

Functional and Nutraceutical Significance of Amla (Phyllanthus emblica L.): A Review

Phyllanthus emblica L. (also popularly known as amla) is a tree native to the India and Southeast Asia regions that produces fruits rich in bioactive compounds that could be explored as part of the increasing interest in naturally occurring compounds with biological activity. Thus, this review aims to highlight the nutritional aspects, rich phytochemistry and health-promoting effects of amla. Scientific evidence indicates that polyphenols are central components in fruits and other sections of the amla tree, as well as vitamin C. The rich composition of polyphenol and vitamin C imparts an important antioxidant activity along with important in vivo effects that include improved antioxidant status and activity of the endogenous antioxidant defense system. Other potential health benefits are the anti-hyperlipidemia and antidiabetic activities as well as the anticancer, anti-inflammatory, digestive tract and neurological protective activities. The promising results provided by the studies about amla bioactive compounds support their potential role in assisting the promotion of health and prevention of diseases.

Oral acute toxicity study extract ethanol of balakka fruit (Phyllanthus emblica)

Phyllanthus emblica (PE) is a plant widely found in Indonesia, especially in Sumatra island, and in India. This study followed the OECD No. 420. The groups were divided based on gender, male and female rats. Male rats were divided into 6 groups, which were male/female control, male/female 2000 mg/kgBW, and male/female 5000 mg/kgBW. This study revealed that the ethanol extract of Phyllanthus emblica (EEPE) doses of 2000 mg/kgBW and 5000 mg/kgBW did not cause histological changes in the heart, liver, testes, ovaries, and kidneys, and did not cause changes to the hematological parameters, kidney biochemical parameters, liver biochemical parameters, and electrolyte parameters both in male and female rats. The results show that the LD50 of EEPE is higher than 5000 mg/kgBW. In short, this study provides information regarding the antioxidant activity and the safe use of EEPE. The LD50 of extract ethanol of Phyllanthus emblica is higher than 5000 mg/kgBW.

Nutraceuticals in the Management of Cardiovascular Risk Factors: Where is the Evidence?

Cardiovascular disease continues to rise at an alarming rate, and research focuses on possible therapies to reduce the risk and slow down its progression. Several epidemiological studies have indicated that dietary modifications, such as increased consumption of fruits and vegetables play an important role in reducing cardiovascular disease risk factors. Food sources rich in antioxidants, anti-inflammatory, hypolipidemic, and hypoglycemic properties are thought to ameliorate the progression of cardiovascular disease and serve as a potential treatment mode. Many in vivo and in vitro studies using turmeric, cinnamon, mango, blueberries, red wine, chocolate, and extra virgin olive oil have demonstrated significant improvements in cholesterol profiles, toxic reactive oxygen species, inflammation, obesity, and hypertension. In this review, we summarize recent evidence on the cardioprotective effect of different food groups, outline their potential mechanisms involved in slowing down the progression of cardiovascular disease, and highlight the beneficial effects associated with increased consumption.

Cardioprotective Properties of Ginkgo Biloba Extract 80 via the Activation of AKT/GSK3β/β-Catenin Signaling Pathway

Elderly people are more likely to experience myocardial infarction (MI) than young people, with worse post-MI mortality and prognosis. Ginkgo biloba extract 50 (GBE50) is an oral GBE product that matches the German product, EGb761, which has been used to treat acute myocardial infarction (AMI). The extraction purity of GBE50 was improved to form a new formulation, Ginkgo biloba extract 80 (GBE80). This study investigates the effect of GBE80 on aged acute myocardial infarction rats. GBE80 injection is a novel formulation that was prepared by mixing Ginkgo flavonoids and lactones in a 4:1 weight ratio, with a Ginkgo content of more than 80%. Cell Counting Kit-8 was used to determine the biological safety and protective effect of GBE80 on cardiomyocytes against oxidative damage. An aged AMI rat model was developed and used to determine the myocardial infarction weight ratio using triphenyltetrazolium chloride staining. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) was applied to detect cell apoptosis in myocardial tissue. Western blotting and immunohistochemistry were used to measure the protein levels of members of the AKT/GSK3β/β-catenin pathway in vitro and in vivo, respectively. We found that GBE80 in vitro suppressed H₂O₂-induced cytotoxicity by promoting AKT/GSK3β/β-catenin signaling, while it did not show cytotoxicity to normal cardiomyocytes in the 0–500 μg/ml dose range. After 7 days of administration to aged AMI rats, GBE80 markedly reduced the weight ratio of the infarction and inhibited cell apoptosis in myocardial tissue. Furthermore, the AKT/GSK3β/β-catenin signaling pathway was activated by GBE80. These results suggest that GBE80 injection effectively inhibited AMI-induced myocardial damage and in vitro H₂O₂-induced cardiomyocyte cytotoxicity by activating the AKT/GSK3β/β-catenin signaling pathway.

Protective effects of safranal on hypoxia/reoxygenation-induced injury in H9c2 cardiac myoblasts via the PI3K/AKT/GSK3β signaling pathway

Safranal (SFR), an active ingredient extracted from saffron, exhibits a protective effect on the cardiovascular system. However, the mechanism of SFR against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury has previously not been investigated in vitro. The aim of the present study was therefore to observe the protective effects of SFR on H/R-induced cardiomyocyte injury and to explore its mechanisms. A H/R injury model of H9c2 cardiac myoblasts was established by administering 800 µmol/l CoCl₂ to H9c2 cells for 24 h and reoxygenating the cells for 4 h to induce hypoxia. H9c2 cardiac myoblasts were pretreated with SFR for 12 h to evaluate the associated protective effects. A Cell Counting Kit-8 assay was used for cell viability detection, and the expression levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), glutathione peroxidase (GSH-px), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and caspase-3, and the intracellular Ca²⁺ concentration were measured using the corresponding commercial kits. Levels of reactive oxygen species (ROS) in the cells were detected using 2,7-dichlorodihydrofluorescein diacetate. Flow cytometry was used to determine the degree of apoptosis and the level of mitochondrial membrane potential (MMP). Moreover, the expression levels of phosphorylated (p-)PI3K, AKT, p-AKT, glycogen synthase kinase 3β (GSK3β), p-GSK3β, Bcl-2, Bax, caspase-3 and cleaved caspase-3 were measured using western blot analysis. Results of the present study demonstrated that the H9c2 cardiac myoblasts treated with SFR exhibited significantly improved levels of viability and significantly reduced levels of ROS, compared with the H/R group. Furthermore, compared with the H/R group, SFR treatment significantly increased the MMP levels and antioxidant enzyme levels, including CAT, SOD and GSH-px; whereas the levels of CK-MB, LDH, MDA and intracellular Ca²⁺ concentration were significantly decreased. Moreover, the results of the present study demonstrated that SFR significantly reduced caspase-3, cleaved caspase-3 and Bax protein expression levels, but upregulated the Bcl-2 protein expression levels. SFR also increased the protein expressions of PI3K/AKT/GSK3β. In summary, the results suggested that SFR may exert a protective effect against H/R-induced cardiomyocyte injury, which occurs in connection with the inhibition of oxidative stress and apoptosis via regulation of the PI3K/AKT/GSK3β signaling pathway.

MeCP2 attenuates cardiomyocyte hypoxia/reperfusion-induced injury via regulation of the SFRP4/Wnt/β-catenin axis

Objective: Methylated CpG binding protein 2 (MeCP2) is closely associated with heart failure, but its role in I/R injury remains unclear. The purpose of this study was to explore the role and underling mechanism of MeCP2 in myocardial I/R injury.Methods: Hypoxia/reperfusion (H/R)-induced H9c2 cardiomyocytes was used to establish an in vitro I/R injury model. Oxidative stress was assessed by measuring reactive oxygen species (ROS) generation, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity. Cell viability and cell cycle arrest were evaluated by the Cell Counting Kit-8 assay and cell cycle assay, respectively. Apoptosis was determined using flow cytometry analysis.Results: The expression of MeCP2 in H9c2 cells was decreased after H/R treatment. The overexpression of MeCP2 inhibited H/R-induced oxidative stress, cell cycle arrest and apoptosis of H9c2 cells. Moreover, MeCP2 inhibited the activation of secreted frizzled related protein 4 (SFRP4)/Wnt/β-catenin axis, and SFRP4 relieved the effect of MeCP2 on oxidative stress, cell cycle arrest and apoptosis in H/R-induced H9c2 cells.Conclusions: MeCP2 attenuated H/R-induced injury in H9c2 cardiomyocytes by modulating the SFRP4/Wnt/β-catenin axis, which suggested that MeCP2 might serve as a therapeutic target of patients with AMI after reperfusion.

Potential effect of tropical fruits Phyllanthus emblica L. for the prevention and management of type 2 diabetic complications: a systematic review of recent advances

Phyllanthus emblica is a fruit widely consumed in subtropical areas, which is rich in polyphenols and other nutrients. There are increasing evidences that as a daily and nutritious fruit, it may have a positive role in controlling diabetic complications. According to the new study, its mechanisms include enhancing the functioning of insulin, reducing insulin resistance, activating the insulin-signaling pathway, protecting β-cells, scavenging free radicals, alleviating inflammatory reactions, and reducing the accumulation of advanced glycation end products. Owing to its few side effects, and low price, it should be easily accepted by patients and has potential for preventing diabetes. Taken together, Phyllanthus emblica may be an ideal fruit for controlling diabetic complications. This review highlights the latest findings of the role of Phyllanthus emblica in anti-diabetes and its complications, especially clarifies the molecular mechanism of the chemical components related to this effect, and prospects some existing problems and future research directions.

An Evaluation of Traditional Persian Medicine for the Management of SARS-CoV-2

A new coronavirus causing severe acute respiratory syndrome (SARS-CoV-2) has emerged and with it, a global investigation of new antiviral treatments and supportive care for organ failure due to this life-threatening viral infection. Traditional Persian Medicine (TPM) is one of the most ancient medical doctrines mostly known with the manuscripts of Avicenna and Rhazes. In this paper, we first introduce a series of medicinal plants that would potentially be beneficial in treating SARS-CoV-2 infection according to TPM textbooks. Then, we review medicinal plants based on the pharmacological studies obtained from electronic databases and discuss their mechanism of action in SARS-CoV-2 infection. There are several medicinal plants in TPM with cardiotonic, kidney tonic, and pulmonary tonic activities, protecting the lung, heart, and kidney, the three main vulnerable organs in SARS-CoV-2 infection. Some medicinal plants can prevent "humor infection", a situation described in TPM which has similar features to SARS-CoV-2 infection. Pharmacological evaluations are in line with the therapeutic activities of several plants mentioned in TPM, mostly through antiviral, cytoprotective, anti-inflammatory, antioxidant, and anti-apoptotic mechanisms. Amongst the primarily-introduced medicinal plants from TPM, rhubarb, licorice, garlic, saffron, galangal, and clove are the most studied plants and represent candidates for clinical studies. The antiviral compounds isolated from these plants provide novel molecular structures to design new semisynthetic antiviral agents. Future clinical studies in healthy volunteers as well as patients suffering from pulmonary infections are necessary to confirm the safety and efficacy of these plants as complementary and integrative interventions in SARS-CoV-2 infection.

(Pro)renin receptor contributes to hypoxia/reoxygenation-induced apoptosis and autophagy in myocardial cells via the beta-catenin signaling pathway

(Pro)renin receptor (PRR) contributes to regulating many physiological and pathological processes; however, the role of PRR-mediated signaling pathways in myocardial ischemia/reperfusion injury (IRI) remains unclear. In this study, we used an in vitro model of hypoxia/reoxygenation (H/R) to mimic IRI and carried out PRR knockdown by siRNA and PRR overexpression using cDNA in H9c2 cells. Cell proliferation activity was examined by MTT and Cell Counting Kit-8 (CCK-8) assays. Apoptosis-related factors, autophagy markers and beta-catenin pathway activity were assessed by real-time PCR and western blotting. After 24 h of hypoxia followed by 2 h of reoxygenation, the expression levels of PRR, LC3B-I/II, Beclin1, cleaved caspase-3, cleaved caspase-9 and Bax were upregulated, suggesting that apoptosis and autophagy were increased in H9c2 cells. Contrary to the effects of PRR downregulation, the overexpression of PRR inhibited proliferation, induced apoptosis, increased the expression of pro-apoptotic factors and autophagy markers, and promoted activation of the beta-catenin pathway. Furthermore, all these effects were reversed by treatment with the beta-catenin antagonist DKK-1. Thus, we concluded that PRR activation can trigger H/R-induced apoptosis and autophagy in H9c2 cells through the beta-catenin signaling pathway, which may provide new therapeutic targets for the prevention and treatment of myocardial IRI.

Evaluation of the Effect of Fish Oil Alone and in Combination with a Proprietary Chromium Complex on Endothelial Dysfunction, Systemic Inflammation and Lipid Profile in Type 2 Diabetes Mellitus - A Randomized, Double-Blind, Placebo-Controlled Clinical Study

PURPOSE

This study was conducted to evaluate the effectiveness of fish oil alone and with an adjunct, a proprietary chromium complex (PCC), on cardiovascular parameters - endothelial dysfunction, lipid profile, systemic inflammation and glycosylated hemoglobin - in a 12-week randomized, double-blind, placebo-controlled clinical study in type 2 diabetes mellitus subjects.

PATIENTS AND METHODS

In this randomized, double-blind, parallel group study, 59 subjects in three groups completed the study: Group A, fish oil 2000 mg; Group B, fish oil 2000 mg + PCC 10 mg (200 µg of Cr³⁺); and Group C, fish oil 2000 mg + PCC 20 mg (400 µg of Cr³⁺) daily for 12 weeks (2000 mg of fish oil contained 600 mg of eicosapentaenoic acid [EPA] and 400 mg of docosahexaenoic acid [DHA], the omega-3 fatty acids). Endothelial function, by estimating reflection index (RI), biomarkers of oxidative stress (nitric oxide [NO], malondialdehyde [MDA], glutathione [GSH]) and inflammatory biomarkers (high-sensitivity C-reactive protein [hsCRP], intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], endothelin-1) were evaluated at baseline, and 4 and 12 weeks. Lipid profile, platelet aggregation and glycosylated hemoglobin [HbA1c) were tested at baseline and 12 weeks. Any reported adverse drug reactions were recorded. Statistical analysis was performed using GraphPad Prism 8.

RESULTS

The present study shows that fish oil by itself, at a dose of 2000 mg (600 mg of EPA + 400 mg of DHA) per day, led to significant, but only modest, improvement in cardiovascular parameters (RI from -2.38±0.75 to -3.92±0.60, MDA from 3.77±0.16 to 3.74±0.16 nM/mL, NO from 30.60±3.18 to 32.12±3.40 µM/L, GSH from 568.93±5.91 to 583.95±6.53 µM/L; p≤0.0001), including triglyceride levels. However, when PCC was added to fish oil, especially at the 20 mg dose, there were highly significant improvements in all the parameters tested (RI from -2.04±0.79 to -8.73±1.36, MDA from 3.67±0.39 to 2.89±0.34 nM/mL, NO from 28.98±2.93 to 40.01±2.53 µM/L, GSH from 553.82±8.18 to 677.99±10.19 µM/L; p≤0.0001), including the lipid profile. It is noteworthy that the triglycerides were decreased significantly by addition of 20 mg of PCC although the dose of fish oil was only 2 g/day and the baseline triglyceride levels were only about 200 mg/dL. Fish oil alone did not significantly decrease the HbA1c, whereas the addition of 20 mg of PCC did.

CONCLUSION

Addition of PCC, especially at 20 mg dose, significantly improves the efficacy of fish oil in addressing cardiovascular risk factors compared to fish oil given alone.

Loss of GCN5L1 in cardiac cells disrupts glucose metabolism and promotes cell death via reduced Akt/mTORC2 signaling

GCN5L1 regulates protein acetylation and mitochondrial energy metabolism in diverse cell types. In the heart, loss of GCN5L1 sensitizes the myocardium to injury from exposure to nutritional excess and ischemia/reperfusion injury. This phenotype is associated with the reduced acetylation of metabolic enzymes and elevated mitochondrial reactive oxygen species (ROS) generation, although the direct molecular targets of GCN5L1 remain largely unknown. In this study, we sought to determine the mechanism by which GCN5L1 impacts energy substrate utilization and mitochondrial health. We find that hypoxia and reoxygenation (H/R) leads to a reduction in cell viability and Akt phosphorylation in GCN5L1 knockdown AC16 cardiomyocytes, in parallel with elevated glucose utilization and impaired fatty acid use. We demonstrate that glycolysis is uncoupled from glucose oxidation under normoxic conditions in GCN5L1-depleted cells. We show that GCN5L1 directly binds to the Akt-activating mTORC2 component Rictor, and that loss of Rictor acetylation is evident in GCN5L1 knockdown cells. Finally, we show that restoring Rictor acetylation in GCN5L1-depleted cells reduces mitochondrial ROS generation and increases cell survival in response to H/R. These studies suggest that GCN5L1 may play a central role in energy substrate metabolism and cell survival via the regulation of Akt/mTORC2 signaling.

A systematic review on the cardiovascular pharmacology of Emblica officinalis Gaertn

Introduction: The Emblica officinalis (EO) fruit has traditionally been considered as a cardioactive medication and has demonstrated remarkable cardiovascular effects in the pharmacological literature. The present study systematically reviews EO’s potential for prevention and therapy of cardiovascular diseases (CVD).

Methods: PubMed, ScienceDirect, Scopus, Proquest, Ebsco, Google, Google Scholar, Ovid, and Cochrane databases were searched from 1966 to 2017 for the English and non-English literature using the terms including the cognates of EO including amla, Emblic myrobalan, Emblica officinalis, Emblica pectinata , Indian gooseberry, and Phyllanthus emblica together with antioxidant, arrhythmia, cardioprotective, cardiotoxicity, heart disease, heart failure, hyperlipidemia, hypertension, myocardial dysfunction, and oxidative stress. The inclusion criteria were in vitro, animal, and clinical cardiovascular pharmacological studies conducted on EO and full-text accessibility. The exclusion criterion was studies in which a combination of EO and at least one other plant was investigated. The reference lists of the retrieved articles were also searched manually for additional eligible articles. The methodological quality of clinical trials was assessed by the Jadad scale, and animal studies were evaluated by the ARRIVE checklist.

Results: Nineteen articles concerning the cardiovascular pharmacological effects of EO were included in this review. The plant has shown antiatherogenic, anticoagulant, hypolipidemic, antihypertensive, antioxidant, antiplatelet, and vasodilatory effects as well as lipid deposition inhibitory properties. Moreover, it prevents from doxorubicin and isoproterenol cardiotoxicity and myocardial ischemia/reperfusion injury, and improves vascular endothelial function in animal studies. Some high-quality clinical studies report the vasodilatory and myocardial antioxidant properties as well as anti-platelet aggregation effects of this plant.

Conclusion: EO influences various cardiovascular risk-factors. However, there is not sufficient evidence to confirm the plant efficacy in preventing and treating CVD.

Aldose reductase modulates acute activation of mesenchymal markers via the β-catenin pathway during cardiac ischemia-reperfusion

Aldose reductase (AR: human, AKR1B1; mouse, AKR1B3), the first enzyme in the polyol pathway, plays a key role in mediating myocardial ischemia/reperfusion (I/R) injury. In earlier studies, using transgenic mice broadly expressing human AKR1B1 to human-relevant levels, mice devoid of Akr1b3, and pharmacological inhibitors of AR, we demonstrated that AR is an important component of myocardial I/R injury and that inhibition of this enzyme protects the heart from I/R injury. In this study, our objective was to investigate if AR modulates the β-catenin pathway and consequent activation of mesenchymal markers during I/R in the heart. To test this premise, we used two different experimental models: in vivo, Akr1b3 null mice and wild type C57BL/6 mice (WT) were exposed to acute occlusion of the left anterior descending coronary artery (LAD) followed by recovery for 48 hours or 28 days, and ex-vivo, WT and Akr1b3 null murine hearts were perfused using the Langendorff technique (LT) and subjected to 30 min of global (zero-flow) ischemia followed by 60 min of reperfusion. Our in vivo results reveal reduced infarct size and improved functional recovery at 48 hours in mice devoid of Akr1b3 compared to WT mice. We demonstrate that the cardioprotection observed in Akr1b3 null mice was linked to acute activation of the β-catenin pathway and consequent activation of mesenchymal markers and genes linked to fibrotic remodeling. The increased activity of the β-catenin pathway at 48 hours of recovery post-LAD was not observed at 28 days post-infarction, thus indicating that the observed increase in β-catenin activity was transient in the mice hearts devoid of Akr1b3. In ex vivo studies, inhibition of β-catenin blocked the cardioprotection observed in Akr1b3 null mice hearts. Taken together, these data indicate that AR suppresses acute activation of β-catenin and, thereby, blocks consequent induction of mesenchymal markers during early reperfusion after myocardial ischemia. Inhibition of AR might provide a therapeutic opportunity to optimize cardiac remodeling after I/R injury.

Attenuation of diabetic nephropathy by Sanziguben Granule inhibiting EMT through Nrf2-mediated anti-oxidative effects in streptozotocin (STZ)-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic nephropathy (DN) is an acute and serious diabetic complication characterized by renal hypertrophy and renal fibrosis with the expansion of extracellular matrices. Diabetic nephropathy has become a major cause of end-stage kidney disease. Sanziguben Granule (SZGB) is a compound prescription which has been widely applied in clinical medicine for the prevention and treatment of diabetic nephropathy as well as for acute and chronic kidney injuries. However, the mechanism of protective effects of SZGB in DN remains unclear.

MATERIALS AND METHODS

In this research, we investigated the effects of SZGB on renal interstitial fibrosis, antioxidant proficiency, and apoptosis in streptozotocin (STZ)-induced diabetic rats. Diabetic rats were prepared by performing a right uninephrectomy along with a single intraperitoneal injection of STZ. Rats were divided into six groups including sham, DN, SZGB-D, SZGB-Z, SZGB-G and fosinopril. SZGB and fosinopril were given to rats by gavage for 12 weeks. Samples from urine, blood and kidneys were collected for biochemical, histological, immunohistochemical and western blot analyses.

RESULTS

We found that rats treated with SZGB showed reduced 24-h urinary protein excretion along with reduced serum total cholesterol (TC) and triglyceride (TG) levels. SZGB was also shown to prevent the disruption of catalase activity and reduce serum urea, creatinine, and renal malondialdehyde while increasing glutathione levels. Moreover, SZGB administration markedly improved the expression levels of E-cadherin, 4-HNE, Nrf2, HO-1, and Bcl-2, while it decreased the expression levels of Vimentin, α-SMA and Cleaved caspase-3 in the kidneys of diabetic rats. The renoprotective effects of SZGB was believed to be mediated by its antioxidant capacity, and SZGB treatment attenuated renal fibrosis through stimulating the nuclear factor erythroid-2-related factor 2 (Nrf2) signaling pathway in the diabetic kidneys.

CONCLUSIONS

Therefore, it is suggested that SZGB can restrain epithelial-mesenchymal transition (EMT) through stimulating the Nrf2 pathway, which improves renal interstitial fibrosis in DN.

Tannoid principles of Emblica officinalis attenuated aluminum chloride induced apoptosis by suppressing oxidative stress and tau pathology via Akt/GSK-3βsignaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Fruits of Phyllanthus emblica Linn. or Emblica officinalis Gaertn. (Phyllanthaceae) are used in Ayurveda, Siddha, Unani, Arabic, Tibetan and various other folk medicinal systems to promote intelligence and memory. Recent study from our lab indicated the neuroprotective effect of tannoids principles of Emblica officinalis (EoT) against memory loss caused by aluminum chloride (AlCl₃) intoxication through attenuating acetylcholine esterase activity and the expression of amyloid β protein biosynthesis related markers. However the molecular mechanism of EoT has not yet been fully elucidated.

AIM OF THE STUDY

The aim of the present study was to further investigate the neuroprotective mechanisms of EoT against AlCl₃-induced cognitive deficits, tau hyperphosphorylation, oxidative stress and apoptosis.

MATERIALS AND METHODS

Rats were treated with AlCl₃ for 60 days to induce biochemical and physiological abnormalities similar to AD patients. AD rats were treated with EoT (100mg/kg., bw. oral) for 60 days. For the examination of neuroprotective effect of EoT, behavior analysis, biochemical estimations and western blot were performed in the hippocampus and cortex of control, EoT treated and untreated AD rats.

RESULTS

Intraperitoneal injections of AlCl₃ (100mg/kg., b.w.) for 60 days enhanced the learning and memory deficits, levels of TBARS and diminished the levels of reduced glutathione and activities of enzymatic antioxidants as compared to control group. Moreover toxicity of AlCl₃ is accompanied by the enhanced expressions of Bax, caspases-3,-9, cytosolic cytochrome c (cyto c), and pTau along with diminished expressions of Bcl-2, mitochondrial cyto c, pGSK-3β and pAkt. Coadministration of EoT nullified the cognitive deficits, biochemical abnormalities and apoptosis induced by AlCl₃ treatment. Moreover EoT prevents tau hyperphosphorylation by targeting the GSK-3β/Akt signaling pathway.

CONCLUSIONS

This study confirms that EoT would be used as a potential drug candidate for AD and other tau pathology-related neuronal degenerative diseases.