Galangin attenuates diabetic cardiomyopathy through modulating oxidative stress, inflammation and apoptosis in rats

Programmed death of cardiomyocytes in cardiovascular disease and new therapeutic approaches

Cardiovascular diseases (CVDs) have a complex pathogenesis and pose a major threat to human health. Cardiomyocytes have a low regenerative capacity, and their death is a key factor in the morbidity and mortality of many CVDs. Cardiomyocyte death can be regulated by specific signaling pathways known as programmed cell death (PCD), including apoptosis, necroptosis, autophagy, pyroptosis, and ferroptosis, etc. Abnormalities in PCD can lead to the development of a variety of cardiovascular diseases, and there are also molecular-level interconnections between different PCD pathways under the same cardiovascular disease model. Currently, the link between programmed cell death in cardiomyocytes and cardiovascular disease is not fully understood. This review describes the molecular mechanisms of programmed death and the impact of cardiomyocyte death on cardiovascular disease development. Emphasis is placed on a summary of drugs and potential therapeutic approaches that can be used to treat cardiovascular disease by targeting and blocking programmed cell death in cardiomyocytes.

A narrative review on the mechanism of natural flavonoids in improving glucolipid metabolism disorders

Glucolipid metabolism disorder (GLMD) is a complex chronic disease characterized by glucose and lipid metabolism disorders with a complex and diverse etiology and rapidly increasing incidence. Many studies have identified the role of flavonoids in ameliorating GLMD, with mechanisms related to peroxisome proliferator-activated receptors, nuclear factor kappa-B, AMP-activated protein kinase, nuclear factor (erythroid-derived 2)-like 2, glucose transporter type 4, and phosphatidylinositol-3-kinase/protein kinase B pathway. However, a comprehensive summary of the flavonoid effects on GLMD is lacking. This study reviewed the roles and mechanisms of natural flavonoids with different structures in the treatment of GLMD reported globally in the past 5 years and provides a reference for developing flavonoids as drugs for treating GLMD.

Unveiling the Antioxidative Potential of Galangin: Complete and Detailed Mechanistic Insights through Density Functional Theory Studies

A comprehensive quantum mechanical investigation delved into the antioxidative activity of galangin (Glg). Thermochemical and kinetic data were used to assess antiradical, chelating, and renewal potential under physiological conditions. A brief comparison with reference antioxidants and other flavonoids characterized Glg as a moderate antioxidative agent. The substance showed significantly lower performance in lipid compared to aqueous solvent─the reaction rates for scavenging •OOH in both media were established at 3.77 × 103 M-1 s-1 and 6.21 × 104 M-1 s-1, respectively, accounting for the molar fraction of both interacting molecules at the given pH. The impact of pH value on the kinetics was assessed. Although efficient at chelating Cu(II) ions, the formed complexes can still undergo the Fenton reaction. On the other hand, they persistently scavenge •OH in statu nascendi. The flavonoid effectively repairs oxidatively damaged biomolecules except model lipid acids. All Glg radicals are readily restored by physiologically prevailing O2•-. Given this, the polyphenol is expected to participate in antiradical and regenerating activities multiple times, amplifying its antioxidative potential.

MARK4 aggravates cardiac dysfunction in mice with STZ-induced diabetic cardiomyopathy by regulating ACSL4-mediated myocardial lipid metabolism

Diabetic cardiomyopathy is a specific type of cardiomyopathy. In DCM, glucose uptake and utilization are impaired due to insulin deficiency or resistance, and the heart relies more heavily on fatty acid oxidation for energy, resulting in myocardial lipid toxicity-related injury. MARK4 is a member of the AMPK-related kinase family, and improves ischaemic heart failure through microtubule detyrosination. However, the role of MARK4 in cardiac regulation of metabolism is unclear. In this study, after successful establishment of a diabetic cardiomyopathy model induced by streptozotocin and a high-fat diet, MARK4 expression was found to be significantly increased in STZ-induced DCM mice. After AAV9-shMARK4 was administered through the tail vein, decreased expression of MARK4 alleviated diabetic myocardial damage, reduced oxidative stress and apoptosis, and facilitated cardiomyocyte mitochondrial fusion, and promoted myocardial lipid oxidation metabolism. In addition, through the RNA-seq analysis of differentially expressed genes, we found that MARK4 deficiency promoted lipid decomposition and oxidative metabolism by downregulating the expression of ACSL4, thus reducing myocardial lipid accumulation in the STZ-induced DCM model.

Therapeutic potential of salvigenin to combat atrazine induced liver toxicity in rats via regulating Nrf-2/Keap-1 and NF-κB pathway

Atrazine (ATR) is the second most extensively used herbicide which adversely affects the body organs including liver. Salvigenin (SGN) is a flavonoid which demonstrates a wide range of biological and pharmacological abilities. This study was planned to assess the protective ability of SGN to avert ATR induced liver damage in rats. Thirty-two rats (Rattus norvegicus) were divided into four groups including control, ATR (5 mg/kg), ATR (5 mg/kg) + SGN (10 mg/kg) and SGN (10 mg/kg) alone supplemented group. ATR exposure reduced the expression of Nrf-2 while instigating an upregulation in Keap-1 expression. Furthermore, the activities of catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), heme‑oxygenase-1 (HO-1) and glutathione reductase (GSR) contents were decreased while increasing reactive oxygen species (ROS) and malondialdehyde (MDA) levels after ATR treatment. Moreover, ATR poisoning increased the levels of ALT, AST, and ALP while reducing the levels of total proteins, and albumin in hepatic tissues of rats. Besides, ATR administration escalated the expressions of Bax and Caspase-3 while inducing a downregulation in the expressions of Bcl-2. Similarly, ATR intoxication increased the levels of Interleukin-6 (IL-6), Nuclear factor kappa-B (NF-κB), Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and the activity of cyclooxygenase-2 (COX-2). Furthermore, ATR disrupted the normal histology of hepatic tissues. However, SGN treatment remarkably protected the liver tissues via regulating antioxidant, anti, inflammatory, anti-apoptotic as well as histology parameters. Therefore, it is concluded that SGN can be used as therapeutic agent to combat ATR-induced hepatotoxicity.

Nerolidol rescues hippocampal injury of diabetic rats through inhibiting NLRP3 inflammasome and regulation of MAPK/AKT pathway

Despite the observation of diabetes-induced brain tissue damage and impaired learning and memory, the underlying mechanism of damage remains elusive, and effective, targeted therapeutics are lacking. Notably, the NLRP3 inflammasome is highly expressed in the hippocampus of diabetic individuals. Nerolidol, a naturally occurring compound with anti-inflammatory and antioxidant properties, has been identified as a potential therapeutic option for metabolic disorders. However, the ameliorative capacity of nerolidol on diabetic hippocampal injury and its underlying mechanism remain unclear. Network pharmacology and molecular docking was used to predict the signaling pathways and therapeutic targets of nerolidol for the treatment of diabetes. Then established a diabetic rat model using streptozotocin (STZ) combined with a high-fat diet and nerolidol was administered. Morris water maze to assess spatial learning memory capacity. Hematoxylin and eosin and Nissl staining was used to detect neuronal damage in the diabetic hippocampus. Transmission electron microscopy was used to detect the extent of damage to mitochondria, endoplasmic reticulum (ER) and synapses. Immunofluorescence was used to detect GFAP, IBA1, and NLRP3 expression in the hippocampus. Western blot was used to detect apoptosis (Bcl-2, BAX, and Cleaved-Caspase-3); synapses (postsynaptic densifying protein 95, SYN1, and Synaptophysin); mitochondria (DRP1, OPA1, MFN1, and MFN2); ER (GRP78, ATF6, CHOP, and caspase-12); NLRP3 inflammasome (NLRP3, ASC, and caspase-1); inflammatory cytokines (IL-18, IL-1β, and TNF-α); AKT (P-AKT); and mitogen-activated protein kinase (MAPK) pathway (P-ERK, P-p38, and P-JNK) related protein expression. Network pharmacology showed that nerolidol's possible mechanisms for treating diabetes are the MAPK/AKT pathway and anti-inflammatory effects. Animal experiments demonstrated that nerolidol could improve blood glucose, blood lipids, and hippocampal neuronal damage in diabetic rats. Furthermore, nerolidol could improve synaptic, mitochondrial, and ER damage in the hippocampal ultrastructure of diabetic rats by potentially affecting synaptic, mitochondrial, and ER-related proteins. Further studies revealed that nerolidol decreased neuroinflammation, NLRP3 and inflammatory factor expression in hippocampal tissue while also decreasing MAPK pathway expression and enhancing AKT pathway expression. However, nerolidol improves hippocampal damage in diabetic rats cannot be shown to improve cognitive function. In conclusion, our study reveals for the first time that nerolidol can ameliorate hippocampal damage, neuroinflammation, synaptic, ER, and mitochondrial damage in diabetic rats. Furthermore, we suggest that nerolidol may inhibit NLRP3 inflammasome and affected the expression of MAPK and AKT. These findings provide a new experimental basis for the use of nerolidol to ameliorate diabetes-induced brain tissue damage and the associated disease.

Irisin attenuates type 1 diabetic cardiomyopathy by anti-ferroptosis via SIRT1-mediated deacetylation of p53

BACKGROUND

Diabetic cardiomyopathy (DCM) is a serious complication in patients with type 1 diabetes mellitus (T1DM), which still lacks adequate therapy. Irisin, a cleavage peptide off fibronectin type III domain-containing 5, has been shown to preserve cardiac function in cardiac ischemia-reperfusion injury. Whether or not irisin plays a cardioprotective role in DCM is not known.

METHODS AND RESULTS

T1DM was induced by multiple low-dose intraperitoneal injections of streptozotocin (STZ). Our current study showed that irisin expression/level was lower in the heart and serum of mice with STZ-induced TIDM. Irisin supplementation by intraperitoneal injection improved the impaired cardiac function in mice with DCM, which was ascribed to the inhibition of ferroptosis, because the increased ferroptosis, associated with increased cardiac malondialdehyde (MDA), decreased reduced glutathione (GSH) and protein expressions of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4), was ameliorated by irisin. In the presence of erastin, a ferroptosis inducer, the irisin-mediated protective effects were blocked. Mechanistically, irisin treatment increased Sirtuin 1 (SIRT1) and decreased p53 K382 acetylation, which decreased p53 protein expression by increasing its degradation, consequently upregulated SLC7A11 and GPX4 expressions. Thus, irisin-mediated reduction in p53 decreases ferroptosis and protects cardiomyocytes against injury due to high glucose.

CONCLUSION

This study demonstrated that irisin could improve cardiac function by suppressing ferroptosis in T1DM via the SIRT1-p53-SLC7A11/GPX4 pathway. Irisin may be a therapeutic approach in the management of T1DM-induced cardiomyopathy.

Post-translational modifications in diabetic cardiomyopathy

The increasing attention towards diabetic cardiomyopathy as a distinctive complication of diabetes mellitus has highlighted the need for standardized diagnostic criteria and targeted treatment approaches in clinical practice. Ongoing research is gradually unravelling the pathogenesis of diabetic cardiomyopathy, with a particular emphasis on investigating various post-translational modifications. These modifications dynamically regulate protein function in response to changes in the internal and external environment, and their disturbance of homeostasis holds significant relevance for the development of chronic ailments. This review provides a comprehensive overview of the common post-translational modifications involved in the initiation and progression of diabetic cardiomyopathy, including O-GlcNAcylation, phosphorylation, methylation, acetylation and ubiquitination. Additionally, the review discusses drug development strategies for targeting key post-translational modification targets, such as agonists, inhibitors and PROTAC (proteolysis targeting chimaera) technology that targets E3 ubiquitin ligases.

Effect of apigenin on dynamin-related protein 1 in type 1 diabetic rats with cardiovascular complications

BACKGROUND AND OBJECTIVE

Cardiovascular complications cause increased mortality rates among diabetics. The molecular mechanisms of aberrant mitochondrial dynamics in diabetes mellitus (DM) are not fully understood. Dynamin-related protein 1 (Drp1) is thought to be a major regulator of mitochondrial fission. There is lack of studies that examined the relationship between apigenin and Drp1 expression in DM. Thus, the current study aimed to explore the expression of Drp1 in diabetic rats with cardiovascular complications, as well as to appraise the role of apigenin in modulating this expression.

METHODS

Twenty-eight adult male albino Wister rats were randomly and equally allocated into four groups: naive, streptozotocin-induced type 1 diabetic control and two apigenin-injected diabetic groups (early and late). Body weight, heart weight, blood pressure and ECG were recorded. Evaluation of blood glucose level, lipid profile and cardiac functions were measured. Determination of Drp1 mRNA expression, and histological examination of cardiac tissues from the four groups were performed.

RESULTS

Diabetic control rats developed decrease of body weight, increase of blood pressure, deterioration of the normal ECG pattern and upregulation of Drp1 mRNA expression in cardiac tissues. There was a significant correlation between the relative expression of Drp1 and all examined parameters. Apigenin-injection improved fasting blood glucose, lipid profile and cardiac function indicators (i.e., ECG parameters, CK-MB and troponin) as well as the cardiac histological structure. The decrease of Drp1 expression was more evident with early than with late apigenin-injection, however, without statistical significance.

CONCLUSIONS

Increased level of Drp1 expression in diabetic rats may be involved in the pathogenesis of diabetic cardiovascular complications. The changes that occurred in response to apigenin injection highlight its potential ameliorative effect on the diabetic cardiovascular complications and pave the route for further investigations.

Betulinic acid attenuates T-2 toxin-induced lung injury by activating Nrf2 signaling pathway and inhibiting MAPK/NF-κB signaling pathway

T-2 toxin, a type-A trichothecene mycotoxin, exists ubiquitously in mildewed foods and feeds. Betulinic acid (BA), a pentacyclic triterpenoid derived from plants, has the effect of relieving inflammation and oxidative stress. The purpose of this study was to investigate whether BA mitigates lung impairment caused by T-2 toxin and elucidate the underlying mechanism. The results indicated that T-2 toxin triggered the inflammatory cell infiltration, morphological alterations and cell apoptosis in the lungs. It is gratifying that BA ameliorated T-2 toxin-caused lung injury. The protein expression of nuclear factor erythrocyte 2-related factor 2 (Nrf2) pathway and the markers of antioxidative capability were improved in T-2 toxin induced lung injury by BA mediated protection. Simultaneously, BA supplementation could suppress T-2 toxin-induced mitogen-activated protein kinase (MAPK)/nuclear factor-kappa B (NF-κB)-dependent inflammatory response and mitochondrial apoptotic pathway. Therefore, T-2 toxin gave rise to pulmonary toxicity, but these changes were moderated by BA administration through regulation of the Nrf2/MAPK/NF-κB pathway, which maybe offer a viable alternative for mitigating the lung impairments caused by the mycotoxin.

The cGAS-STING pathway: a therapeutic target in diabetes and its complications

Diabetic wound healing (DWH) represents a major complication of diabetes where inflammation is a key impediment to proper healing. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway has emerged as a central mediator of inflammatory responses to cell stress and damage. However, the contribution of cGAS-STING activation to impaired healing in DWH remains understudied. In this review, we examine the evidence that cGAS-STING-driven inflammation is a critical factor underlying defective DWH. We summarize studies revealing upregulation of the cGAS-STING pathway in diabetic wounds and discuss how this exacerbates inflammation and senescence and disrupts cellular metabolism to block healing. Partial pharmaceutical inhibition of cGAS-STING has shown promise in damping inflammation and improving DWH in preclinical models. We highlight key knowledge gaps regarding cGAS-STING in DWH, including its relationships with endoplasmic reticulum stress and metal-ion signaling. Elucidating these mechanisms may unveil new therapeutic targets within the cGAS-STING pathway to improve healing outcomes in DWH. This review synthesizes current understanding of how cGAS-STING activation contributes to DWH pathology and proposes future research directions to exploit modulation of this pathway for therapeutic benefit.

Rev-erbα attenuates diabetic myocardial injury through regulation of ferroptosis

Diabetes is a widespread disease that threatens the life and health of human beings, and diabetic cardiomyopathy (DCM) is one of the major complications of diabetic patients. The pathological mechanisms of DCM are complex, including inflammation, endoplasmic reticulum stress, and oxidative stress that have been reported previously. Although recent studies suggested that ferroptosis is also involved in the progression of DCM, the exact mechanism remains unclear. Rev-erbα cardiac conditional knockout mice were generated and type 2 diabetes were induced by high fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ) in in vivo experiments. In parallel, our in vitro experiments entailed the introduction of elevated levels of glucose (HG) and palmitic acid (PA) to induce glycolipid toxicity in H9c2 cardiomyocytes. Further deterioration of cardiac function was detected by echocardiography after the clock gene rev-erbα was knocked out. This was accompanied by significant elevations in markers of inflammation, myocardial fibrosis, and oxidative stress. In addition, iron content, transmission electron microscopy (TEM), and RT-PCR assays confirmed significantly increased levels of ferroptosis in rev-erbα-deficient DCM. Intriguingly, Co-Immunoprecipitation (Co-IP) data uncovered an interaction between rev-erbα and nuclear factor E2-related factor 2 (NRF2) in diabetic myocardial tissues. It is worth highlighting that ferroptosis within cardiomyocytes witnessed significant mitigation upon the administration of sulforaphane (SFN), an NRF2 agonist, to HG + PA-incubated H9c2 cells. Our study demonstrates for the first time that knockdown of the clock gene rev-erbα exacerbates myocardial injury and ferroptosis in type 2 diabetic mice, which can be reversed by activating NRF2.

Galangin: A food-derived flavonoid with therapeutic potential against a wide spectrum of diseases

Galangin is an important flavonoid with natural activity, that is abundant in galangal and propolis. Currently, various biological activities of galangin have been disclosed, including anti-inflammation, antibacterial effect, anti-oxidative stress and aging, anti-fibrosis, and antihypertensive effect. Based on the above bioactivities, more and more attention has been paid to the role of galangin in neurodegenerative diseases, rheumatoid arthritis, osteoarthritis, osteoporosis, skin diseases, and cancer. In this paper, the natural sources, pharmacokinetics, bioactivities, and therapeutic potential of galangin against various diseases were systematically reviewed by collecting and summarizing relevant literature. In addition, the molecular mechanism and new preparation of galangin in the treatment of related diseases are also discussed, to broaden the application prospect and provide reference for its clinical application. Furthermore, it should be noted that current toxicity and clinical studies of galangin are insufficient, and more evidence is needed to support its possibility as a functional food.

Galangin attenuates doxorubicin-induced cardiotoxicity via activating nuclear factor erythroid 2-related factor 2/heme oxygenase 1 signaling pathway to suppress oxidative stress and inflammation

Doxorubicin (DOX) has aroused contradiction between its potent anti-tumor capacity and severe cardiotoxicity. Galangin (Gal) possesses antioxidant, anti-inflammatory, and antiapoptotic activities. We aimed to explore the role and underlying mechanisms of Gal on DOX-induced cardiotoxicity. Mice were intraperitoneally injected with DOX (3 mg/kg, every 2 days for 2 weeks) to generate cardiotoxicity model and Gal (15 mg/kg, 2 weeks) was co-administered via gavage daily. Nuclear factor erythroid 2-related factor 2 (Nrf2) specific inhibitor, ML385, was employed to explore the underlying mechanisms. Compared to DOX-insulted mice, Gal effectively improved cardiac dysfunction and ameliorated myocardial damage. DOX-induced increase of reactive oxygen species, malondialdehyde, and NADPH oxidase activity and downregulation of superoxide dismutase (SOD) activity were blunted by Gal. Gal also markedly blocked increase of IL-1β, IL-6, and TNF-α in DOX-insulted heart. Mechanistically, Gal reversed DOX-induced downregulation of Nrf2, HO-1, and promoted nuclear translocation of Nrf2. ML385 markedly blunted the cardioprotective effects of Gal, as well as inhibitive effects on oxidative stress and inflammation. Gal ameliorates DOX-induced cardiotoxicity by suppressing oxidative stress and inflammation via activating Nrf2/HO-1 signaling pathway. Gal may serve as a promising cardioprotective agent for DOX-induced cardiotoxicity.

Chinese herbal medicine and active ingredients for diabetic cardiomyopathy: molecular mechanisms regulating endoplasmic reticulum stress

Background: Diabetic cardiomyopathy (DCM) is one of the serious microvascular complications of diabetes mellitus. It is often associated with clinical manifestations such as arrhythmias and heart failure, and significantly reduces the quality of life and years of survival of patients. Endoplasmic reticulum stress (ERS) is the removal of unfolded and misfolded proteins and is an important mechanism for the maintenance of cellular homeostasis. ERS plays an important role in the pathogenesis of DCM by causing cardiomyocyte apoptosis, insulin resistance, calcium imbalance, myocardial hypertrophy and fibrosis. Targeting ERS is a new direction in the treatment of DCM. A large number of studies have shown that Chinese herbal medicine and active ingredients can significantly improve the clinical outcome of DCM patients through intervention in ERS and effects on myocardial structure and function, which has become one of the hot research directions. Purpose: The aim of this review is to elucidate and summarize the roles and mechanisms of Chinese herbal medicine and active ingredients that have the potential to modulate endoplasmic reticulum stress, thereby contributing to better management of DCM. Methods: Databases such as PubMed, Web of Science, China National Knowledge Internet, and Wanfang Data Knowledge Service Platform were used to search, analyze, and collect literature, in order to review the mechanisms by which phytochemicals inhibit the progression of DCM by targeting the ERS and its key signaling pathways. Keywords used included "diabetic cardiomyopathy" and "endoplasmic reticulum stress." Results: This review found that Chinese herbs and their active ingredients can regulate ERS through IRE1, ATF6, and PERK pathways to reduce cardiomyocyte apoptosis, ameliorate myocardial fibrosis, and attenuate myocardial hypertrophy for the treatment of DCM. Conclusion: A comprehensive source of information on potential ERS inhibitors is provided in this review. The analysis of the literature suggests that Chinese herbal medicine and its active ingredients can be used as potential drug candidates for the treatment of DCM. In short, we cannot ignore the role of traditional Chinese medicine in regulating ERS and treating DCM, and look forward to more research and new drugs to come.

Linderalactone mitigates diabetic cardiomyopathy in mice via suppressing the MAPK/ATF6 pathway

Diabetic cardiomyopathy (DCM) is a challenging diabetic complication that manifests as chronic inflammation. Yet, the mechanism underlying diabetes-associated myocardial injury is not fully understood. We investigated the pharmacological effects and mechanisms of linderalactone, a natural compound that can prevent diabetes-induced cardiomyopathy in mice. Diabetes was induced by a single dose of streptozotocin (120 mg/kg, i.p.). Diabetic mice were administrated with linderalactone (2.5 or 5 mg/kg) by gavage for five weeks. Harvested heart tissues were then subjected to RNA-sequencing analysis to explore the potential mechanism of linderalactone. Linderalactone prevented heart dysfunction by inhibiting myocardial hypertrophy, fibrosis, and inflammation, without altering blood glucose. RNA-sequencing indicated that linderalactone exerted its cardioprotective effects mainly by affecting the mitogen-activated protein kinase (MAPK)/ activating transcription factor 6 (ATF6) pathway. Linderalactone also suppressed endoplasmic reticulum (ER) stress mediated by the diabetes-activated MAPKs/ATF6 pathway, thereby reducing myocardial hypertrophy and inflammation in heart tissues and in cultured cardiomyocytes. Inhibition of MAPKs or a deficiency of ATF6 in cardiomyocytes mimicked the linderalactone-associated decreases in high glucose-induced hypertrophy and inflammation. Linderalactone showed beneficial effects in alleviating diabetic cardiomyopathy, in part by modulating the MAPK/ATF6 signaling pathway to mitigate myocardial hypertrophy and inflammation. Linderalactone may have clinical utility in the treatment for diabetes-associated cardiomyopathy.

Potential Benefits of Antioxidant Phytochemicals in Type 2 Diabetes

The clinical relationship between diabetes and inflammation is well established. Evidence clearly indicates that disrupting oxidant-antioxidant equilibrium and elevated lipid peroxidation could be a potential mechanism for chronic kidney disease associated with type 2 diabetes mellitus (T2DM). Under diabetic conditions, hyperglycemia, especially inflammation, and increased reactive oxygen species generation are bidirectionally associated. Inflammation, oxidative stress, and tissue damage are believed to play a role in the development of diabetes. Although the exact mechanism underlying oxidative stress and its impact on diabetes progression remains uncertain, the hyperglycemia-inflammation-oxidative stress interaction clearly plays a significant role in the onset and progression of vascular disease, kidney disease, hepatic injury, and pancreas damage and, therefore, holds promise as a therapeutic target. Evidence strongly indicates that the use of multiple antidiabetic medications fails to achieve the normal range for glycated hemoglobin targets, signifying treatment-resistant diabetes. Antioxidants with polyphenols are considered useful as adjuvant therapy for their potential anti-inflammatory effect and antioxidant activity. We aimed to analyze the current major points reported in preclinical, in vivo, and clinical studies of antioxidants in the prevention or treatment of inflammation in T2DM. Then, we will share our speculative vision for future diabetes clinical trials.

Esculeoside A Decreases Diabetic Cardiomyopathy in Streptozotocin-Treated Rats by Attenuating Oxidative Stress, Inflammation, Fibrosis, and Apoptosis: Impressive Role of Nrf2

Background and Objectives: This experiment evaluated the preventative influence of the tomato-derived Esculeoside A (ESA) on diabetic cardiomyopathy in type 1 diabetes mellitus (T1DM) in rats induced by streptozotocin (STZ). It also examined whether the activation of Nrf2 signaling affords this protection. Materials and Methods: Adult male Wistar control nondiabetic rats and rats with T1DM (STZ-T1DM) were given either carboxymethylcellulose as a vehicle or ESA (100 mg/kg) (eight rats/group) orally daily for 12 weeks. A group of STZ-T1DM rats was also treated with 100 mg/kg ESA and co-treated i.p. with 2 mg/kg (twice/week), brusatol, and Nrf2 inhibitors for 12 weeks. Results and Conclusions: Treatment with ESA prevented the gain in heart weight and cardiomyocyte hypertrophy and improved the left ventricular (LV) systolic and diastolic function (LV) in the STZ-T1DM rat group. Likewise, it reduced their serum levels of triglycerides, cholesterol, and low-density lipoproteins (LDL-c), as well as their LV mRNA, cytoplasmic total, and nuclear total levels of NF-κB. ESA also reduced the total levels of malondialdehyde, tumor necrosis factor-α, interleukine-6 (IL-6), Bax, cytochrome-c, and caspase-3 in the LV of the STZ-T1DM rats. In parallel, ESA enhanced the nuclear and cytoplasmic levels of Nrf2 and the levels of superoxide dismutase, glutathione, and heme oxygenase-1, but decreased the mRNA and cytoplasmic levels of keap-1 in the LVs of the STZ-T1DM rats. Interestingly, ESA did not affect the fasting insulin and glucose levels of the diabetic rats. All of these beneficially protective effects of ESA were not seen in the ESA-treated rats that received brusatol. In conclusion, ESA represses diabetic cardiomyopathy in STZ-diabetic hearts by activating the Nrf2/antioxidant/NF-κB axis.

Galangin Attenuates Myocardial Ischemic Reperfusion-Induced Ferroptosis by Targeting Nrf2/Gpx4 Signaling Pathway

Purpose

Myocardial ischemic reperfusion injury (MIRI) is a crucial clinical problem globally. The molecular mechanisms of MIRI need to be fully explored to develop new therapeutic methods. Galangin (Gal), which is a natural flavonoid extracted from Alpinia Officinarum Hance and Propolis, possesses a wide range of pharmacological activities, but its effects on MIRI remain unclear. This study aimed to determine the pharmacological effects of Gal on MIRI.

Methods

C57BL/6 mice underwent reperfusion for 3 h after 45 min of ischemia, and neonatal rat cardiomyocytes (NRCs) subjected to hypoxia and reoxygenation (HR) were cultured as in vivo and in vitro models. Echocardiography and TTC-Evans Blue staining were performed to evaluate the myocardial injury. Transmission electron microscope and JC-1 staining were used to validate the mitochondrial function. Additionally, Western blot detected ferroptosis markers, including Gpx4, FTH, and xCT.

Results

Gal treatment alleviated cardiac myofibril damage, reduced infarction size, improved cardiac function, and prevented mitochondrial injury in mice with MIRI. Gal significantly alleviated HR-induced cell death and mitigated mitochondrial membrane potential reduction in NRCs. Furthermore, Gal significantly inhibited ferroptosis by preventing iron overload and lipid peroxidation, as well as regulating Gpx4, FTH, and xCT expression levels. Moreover, Gal up-regulated nuclear transcriptive factor Nrf2 in HR-treated NRCs. Nrf2 inhibition by Brusatol abolished the protective effect of Gal against ferroptosis.

Conclusion

This study revealed that Gal alleviates myocardial ischemic reperfusion-induced ferroptosis by targeting Nrf2/Gpx4 signaling pathway.

MiR-29c alleviates hyperglycemia-induced inflammation via targeting TGF-β in cardiomyocytes

This study aims to investigate whether miR-29c is involved in regulating transforming growth factor-β (TGF-β) mediated inflammation in diabetic cardiomyopathy (DCM). Our data showed increased inflammation and oxidative stress in diabetic myocardium together with decrease of miR-29c and elevation of TGF-β expression. In vitro experiments, we transfected miR-29c mimic and antagomir into HL-1 cells to explore the effect of miR-29c on inflammation in hyperglycemic conditions. Overexpression of miR-29c down-regulated the elevated TNF-α level, ROS production and NADPH oxidase activity which caused by high glucose. However, above changes were reversed by miR-29c antagomir. Interestingly, TGF-β protein rather than mRNA expression was changed significantly after transfection with miR-29c mimic, indicating that the modulation of TGF-β mediated by miR-29c was at the posttranslational level. Meanwhile, we found that 3'-UTR of TGF-β was the direct target of miR-29c confirmed by dual-luciferase assay. In conclusion, our study revealed that miR-29c could alleviate hyperglycemic-induced inflammation and ROS production via targeting TGF-β in cardiomyocytes, which provides a potential target for the treatment of DCM.

β-Caryophyllene, a Dietary Phytocannabinoid, Alleviates Diabetic Cardiomyopathy in Mice by Inhibiting Oxidative Stress and Inflammation Activating Cannabinoid Type-2 Receptors

Diabetes mellitus (DM) and its associated complications are considered one of the major health risks globally. Among numerous complications, diabetic cardiomyopathy (DCM) is characterized by increased accumulation of lipids and reduced glucose utilization following abnormal lipid metabolism in the myocardium along with oxidative stress, myocardial fibrosis, and inflammation that eventually result in cardiac dysfunction. The abnormal metabolism of lipids plays a fundamental role in cardiac lipotoxicity following the occurrence and development of DCM. Recently, it has been revealed that cannabinoid type-2 (CB2) receptors, an essential component of the endocannabinoid system, play a crucial role in the pathogenesis of obesity, hyperlipidemia, and DM. Provided the role of CB2R in regulating the glucolipid metabolic dysfunction and its antioxidant as well as anti-inflammatory activities, we carried out the current study to investigate the protective effects of a selective CB2R agonist, β-caryophyllene (BCP), a natural dietary cannabinoid in the murine model of DCM and elucidated the underlying pharmacological and molecular mechanisms. Mice were fed a high-fat diet for 4 weeks followed by a single intraperitoneal injection of streptozotocin (100 mg/kg) to induce the model of DCM. BCP (50 mg/kg body weight) was given orally for 12 weeks. AM630, a CB2R antagonist, was given 30 min before BCP treatment to demonstrate the CB2R-dependent mechanism of BCP. DCM mice exhibited hyperglycemia, increased serum lactate dehydrogenase, impaired cardiac function, and hypertrophy. In addition, DCM mice showed alternations in serum lipids and increased oxidative stress concomitant to reduced antioxidant defenses and enhanced cardiac lipid accumulation in the diabetic heart. DCM mice also exhibited activation of TLR4/NF-κB/MAPK signaling and triggered the production of inflammatory cytokines and inflammatory enzyme mediators. However, treatment with BCP exerted remarkable protective effects by favorable modulation of the biochemical and molecular parameters, which were altered in DCM mice. Interestingly, pretreatment with AM630 abrogated the protective effects of BCP in DCM mice. Taken together, the findings of the present study demonstrate that BCP possesses the capability to mitigate the progression of DCM by inhibition of lipotoxicity-mediated cardiac oxidative stress and inflammation and favorable modulation of TLR4/NF-κB/MAPK signaling pathways mediating the CB2R-dependent mechanism.

Modulation of TLR4/NFκB Pathways in Autoimmune Myocarditis

Myocarditis is an inflammatory and oxidative disorder characterized by immune cell recruitment in the damaged tissue and organ dysfunction. In this paper, we evaluated the molecular pathways involved in myocarditis using a natural compound, Coriolus versicolor, in an experimental model of autoimmune myocarditis (EAM). Animals were immunized with an emulsion of pig cardiac myosin and complete Freund's adjuvant supplemented with mycobacterium tuberculosis; thereafter, Coriolus versicolor (200 mg/Kg) was orally administered for 21 days. At the end of the experiment, blood pressure and heart rate measurements were recorded and the body and heart weights as well. From the molecular point of view, the Coriolus versicolor administration reduced the activation of the TLR4/NF-κB pathway and the levels of pro-inflammatory cytokines (INF-γ, TNF-α, IL-6, IL-17, and IL-2) and restored the levels of anti-inflammatory cytokines (IL-10). These anti-inflammatory effects were accompanied with a reduced lipid peroxidation and nitrite levels and restored the antioxidant enzyme activities (SOD and CAT) and GSH levels. Additionally, it reduced the histological injury and the immune cell recruitment (CD4+ and CD68+ cells). Moreover, we observed an antiapoptotic activity in both intrinsic (Fas/FasL/caspase-3) and extrinsic (Bax/Bcl-2) pathways. Overall, our data showed that Coriolus versicolor administration modulates the TLR4/NF-κB signaling in EAM.

Diabetic cardiomyopathy: Early diagnostic biomarkers, pathogenetic mechanisms, and therapeutic interventions

Diabetic cardiomyopathy (DCM) mainly refers to myocardial metabolic dysfunction caused by high glucose, and hyperglycemia is an independent risk factor for cardiac function in the absence of coronary atherosclerosis and hypertension. DCM, which is a severe complication of diabetes, has become the leading cause of heart failure in diabetic patients. The initial symptoms are inconspicuous, and patients gradually exhibit left ventricular dysfunction and eventually develop total heart failure, which brings a great challenge to the early diagnosis of DCM. To date, the underlying pathological mechanisms of DCM are complicated and have not been fully elucidated. Although there are therapeutic strategies available for DCM, the treatment is mainly focused on controlling blood glucose and blood lipids, and there is a lack of effective drugs targeting myocardial injury. Thus, a large percentage of patients with DCM inevitably develop heart failure. Given the neglected initial symptoms, the intricate cellular and molecular mechanisms, and the lack of available drugs, it is necessary to explore early diagnostic biomarkers, further understand the signaling pathways involved in the pathogenesis of DCM, summarize the current therapeutic strategies, and develop new targeted interventions.

Protective Mechanism Pathway of Swietenia macrophylla Extract Nanoparticles against Cardiac Cell Damage in Diabetic Rats

Hyperglycemia causes cardiac cell damage through increasing ROS production during diabetic complications. The current study proves the antioxidant activity of Swietenia macrophylla (S. macrophylla) extract nanoparticles as a protector against streptozotocin (STZ)-induced cardiac cell damage. In this research, high-energy ball milling is used to create S. macrophylla extract nanoparticles. The active chemical compounds in the S. macrophylla extract nanoparticles were analyzed through phytochemical screening and GC-MS. Furthermore, we characterized the size of S. macrophylla extract nanoparticles with Dynamic Light Scattering (DLS). Forty male rats were divided randomly into five groups. In the control group, rats received aqua dest orally; in the diabetic group, rats were injected intraperitoneally with STZ; in the S. macrophylla group, rats were injected with STZ and orally given S. macrophylla extract nanoparticles. The results of phytochemical screening showed that S. macrophylla extract nanoparticles contain saponins, flavonoids, alkaloids, phenolics and tannins. Seven chemical compounds in S. macrophylla extract nanoparticles were identified using GC-MS, including phenol, piperidine, imidazole, hexadecene, heptadecanol, dihexylsulfide and heptanol. DLS showed that the S. macrophylla extract nanoparticles' size was 91.50 ± 23.06 nm. Injection with STZ significantly increased malondialdehyde (MDA) levels in cardiac tissue and creatine kinase-myocardial band (CK-MB) and lactate dehydrogenase (LDH) levels in serum. STZ also significantly reduced the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and the level of superoxide dismutase (SOD) and glutathione peroxidase (GPx) in cardiac tissue compared with the control group (p < 0.05). In contrast, the administration of S. macrophylla extract nanoparticles can prevent STZ-induced cardiac cell damage through decreasing the level of CK-MB and LDH in serum and the level of MDA in cardiac tissue. S. macrophylla extract nanoparticles also significantly increased Nrf2 expression as well as SOD and GPx levels in cardiac tissue. These effects are related to the prevention of cardiac histopathological alteration (degeneration and necrosis) in diabetic rats. These results suggest that S. macrophylla nanoparticles contain active compounds such as flavonoids, phenols, piperidine, imidazole and hexadecene and have strong antioxidant activity. These can act as a potential cardioprotective agent against STZ-induced cardiac cell damage due to its antioxidant properties.

A flavonoid-rich fraction of Euphorbia peplus attenuates hyperglycemia, insulin resistance, and oxidative stress in a type 2 diabetes rat model

Background: Type 2 diabetes (T2D) is a metabolic disorder characterized by insulin resistance (IR) and hyperglycemia. Plants are valuable sources of therapeutic agents for the management of T2D. Euphorbia peplus has been widely used as a traditional medicine for the treatment of various diseases, but its beneficial role in T2D has not been fully explored. Methods: The anti-diabetic efficacy of E. peplus extract (EPE) was studied using rats with T2D induced by high-fat diet (HFD) and streptozotocin (STZ). The diabetic rats received 100, 200, and 400 mg/kg EPE for 4 weeks. Results: Phytochemical fractionation of the aerial parts of E. peplus led to the isolation of seven known flavonoids. Rats with T2D exhibited IR, impaired glucose tolerance, decreased liver hexokinase and glycogen, and upregulated glycogen phosphorylase, glucose-6-phosphatase (G-6-Pase), and fructose-1,6-bisphosphatase (F-1,6-BPase). Treatment with 100, 200, and 400 mg/kg EPE for 4 weeks ameliorated hyperglycemia, IR, liver glycogen, and the activities of carbohydrate-metabolizing enzymes. EPE attenuated dyslipidemia, serum transaminases, tumor necrosis factor (TNF)-α, interleukin (IL)-1β and liver lipid accumulation, nuclear factor (NF)-κB p65, and lipid peroxidation, nitric oxide and enhanced antioxidants. All EPE doses upregulated serum adiponectin and liver peroxisome proliferator-activated receptor γ (PPARγ) in HFD/STZ-induced rats. The isolated flavonoids showed in silico binding affinity toward hexokinase, NF-κB, and PPARγ. Conclusion: E. peplus is rich in flavonoids, and its extract ameliorated IR, hyperglycemia, dyslipidemia, inflammation and redox imbalance, and upregulated adiponectin and PPARγ in rats with T2D.

Focal adhesion kinase induces cardiac remodeling through NF-κB-mediated inflammatory responses in diabetic cardiomyopathy

BACKGROUND

Hyperglycemia-induced chronic inflammation is a crucial risk factor that causes undesirable cardiac alternations in diabetic cardiomyopathy (DCM). Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase that primarily regulates cell adhesion and migration. Based on recent studies, FAK is involved in inflammatory signaling pathway activation in cardiovascular diseases. Here, we evaluated the possibility of FAK as a therapeutic target for DCM.

METHODS

A small molecular selective FAKinhibitor, PND-1186 (PND), was used to evaluate the effect of FAK on DCM in both high glucose-stimulated cardiomyocytes and streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) mice.

RESULTS

Increased FAK phosphorylation was found in the hearts of STZ-induced T1DM mice. PND treatment significantly decreased the expression of inflammatory cytokines and fibrogenic markers in cardiac specimens of diabetic mice. Notably, these reductions were correlated with improved cardiac systolic function. Furthermore, PND suppressed transforming growth factor-β-activated kinase 1 (TAK1) phosphorylation and NF-κB activation in the hearts of diabetic mice. Cardiomyocytes were identified as the main contributor to FAK-mediated cardiac inflammation and the involvement of FAK in cultured primary mouse cardiomyocytes and H9c2 cells was identified. Both FAK inhibition or FAK deficiency prevented hyperglycemia-induced inflammatory and fibrotic responses in cardiomyocytes owing to the inhibition of NF-κB. Herein, FAK activation was revealed to FAK directly binding to TAK1, leading to activation of TAK1 and downstream NF-κB signaling pathway.

CONCLUSIONS

FAK is a key regulator of diabetes-associated myocardial inflammatory injury by directly targeting to TAK1.

Galangin alleviated myocardial ischemia-reperfusion injury by enhancing autophagic flux and inhibiting inflammation

Autophagy is critically involved in myocardial ischemia-reperfusion (I/R). Autophagy inhibition exacerbates myocardial I/R injury. Few effective agents target autophagy to prevent myocardial I/R injury. Effective drugs that promote autophagy in myocardial I/R warrant further investigation. Galangin (Gal) enhances autophagy and alleviates I/R injury. Here we conducted both in vivo and in vitro experiments to observe the changes in autophagy after galangin treatment and investigated the cardioprotective effects of galangin on myocardial I/R.

METHODS

After 45-min occlusion of the left anterior descending coronary artery, myocardial I/R was induced by slipknot release. One day before surgery and immediately after surgery, the mice were injected intraperitoneally with the same volume of saline or Gal. The effects of Gal were evaluated using echocardiography, 2,3,5-triphenyltetrazolium chloride staining (TTC staining), western blotting, and transmission electron microscopy. Primary cardiomyocytes and bone marrow-derived macrophages were extracted in vitro to measure the cardioprotective effects of Gal.

RESULTS

Compared with the saline-treated group, Gal significantly improved cardiac function and limited infarct enlargement after myocardial I/R. In vivo and in vitro studies demonstrated that Gal treatment promoted autophagy during myocardial I/R. The anti-inflammatory effects of Gal were validated in bone marrow-derived macrophages. These results strongly suggest that Gal treatment can attenuate myocardial I/R injury.

CONCLUSION

Our data demonstrated that Gal could improve left ventricular ejection fraction and reduce infarct size after myocardial I/R by promoting autophagy and inhibiting inflammation.

Galangin as an inflammatory response modulator: An updated overview and therapeutic potential

Numerous chronic diseases, such as cancer, diabetes, rheumatoid arthritis, cardiovascular disease, and gastrointestinal disorders, all have an inflammation-based etiology. In cellular and animal models of inflammation, flavonols were used to show potent anti-inflammatory activity. The flavonols enhanced the synthesis of the anti-inflammatory cytokines transforming growth factor and interleukin-10 (IL-10) and reduced the synthesis of the prostaglandins IL-6, tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2), IL-1. Galangin (GAL), a natural flavonol, has a strong ability to control apoptosis and inflammation. GAL was discovered to suppress extracellular signal-regulated kinase (ERK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)p65 phosphorylation, which results in anti-inflammatory actions. Arthritis, inflammatory bronchitis, stroke, and cognitive dysfunction have all been treated with GAL. The current review aimed to demonstrate the anti-inflammatory properties of GAL and their protective effects in treating various chronic illnesses, including those of the heart, brain, skin, lungs, liver, and inflammatory bowel diseases.

Betulinic acid protects against cardiotoxicity of the organophosphorus pesticide chlorpyrifos by suppressing oxidative stress, inflammation, and apoptosis in rats

The widespread application of organophosphorus (OP) pesticides can affect the environment as well as the animal and human health. Chlorpyrifos (CPF) is a broad-spectrum OP pesticide used in agriculture and can cause several toxic effects in which oxidative stresses and inflammation play a key role. This study aimed to evaluate the protective activity of betulinic acid (BA), an antioxidant and anti-inflammatory pentacyclic triterpene, against CPF cardiotoxicity in rats. The rats were divided into four groups. CPF (10 mg/kg) and BA (25 mg/kg) were orally administered for 28 days, and blood and heart samples were collected. CPF-administered rats showed an increase in serum cardiac troponin I (cTnI), creatine kinase (CK)-MB, and lactate dehydrogenase (LDH), accompanied with multiple myocardial tissue alterations. Lipid peroxidation (LPO), nitric oxide (NO), nuclear factor-kappaB (NF-κB), interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α were increased, and antioxidant were decrease in CPF-administered rats. BA ameliorated cardiac function markers and tissue injury, decreased LPO, NO, NF-κB, and proinflammatory cytokines, and increased antioxidants. In addition, BA decreased proapoptosis markers, and increased B-cell lymphoma (Bcl)-2, IL-10, Nrf2, and HO-1 in the heart of CPF-treated rats. In conclusion, BA protected against cardiotoxicity in CPF-administered rats by mitigating oxidative stress, inflammation, and apoptosis, and enhanced Nrf2 and antioxidants.

Arbutin ameliorates hyperglycemia, dyslipidemia and oxidative stress and modulates adipocytokines and PPARγ in high-fat diet/streptozotocin-induced diabetic rats

Arbutin is a glycosylated hydroquinone with antioxidant and anti-hyperglycemia effects. However, its beneficial effects in type 2 diabetes (T2D) were not clarified. This study evaluated the effect of arbutin on hyperglycemia, dyslipidemia, insulin resistance, oxidative stress, and inflammatory response in T2D. Rats induced by high fat diet and streptozotocin were treated with arbutin (25 and 50 mg/kg for 4 weeks). Diabetic rats exhibited glucose intolerance, elevated HbA1c%, reduced insulin, and high HOMA-IR. Liver glycogen and hexokinase activity were decreased in T2D rats while glucose-6-phosphatase (G6Pase), fructose-1,6- biphosphatase (FBPase), and glycogen phosphorylase were upregulated. Circulating and hepatic cholesterol and triglycerides and serum transaminases were elevated in T2D rats. Arbutin ameliorated hyperglycemia, dyslipidemia, insulin deficiency and resistance, and liver glycogen and alleviated the activity of carbohydrate-metabolizing enzymes. Both doses of arbutin decreased serum transaminases and resistin, and liver lipids, TNF-α, IL-6, malondialdehyde and nitric oxide, downregulated liver resistin and fatty acid synthase, and increased serum and liver adiponectin, and liver reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT). These effects were associated with the upregulation of hepatic PPARγ. Arbutin inhibited α-glucosidase in vitro and in silico investigations revealed the ability of arbutin to bind PPARγ, hexokinase, and α-glucosidase. In conclusion, arbutin effectively ameliorated glucose intolerance, insulin resistance, dyslipidemia, inflammation, and oxidative stress, and modulated carbohydrate-metabolizing enzymes, antioxidants, adipokines and PPARγ in T2D in rats.

Oxymatrine and insulin resistance: Focusing on mechanistic intricacies involve in diabetes associated cardiomyopathy via SIRT1/AMPK and TGF-β signaling pathway

Cardiomyopathy (CDM) and related morbidity and mortality are increasing at an alarming rate, in large part because of the increase in the number of diabetes mellitus cases. The clinical consequence associated with CDM is heart failure (HF) and is considerably worse for patients with diabetes mellitus, as compared to nondiabetics. Diabetic cardiomyopathy (DCM) is characterized by structural and functional malfunctioning of the heart, which includes diastolic dysfunction followed by systolic dysfunction, myocyte hypertrophy, cardiac dysfunctional remodeling, and myocardial fibrosis. Indeed, many reports in the literature indicate that various signaling pathways, such as the AMP-activated protein kinase (AMPK), silent information regulator 1 (SIRT1), PI3K/Akt, and TGF-β/smad pathways, are involved in diabetes-related cardiomyopathy, which increases the risk of functional and structural abnormalities of the heart. Therefore, targeting these pathways augments the prevention as well as treatment of patients with DCM. Alternative pharmacotherapy, such as that using natural compounds, has been shown to have promising therapeutic effects. Thus, this article reviews the potential role of the quinazoline alkaloid, oxymatrine obtained from the Sophora flavescensin CDM associated with diabetes mellitus. Numerous studies have given a therapeutic glimpse of the role of oxymatrine in the multiple secondary complications related to diabetes, such as retinopathy, nephropathy, stroke, and cardiovascular complications via reductions in oxidative stress, inflammation, and metabolic dysregulation, which might be due to targeting signaling pathways, such as AMPK, SIRT1, PI3K/Akt, and TGF-β pathways. Thus, these pathways are considered central regulators of diabetes and its secondary complications, and targeting these pathways with oxymatrine might provide a therapeutic tool for the diagnosis and treatment of diabetes-associated cardiomyopathy.

Potential clinical biomarkers and perspectives in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious cardiovascular complication and the leading cause of death in diabetic patients. Patients typically do not experience any symptoms and have normal systolic and diastolic cardiac functions in the early stages of DCM. Because the majority of cardiac tissue has already been destroyed by the time DCM is detected, research must be conducted on biomarkers for early DCM, early diagnosis of DCM patients, and early symptomatic management to minimize mortality rates among DCM patients. Most of the existing implemented clinical markers are not very specific for DCM, especially in the early stages of DCM. Recent studies have shown that a number of new novel markers, such as galactin-3 (Gal-3), adiponectin (APN), and irisin, have significant changes in the clinical course of the various stages of DCM, suggesting that we may have a positive effect on the identification of DCM. As a summary of the current state of knowledge regarding DCM biomarkers, this review aims to inspire new ideas for identifying clinical markers and related pathophysiologic mechanisms that could be used in the early diagnosis and treatment of DCM.

Ultrasound-assisted extraction of polyphenols from Chinese propolis

Introduction

Propolis is a beneficial bioactive food with rich polyphenols content. Nowadays, an increasing interest is attracted to the extraction of polyphenols from raw propolis. This study utilized the novel ultrasound-assisted approach for polyphenol extraction from Chinese propolis, aiming to improve its extraction yield and reveal the relevant mechanisms via extraction kinetic study as well as the compositional and structural analysis.

Methods

The optimum ultrasound-assisted extraction conditions were optimized according to the total phenolic content and total flavonoids content. Compositional and structural analysis were conducted using high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry, high-performance liquid chromatography, Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM).

Results and discussion

The optimum ultrasound-assisted extraction conditions were as follows: ratio of liquid to solid, 60:1; ultrasound power, 135 W; ultrasound duration, 20 min. Under the optimum conditions, the antioxidant activities of the extract were increased by 95.55% and 64.46% by 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability assay and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability assay, respectively, compared to those obtained by traditional maceration. The second-order kinetics model was employed to study the extraction process; it was found that ultrasound significantly accelerated the extraction of propolis and increased the maximum extraction volume of phenolic compounds. The qualitative and quantitative analysis of polyphenol compositions showed that ultrasound did not change the polyphenol types in the extract but it significantly improved the contents of various flavonoids and phenolic acids such as galangin, chrysin, pinocembrin, pinobanksin and isoferulic acid. Likewise, the FT-IR analysis indicated that the types of functional groups were similar in the two extracts. The SEM analysis revealed that the ultrasound-assisted extraction enhanced the contact areas between propolis and ethanol by breaking down the propolis particles and eroding the propolis surface.

Beneficial effects of quercetin on vincristine-induced liver injury in rats: Modulating the levels of Nrf2/HO-1, NF-kB/STAT3, and SIRT1/PGC-1α

Our experimental objective was to investigate the hepatotoxic effect of vincristine (VCR) administration in rats and determined whether combined therapy with Quercetin (Quer) ensured protection. Five groups with seven rats each were used for this purpose, and experimental groups were formulated as follows: Control group; Quer group; VCR group; VCR plus Quer 25 group; VCR plus Quer 50 group. The results showed that VCR significantly increased the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes. Besides, VCR caused considerable increases in the malondialdehyde (MDA) contents, along with significant decreases in reduced glutathione levels, superoxide dismutase, catalase, and glutathione peroxidase enzyme activities in the rat livers. Quer treatment in VCR toxicity markedly decreased the activity of ALT, AST, ALP enzymes, and MDA contents and enhanced the activities of antioxidant enzymes. The results also showed that VCR significantly increased the levels of NF-kB, STAT3, and the expression of caspase 3, Bax, and MAP LC3 and decreased the expression of Bcl2 and levels of Nrf2, HO-1, SIRT1, and PGC-1α. Compared to the VCR group, Quer treatment exhibited significantly lower levels of NF-kB, STAT3, and the expression of caspase 3, Bax, and MAP LC3, and higher levels of Nrf2, HO-1, SIRT1, and PGC-1α. In conclusion, our study demonstrated that Quer could alleviate the harmful effects of VCR via activation of NRf2/HO-1 and SIRT1/PGC-1α pathways, and via attenuation of oxidative stress, apoptosis, autophagy, and NF-kB/STAT3 pathways.

Dihydromyricetin Attenuates Diabetic Cardiomyopathy by Inhibiting Oxidative Stress, Inflammation and Necroptosis via Sirtuin 3 Activation

Dihydromyricetin (DHY), the main flavonoid component in Ampelopsis grossedentata, has important benefits for health. The present study aimed to investigate the exact effects and possible mechanisms of DHY on diabetic cardiomyopathy (DCM). Male C57BL/6 mice and sirtuin 3 (SIRT3) knockout (SIRT3-KO) mice were injected with streptozotocin (STZ) to induce a diabetic model. Two weeks later, DHY (250 mg/kg) or carboxymethylcellulose (CMC) were administrated once daily by gavage for twelve weeks. We found that DHY alleviated fasting blood glucose (FBG) and triglyceride (TG) as well as glycosylated hemoglobin (HbA1c) levels; increased fasting insulin (FINS); improved cardiac dysfunction; ameliorated myocardial hypertrophy, fibrosis and injury; suppressed oxidative stress, inflammasome and necroptosis; but improved SIRT3 expression in STZ-induced mice. Neonatal rat cardiomyocytes were pre-treated with DHY (80 μM) with or without high glucose (HG) stimulation. The results showed that DHY attenuated cell damage but improved SIRT3 expression and inhibited oxidative stress, inflammasome and necroptosis in cardiomyocytes with high glucose stimulation. Moreover, the above protective effects of DHY on DCM were unavailable in SIRT3-KO mice, implying a promising medical potential of DHY for DCM treatment. In sum, DHY improved cardiac dysfunction; ameliorated myocardial hypertrophy, fibrosis and injury; and suppressed oxidative stress, inflammation and necroptosis via SIRT3 activation in STZ-induced diabetic mice, suggesting DHY may serve as a candidate for an agent to attenuate diabetic cardiomyopathy.

Targeting epigenetics in diabetic cardiomyopathy: Therapeutic potential of flavonoids

The pathophysiological mechanisms of diabetic cardiomyopathy have been extensively studied, but there is still a lack of effective prevention and treatment methods. The ability of flavonoids to protect the heart from diabetic cardiomyopathy has been extensively described. In recent years, epigenetics has received increasing attention from scholars in exploring the etiology and treatment of diabetes and its complications. DNA methylation, histone modifications and non-coding RNAs play key functions in the development, maintenance and progression of diabetic cardiomyopathy. Hence, prevention or reversal of the epigenetic alterations that have occurred during the development of diabetic cardiomyopathy may alleviate the personal and social burden of the disease. Flavonoids can be used as natural epigenetic modulators in alternative therapies for diabetic cardiomyopathy. In this review, we discuss the epigenetic effects of different flavonoid subtypes in diabetic cardiomyopathy and summarize the evidence from preclinical and clinical studies that already exist. However, limited research is available on the potential beneficial effects of flavonoids on the epigenetics of diabetic cardiomyopathy. In the future, clinical trials in which different flavonoids exert their antidiabetic and cardioprotective effects through various epigenetic mechanisms should be further explored.

Melatonin Attenuates Extracellular Matrix Accumulation and Cardiac Injury Manifested by Copper

Copper-induced cardiac injury is not widely reported in spite of its ability to cause oxidative damage and tissue injury. Structural and morphological changes in the cardiac tissue are triggered via oxidative stress and inflammatory responses following copper exposure. The varied and unavoidable exposure of copper through contaminated food and water warrants a safe and effective agent against its harmful effects. Since the heart is highly sensitive to changes in the redox balance, the present study was undertaken to examine the protective effects of melatonin against copper-induced cardiac injury. Sprague Dawley (SD) rats were exposed to 100 ppm of elemental copper via drinking water for 4 months. The cardiac tissue was evaluated for various biochemical, histological, and protein expression studies. Animals exposed to copper exhibited induced oxidative stress and cardiac injury compared to normal control. To this end, we found that melatonin treatment ameliorated copper-induced alterations in tissue oxidative variables like ROS, nitrate, MDA, and GSH. In addition, histological examinations unravelled decreased cardiac muscle dilation, atrophy, and cardiomyopathy in melatonin-treated rats. Furthermore, melatonin-treated rats were associated with reduced tissue copper levels, collagen deposition, α-SMA, and increased HO-1 expression as compared to rats exposed exclusively to copper. Moreover, the levels of NF-κB and cardiac markers such as CK-MB, cTnI, and cTnT were found to be decreased in the melatonin-treated animals. Altogether, melatonin-triggered increase in antioxidant capacity resulting in reduced aggregation of ECM components demonstrates the therapeutic potential of melatonin in the treatment of cardiac injury and tissue fibrosis.

Integrative pharmacology reveals the mechanisms of Erzhi Pill, a traditional Chinese formulation, against diabetic cardiomyopathy

ETHNOPHARMACOLOGICAL RELEVANCE

Erzhi Pill (EZP) is a traditional Chinese prescription that has marked effects in treating type 2 diabetes mellitus and diabetic nephropathy. However, its underlying pharmacological mechanisms in the treatment of diabetic cardiomyopathy (DCM), remain to be elucidated.

AIM OF THE STUDY

This study aimed to apply an integrative pharmacological strategy to systematically evaluate the pharmacological effects and molecular mechanisms of EZP, and provide a solid theoretical basis for the clinical application of EZP in the treatment of DCM.

MATERIALS AND METHODS

In this study, the potential targets and key pathways of EZP were predicted and validated using network pharmacology and molecular docking, respectively. Changes in cardiac metabolites and major metabolic pathways in rat heart samples were examined using ¹H-nuclear magnetic resonance (NMR) metabolomics. Finally, biochemical analysis was conducted to detect the protein expression levels of key pathways.

RESULTS

We found that EZP decreased fasting blood glucose (FBG), triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL) levels, increased high-density lipoprotein (HDL) levels in the serum, and alleviated the morphological abnormalities of the heart tissue in diabetic rats. Furthermore, EZP effectively restored superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-8, and caspase-9 activity levels, as well as the levels of reactive oxygen species (ROS), malondialdehyde (MDA), B-cell lymphoma (Bcl)-2, and Bcl-2-associated X protein (Bax) in the heart tissue. Network pharmacology prediction results indicated that the mechanism of EZP in treating DCM was closely related to apoptosis, oxidative stress, and the HIF-1, PI3K-Akt, and FoxO signaling pathways. In addition, ¹H-NMR metabolomics confirmed that EZP primarily regulated both energy metabolism and amino acid metabolism, including the tricarboxylic acid (TCA) cycle, ketone bodies metabolism, glutamine and glutamate metabolism, glycine metabolism, and purine metabolism. Finally, immunohistochemistry results indicated that EZP reduced the expression levels of p-AMPK, p-PI3K, p-Akt, and p-FoxO3a proteins, in the heart tissue of DCM rats.

CONCLUSION

The results confirmed that the overall therapeutic effect of EZP in the DCM rat model is exerted via inhibition of oxidative stress and apoptosis, alongside the regulation of energy metabolism and amino acid metabolism, as well as the AMPK and PI3K/Akt/FoxO3a signaling pathways. This study provides an experimental basis for the use of EZP in DCM treatment.

Ameliorative potentials of the ethanolic extract from Lycium chinense leaf extract against diabetic cardiomyopathy. Insight into oxido-inflammatory and apoptosis modulation

The prevalence of cardiovascular complications in diabetes has become one of the major cause of diabetes related morbidity/mortality. The onset and progression of diabetic cardiomyopathy (DCM) has been majorly linked to lipid alterations, oxidative stress, inflammation and apoptosis. This present study investigated the cardioprotective role of Lycium chinense leaf extract (LCME) in fructose/streptozotocin induced diabetic rats. Diabetic animals were orally gavaged with LCME (100 and 400 mg/kg) for five weeks. The results indicated that diabetic rats showed increased blood glucose concentration, serum cardiac function markers (troponin T, creatine kinase-MB, aspartate aminotransferase and lactate dehydrogenase) and lipid profile (triglycerides and cholesterol). In addition, the cardiac tissues of diabetic rats showed increased levels of nuclear factor-κB (NF-κB), tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL 1β), interleukin 6 (IL-6), caspase-3 and malondialdehyde as well as significantly reduced activities of catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase. LCME significantly ameliorated hyperglycemia and markedly decreased serum concentrations of troponin T, creatine kinase-MB, aspartate aminotransferase and lactate dehydrogenase, triglycerides and cholesterol. Furthermore, LCME notably suppressed cardiac oxido-inflammatory mediators and boosted cardiac antioxidant defense. Histopathologically, LCME restored cardiac structural alterations and also suppressed the immunohistochemical expression of collagen IV, smooth muscle alpha-actin (α-SMA) and p53, while Bcl2 expression was significantly increased. In conclusion, our result indicated that LCME protected against diabetic cardiomyopathy suppressing oxidative stress, inflammation, apoptosis and fibrosis.

Galangin Exhibits Neuroprotective Effects in 6-OHDA-Induced Models of Parkinson’s Disease via the Nrf2/Keap1 Pathway

Parkinson’s disease (PD) is the second most common neurodegenerative disease, and there is still no cure for it. PD is characterized by the degeneration of dopaminergic neurons, and oxidative stress has been considered an important pathological mechanism. Therefore, the discovery of antioxidants to alleviate the oxidative damage of dopaminergic neurons is a promising therapeutic strategy for PD. First, a network pharmacology approach was used, and nine common core targets of galangin and PD were screened, mainly involving cell aging, apoptosis, and cellular responses to hydrogen peroxide and hypoxia. In addition, the Gene Ontology (GO) function and pathway enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) identified apoptosis, PI3K/Akt, and HIF-1 signaling pathways. Furthermore, the molecular docking results revealed a strong affinity between galangin and the NFE2L2/Nrf2 protein. To validate the above predictions, we employed 6-hydroxydopamine (6-OHDA) to induce neuronal death in HT22 cells and Caenorhabditis elegans (C. elegans). MTT, cell morphology observation, and Hoechst 33342-PI staining results showed that galangin significantly increased the viability of 6-OHDA-treated HT22 cells. In addition, galangin inhibited 6-OHDA-induced ROS generation and apoptosis in HT22 cells. Mechanistic studies demonstrated that galangin activates the Nrf2/Keap1 signaling pathway, as evidenced by the decreased protein expression of Keap1 and increased protein expression of Nrf2 and HO-1. In the 6-OHDA-induced PD model of C. elegans, galangin indeed inhibited the degeneration of dopaminergic neurons, improved behavioral ability, and decreased ROS generation. In conclusion, the current study is the first to show that galangin has the capacity to inhibit neuronal degeneration via the Nrf2/Keap1 pathway, suggesting that galangin is a possible PD treatment.

Perspectives for Forkhead box transcription factors in diabetic cardiomyopathy: Their therapeutic potential and possible effects of salvianolic acids

Diabetic cardiomyopathy (DCM) is the primary cause of morbidity and mortality in diabetic cardiovascular complications, which initially manifests as cardiac hypertrophy, myocardial fibrosis, dysfunctional remodeling, and diastolic dysfunction, followed by systolic dysfunction, and eventually end with acute heart failure. Molecular mechanisms underlying these pathological changes in diabetic hearts are complicated and multifactorial, including but not limited to insulin resistance, oxidative stress, lipotoxicity, cardiomyocytes apoptosis or autophagy, inflammatory response, and myocardial metabolic dysfunction. With the development of molecular biology technology, accumulating evidence illustrates that members of the class O of Forkhead box (FoxO) transcription factors are vital for maintaining cardiomyocyte metabolism and cell survival, and the functions of the FoxO family proteins can be modulated by a wide variety of post-translational modifications including phosphorylation, acetylation, ubiquitination, arginine methylation, and O-glycosylation. In this review, we highlight and summarize the most recent advances in two members of the FoxO family (predominately FoxO1 and FoxO3a) that are abundantly expressed in cardiac tissue and whose levels of gene and protein expressions change as DCM progresses, with the goal of providing valuable insights into the pathogenesis of diabetic cardiovascular complications and discussing their therapeutic potential and possible effects of salvianolic acids, a natural product.

Naringenin ameliorates myocardial injury in STZ-induced diabetic mice by reducing oxidative stress, inflammation and apoptosis via regulating the Nrf2 and NF-κB signaling pathways

Diabetes-induced myocardial damage leads to diabetic cardiomyopathy and is closely associated with the generation of oxidative stress and inflammation. Naringenin (NG) exhibits antioxidant and anti-inflammatory effects. However, whether NG has cardioprotective effects against diabetic cardiomyopathy by regulating oxidative stress and inflammation remains unknown. This study investigated the effect of NG on diabetic cardiomyopathy based on an analysis of streptozotocin (STZ)-induced type 1 diabetic mice. The results indicated that NG reduced cardiac fibrosis and cardiomyocyte apoptosis in this diabetic model, accompanied by reduced blood glucose. NG inhibited pro-inflammatory cytokines, the level of reactive oxygen species and the expression of nuclear factor kappa-B (NF-κB), whereas the expression of antioxidant enzymes and nuclear factor erythroid 2-related factor 2 (Nrf2) were greatly enhanced by NG. Furthermore, in high glucose-treated H9C2 myocardial cells, NG effectively reduced cell apoptosis by inhibiting the formation of reactive oxygen species and pro-inflammatory cytokines. NG's antioxidant and anti-inflammatory activities were mechanistically associated with NF-κB inhibition and Nrf2 activation in animal and cell experiments. Data analysis showed that NG could regulate Nrf2 and NF-κB pathways to protect against diabetes-induced myocardial damage by reducing oxidative stress and inhibiting inflammation.

Galangin Mitigates DOX-induced Cognitive Impairment in Rats: Implication of NOX-1/Nrf-2/HMGB1/TLR4 and TNF-α/MAPKs/RIPK/MLKL/BDNF

The cognitive and behavioral decline observed in cancer survivors who underwent doxorubicin (DOX)-based treatment raises the need for therapeutic interventions to counteract these complications. Galangin (GAL) is a flavonoid-based phytochemical with pronounced protective effects in various neurological disorders. However, its impact on DOX-provoked neurotoxicity has not been clarified. Hence, the current investigation aimed to explore the ability of GAL to ameliorate DOX-provoked chemo-brain in rats. DOX (2mg/kg, once/week, i.p.) and GAL (50mg/kg, 5 times/week., via gavage) were administered for four successive weeks. The MWM and EPM tests were used to evaluate memory disruption and anxiety-like behavior, respectively. Meanwhile, targeted biochemical markers and molecular signals were examined by the aid of ELISA, Western blotting, and immune-histochemistry. In contrast to DOX-impaired rats, GAL effectively preserved hippocampal neurons, improved cognitive/behavioral functions, and enhanced the expression of the cell repair/growth index and BDNF. The antioxidant feature of GAL was confirmed by the amelioration of MDA, NO and NOX-1, along with restoring the Nrf-2/HO-1/GSH cue. In addition, GAL displayed marked anti-inflammatory properties as verified by the suppression of the HMGB1/TLR4 nexus and p-NF-κB p65 to inhibit TNF-α, IL-6, IL-1β, and iNOS. This inhibitory impact extended to entail astrocyte activation, as evidenced by the diminution of GFAP. These beneficial effects were associated with a notable reduction in p-p38^MAPK, p-JNK1/2, and p-ERK1/2, as well as the necroptosis cascade p-RIPK1/p-RIPK3/p-MLKL. Together, these pleiotropic protective impacts advocate the concurrent use of GAL as an adjuvant agent for managing DOX-driven neurodegeneration and cognitive/behavioral deficits. DATA AVAILABILITY: The authors confirm that all relevant data are included in the supplementary materials.

The Role of H2S Regulating NLRP3 Inflammasome in Diabetes

Nucleotide-binding oligomeric domain (NOD)-like receptor protein 3 (NLRP3) is a recently discovered cytoplasmic multiprotein complex involved in inflammation. The NLRP3 inflammasome contains NLRP3, apoptosis-related specific protein (ASC) and precursor caspase-1. The NLRP3 inflammasome is involved in many diseases, including diabetes. H₂S is a harmful gas with a rotten egg smell. Recently, it has been identified as the third gas signal molecule after nitric oxide and carbon monoxide. It has many biological functions and plays an important role in many diseases, including diabetes. In recent years, it has been reported that H₂S regulation of the NLRP3 inflammasome contributes to a variety of diseases. However, the mechanism has not been fully understood. In this review, we summarized the recent role and mechanism of H₂S in regulating the NLRP3 inflammasome in diabetes, in order to provide a theoretical basis for future research.

Antioxidative Stress and Antiapoptosis Effect of Chitosan Nanoparticles to Protect Cardiac Cell Damage on Streptozotocin-Induced Diabetic Rat

The antioxidant can inhibit oxidative stress and apoptosis, which has a role in an important mechanism on diabetic-induced cardiac cell damage. The research goal was to prove the antioxidative stress and antiapoptosis effect of chitosan nanoparticles as a cardioprotector in streptozotocin-induced diabetic rats. Scanning electron microscope (SEM) and dynamic light scattering (DLS) characterize the chitosan nanoparticles. This research is a laboratory experiment which consists of the control group (rats were given distilled water), the streptozotocin group (rats were injected streptozotocin at dose of 55 mg/kg BW i.p), and the chitosan nanoparticle group (rats were given streptozotocin at dose 55 mg/kg BW i.p, and then given chitosan nanoparticles at dose 75 mg/kg BW, 150 mg/kg BW, and 300 mg/kg BW peroral). Creatine kinase-myoglobin (CK-MB) and lactate dehydrogenase (LDH) were measured from the blood sample. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) from cardiac tissue were examined by ELISA; nuclear factor erythroid 2-related factor 2 (Nrf2) was evaluated by western blotting; B-cell lymphoma 2 (Bcl-2) and Caspase-3 expression were investigated by immunohistochemical staining and also were evaluated histological preparation by hematoxylin & eosin (H&E) staining. The chitosan nanoparticles have a rough surface and an irregular shape. Its size is 247.3 ± 38.1 μm. Streptozotocin injection significantly increased the levels of CK-MB, LDH, MDA, and expression of caspase-3. In contrast, the levels of SOD, GPx, Nrf2, and expression of Bcl-2 decreased as compared with the control group (p < 0.05). This is accompanied by the loss of normal cardiac cell structure and necrosis. The administration of chitosan nanoparticles significantly reduced levels of CK-MB, LDH, MDA, and expression of Caspase-3. However, the levels of SOD, GPx, Nrf2, and expression of Bcl-2 increased as compared with the streptozotocin group (p < 0.05). And also, chitosan nanoparticles inhibited cell necrosis in diabetic rats. This study suggests that the administration of chitosan nanoparticles can protect cardiac cell damage in diabetic rats through antioxidative stress by decreasing ROS and increasing Nrf2 expression, level of SOD, and GPx and through antiapoptosis by increasing expression of Bcl-2 and decreasing expression of Caspase-3.

Galangin mitigates oxidative stress, inflammation, and apoptosis in a rat model of methotrexate hepatotoxicity

Methotrexate (MTX) is an efficient chemotherapeutic agent for treating various malignancies and autoimmune diseases. However, the long-term use of MTX can result in hepatotoxicity and this limits its use. Galangin (Gal) is a potent flavonoid with various biological activities; however, its protective effect against MTX hepatotoxicity has not been previously investigated. This study evaluated the hepatoprotective of Gal against MTX-induced liver injury. Rats received Gal for 10 days and a single dose of MTX (20 mg/kg) at day 7. The administration of MTX induced liver damage reflected by increased serum biomarkers of liver function and histopathological manifestations. MTX increased hepatic reactive oxygen species (ROS), nitric oxide (NO), malondialdehyde (MDA), and pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), and diminished GSH and antioxidant enzymes. Gal relieved liver injury, ameliorated liver function, oxidative stress, and inflammation markers, and increased antioxidants in MTX-treated rats. In addition, Gal decreased the expression of inflammation and apoptosis markers in MTX-treated rats. In conclusion, Gal possesses a hepatoprotective effect mediated by attenuating oxidative damage, inflammation, and apoptosis in rats.

Supplementation with a Cocoa-Carob Blend, Alone or in Combination with Metformin, Attenuates Diabetic Cardiomyopathy, Cardiac Oxidative Stress and Inflammation in Zucker Diabetic Rats

Diabetic cardiomyopathy (DCM) is one of the main causes of mortality among diabetic patients, with oxidative stress and inflammation major contributors to its development. Dietary flavonoids show strong antioxidant and anti-inflammatory activities, although their potential additive outcomes in combination with antidiabetic drugs have been scarcely explored. The present study investigates the cardioprotective effects of a cocoa–carob blend (CCB) diet, rich in flavonoids, alone or in combination with metformin, in the development of DCM. Zucker diabetic fatty rats (ZDF) were fed with a CCB rich-diet or a control diet, with or without metformin for 12 weeks. Glucose homeostasis, cardiac structure and function, and oxidative and inflammatory biomarkers were analysed. CCB improved glucose homeostasis, and mitigated cardiac dysfunction, hypertrophy, and fibrosis in ZDF rats. Mechanistically, CCB counteracted oxidative stress in diabetic hearts by down-regulating NADPH oxidases, reducing reactive oxygen species (ROS) generation and modulating the sirtuin-1 (SIRT1)/ nuclear factor E2-related factor 2 (Nrf2) signalling pathway, overall improving antioxidant defence. Moreover, CCB suppressed inflammatory and fibrotic reactions by inhibiting nuclear factor kappa B (NFκB) and pro-inflammatory and pro-fibrotic cytokines. Noteworthy, several of these effects were further improved in combination with metformin. Our results demonstrate that CCB strongly prevents the cardiac remodelling and dysfunction observed in diabetic animals, highlighting its potential, alone or in adjuvant therapy, for treating DCM.

Targeting oxidative stress, apoptosis, and autophagy by galangin mitigates cadmium-induced renal damage: Role of SIRT1/Nrf2 and AMPK/mTOR pathways

BACKGROUND

Galangin, a bioactive flavonoid with remarkable antioxidant and anti-apoptotic actions, has demonstrated promising amelioration of experimental hepatotoxicity, cardiomyopathy, and colitis. Yet, its impact on cadmium-induced renal injury has not been explored. Herein, we aimed at exploring the potential of galangin to attenuate cadmium-induced nephrotoxicity in rats, focusing on oxidative stress, apoptosis, and autophagy.

METHODOLOGY

Cadmium chloride (5 mg/kg/day) and galangin (15 mg/kg/day) were received by oral gavage and the kidney tissues were inspected using ELISA, biochemical measurements, histology, and immunohistochemistry.

KEY FINDINGS

Galangin attenuated cadmium-induced renal damage by diminishing the histopathological alterations alongside KIM-1, BUN, and creatinine. At the molecular level, galangin attenuated the oxidative insult by significantly lowering the lipid peroxides and NOX-1 and augmenting GSH and GPx antioxidants. It also activated the cytoprotective SIRT1/Nrf2/HO-1 pathway by significantly upregulating the protein expression of SIRT1, Nrf2, and HO-1. Consistently, galangin suppressed renal apoptotic cell death by significantly lowering the protein expression of Bax and cytochrome C and activity of caspase-3 alongside upregulating the protein expression of the anti-apoptotic Bcl-2. Additionally, galangin activated the impaired autophagy flux as seen by diminishing the accumulation of SQSTM1/p62 and increasing the protein expression of Beclin 1. Meanwhile, galangin stimulated the autophagy-linked AMPK/mTOR pathway by significantly increasing the p-AMPK/total AMPK and lowering p-mTOR/total mTOR ratios.

CONCLUSION

Galangin mitigated cadmium-induced nephrotoxicity thanks to its promising antioxidant, anti-apoptotic, and pro-autophagic effects. In perspective, galangin stimulated the SIRT1/Nrf2/HO-1 and AMPK/mTOR pathways. Hence, it may act as a complementary tool for the management of cadmium-induced renal injury.

Galangin alleviates vascular dysfunction and remodelling through modulation of the TNF-R1, p-NF-κB and VCAM-1 pathways in hypertensive rats

Galangin is a natural flavonoid isolated from ginger, honey and propolis.

AIMS

To investigate the effect of galangin on blood pressure, vascular changes, sympathoexcitation, oxidative stress and inflammation in rats treated with N^G-nitro-l-arginine methyl ester (l-NAME).

MATERIALS AND METHODS

Male Wistar rats (220-250 g) were given l-NAME (0.5 mg/mL in drinking water) to induce hypertension for 5 weeks. They were treated with vehicle, galangin (30 or 60 mg/kg), or amlodipine (10 mg/kg) for the final two weeks (n = 6/group).

KEY FINDINGS

Galangin significantly reduced blood pressure and improved the impairment of endothelium-dependent vasodilation in hypertensive rats. Sympathoexcitation, including enhancement of contractile responses to electrical field stimulation, increases in intensity of tyrosine hydroxylase and plasma norepinephrine concentration in hypertensive rats, was attenuated by galangin treatment. Galangin also reduced systemic and vascular oxidative damage and increased plasma nitric oxide levels in the hypertensive groups. Aortic remodelling accompanied by aortic wall hypertrophy and fibrosis observed in hypertensive rats were alleviated by galangin treatment. Furthermore, galangin exhibited an anti-inflammatory effect by suppressing the upregulation of tumour necrosis factor receptor 1 (TNF-R1), phospho-nuclear factor kappa B (p-NF-κB) and vascular cell adhesion protein 1 (VCAM-1) in aortic tissue and reducing plasma tumour necrosis factor alpha (TNF-α) in l-NAME rats. In conclusion, galangin had antihypertensive effects that were relevant to attenuating endothelial dysfunction, sympathoexcitation and vascular remodelling. These effects might be contributed by antioxidant and anti-inflammatory capacities and modulation of the TNF-R1, p-NF-κB and VCAM-1 pathways in hypertensive rats.

Galangin Attenuates Liver Injury, Oxidative Stress and Inflammation, and Upregulates Nrf2/HO-1 Signaling in Streptozotocin-Induced Diabetic Rats

Chronic hyperglycemia increases the risk of liver damage. Oxidative stress and aberrant inflammatory response are entangled in diabetes-associated liver injury. This study evaluated the protective effect of the flavonoid galangin (Gal) on glucose intolerance, liver injury, oxidative stress, inflammatory response, and Nrf2/HO-1 signaling in diabetic rats. Diabetes was induced by streptozotocin (STZ), and the rats received Gal for six weeks. STZ-induced rats showed glucose intolerance, hypoinsulinemia, elevated glycated hemoglobin (HbA1c), and decreased liver glycogen. Gal ameliorated glucose intolerance, reduced HbA1c%, increased serum insulin and liver glycogen and hexokinase activity, and suppressed glycogen phosphorylase, glucose-6-phosphatase and fructose-1,6-biphosphatase in diabetic rats. Circulating transaminases, ALP and LDH, and liver ROS, MDA, TNF-α, IL-1β, and IL-6 were increased and GSH, SOD, and CAT were diminished in diabetic rats. In addition, diabetic rats exhibited multiple histopathological alterations and marked collagen deposition. Treatment with Gal mitigated liver injury, prevented histopathological alterations, decreased ROS, MDA, pro-inflammatory cytokines, Bax and caspase-3, and enhanced cellular antioxidants and Bcl-2. Gal downregulated hepatic Keap1 in diabetic rats and upregulated Nrf2 and HO-1 mRNA as well as HO-1 activity. Molecular modeling studies revealed the ability of Gal to bind to and inhibit NF-κB and Keap1, and also showed its binding pattern with HO-1. In conclusion, Gal ameliorates hyperglycemia, glucose intolerance, oxidative stress, inflammation, and apoptosis in diabetic rats. Gal improved carbohydrate metabolizing enzymes and upregulated Nrf2/HO-1 signaling.