Hesperidin and naringin attenuate hyperglycemia-mediated oxidative stress and proinflammatory cytokine production in high fat fed/streptozotocin-induced type 2 diabetic rats

Naringin: Cardioprotective properties and safety profile in diabetes treatment

Flavonoids derived from plants offer a broad spectrum of therapeutic potential for addressing metabolic syndrome, particularly diabetes mellitus (DM), a prevalent non-communicable disease. Hyperglycemia in DM is a known risk factor for cardiovascular diseases (CVDs), which substantially impact global mortality rates. This review examines the potential effects of naringin, a citrus flavonoid, on both DM and its associated cardiovascular complications, including conditions like diabetic cardiomyopathy. The safety profile of naringin is summarized based on various pre-clinical studies. The data for this review was gathered from diverse electronic databases, including Medline, PubMed, ScienceDirect, SpringerLink, Google Scholar, and Emerald Insight. Multiple pre-clinical studies have demonstrated that naringin exerts hypoglycemic and cardioprotective effects by targeting various vascular mechanisms. Specifically, research indicates that naringin down-regulates the renin-angiotensin and oxidative stress systems while concurrently upregulating β-cell and immune system functions. Clinical trial outcomes also support the therapeutic potential of naringin in managing hyperglycemic states and associated cardiovascular issues. Moreover, toxicity studies have confirmed the safety of naringin in animal models, suggesting its potential for safe administration in humans. In conclusion, naringin emerges as a promising natural candidate for both antidiabetic and cardioprotective purposes, offering potential improvements in health outcomes. While naringin presents a new avenue for therapies targeting DM and CVDs, additional controlled and long-term clinical trials are necessary to validate its efficacy and safety for human use.

Effect of Hesperidin on Sciatic Nerve Damage in STZ-Induced Diabetic Neuropathy: Modulation of TRPM2 Channel

Diabetic neuropathy (DNP) is a severe complication of diabetes mellitus. In this study, we examined the potential of hesperidin (HES) to attenuate DNP and the involvement of the TRPM2 channel in this process. The rats were given a single dose of 45 mg/kg of streptozotocin (STZ) intraperitoneally to induce diabetic neuropathic pain. On the third day, we confirmed the development of diabetes in the DNP and DNP + HES groups. The HES groups were treated with 100 mg/kg and intragastric gavage daily for 14 days. The results showed that treatment with HES in diabetic rats decreased STZ-induced hyperglycemia and thermal hyperalgesia. Furthermore, in the histopathological examination of the sciatic nerve, HES treatment reduced STZ-induced damage. The immunohistochemical analysis also determined that STZ-induced increased TRPM2 channel, type-4 collagen, and fibrinogen immunoactivity decreased with HES treatment. In addition, we investigated the TRPM2 channel activation in the sciatic nerve damage mechanism of DNP model rats created by STZ application using the ELISA method. We determined the regulatory effect of HES on increased ROS, and PARP1 and TRPM2 channel activation in the sciatic nerves of DNP model rats. These findings indicated that hesperidin treatment could attenuate diabetes-induced DNP by reducing TRPM2 channel activation.

A narrative review on the role of hesperidin on metabolic parameters, liver enzymes, and inflammatory markers in nonalcoholic fatty liver disease

Insulin resistance, oxidative stress, hyperlipidemia, and inflammation play main roles in the development of nonalcoholic fatty liver disease (NAFLD). Some studies have reported that hesperidin can reduce hyperglycemia and hyperlipidemia by inhibiting inflammatory pathways. In the current study, our purpose was to evaluate whether it can influence the primary parameters in NAFLD and improve the treatment effectiveness for future trials. Various studies have found that hesperidin involves multiple signaling pathways such as cell proliferation, lipid and glucose metabolism, insulin resistance, oxidative stress, and inflammation, which can potentially affect NAFLD development and prognosis. Recent findings indicate that hesperidin also regulates key enzymes and may affect the severity of liver fibrosis. Hesperidin inhibits reactive oxygen species production that potentially interferes with the activation of transcription factors like nuclear factor-κB. Appropriate adherence to hesperidin may be a promising approach to modulate inflammatory pathways, metabolic indices, hepatic steatosis, and liver injury.

Okra [Abelmoschus esculentus (L.) Moench] improved blood glucose and restored histopathological alterations in splenic tissues in a rat model with streptozotocin-induced type 1 diabetes through CD8+ T cells and NF-kβ expression

Diabetes mellitus is a complex metabolic syndrome that involves dysfunction of spleen and other lymphoid organs. Medicinal plants, including okra (Abelmoschus esculentus (L.) Moench), were used widely for diabetes treatment. Scarce data are available about the potential anti-diabetic effects of okra, the histopathological alterations in splenic tissues and the mechanistic pathways underlying this association. The current research investigated the effects of okra pod extract on the biochemical parameters and expression of CD8+ T cells and nuclear factor kappa (NF-k) B and releasing proinflammatory cytokines in spleen in streptozotocin (STZ)-induced diabetic rat models. A total of 50 mature male Wister albino rats were divided into five isolated groups; the first served as control (untreated) animals, the second (DM group) diabetes induced by STZ (at a dose of 45 mg/kg body weight, administered intraperitoneally), the third group (DM + Insulin): diabetic rats administered insulin subcutaneously (10 units/kg bw/day) daily for 4 weeks, the fourth group was administrated 400 mg/kg okra extract daily for 4 weeks, and diabetic induced rats in the fifth group were administrated 400 mg/kg okra extract daily for 4 weeks. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity in Abelmoschus esculentus (L.) Moench was studied, and the content of phenolic compounds in okra pods was estimated using high-performance liquid chromatography. Diabetes induction led to decreased body weight, increased blood glucose levels. Capsular thickness was significantly increased, white pulp was widely dispersed, and mature lymphocytes in the periphery were also drastically decreased, with thick follicular arteries, necrosis, and depletion of lymphocytes in the germinal center. Red pulp revealed severe congestion and degenerative changes, deposition of hemosiderin granules and lymphocytic depletion. In addition, collagen fiber deposition was increased also in this group. The induction of diabetes exaggerated NF-kβ expression and mediated downregulation of the expression of CD8+ T cells in spleen tissue. Interestingly, oral administration of okra extracts post diabetes induction could mitigate and reverse such adverse effects. Altogether, our study points out the potential benefits of okra in improving blood glucose levels and restoring histopathological alterations in splenic tissues through CD8+ T cells and NF-kβ expression in a diabetic rat model.

Development of novel thiazolidine-2,4-dione derivatives as PPAR-γ agonists through design, synthesis, computational docking, MD simulation, and comprehensive in vitro and in vivo evaluation

The present study was conducted to develop new novel 2,4-thiazolidinedione derivatives (3h-3j) as peroxisome proliferator-activated receptor-γ (PPAR-γ) modulators for antidiabetic activity. The objective was to overcome the adverse effects of existing thiazolidinediones while maintaining their pharmacological benefits. The synthesized compounds were elucidated based on FT-IR, 1H-NMR, 13C-NMR, and MS techniques. Molecular docking was utilized to investigate the interaction binding modes, binding free energy, and amino acids engaged in the compounds' interactions with the target protein. Subsequently, molecular dynamics modelling was used to assess the stability of the top-docked complexes and an assay was utilized to assess the cytotoxicity of the compounds to C2C12 myoblasts. Compounds 3h-3j exhibited PPAR-γ modulatory activity and demonstrated significant hypoglycaemic effects when compared to the reference drug pioglitazone. The new compounds were evaluated for their in vivo blood glucose-lowering potential by using a dexamethasone-induced diabetic rat model. All the compounds showed a hypoglycaemic effect of 108.04 ± 4.39, 112.55 ± 6.10, and 117.48 ± 43.93, respectively, along with pioglitazone (153.93 ± 4.61) compared to the diabetic control. Additionally, all the compounds significantly reduced AST and ALT levels and did not cause liver damage.

Mechanisms of action of natural products on type 2 diabetes

Over the past several decades, type 2 diabetes mellitus (T2DM) has been considered a global public health concern. Currently, various therapeutic modalities are available for T2DM management, including dietary modifications, moderate exercise, and use of hypoglycemic agents and lipid-lowering medications. Although the curative effect of most drugs on T2DM is significant, they also exert some adverse side effects. Biologically active substances found in natural medicines are important for T2DM treatment. Several recent studies have reported that active ingredients derived from traditional medicines or foods exert a therapeutic effect on T2DM. This review compiled important articles regarding the therapeutic effects of natural products and their active ingredients on islet β cell function, adipose tissue inflammation, and insulin resistance. Additionally, this review provided an in-depth understanding of the multiple regulatory effects on different targets and signaling pathways of natural medicines in the treatment of T2DM as well as a theoretical basis for clinical effective application.

Anti-Diabetic Activity of Glycyrrhetinic Acid Derivatives FC-114 and FC-122: Scale-Up, In Silico, In Vitro, and In Vivo Studies

Type 2 diabetes (T2D) is one of the most common diseases and the 8th leading cause of death worldwide. Individuals with T2D are at risk for several health complications that reduce their life expectancy and quality of life. Although several drugs for treating T2D are currently available, many of them have reported side effects ranging from mild to severe. In this work, we present the synthesis in a gram-scale as well as the in silico and in vitro activity of two semisynthetic glycyrrhetinic acid (GA) derivatives (namely FC-114 and FC-122) against Protein Tyrosine Phosphatase 1B (PTP1B) and α-glucosidase enzymes. Furthermore, the in vitro cytotoxicity assay on Human Foreskin fibroblast and the in vivo acute oral toxicity was also conducted. The anti-diabetic activity was determined in streptozotocin-induced diabetic rats after oral administration with FC-114 or FC-122. Results showed that both GA derivatives have potent PTP1B inhibitory activity being FC-122, a dual PTP1B/α-glucosidase inhibitor that could increase insulin sensitivity and reduce intestinal glucose absorption. Molecular docking, molecular dynamics, and enzymatic kinetics studies revealed the inhibition mechanism of FC-122 against α-glucosidase. Both GA derivatives were safe and showed better anti-diabetic activity in vivo than the reference drug acarbose. Moreover, FC-114 improves insulin levels while decreasing LDL and total cholesterol levels without decreasing HDL cholesterol.

The effects of hesperidin supplementation on cardiovascular risk factors in adults: a systematic review and dose-response meta-analysis

Hesperidin is a naturally occurring bioactive compound that may have an impact on cardiovascular disease risks, but the evidence is not conclusive. To investigate further, this study aimed to explore the effects of hesperidin supplementation on cardiovascular risk factors in adults. A comprehensive search was conducted up to August 2022 using relevant keywords in databases such as Scopus, PubMed, Embase, Cochrane Library, and ISI Web of Science for all randomized controlled trials (RCTs). The results showed that hesperidin supplementation had a significant effect on reducing serum triglyceride (TG), total cholesterol (TC), low-density cholesterol (LDL), tumor necrosis factor-alpha (TNF-α), and systolic blood pressure (SBP), whereas weight was increased. However, no significant effect was observed on high-density cholesterol (HDL), waist circumference (WC), fasting blood glucose (FBG), insulin, homeostatic model assessment for insulin resistance (HOMA-IR), C-reactive protein (CRP), interleukin-6 (IL-6), body mass index (BMI), and diastolic blood pressure (DBP). The study also found that an effective dosage of hesperidin supplementation was around 1,000 mg/d, and a more effective duration of supplementation was more than eight weeks to decrease insulin levels. Furthermore, the duration of intervention of more than six weeks was effective in decreasing FBG levels.

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.

Genetics of diabetes

Diabetes mellitus is a complicated disease characterized by a complex interplay of genetic, epigenetic, and environmental variables. It is one of the world's fastest-growing diseases, with 783 million adults expected to be affected by 2045. Devastating macrovascular consequences (cerebrovascular disease, cardiovascular disease, and peripheral vascular disease) and microvascular complications (like retinopathy, nephropathy, and neuropathy) increase mortality, blindness, kidney failure, and overall quality of life in individuals with diabetes. Clinical risk factors and glycemic management alone cannot predict the development of vascular problems; multiple genetic investigations have revealed a clear hereditary component to both diabetes and its related complications. In the twenty-first century, technological advancements (genome-wide association studies, next-generation sequencing, and exome-sequencing) have led to the identification of genetic variants associated with diabetes, however, these variants can only explain a small proportion of the total heritability of the condition. In this review, we address some of the likely explanations for this "missing heritability", for diabetes such as the significance of uncommon variants, gene-environment interactions, and epigenetics. Current discoveries clinical value, management of diabetes, and future research directions are also discussed.

Biological Activities and Solubilization Methodologies of Naringin

Naringin (NG), a natural flavanone glycoside, possesses a multitude of pharmacological properties, encompassing anti-inflammatory, sedative, antioxidant, anticancer, anti-osteoporosis, and lipid-lowering functions, and serves as a facilitator for the absorption of other drugs. Despite these powerful qualities, NG's limited solubility and bioavailability primarily undermine its therapeutic potential. Consequently, innovative solubilization methodologies have received considerable attention, propelling a surge of scholarly investigation in this arena. Among the most promising solutions is the enhancement of NG's solubility and physiological activity without compromising its inherent active structure, therefore enabling the formulation of non-toxic and benign human body preparations. This article delivers a comprehensive overview of NG and its physiological activities, particularly emphasizing the impacts of structural modification, solid dispersions (SDs), inclusion compound, polymeric micelle, liposomes, and nanoparticles on NG solubilization. By synthesizing current research, this research elucidates the bioavailability of NG, broadens its clinical applicability, and paves the way for further exploration and expansion of its application spectrum.

The protective roles of citrus flavonoids, naringenin, and naringin on endothelial cell dysfunction in diseases

The endothelial cells (ECs) make up the inner lining of blood vessels, acting as a barrier separating the blood and the tissues in several organs. ECs maintain endothelium integrity by controlling the constriction and relaxation of the vasculature, blood fluidity, adhesion, and migration. These actions of ECs are efficiently coordinated via an intricate signaling network connecting receptors, and a wide range of cellular macromolecules. ECs are naturally quiescent i.e.; they are not stimulated and do not proliferate. Upon infection or disease, ECs become activated, and this alteration is pivotal in the pathogenesis of a spectrum of human neurological, cardiovascular, diabetic, cancerous, and viral diseases. Considering the central position that ECs play in disease pathogenesis, therapeutic options have been targeted at improving ECs integrity, assembly, functioning, and health. The dietary intake of flavonoids present in citrus fruits has been associated with a reduced risk of endothelium dysfunction. Naringenin (NGN) and Naringin (NAR), major flavonoids in grapefruit, tomatoes, and oranges possess anti-inflammatory, antioxidant properties, and cell survival potentials, which improve the health of the vascular endothelium. In this review, we provide a comprehensive summary and present the advances in understanding of the mechanisms through which NGN and NAR modulate the biomarkers of vascular dysfunction and protect the endothelium against unresolved inflammation, oxidative stress, atherosclerosis, and angiogenesis. We also provide perspectives and suggest further studies that will help assess the efficacy of citrus flavonoids in the therapeutics of human vascular diseases.

Underlying biochemical effects of intermittent fasting, exercise and honey on streptozotocin-induced liver damage in rats

Purpose

Derangements of liver transcriptional factors and enzymes have important implications in diabetes-induced related complications. Hence, this study which consists of two experimental phases was aimed at evaluating the possible underlying molecular mechanisms of intermittent fasting (IF), exercise starvation and honey in streptozotocin (STZ)-mediated liver damage in diabetic rats.

Methods

The diabetic rats were treated orally with distilled water (0.5 ml/kg), IF, starvation and honey at 1 g/kg body weight in the non-diabetic phase for four (4) weeks. After STZ injections, four (4) weeks of IF, exercise, starvation, and honey therapy were used as interventions prior to a biochemical evaluation of the liver.

Results

IF and exercise greatly decreased liver transcription factor (resistin, SREBP-1c), inflammatory cytokines/enzyme (TNF-α, IL-6, IL-1ß, MPO) as well as oxidative and nitrergic stress with correspondence increased liver PPAR-γ, IL-10, SOD, CAT and GSH in diabetic rats unlike starvation and honey regimen relative to diabetic controls. Furthermore, IF and exercise significantly improved hepatic glycogen synthase and decreased glycogen phosphorylase in diabetic rats compared to the diabetic control group, but starvation and honey therapy had no such influence. IF and exercise strategically reduces STZ-induced liver metabolic disorder via through modulation of liver transcriptional factors and inhibition of pro-inflammatory cytokines, oxido-nitrergic and adipokine signaling pathway.

Natural products targeting inflammation-related metabolic disorders: A comprehensive review

Currently, the incidence of metabolic disorders is increasing, setting a challenge to global health. With major advancement in the diagnostic tools and clinical procedures, much has been known in the etiology of metabolic disorders and their corresponding pathophysiologies. In addition, the use of in vitro and in vivo experimental models prior to clinical studies has promoted numerous biomedical breakthroughs, including in the discovery and development of drug candidates to treat metabolic disorders. Indeed, chemicals isolated from natural products have been extensively studied as prospective drug candidates to manage diabetes, obesity, heart-related diseases, and cancer, partly due to their antioxidant and anti-inflammatory properties. Continuous efforts have been made in parallel to improve their bioactivity and bioavailability using selected drug delivery approaches. Here, we provide insights on recent progress in the role of inflammatory-mediated responses on the initiation of metabolic disorders, with particular reference to diabetes mellitus, obesity, heart-related diseases, and cancer. In addition, we discussed the prospective role of natural products in the management of diabetes, obesity, heart-related diseases, and cancers and provide lists of potential biological targets for high throughput screening in drug discovery and development. Lastly, we discussed findings observed in the preclinical and clinical studies prior to identifying suitable approaches on the phytochemical drug delivery systems that are potential to be used in the treatment of metabolic disorders.

Flavonoids improve type 2 diabetes mellitus and its complications: a review

The prevalence of type 2 diabetes mellitus (T2DM) is increasing every year. Medications are currently the most common therapy for T2DM. However, these medications have certain adverse effects. In order to find safe and effective ways to improve this disease, researchers have discovered that some natural products can decrease blood sugar. Flavonoids are one of the most essential low molecular weight phenolic chemicals in the plant world, which widely exist in plant roots, stems, leaves, flowers, and fruits. They possess a variety of biological activities, including organ protection, hypoglycemic, lipid-lowering, anti-oxidative and anti-inflammatory effects. Some natural flavonoids ameliorate T2DM and its complications through anti-oxidation, anti-inflammatory action, glucose and lipid metabolism regulation, insulin resistance management, etc. Hence, this review aims at demonstrating the potential benefits of flavonoids in T2DM and its complications. This laid the foundation for the development of novel hypoglycemic medications from flavonoids.

Bioactive compounds from Polygonatum genus as anti-diabetic agents with future perspectives

Diabetes mellitus (DM) is one of the most serious health problems worldwide. Species in the genus Polygonatum are traditional food and medicinal plants, which play an important role in controlling blood glucose. In this reveiw, we systematically summarized the traditional and modern applications of the genus Polygonatum in DM, focused on the material bases of polysaccharides, flavonoids and saponins. We highlighted their mechanisms of action in preventing obese diabetes, improving insulin resistance, promoting insulin secretion, regulating intestinal microecology, inhibiting advanced glycation end products (AGEs) accumulation, suppressing carbohydrate digestion and obsorption and modulating gluconeogenesis. Based on the safety and efficacy of this 'medicinal food' and its utility in the prevention and treatment of diabetes, we proposed a research and development program that includs diet design (supplementary food), medical nutrition therapy and new drugs, which could provide new pathways for the use of natural plants in prevention and treatment of DM.

Betulin prevents high fat diet-induced non-alcoholic fatty liver disease by mitigating oxidative stress and upregulating Nrf2 and SIRT1 in rats

Non-alcoholic fatty liver disease (NAFLD) is a common chronic hepatic disorder characterized by hepatic lipid accumulation. This study explored the effect of betulin (BE), a terpenoid with promising antioxidant, anti-inflammatory and insulin sensitizing effects, on NAFLD induced by high fat diet (HFD). Rats received HFD and BE (15 and 30 mg/kg) for 12 weeks and blood and liver samples were collected for analyses. HFD caused hyperlipidemia, cholesterol and triglycerides accumulation in the liver, hepatocellular ballooning, fibrosis, insulin resistance (IR), lipid peroxidation (LPO), and NF-kB p65 upregulation. BE ameliorated serum and liver lipids, blood glucose, and insulin, liver LPO, prevented steatosis and fibrosis, suppressed NF-kB p65 and enhanced antioxidants in HFD-fed rats. BE downregulated ACC1 and FAS, and upregulated Nrf2, HO-1 and SIRT1 in the liver of HFD-fed rats. In silico investigations revealed the binding affinity of BE towards NF-kB, Keap1, HO-1 and SIRT1. In conclusion, BE attenuated HFD-induced NAFLD by ameliorating hyperlipidemia, IR, lipogenesis, liver lipid accumulation, and oxidative stress. The protective effect of BE was associated with enhanced Nrf2/HO-1 signaling and SIRT1.

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.

Averrhoa carambola leaves prevent dyslipidemia and oxidative stress in a rat model of poloxamer-407-induced acute hyperlipidemia

Background: The star fruit [Averrhoa carambola L (Oxalidaceae)] is traditionally used in the treatment of many ailments in many countries. It possesses several pharmacological activities, including antioxidant and anti-inflammatory effects. However, it contains the neurotoxic caramboxin and its high content of oxalic acid limits its consumption by individuals with compromised kidney function. This study assessed the anti-hyperlipidemic and antioxidant activities of different fractions of the methanolic extract of A. carambola leaves (MEACL). Methods: The antioxidant activity was investigated using FRAP, and ABTS and DPPH radical-scavenging assays and the inhibitory activity toward pancreatic lipase (PL) and HMG-CoA reductase was assayed in vitro. Acute hyperlipidemia was induced by poloxamer-407 (P-407) in rats and different fractions of MEACL (n-hexane, chloroform, n-butanol, ethyl acetate (EA), water, and chloroform) were orally administered. Cholesterol and triglycerides were determined at 0, 12, 24, and 48 h and LDL-C, vLDL-C, HDL-C, lipid peroxidation (LPO) and antioxidants were assayed after 48 h. The expression of ABCA1, ABCG5, ABCG8, LDL-R, SREBP-1, and SREBP-2 and the activity of HMG-CoA reductase were assayed in the liver of P-407-administered rats treated with the EA fraction. Results: The in vitro data revealed potent radical-scavenging activities of MEACL fractions with the most potent effect showed by the EA fraction that also suppressed the activities of HMG-CoA reductase and PL. In P-407-induced hyperlipidemic rats, all fractions prevented dyslipidemia as shown by the decrease in total cholesterol, triglycerides, LDL-C, vLDL-C and atherogenic index. MEACL and its fractions prevented LPO and boosted GSH, superoxide dismutase, glutathione peroxidase, and catalase in P-407-administered rats. The EA fraction showed more effective anti-hyperlipidemic and antioxidant effects than other fractions and downregulated SREBP-2 while upregulated ABCA1 and LDL-R and ameliorated LPL and HMG-CoA reductase in hyperlipidemic rats. Conclusion: MEACL showed in vitro and in vivo antioxidant activity and the EA fraction significantly ameliorated dyslipidemia in a rat model of P-407-induced acute hyperlipidemia by modulating LPL, PL, HMG-CoA reductase, and cholesterolgenesis-related factors. Therefore, the leaves of A. carambola represent a safe alternative for the star fruit particularly in kidney disease patients, and the EA is the most effective anti-hyperlipidemic and antioxidant fraction.

Cyclopia intermedia (Honeybush) Induces Uncoupling Protein 1 and Peroxisome Proliferator-Activated Receptor Alpha Expression in Obese Diabetic Female db/db Mice

Previously, we reported that a crude polyphenol-enriched fraction of Cyclopia intermedia (CPEF), a plant consumed as the herbal tea, commonly known as honeybush, reduced lipid content in 3T3-L1 adipocytes and inhibited body weight gain in obese, diabetic female leptin receptor-deficient (db/db) mice. In the current study, the mechanisms underlying decreased body weight gain in db/db mice were further elucidated using western blot analysis and in silico approaches. CPEF induced uncoupling protein 1 (UCP1, 3.4-fold, p < 0.05) and peroxisome proliferator-activated receptor alpha (PPARα, 2.6-fold, p < 0.05) expression in brown adipose tissue. In the liver, CPEF induced PPARα expression (2.2-fold, p < 0.05), which was accompanied by a 31.9% decrease in fat droplets in Hematoxylin and Eosin (H&E)-stained liver sections (p < 0.001). Molecular docking analysis revealed that the CPEF compounds, hesperidin and neoponcirin, had the highest binding affinities for UCP1 and PPARα, respectively. This was validated with stabilising intermolecular interactions within the active sites of UCP1 and PPARα when complexed with these compounds. This study suggests that CPEF may exert its anti-obesity effects by promoting thermogenesis and fatty acid oxidation via inducing UCP1 and PPARα expression, and that hesperidin and neoponcirin may be responsible for these effects. Findings from this study could pave the way for designing target-specific anti-obesity therapeutics from C. intermedia.

Mathematical Modelling of Convective Drying of Orange By-Product and Its Influence on Phenolic Compounds and Ascorbic Acid Content, and Its Antioxidant Activity

Orange peel is one of the main by-products from juice processing, and is considered as a promising source of phenolic compounds with anti-carcinogenic, anti-inflammatory, anti-microbial and antioxidant properties. The drying is an essential step to ensure the storage of this by-product at an industrial level, in order to use it as a functional ingredient or as a nutraceutical. Thus, this research focuses on the evaluation of the effect of the convective air-drying process in orange by-products at three different temperatures (40, 60 and 80 °C) and air flows (0, 0.8 and 1.6 m/s) on the phenolic content (measured by HPLC-MS), the antioxidant activity (measured by DPPH, ABTS and FRAP), and the vitamin C content (measured by HPLC-UV/VIS). Moreover, the mathematical modelling of its drying kinetics was carried out to examine the orange by-product behavior. Among the tested mathematical models, the Page model reported the highest fit and the best drying conditions, which showed the lowest reductions were at 60 °C with an air flow of 1.6 m/s and taking 315 min.

Naringin reduces fat deposition by promoting the expression of lipolysis and β-oxidation related genes

AIMS

Naringin, a flavonoid present in citrus fruits, has been known for the capacity to reduce lipid synthesis and anti-inflammatory. In this study, we investigated whether naringin increases lipolysis and fatty acid β-oxidation to change fat deposition.

METHODS

In in vivo experiment, obese adult mice (20-weeks-old, n = 18) were divided into control group fed with normal diet and naringin-treated group fed with naringin-supplemented diet (5 g/kg) for 60 days, respectively. In in vitro experiment, differentiated 3T3-L1 adipocytes were treated for four days with or without naringin (100 µg/mL).

RESULTS

Supplementing naringin significantly reduced the body weight, abdominal fat weight, blood total cholesterol content of mice, but did not affect food intake. In addition, naringin decreased levels of pro-inflammatory factors in adipose tissue including interleukin-1β (IL-1β), interleukin-6 (IL-6), and monocyte chemotactic protein 1 (MCP-1). Naringin increased the expression of AMP-activated protein kinase (AMPK), a key factor in cellular energy metabolism, and raised the ratio of p-AMPK/AMPK in mouse liver tissue. The protein expression of hormone-sensitive lipase (HSL), phospho-HSL563 (p-HSL563), p-HSL563/HSL, and adipocyte triglyceride lipase (ATGL) was significantly increased in the adipose tissue of naringin-treated mice. Furthermore, naringin enhanced the expression of fatty acid β-oxidation genes, including carnitine palmitoyl transferase 1 (CPT1), uncoupling protein 2 (UCP2), and acyl-coenzyme A oxidase 1 (AOX1) in mouse adipose tissue. In in vitro experiment, similar findings were observed in differentiated 3T3-L1 adipocytes with naringin treatment. The treatment remarkably reduced intracellular lipid content, increased the number of mitochondria and promoted the gene expression of HSL, ATGL, CPT1, AOX1, and UCP2 and the phosphorylation of HSL protein.

CONCLUSION

Naringin reduced body fat in obese mice and lipid content in differentiated 3T3-L1 adipocytes, which was associated with enhanced AMPK activation and upregulation of the expression of the lipolytic genes HSL, ATGL, and β-oxidation genes CPT1, AOX1, and UCP2.

Antinociceptive, anti-inflammatory and hypoglycemic activities of the ethanolic Turnera subulata Sm. flower extract in adult zebrafish (Danio rerio)

Turnera subulata Sm. belongs to the family Turneraceae and is found in Brazil. The present study evaluated the antinociceptive, anti-inflammatory, and hypoglycemic potential of T. subulata flower extract (EtFloTsu) in zebrafish (Danio rerio). The total phenol and flavonoid contents of EtFloTsu were determined and identified using the Folin Ciocalteu reagent and aluminum chloride (AlCl₃), respectively. The constituents of the extract were identified by HPLC-DAD, and the in vitro antioxidant activity (DPPH) was determined, toxicity in brine shrimp, and acute toxicity of 96 h in adult zebrafish. In addition, adult zebrafish (n = 6/fish) were treated orally with EtFloTsu (4, 20, or 40 mg/kg; vo) and subjected to formalin-induced nociception tests (with its possible mechanism of action with camphor), carrageenan-induced inflammation, and D-glucose-induced hyperglycemia (111 mM). Oxidative stress in the liver and brain tissues was assessed. EtFloTsu showed high levels of phenolic and flavonoid compounds with antioxidant activity. The phytochemicals chlorogenic acid, luteolin-7-o-glucoside, vitexin, and apigenin-7-o-glucoside were also identified in EtFloTsu. The synergism between these constituents was possibly responsible for the antinociceptive (via TRPA1), anti-inflammatory, and hypoglycemic effects of EtFloTsu in adult zebrafish, without causing toxicity in animals. Therefore, T. subulata flowers have therapeutic agents that could treat pain, inflammation, diabetes, and related complications.Communicated by Ramaswamy H. Sarma.

Naringin Attenuates the Diabetic Neuropathy in STZ-Induced Type 2 Diabetic Wistar Rats

The application of traditional medicines for the treatment of diseases, including diabetic neuropathy (DN), has received great attention. The aim of this study was to investigate the ameliorative potential of naringin, a flavanone, to treat streptozotocin-induced DN in rat models. After the successful induction of diabetes, DN complications were measured by various behavioral tests after 4 weeks of post-induction of diabetes with or without treatment with naringin. Serum biochemical assays such as fasting blood glucose, HbA1c%, insulin, lipid profile, and oxidative stress parameters were determined. Proinflammatory cytokines such as TNF-α and IL-6, and neuron-specific markers such as BDNF and NGF, were also assessed. In addition, pancreatic and brain tissues were subjected to histopathology to analyze structural alterations. The diabetic rats exhibited increased paw withdrawal frequencies for the acetone drop test and decreased frequencies for the plantar test, hot plate test, and tail flick test. The diabetic rats also showed an altered level of proinflammatory cytokines and oxidative stress parameters, as well as altered levels of proinflammatory cytokines and oxidative stress parameters. Naringin treatment significantly improved these parameters and helped in restoring the normal architecture of the brain and pancreatic tissues. The findings show that naringin's neuroprotective properties may be linked to its ability to suppress the overactivation of inflammatory molecules and mediators of oxidative stress.

Hibiscus sabdariffa L. polyphenolic-rich extract promotes muscle glucose uptake and inhibits intestinal glucose absorption with concomitant amelioration of Fe2+ -induced hepatic oxidative injury

In this current study, the antidiabetic effectiveness of Hibiscus sabdariffa and its protective function against Fe²⁺ -induced oxidative hepatic injury were elucidated using in vitro, in silico, and ex vivo studies. The oxidative damage was induced in hepatic tissue by incubation with 0.1 mMolar ferrous sulfate (FeSO4) and then treated with different concentrations of crude extracts (ethyl acetate, ethanol, and aqueous) of H. sabdariffa flowers for 30 min at 37°C. When compared to ethyl acetate and aqueous extracts, the ethanolic extract displayed the most potent scavenging activity in ferric-reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and nitric oxide (NO) assays, with IC₅₀ values of 2.8 μl/ml, 3.3 μl/ml, and 9.2 μl/ml, respectively. The extracts significantly suppressed α-glucosidase and α-amylase activities (p < .05), with the ethanolic extract demonstrating the highest activity. H. sabdariffa significantly (p < .05) raised reduced glutathione (GSH) levels while simultaneously decreasing malondihaldehyde (MDA) and NO levels and increasing superoxide dismutase (SOD) and catalase activity in Fe²⁺ induced oxidative hepatic injury. The extract of the plant inhibited intestinal glucose absorption and increased muscular glucose uptake. The extract revealed the presence of several phenolic compounds when submitted to gas chromatography-mass Spectroscopy (GC-MS) screening, which was docked with α-glucosidase and α- amylase. The molecular docking displayed the compound 4-(3,5-Di-tert-butyl-4-hydroxyphenyl)butyl acrylate strongly interacted with α-glucosidase and α-amylase and had the lowest free binding energy compared to other compounds and acarbose. These results suggest that H. sabdariffa has promising antioxidant and antidiabetic activity. PRACTICAL APPLICATIONS: In recent years, there has been increased concern about the side effects of synthetic anti-diabetic drugs, as well as their expensive cost, especially in impoverished nations. This has instigated a radical shift towards the use of traditional plants, which are rich in phytochemicals many years ago. Among these plants, H. sabdariffa has been used to treat diabetes in traditional medicine. In this present study, H. sabdariffa extracts demonstrated the ability to inhibit carbohydrate digesting enzymes, facilitate muscle glucose uptake and attenuate oxidative stress in oxidative hepatic injury. Hence, demonstrating H. sabdariffa's potential to protect against oxidative damage and the complications associated with diabetes. Consumption of Hibiscus tea or juice may be a potential source for developing an anti-diabetic drug.

Protective role of hesperidin against diabetes induced spleen damage: Mechanism associated with oxidative stress and inflammation

Diabetes mellitus is a metabolic disease affecting various organs, including the spleen and is characterized by chronic hyperglycemia. Oxidative and inflammatory stress are key mediators in the development of spleen damage caused by diabetes. This study aimed to examine the splenoprotective effect of hesperidin and the mechanisms underlying its capacity to reduce oxidative stress and inflammation-mediated spleen damage in diabetes. The diabetic rats used in this study were induced with a 65 mg per kg body weight of streptozotocin. This was followed by 4 weeks of continuous daily dosage of hesperidin treatment at 100 mg/kg body weight. The results showed that hesperidin improved spleen weight and histopathological alterations in the diabetic rats. The hesperidin-treated diabetic group showed a marked induction of SOD and GPx enzymes and moderated malondialdehyde level. This was in addition to an obvious decrease in the levels of TNF-α and NF-ᴋB in the diabetic rat spleen. Through a remarkable upregulation in Bcl-xL and downregulation in Bax and cleaved caspase-3 proteins, hesperidin supplementation rescued splenic cell apoptosis in the diabetic rats. These findings demonstrate the effectiveness of hesperidin in helping regulate Bcl-2 family proteins and inhibiting the oxidative stress and inflammatory status of hyperglycemia-mediated spleen apoptosis. PRACTICAL APPLICATIONS: Diabetes-related spleen damage increases immune dysfunction, which often results in the heightened risks of infection, morbidity and mortality in diabetic patients. In this work, hesperidin was used in the treatment of rats with diabetes-induced splenic damage. The results were highly encouraging with hesperidin consistently presenting beneficial antioxidant and anti-inflammatory qualities and splenoprotective effect. Research outcomes support the notion that hesperidin treatment could be considered a good strategy for the prevention of diabetic complications in the spleen.

An Overview of the Potential of Medicinal Plants Used in the Development of Nutraceuticals for the Management of Diabetes Mellitus: Proposed Biological Mechanisms

Diabetes mellitus (DM) is a chronic metabolic disorder in which the pancreas does not produce enough insulin or the body cannot effectively use it. The prevalence of diabetes is increasing steadily, making it a global public health problem. Several serious complications are associated with this disease. There are a number of different classes of antidiabetic medications. Interestingly, traditional medicine can also be used for the development of novel classes of hypoglycemic therapeutics. This article summarizes an update of the potential of various important medicinal plants used in the development of nutraceuticals for the management of diabetes mellitus, and a proposal of their biological mechanisms.

Protective Mechanism of Fagopyrum esculentum Moench. Bee Pollen EtOH Extract Against Type II Diabetes in a High-Fat Diet/Streptozocin-Induced C57BL/6J Mice

Bee pollen is known as a natural nutrient storehouse and plays a key role in many biological processes. Based on the preliminary separation, identification, and characterization of the main active components of Fagopyrum esculentum Moench. bee pollen (FBP), the protective effects of F. esculentum bee pollen extract (FBPE) on high-fat-diet (HFD) and streptozocin (STZ) induced type II diabetes mellitus (T2DM) was evaluated in this study. The results revealed that FBPE contains 10 active compounds mainly including luteolin (9.46 g/kg), resveratrol (5.25 g/kg), kaemferol (3.67 g/kg), etc. The animal experiment results showed that FBPE could improve HFD-STZ induced T2DM mice. Moreover, the underlying mechanism of the above results could be: (i) FBPE could reduce the inflammation related to phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway, and (ii) the gut microbiota remodeling. The results of correlation analysis showed Candidatus Arthromitus and SMB53 indicated positive correlations to tumor necrosis factor-α (TNF-α); Coprococcus, Ruminocossus, and Odoribacteraceae reported negative correlations to transforming growth factor-β (TGF-β). That FBPE has an outstanding ability to improve T2DM and could be used as a kind of potential functional food for the prevention of T2DM.

Evaluation of the Acute and Sub-Acute Oral Toxicity of Jaranol in Kunming Mice

Background: Jaranol has shown a wide range of pharmacological activities; however, no study has yet examined in vivo toxicity. The study aimed to investigate the oral acute and sub-acute toxicity of jaranol in mice.

Methods: The acute toxicity was determined by a single oral dose of jaranol (2000 mg/kg). Therein animal behaviour and mortality rate were observed for 14 days. The jaranol (50, 100 and 200 mg/kg BW·d⁻¹) was given by gavage for 28 days daily in the sub-acute study. The mouse body weight (BW), organ weight, food, water intake, biochemical, haematological parameters, and histopathology were studied in acute and sub-acute toxicity.

Results: During the acute toxicity test, a single oral dose (2000 mg/kg) jaranol did not cause significant alteration in majority of the hematological indices. However, jaranol decreased the level of serum alanine aminotransferase and aspartate aminotransferase. Those results showed that the oral lethal dose 50 (LD₅₀) of jaranol was higher than 2000 mg/kg BW, regardless of sex. In repeated daily oral doses (50, 100 and 200 mg/kg BW·d⁻¹), no mortality was recorded in the various experimental groups. The jaranol reduced body weight gain (200 mg/kg BW·d⁻¹), the relative spleen weight (all doses) and serum alanine aminotransferase activity (200 mg/kg BW·d⁻¹). On the other hand, jaranol significantly elevated red blood cell count (100 and 200 mg/kg BW·d⁻¹) and serum creatinine levels (200 mg/kg BW·d⁻¹). Histological study revealed that spleen bleeding was identified in 200 mg/kg jaranol-treated mice.

Conclusion: Jaranol was relatively safe in Kunming Mice when repetitively administered orally in small doses for a prolonged period of time. We recommend more chronic toxicity studies and clinical trials on jaranol to ensure that its use is free of potential toxicity to humans.

Bioavailability of Hesperidin and Its Aglycone Hesperetin—Compounds Found in Citrus Fruits as a Parameter Conditioning the Pro-Health Potential (Neuroprotective and Antidiabetic Activity)—Mini-Review

Hesperidin and hesperetin are polyphenols that can be found predominantly in citrus fruits. They possess a variety of pharmacological properties such as neuroprotective and antidiabetic activity. However, the bioavailability of these compounds is limited due to low solubility and restricts their use as pro-healthy agents. This paper described the limitations resulting from the low bioavailability of the presented compounds and gathered the methods aiming at its improvement. Moreover, this work reviewed studies providing pieces of evidence for neuroprotective and antidiabetic properties of hesperidin and hesperetin as well as providing a detailed look into the significance of reported modes of action in chronic diseases. On account of a well-documented pro-healthy activity, it is important to look for ways to overcome the problem of poor bioavailability.

Callus-Mediated High-Frequency Plant Regeneration, Phytochemical Profiling, Antioxidant Activity and Genetic Stability in Ruta chalepensis L

Efficient methods for callus induction and the high-frequency plant regeneration of Ruta chalepensis L. were established, and the phytochemical potential and antioxidant activity of a donor plant, ex-vitro-established micropropagated plants, and callus were also studied. Yellowish-green callus was induced with a frequency of 97.8% from internode shoot segments of the donor plant growing in soil in the botanical garden cultured on Murashige and Skoog (MS) medium containing 10 μM 2,4-D (2,4-dichlorophenoxyacetic acid) and 1 μM BA (6-benzyladenine). Adventitious shoots were regenerated from the yellowish-green callus on MS medium containing 5.0 μM (BA) and 1.0 μM 1-naphthaleneacetic acid (NAA), with a regeneration frequency of 98.4% and a maximum of 54.6 shoots with an average length of 4.5 cm after 8 weeks. The regenerated shoots were rooted in a medium containing 1.0 μM IBA (indole-3-butyric acid) and successfully transferred to ex vitro conditions in pots containing normal garden soil, with a 95% survival rate. The amounts of alkaloids, phenolics, flavonoids, tannins, and antioxidant activity of the ex-vitro-established micropropagated plants were higher than in the donor plant and callus. The highest contents of hesperidin and rutin (93.3 and 55.9 µg/mg, respectively) were found in the ex-vitro-established micropropagated plants compared to those obtained from the donor plant (91.4 and 31.0 µg/mg, respectively) and callus (59.1 and 21.6 µg/mg, respectively). The genetic uniformity of the ex-vitro-established micropropagated plants was appraised by the ISSR markers and compared with the donor plant. This is the first report describing the callus-mediated plant regeneration, as well as the production of phenolic compounds and antioxidant activities in R. chalepensis, which might be a potential alternative technique for the mass propagation and synthesis of bioactive compounds such as hesperidin and rutin.

Inflammation, oxidative stress and altered heat shock response in type 2 diabetes: the basis for new pharmacological and non-pharmacological interventions

Type 2 diabetes mellitus (DM2) is a chronic disease characterised by variable degrees of insulin resistance and impaired insulin secretion. Besides, several pieces of evidence have shown that chronic inflammation, oxidative stress, and 70 kDa heat shock proteins (HSP70) are strongly involved in DM2 and its complications, and various pharmacological and non-pharmacological treatment alternatives act in these processes/molecules to modulate them and ameliorate the disease. Besides, uncontrolled hyperglycaemia is related to several complications as diabetic retinopathy, neuropathy and hepatic, renal and cardiac complications. In this review, we address discuss the involvement of different inflammatory and pro-oxidant pathways related to DM2, and we described molecular targets modulated by therapeutics currently available to treat DM2.

Extracts of Citrus Juice Processing Wastes Induce Weight Gain and Decrease Serum Glucose in Sprague-Dawley Rats

In this study, the safety and functionality of using citrus juice processing waste (CJPW) was confirmed. Large quantities of CJPW are generated on Jeju Island and cause environmental problems. CJPW extract (2,000 mg/kg) was administered intragastrically to male and female Sprague-Dawley (SD) rats for 14 days and the rats were analyzed. No general signs of toxicity were observed in SD rats administered CJPW extract. Feed intake did not differ between experimental and control animals. However, male and female rats administered CJPW extract had greater weight gain (102.9±5.53% and 114.15±6.89%, respectively) compared with the control animals. Higher weight gain was found in male and female experimental animals, but the difference was only significant in female animals. Serum analyses indicated that total protein and albumin, indicators of nutritional status, were significantly increased in animals administered CJPW. Further, serum glucose values were lower in male and female rats treated with CJPW (91.6±9.02% and 69.9±4.11%, respectively) compared with the controls; again, the difference was significant only for female animals. From the results of this study, CJPW can be considered as a safe material that does not induce toxicity in experimental animals. Therefore, CJPW is a potential raw material that can be used as a supplement in animal feed to help improve weight gain and achieve serum glucose con-trol.

Theophylline Extracted from Fu Brick Tea Affects the Metabolism of Preadipocytes and Body Fat in Mice as a Pancreatic Lipase Inhibitor

The dramatic increase in obesity is putting people under increasing pressure. Lipase inhibitors, as a kind of effective anti-obesity drug, have attracted more and more researchers’ attention in recent years because of their advantages of acting on the intestinal tract and having no side effects on the central nervous system. In this study, lipase inhibitor Fu Brick Theophylline (FBT) was screened based on enzyme molecular dynamics, and the inhibition mechanism of lipase inhibitors on obesity was analyzed and discussed at the cellular level and animal model level. We found that FBT had high inhibition effects of lipase with an IC₅₀ of 1.02~0.03 μg/mL. Firstly, the laboratory used 3T3-L1 proadipocytes as models, flow cytometry was used to detect the effects of FBT on the cycle, apoptosis and intracellular ROS activity of proadipocytes. To study the contents of triglyceride, total cholesterol, related metabolites and related gene and protein expression in adipocytes. The results showed that FBT could reduce ROS production and inflammatory factor mRNA expression during cell differentiation. Secondly, by establishing the animal model of high-fat feed ob nutritional obese mice, the morphological observation and gene expression analysis of body weight, fat rate, adipocyte and hepatocyte metabolism of FBT obese mice were further discussed. It was proven that FBT can effectively reduce the degree of fatty liver, prevent liver fibrosis and fat accumulation, and improve the damage of mitochondrial membrane structure. This study provides a theoretical basis for the screening and clinical treatment of lipase inhibitors.

The role of flavonoids in inhibiting IL-6 and inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that primarily affects the synovial joints. RA has well-known clinical manifestations and can cause progressive disability and premature death along with socioeconomic burdens. Interleukin-6 (IL-6) has been implicated in the pathology of RA where it can stimulate pannus formation, osteoclastogenesis, and oxidative stress. Flavonoids are plant metabolites with beneficial pharmacological effects, including anti-inflammatory, antioxidant, antidiabetic, anticancer, and others. Flavonoids are polyphenolic compounds found in a variety of plants, vegetables, and fruits. Many flavonoids have demonstrated anti-arthritic activity mediated mainly through the suppression of pro-inflammatory cytokines. This review thoroughly discusses the accumulate data on the role of flavonoids on IL-6 in RA.

The potential therapeutic effects of Trifolium alexandrinum extract, hesperetin and quercetin against diabetic nephropathy via attenuation of oxidative stress, inflammation, GSK-3β and apoptosis in male rats

Diabetic nephropathy (DN) is one of the manifestations of systemic microangiopathy in diabetes. Trifolium alexandrinum extract (TAE) contains biologically active phenolic compounds such as hesperetin (HES) and quercetin, possess various pharmacological properties, including anti-inflammatory, and anti-oxidative potentials. The present study aimed to assess the therapeutic effects and mechanisms underlying the anti-diabetic, antioxidant, and anti-inflammatory effects of HES and quercetin extracted from TAE, and TAE in STZ-induced DN. Male albino rats (170 ± 10 g) were divided into group (1); control rats and groups (2-5); diabetic/HFD were intraperitoneal (i.p.) injected with STZ (35 mg/kg), diabetic rats were randomly classified into STZ, STZ + HES (40 mg/kg), STZ + quercetin (50 mg/kg), and STZ + TAE (200 mg/kg) groups. After 5 weeks, blood and kidney samples were collected for further biochemical, western blotting and histopathological studies. Serum renal functions, renal oxidative status biomarkers and proinflammatory cytokines were determined. The results revealed that there were significant increases in urea, BUN, creatinine, ALP, total protein, albumin, and globulin with a significant decrease in Na⁺ and K⁺ levels, as well as significant elevation in TBARS, TGF-β, TNF-α, IL-6 and the expression levels of GSK-3β, as well as significant decline in TAC, GSH and CAT levels in STZ-treated group compared to the control rats. The previous deleterious alterations were significantly ameliorated after the treatment of diabetic rats with HES, quercetin and TAE. In conclusion, our data demonstrated that HES, quercetin and TAE could be used as potent therapeutic agents to counter DN through antioxidant, anti-inflammatory, and antidiabetic effects.

Therapeutic potentials of agonist and antagonist of adenosine receptors in type 2 diabetes

Type 2 diabetes has been a global health challenge over the decades and is among the leading causes of death. Several treatment approaches have been developed, but more effective and new therapies are still needed. The role of adenosine in glucose and lipid homeostasis has offered a different therapeutic approach. Adenosine mediates its physiological role through the activation of adenosine receptors. These adenosine receptors have been implicated in glucose and lipid homeostasis. The ability of agonists and antagonists of adenosine receptors to activate or inhibit the adenosine signalling cascade and thereby affecting the balance of glucose and lipid homeostasis has challenged the studies of agonists and antagonists of adenosine receptors, both preclinical and clinical, as potential anti-diabetic drugs. This review provides a background on different anti-diabetic therapeutic approaches, outlining the role of adenosine receptors in glucose and lipid homeostasis, and mechanisms underlying the action of agonists/antagonists of adenosine receptors as a therapeutic potential towards type 2 diabetes.

Washingtonia filifera seed extracts inhibit the islet amyloid polypeptide fibrils formations and α-amylase and α-glucosidase activity

Washingtonia filifera seeds have revealed to possess antioxidant properties, butyrylcholinesterase and xanthine oxidase inhibition activities. The literature has indicated a relationship between Alzheimer's disease (AD) and type-2 diabetes (T2D). Keeping this in mind, we have now evaluated the inhibitory properties of W. filifera seed extracts on α-amylase, α-glucosidase enzyme activity and the Islet Amyloid Polypeptide (IAPP) fibrils formation. Three extracts from seeds of W. filifera were evaluated for their enzyme inhibitory effect and IC50 values were calculated for all the extracts. The inhibition mode was investigated by Lineweaver-Burk plot analysis and the inhibition of IAPP aggregate formation was monitored. W. filifera methanol seed extract appears as the most potent inhibitor of α-amylase, α-glucosidase, and for the IAPP fibril formation. Current findings indicate new potential of this extract that could be used for the identification or development of novel potential agents for T2D and AD.

Momordica charantia nanoparticles promote mitochondria biogenesis in the pancreas of diabetic-induced rats: gene expression study

Background

Mitochondria dysfunction is one of the clinical features of diabetes mellitus (DM), which is a hallmark of insulin resistance (IR). This study investigates the therapeutic effect of Momordica charantia nanoparticles on mitochondria biogenesis in diabetic-induced rats. Forty-two adult wistar rats (average weight of 189 ± 10.32) were grouped as follows: STZ (65 mg/kg), control group, STZ + silver nitrate (10 mg/kg), STZ + M. charantia silver nanoparticles (50 mg/kg), STZ + metformin (100 mg/kg), and STZ + M. charantia aqueous extract (100 mg/kg). DM was induced intraperitoneal using freshly prepared solution of STZ (65 mg/kg), and rats with fasting blood sugar (FBS) above 250 mg/dl after 72 h of induction were considered diabetic. Treatment started after the third day of induction and lasted for 11 days. Effect of M. charantia nanoparticles on glucose level and pancreatic expression of genes involved in mitochondria biogenesis (PGC-1α, AMPK, GSK-3β, PPARϒ), inflammation (IL-1B, TNFα) and glucose sensitivity (PI3K, AKT, PTEN Insulin and Glut2) were quantified using reverse-transcriptase polymerase chain reaction (RT-PCR).

Results

The results showed that M. charantia nanoparticles promote mitochondria biogenesis, glucose sensitivity and reverse inflammation in the pancreas of diabetes rat model through upregulation of PGC-1α, AMPK, PPARϒ, AKT, Insulin and Glut2 mRNA expression and downregulation of GSK-3β, PI3K, IL-1B and TNFα mRNA expression in the pancreas of diabetic rats.

Conclusion

This study thus concludes that M. charantia nanoparticles may provide effective therapeutics against mitochondria dysfunction in the pancreas of diabetic model.

Maackiain Protects the Kidneys of Type 2 Diabetic Rats via Modulating the Nrf2/HO-1 and TLR4/NF-κB/Caspase-3 Pathways

BACKGROUND

Type 2 diabetes (T2D) is aglobal health burden that accounts for about 90% of all cases of diabetes. Injury to the kidneys is aserious complication of type 2 diabetes. Maackiain, apterocarpan extracted from roots of Sophora flavescens, has been traditionally used for various disease conditions. However, nothing is known about its possible potential effect on HFD/STZ-T2D-induced nephrotoxicity.

METHODS

In this study, T2D rat model is created by high-fat diet (HFD) for 2 weeks with injection of asingle dose of streptozotocin (35mg/kg body weight). T2D rats were orally administered with maackiain (10 and 20mg/kg body weight) for 7 weeks.

RESULTS

Maackiain suppressed T2D-induced alterations in metabolic parameters, lipid profile and kidney functionality markers. By administering 10 and 20mg/kg maackiain to T2D rats, it was able to reduce lipid peroxidation while improving antioxidant levels (SOD, CAT, and GSH). Furthermore, the present study demonstrated the molecular mechanisms through which maackiain attenuated T2D-induced oxidative stress (mRNA: Nrf2, Nqo-1, Ho-1, Gclc and Gpx-1; protein: NRF2, NQO-1, HO-1 and NOX-4), inflammation (mRNA: Tlr, Myd88, IκBα, Mcp-1, Tgf-β, col4, Icam1, Vcam1 and E-selectin; Protein: TLR4, MYD88, NF-κB, IκBα, MCP-1; levels: TNF-α and MCP-1) and apoptosis (mRNA: Bcl-2, Bax, Bad, Apaf-1, Caspase-9 and Caspase-3; protein: Bcl-2, Bax, Caspase-3 and Caspase-9) mediated renal injury. Additionally, significant improvement in kidney architecture was observed after treatment of diabetic rats with 10 or 20mg/kg maackiain.

CONCLUSION

Maackiain protects the kidney by decreasing oxidative stress, inflammation, and apoptosis to preserve normal renal function in type 2 diabetes.

Concomitant use of tea catechins affects absorption and serum triglyceride-lowering effects of monoglucosyl hesperidin

The present study investigated whether combined ingestion of green tea catechins (GTC) and monoglucosyl hesperidin (GHES) influences the pharmacokinetic parameters of polyphenols and serum triglycerides (TG). We conducted 2 randomized, controlled trials. Study 1: 8 healthy male subjects participated in a crossover study in which they ingested a test beverage containing GHES (0, 84, 168, or 336 mg GHES) with GTC, or 336 mg GHES without GTC. After ingestion, the pharmacokinetic changes in plasma hesperetin (HEP) and catechins were measured. Study 2: 36 healthy male and female subjects (mean age, 53 ± 2 years; mean BMI, 25.2 ± 0.5 kg m^-2) were recruited for a double-blind, placebo-controlled study in which they ingested a test beverage containing 165 mg GHES with 387 mg GTC or a placebo beverage daily for 4 weeks. Fasting serum TG and other lipids and glucose metabolites were analyzed. Study 1 showed that the pharmacokinetics of HEP did not differ significantly between the 336 mg GHES without GTC treatment and the 168 mg GHES with GTC treatment. Study 2 showed that continuous ingestion of 165 mg GHES and 387 mg GTC for 4 weeks significantly decreased fasting serum TG levels compared with baseline values (change in TG, -30 ± 13 mg dl^-1, P = 0.040) in the intention-to-treat analysis. In conclusion, our findings suggest that GTC affects the oral bioavailability of GHES, and combined ingestion of low doses of GHES with GTC effectively improves fasting TG levels.

Impact of Analog Rice Derived from Different Composite Flours from Tubers, Germinated Legumes, and Cereals on Improving Serum Markers in Alloxan-Induced Diabetic Rats

This study aimed to evaluate the consumption of four types of analog rice made from different composite flours in alloxan-induced diabetic rats. Forty-two male Wistar rats were divided into seven groups and fed different food for six weeks: normal standard food (NSF), diabetic standard food (DSF), diabetic commercial rice (DCR), and diabetic analog rice (DAR) I∼IV. Total phenolic, dietary fiber, and resistant starch contents were evaluated in every analog and commercial type of rice. The parameters studied were fasting blood glucose, homeostatic model assessment (HOMA) insulin resistance (IR), HOMA β, lipid profile, atherogenic indexes (AI), weight changes, serum insulin and antioxidant activities. Total phenol, dietary fiber, and resistant starch were higher for analog rice IV than the other three analog rice. In addition, analog rice IV had a greater ability to lower fasting blood glucose, total cholesterol, triglycerides, and low-density lipoprotein levels. High density lipoprotein levels increased in all groups fed analog rice, and all diabetic rats fed four types of analog rice had improved weight, antioxidant activity, serum insulin levels, HOMA IR, HOMA β, and AI. Commercial rice consumption did not improve glucose or lipids profiles, antioxidant activity, serum insulin level, HOMA IR, HOMA β, or AI in diabetic mice. These results show that the four types of analog rice significantly improved serum markers in diabetic 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.

Effects of Naringin on Cardiomyocytes From a Rodent Model of Type 2 Diabetes

Diabetic cardiomyopathy (DCM) is a primary disease in diabetic patients characterized by diastolic dysfunction leading to heart failure and death. Unfortunately, even tight glycemic control has not been effective in its prevention. We have found aberrant diastolic Ca2+ concentrations ([Ca2+]d), decreased glucose transport, elevated production of reactive oxygen species (ROS), and increased calpain activity in cardiomyocytes from a murine model (db/db) of type 2 diabetes (T2D). Cardiomyocytes from these mice demonstrate significant cell injury, increased levels of tumor necrosis factor-alpha and interleukin-6 and expression of the transcription nuclear factor-κB (NF-κB). Furthermore, decreased cell viability, and reduced expression of Kir6.2, SUR1, and SUR2 subunits of the ATP-sensitive potassium (KATP) channels. Treatment of T2D mice with the citrus fruit flavonoid naringin for 4 weeks protected cardiomyocytes by reducing diastolic Ca2+ overload, improving glucose transport, lowering reactive oxygen species production, and suppressed myocardial inflammation. In addition, naringin reduced calpain activity, decreased cardiac injury, increased cell viability, and restored the protein expression of Kir6.2, SUR1, and SUR2 subunits of the KATP channels. Administration of the KATP channel inhibitor glibenclamide caused a further increase in [Ca2+]d in T2D cardiomyocytes and abolished the naringin effect on [Ca2+]d. Nicorandil, a KATP channel opener, and nitric oxide donor drug mimic the naringin effect on [Ca2+]d in T2D cardiomyocyte; however, it aggravated the hyperglycemia in T2D mice. These data add new insights into the mechanisms underlying the beneficial effects of naringin in T2D cardiomyopathy, thus suggesting a novel approach to treating this cardiovascular complication.

A review of the lipolytic effects and the reduction of abdominal fat from bioactive compounds and moro orange extracts

Dietary supplementation containing Citrus sinensis extract is being widely used for weight loss due to its anti-adipogenic and antioxidant effects that regulate the metabolism of fatty acids. Bioactive compounds upregulate PPARα in the liver tissue, increasing oxidation of fatty acids and improving insulin sensitivity in addition to decreasing the expression of genes involved in the synthesis of fatty acids, such as LXRα and FAS. Studies on synephrine demonstrated their ability to stimulate the development of beige adipose tissue through greater expression of UCP1 and mtTFA, contributing to an increase in thermogenesis and mitochondrial biogenesis. However, despite its widespread use to reduce abdominal fat, few scientific studies have consensually proven the effectiveness of Moro orange extract for weight loss. This literature review summarizes the current information on the pharmacological and molecular mechanisms involved in the modulation of lipid metabolism by the bioactive compounds present in Moro orange extract.