Naringenin suppresses macrophage infiltration into adipose tissue in an early phase of high-fat diet-induced obesity

Novel Insights Into Naringenin: A Multifaceted Exploration of Production, Synthesis, Health Effects, Nanodelivery Systems, and Molecular Simulation

Naringenin, a flavonoid widely present in citrus fruits, has garnered considerable attention due to its diverse biological activities and health-promoting benefits. As research on naringenin advances, the application scope of naringenin has significantly expanded. This paper provides a systematic overview of the production and synthesis methods of naringenin, focusing especially on the application of green extraction techniques and the strategies for constructing microbial metabolic engineering. Naringenin not only achieves its diverse biological activities including antioxidant, antiinflammatory, and glucolipid metabolism regulation through multiple mechanisms but also modulates the balance of gut microbiota, thereby mediating synergistic health effects via the host-microbial metabolic axis. Given the low oral bioavailability of naringenin, various nanodelivery systems have been developed to improve its bioavailability. Meanwhile, molecular simulation techniques elucidate the binding conformation characteristics with receptors at the molecular level, providing novel insights into its mechanisms of action. In conclusion, this review seeks to offer a theoretical basis and future directions for further research and application of naringenin.

Recent advancements in drug delivery system of flavonoids with a special emphasis on the flavanone naringenin: exploring their application in wound healing and associated processes

Numerous flavonoids have been identified in citrus fruits which show potential to cure several complex diseases. These natural polyphenolic bioactive compounds are the secondary metabolites of various plants, among which naringenin has been explored in several pre-clinical research for its beneficial role in promoting health by modulating various biochemical processes. Its antioxidant, anti-inflammatory, and anti-microbial effects have been projected toward healing of wounds. Further, its application has also been shown to regrow vascular networks, which are known to facilitate the healing of chronic wounds. Thus, the potential of naringenin to modulate various molecular pathways aids in the healing process of wounds. Considering the recent literature, an update has been attempted to present the correlation between the healing mechanisms of wounds by the application of naringenin. Furthermore, the application of naringenin is challenging because of its properties of poor solubility and limited permeability, which can be overcome by the nanotechnology platform. Thus, several nanocarriers that have been employed for the improvement of naringenin delivery are highlighted. Thereby, it can be concluded that a suitable nanocarrier of naringenin could be an effective tool in treating wounds to improve the quality of life of such patients.

Potential Beneficial Effects of Naringin and Naringenin on Long COVID-A Review of the Literature

Coronavirus disease 2019 (COVID-19) caused a severe epidemic due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Recent studies have found that patients do not completely recover from acute infections, but instead, suffer from a variety of post-acute sequelae of SARS-CoV-2 infection, known as long COVID. The effects of long COVID can be far-reaching, with a duration of up to six months and a range of symptoms such as cognitive dysfunction, immune dysregulation, microbiota dysbiosis, myalgic encephalomyelitis/chronic fatigue syndrome, myocarditis, pulmonary fibrosis, cough, diabetes, pain, reproductive dysfunction, and thrombus formation. However, recent studies have shown that naringenin and naringin have palliative effects on various COVID-19 sequelae. Flavonoids such as naringin and naringenin, commonly found in fruits and vegetables, have various positive effects, including reducing inflammation, preventing viral infections, and providing antioxidants. This article discusses the molecular mechanisms and clinical effects of naringin and naringenin on treating the above diseases. It proposes them as potential drugs for the treatment of long COVID, and it can be inferred that naringin and naringenin exhibit potential as extended long COVID medications, in the future likely serving as nutraceuticals or clinical supplements for the comprehensive alleviation of the various manifestations of COVID-19 complications.

The Effect of an Innovative Combination of Bergamot Polyphenolic Fraction and Cynara cardunculus L. Extract on Weight Gain Reduction and Fat Browning in Obese Mice

Obesity is one of the world's most serious public health issues, with a high risk of developing a wide range of diseases. As a result, focusing on adipose tissue dysfunction may help to prevent the metabolic disturbances commonly associated with obesity. Nutraceutical supplementation may be a crucial strategy for improving WAT inflammation and obesity and accelerating the browning process. The aim of this study was to perform a preclinical "proof of concept" study on Bergacyn®, an innovative formulation originating from a combination of bergamot polyphenolic fraction (BPF) and Cynara cardunculus (CyC), for the treatment of adipose tissue dysfunction. In particular, Bergacyn® supplementation in WD/SW-fed mice at doses of 50 mg/kg given orally for 12 weeks, was able to reduce body weight and total fat mass in the WD/SW mice, in association with an improvement in plasma biochemical parameters, including glycemia, total cholesterol, and LDL levels. In addition, a significant reduction in serum ALT levels was highlighted. The decreased WAT levels corresponded to an increased weight of BAT tissue, which was associated with a downregulation of PPARγ as compared to the vehicle group. Bergacyn® was able to restore PPARγ levels and prevent NF-kB overexpression in the WAT of mice fed a WD/SW diet, suggesting an improved oxidative metabolism and inflammatory status. These results were associated with a significant potentiation of the total antioxidant status in WD/SW mice. Finally, our data show, for the first time, that Bergacyn® supplementation may be a valuable approach to counteract adipose tissue dysfunction and obesity-associated effects on cardiometabolic risk.

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.

Biological activities of naringenin: A narrative review based on in vitro and in vivo studies

Naringenin (4',5,7-trihydroxyflavonone) is a phytochemical mainly found in citrus fruits. It is a promising phytochemical for human health because of its beneficial effects. This review aims to present comprehensive information on naringenin biological activities along with its action mechanisms and explain the pharmacokinetic properties of naringenin. This study involves a comprehensive literature review of in vitro and in vivo studies examining the effects of naringenin. Naringenin has antidiabetic, anticancer, antimicrobial, antiobesity, gastroprotective, immunomodulator, cardioprotective, nephroprotective, and neuroprotective properties. These properties are primarily attributed to its antioxidant and anti-inflammatory activities. The most important antioxidant activities of naringenin including free radical scavenging and preventing lipid peroxidation. Naringenin can increase the concentration of antioxidant enzymes and inhibit metal chelation and various pro-oxidant enzymes. Anti-inflammatory activities of naringenin are associated with decreased mitogen-activated protein kinase activities and nuclear factor kappa B by modulating the expression and release of proinflammatory cytokine and enzymes. In vitro and in vivo studies show that naringenin has promising biological activities for a variety of diseases. More research must be conducted on the bioactivities of naringenin, and to determine its optimum dose. In addition, the efficiency of naringenin must be examined with enhanced bioavailability methods to be able to increase its therapeutic effect.

Unraveling Obesity: Transgenerational Inheritance, Treatment Side Effects, Flavonoids, Mechanisms, Microbiota, Redox Balance, and Bioavailability-A Narrative Review

Obesity is known as a transgenerational vicious cycle and has become a global burden due to its unavoidable complications. Modern approaches to obesity management often involve the use of pharmaceutical drugs and surgeries that have been associated with negative side effects. In contrast, natural antioxidants, such as flavonoids, have emerged as a promising alternative due to their potential health benefits and minimal side effects. Thus, this narrative review explores the potential protective role of flavonoids as a natural antioxidant in managing obesity. To identify recent in vivo studies on the efficiency of flavonoids in managing obesity, a comprehensive search was conducted on Wiley Online Library, Scopus, Nature, and ScienceDirect. The search was limited to the past 10 years; from the search, we identified 31 articles to be further reviewed. Based on the reviewed articles, we concluded that flavonoids offer novel therapeutic strategies for preventing obesity and its associated co-morbidities. This is because the appropriate dosage of flavonoid compounds is able to reduce adipose tissue mass, the formation of intracellular free radicals, enhance endogenous antioxidant defences, modulate the redox balance, and reduce inflammatory signalling pathways. Thus, this review provides an insight into the domain of a natural product therapeutic approach for managing obesity and recapitulates the transgenerational inheritance of obesity, the current available treatments to manage obesity and its side effects, flavonoids and their sources, the molecular mechanism involved, the modulation of gut microbiota in obesity, redox balance, and the bioavailability of flavonoids. In toto, although flavonoids show promising positive outcome in managing obesity, a more comprehensive understanding of the molecular mechanisms responsible for the advantageous impacts of flavonoids-achieved through translation to clinical trials-would provide a novel approach to inculcating flavonoids in managing obesity in the future as this review is limited to animal studies.

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.

Could Naringenin Participate as a Regulator of Obesity and Satiety?

Obesity is a serious health problem worldwide, since it is associated with multiple metabolic disorders and complications such as cardiovascular disease, type 2 diabetes, fatty liver disease and overall metabolic dysfunction. Dysregulation of the hunger-satiety pathway, which includes alterations of central and peripheral signaling, explains some forms of obesity by favoring hyperphagia and weight gain. The present work comprehensively summarizes the mechanisms by which naringenin (NAR), a predominant flavanone in citrus fruits, could modulate the main pathways associated with the development of obesity and some of its comorbidities, such as oxidative stress (OS), inflammation, insulin resistance (IR) and dyslipidemia, as well as the role of NAR in modulating the secretion of enterohormones of the satiety pathway and its possible antiobesogenic effect. The results of multiple in vitro and in vivo studies have shown that NAR has various potentially modulatory biological effects against obesity by countering IR, inflammation, OS, macrophage infiltration, dyslipidemia, hepatic steatosis, and adipose deposition. Likewise, NAR is capable of modulating peptides or peripheral hormones directly associated with the hunger-satiety pathway, such as ghrelin, cholecystokinin, insulin, adiponectin and leptin. The evidence supports the use of NAR as a promising alternative to prevent overweight and obesity.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

Naringenin Protects against Hypertension by Regulating Lipid Disorder and Oxidative Stress in a Rat Model

BACKGROUND

Naringenin, a natural resource-derived flavanone, exhibits a plethora of pharmacological properties. The present study aimed to investigate the effects of naringenin on obesity-associated hypertension and its underlying mechanism.

METHODS

Obesity-associated hypertension rat model was established with a high-fat diet (HFD) and was administrated with naringenin (25, 50, 100 mg/kg). Body and fat weights were recorded and blood pressure was measured. Serum lipid parameters (cholesterol, low-density lipoprotein [LDL], high-density lipoprotein [HDL], and triglycerides), oxidative stress biomarkers (malondialdehyde [MDA], superoxide dismutase [SOD], nitrite oxide [NO], and glutathione [GSH]), and adipocytokines (leptin and adiponectin) were determined. The expressions of signal transducer and activator of transcription (STAT) 3 were determined by using Western blotting.

RESULTS

Treatment with naringenin (100 mg/kg) reduced body and fat weight in HFD-induced rats. Besides, treatment with naringenin (50 and 100 mg/kg) reduced blood pressure and regulated lipid parameters by decreasing cholesterol, triglycerides, and LDL and increasing HDL. Treatment with naringenin (50 and 100 mg/kg) reduced serum MDA and NO, whereas it increased serum SOD and GSH. Furthermore, treatment with naringenin (50 and 100 mg/kg) regulated adipocytokines and decreased the phosphorylation of STAT3.

CONCLUSION

Naringenin ameliorates obesity-associated hypertension by regulating lipid disorder and oxidative stress.

Physicochemical and Biochemical Evaluation of Amorphous Solid Dispersion of Naringenin Prepared Using Hot-Melt Extrusion

Naringenin (NRG) is a plant-derived flavonoid. Due to its antioxidant, anti-inflammatory, and analgesic activities it is beneficial to human health and is often used as a functional food ingredient; however, it has poor water solubility and low in vivo bioavailability. Therefore, the efficacy of NRG can be improved by enhancing its water solubility to increase gastrointestinal absorption. Conventional methods for the formulation of NRG are very complex and use toxic organic solvents, making them impractical for the production of functional foods. The objective of this study was to develop a safe and effective NRG-based functional food material. Previously, we established a technology to prepare amorphous solid dispersions (SDs) from functional food ingredients with poor water solubility and used hot-melt extrusion technology that is comparatively simple and does not involve the use of organic solvents. In this study, we prepared NRG SD and evaluated them both physicochemically and biochemically. NRG SD had superior water solubility and gastrointestinal absorption relative to native NRG and showed higher analgesic efficacy in rats than crystalline NRG. NRG SD was administered to mice in a mixed diet for 28 days, and organ weights and hematological/clinical biochemical parameters were assessed. NRG SD did not demonstrate severe adverse effects. The results suggest that NRG SD is a safe and highly efficacious formulation that can be used as a functional food material in the future.

[Preventive and Ameliorating Effects of Food Factors on Obesity-related Diseases by Regulating Inflammation]

Japan is currently a super-aging society, and lifestyle-related diseases that increase in incidence with age and the related rise in national medical expenses are major social problems. Preventive medicine and self-medication are becoming more important. Recently, various in vitro and in vivo studies have shown that food-derived natural compounds may contribute to the prevention and treatment of obesity-related diseases, such as diabetes mellitus. This report reviews our previous studies on the usefulness of the citrus flavonoid naringenin for obesity-related diseases. We showed that naringenin exerts an anti-diabetic effect by regulating inflammation pathways involving adipocytes and adipose tissue, and also showed an interaction between naringenin and anti-diabetic drugs. Because natural compounds are generally inexpensive and safe, they have the advantage of being easily applied to clinical applications. However, more detailed studies, such as clinical trials in humans, are required. Further research and scientific evidence will be required for the proper use of food factors in disease prevention and treatment.

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.

Anti-obesity properties and mechanism of action of flavonoids: A review

Obesity is a major public health problem, and there is increasing scientific interest in its mechanisms, as well as a search for new compounds with antioxidant and anti-inflammatory properties that can minimize the metabolic complications associated with its pathology. One potential source of these compounds is natural products; Among these, flavonoids are a promising group of natural substances. Flavonoids are active constituents with diverse biological activities and are widely found in plants kingdom. Numerous studies have shown that flavonoids can effectively inhibit obesity and related metabolic disorders. The review synthesizes recent evidence in respect of progress in the understanding of the anti-obesity effects of flavonoids. Such effects which occurs through the modulation of proteins, genes and transcriptional factors involved in decreasing lipogenesis, increasing lipolysis, expenditure energy, stimulating fatty acids B-oxidation, digestion and metabolism of carbohydrates. In addition to mitigating inflammatory responses and suppress oxidative stress. A better understanding of the modulating effects and mechanisms of flavonoids in relation to obesity will allow us to better use these compounds to treat or even prevent obesity and its associated comorbidities.

The Discovery of Naringenin as Endolysosomal Two-Pore Channel Inhibitor and Its Emerging Role in SARS-CoV-2 Infection

The flavonoid naringenin (Nar), present in citrus fruits and tomatoes, has been identified as a blocker of an emerging class of human intracellular channels, namely the two-pore channel (TPC) family, whose role has been established in several diseases. Indeed, Nar was shown to be effective against neoangiogenesis, a process essential for solid tumor progression, by specifically impairing TPC activity. The goal of the present review is to illustrate the rationale that links TPC channels to the mechanism of coronavirus infection, and how their inhibition by Nar could be an efficient pharmacological strategy to fight the current pandemic plague COVID-19.

Potential of Nutraceutical Supplementation in the Modulation of White and Brown Fat Tissues in Obesity-Associated Disorders: Role of Inflammatory Signalling

The high incidence of obesity is associated with an increasing risk of several chronic diseases such as cardiovascular disease, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). Sustained obesity is characterized by a chronic and unsolved inflammation of adipose tissue, which leads to a greater expression of proinflammatory adipokines, excessive lipid storage and adipogenesis. The purpose of this review is to clarify how inflammatory mediators act during adipose tissue dysfunction in the development of insulin resistance and all obesity-associated diseases. In particular, we focused our attention on the role of inflammatory signaling in brown adipose tissue (BAT) thermogenic activity and the browning of white adipose tissue (WAT), which represent a relevant component of adipose alterations during obesity. Furthermore, we reported the most recent evidence in the literature on nutraceutical supplementation in the management of the adipose inflammatory state, and in particular on their potential effect on common inflammatory mediators and pathways, responsible for WAT and BAT dysfunction. Although further research is needed to demonstrate that targeting pro-inflammatory mediators improves adipose tissue dysfunction and activates thermogenesis in BAT and WAT browning during obesity, polyphenols supplementation could represent an innovative therapeutic strategy to prevent progression of obesity and obesity-related metabolic diseases.

Glucosyl Hesperidin Has an Anti-diabetic Effect in High-Fat Diet-Induced Obese Mice

Glucosyl hesperidin (GH) is a water-soluble derivative of hesperidin, a citrus flavonoid. GH has various pharmacological effects, such as hypolipidemic and hypouricemic effects, and may therefore be a useful supplement or drug. In the present study, we evaluated the effects of long- and short-term intake of GH on hyperglycemia and macrophage infiltration into the adipose tissue of high-fat diet (HFD)-fed mice. Long-term (11-week) consumption of GH tended to reduce body weight and the fasting blood glucose concentration of the HFD-fed mice, and ameliorated glucose intolerance and insulin resistance, according to glucose and insulin tolerance tests. Additionally, although GH did not affect fat pad weight, it reduced HFD-induced macrophage infiltration into adipose tissue. Short-term (2-week) consumption of GH did not affect the HFD-induced increases in body weight or fasting blood glucose, and it did not ameliorate glucose intolerance or insulin resistance. However, short-term intake did reduce the HFD-induced macrophage infiltration and monocyte chemotactic protein 1 (MCP-1) expression in adipose tissue. Furthermore, hesperetin, which is an aglycone of GH, inhibited MCP-1 expression in 3T3-L1 adipocytes, 3T3-L1 adipocytes co-cultured with RAW264 macrophages, and tumor necrosis factor-α-treated 3T3-L1 adipocytes. The present findings suggest that daily consumption of GH may have preventive and/or therapeutic effects on obesity-related diseases, such as diabetes mellitus.

Multi-Therapeutic Potential of Naringenin (4',5,7-Trihydroxyflavonone): Experimental Evidence and Mechanisms

Extensive research has been carried out during the last few decades, providing a detailed account of thousands of discovered phytochemicals and their biological activities that have the potential to be exploited for a wide variety of medicinal purposes. These phytochemicals, which are pharmacologically important for clinical use, primarily consist of polyphenols, followed by terpenoids and alkaloids. There are numerous published reports indicating the primary role of phytochemicals proven to possess therapeutic potential against several diseases. However, not all phytochemicals possess significant medicinal properties, and only some of them exhibit viable biological effects. Naringenin, a flavanone found in citrus fruits, is known to improve immunity, repair DNA damage, and scavenge free radicals. Despite the very low bioavailability of naringenin, it is known to exhibit various promising biological properties of medicinal importance, including anti-inflammatory and antioxidant activities. This review focuses on the various aspects related to naringenin, particularly its physicochemical, pharmacokinetic, and pharmacodynamic properties. Furthermore, various pharmacological activities of naringenin, such as anticancer, antidiabetic, hepatoprotective, neuroprotective, cardioprotective, nephroprotective, and gastroprotective effects, have been discussed along with their mechanisms of action.

Naringenin attenuates experimental autoimmune encephalomyelitis by protecting the intact of blood-brain barrier and controlling inflammatory cell migration

Targeting pathogenic immune cell trafficking poses an attractive opportunity to attenuate autoimmune disorders such as multiple sclerosis (MS). MS and its animal model, experimental autoimmune encephalomyelitis (EAE), are characterized by the immune cells-mediated demyelination and neurodegeneration of the central nervous system (CNS). Our previous study has proven that dietary naringenin ameliorates EAE clinical symptoms via reducing the CNS cell infiltration. The present study examined the beneficial effects of naringenin on maintaining the blood-brain barrier in EAE mice via dietary naringenin intervention. The results showed that naringenin-treated EAE mice had an intact blood-CNS barrier by increasing tight junction-associated factors and decreasing Evans Blue dye in the CNS. Naringenin decreased the accumulation and maturation of conventional dendritic cells (cDCs), CCL19, and CCR7 in the CNS. Also, naringenin blocked the chemotaxis and antigen-presenting function of cDCs that resulted in reducing T-cell secreting cytokines (IFN-γ, IL-17, and IL-6) in the spleen. Importantly, naringenin blocked pathogenic T cells infiltrated into the CNS and attenuates passive EAE. Therefore, by blocking chemokine-mediated migration of DCs and pathogenic T cells into the CNS, naringenin attenuates EAE pathogenesis and might be a potential candidate for the treatment of autoimmune diseases, such as MS and other chronic T-cell mediated autoimmune diseases.

Role of Flavonoids in The Interactions among Obesity, Inflammation, and Autophagy

Nowadays, obesity is considered as one of the main concerns for public health worldwide, since it encompasses up to 39% of overweight and 13% obese (WHO) adults. It develops because of the imbalance in the energy intake/expenditure ratio, which leads to excess nutrients and results in dysfunction of adipose tissue. The hypertrophy of adipocytes and the nutrients excess trigger the induction of inflammatory signaling through various pathways, among others, an increase in the expression of pro-inflammatory adipocytokines, and stress of the endoplasmic reticulum (ER). A better understanding of obesity and preventing its complications are beneficial for obese patients on two facets: treating obesity, and treating and preventing the pathologies associated with it. Hitherto, therapeutic itineraries in most cases are based on lifestyle modifications, bariatric surgery, and pharmacotherapy despite none of them have achieved optimal results. Therefore, diet can play an important role in the prevention of adiposity, as well as the associated disorders. Recent results have shown that flavonoids intake have an essential role in protecting against oxidative damage phenomena, and presents biochemical and pharmacological functions beneficial to human health. This review summarizes the current knowledge of the anti-inflammatory actions and autophagic flux of natural flavonoids, and their molecular mechanisms for preventing and/or treating obesity.

Citrus Flavonoids as Promising Phytochemicals Targeting Diabetes and Related Complications: A Systematic Review of In Vitro and In Vivo Studies

The consumption of plant-based food is important for health promotion, especially concerning the prevention and management of chronic diseases. Flavonoids are the main bioactive compounds in citrus fruits, with multiple beneficial effects, especially antidiabetic effects. We systematically review the potential antidiabetic action and molecular mechanisms of citrus flavonoids based on in vitro and in vivo studies. A search of the PubMed, EMBASE, Scopus, and Web of Science Core Collection databases for articles published since 2010 was carried out using the keywords citrus, flavonoid, and diabetes. All articles identified were analyzed, and data were extracted using a standardized form. The search identified 38 articles, which reported that 19 citrus flavonoids, including 8-prenylnaringenin, cosmosiin, didymin, diosmin, hesperetin, hesperidin, isosiennsetin, naringenin, naringin, neohesperidin, nobiletin, poncirin, quercetin, rhoifolin, rutin, sineesytin, sudachitin, tangeretin, and xanthohumol, have antidiabetic potential. These flavonoids regulated biomarkers of glycemic control, lipid profiles, renal function, hepatic enzymes, and antioxidant enzymes, and modulated signaling pathways related to glucose uptake and insulin sensitivity that are involved in the pathogenesis of diabetes and its related complications. Citrus flavonoids, therefore, are promising antidiabetic candidates, while their antidiabetic effects remain to be verified in forthcoming human studies.

A Comprehensive Systematic Review of the Effects of Naringenin, a Citrus-Derived Flavonoid, on Risk Factors for Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of liver dysfunction worldwide. Recently, some natural compounds have attracted growing interest in the treatment of NAFLD. In this context, most attention has been paid to natural products derived from fruits, vegetables, and medicinal herbs. Naringenin, a natural flavanone, has been revealed to have pharmacological effects in the treatment of obesity and associated metabolic disorders such as NAFLD. The aim of this study was to examine the therapeutic effects of naringenin and its possible mechanisms of action in the management of NAFLD and related risk factors. The current systematic review was performed according to the guidelines of the 2015 PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) statements. We searched PubMed/Medline, Science Direct, Scopus, ProQuest, and Google Scholar databases up until February 2020. Of 1217 full-text articles assessed, 36 studies met the inclusion criteria. The evidence reviewed in the present study indicates that naringenin modulates several biological processes related to NAFLD including energy balance, lipid and glucose metabolism, inflammation, and oxidative stress by different mechanisms. Overall, the favorable effects of naringenin along with its more potency and efficacy, compared with other antioxidants, indicate that naringenin may be a promising therapeutic approach for the management of NAFLD and associated complications. However, due to the lack of clinical trials, future robust human randomized clinical trials that address the effects of naringenin on NAFLD and other liver-related diseases are crucial. Further careful human pharmacokinetic studies are also needed to establish dosage ranges, as well as addressing preliminary safety and tolerability of naringenin, before proceeding to larger-scale endpoint trials.

Citri reticulatae Pericarpium attenuates Ang II-induced pathological cardiac hypertrophy via upregulating peroxisome proliferator-activated receptors gamma

Background

Pathological cardiac hypertrophy is a major risk factor for cardiovascular diseases, including heart failure. However, limited pharmacological therapies are available for reversing the maladaptive process and restoring cardiac function. Citri reticulatae Pericarpium (CRP) has been used in traditional Chinese medicine prescriptions for clinical treatment. Previous studies have shown that CRP and its ingredients have beneficial effects on the cardiovascular system. However, whether CRP has a protective effect against pathological cardiac hypertrophy remains unknown.

Methods

Primary neonatal rat cardiomyocytes (NRCMs) were treated with angiotensin II (Ang II) to induce pathological hypertrophy in vitro. Immunofluorescent staining and quantitative real-time PCR (qRT-PCR) were used to determine the cell size and the expression of hypertrophic gene markers (Anp and Bnp), respectively. Male C57BL/6 mice were subjected to the investigation of cardiac hypertrophy induced by Ang II (2.5 mg/kg/d for 4 weeks). CRP (0.5 g/kg/d for 4 weeks) was administrated to treat mice with or without peroxisome proliferator-activated receptors gamma (PPARγ) inhibitor T0070907 (1 mg/kg/d for 4 weeks treatment) infused with Ang II. Cardiac hypertrophy (hematoxylin-eosin staining and qRT-PCR), fibrosis (Masson’s Trichrome staining, qRT-PCR, and western blot), and cardiac function (echocardiography) were examined in these mice. Western blot was used to determine the protein level of PPARγ and PGC-1α both in NRCMs and in mice.

Results

We found that CRP could prevent Ang II-induced pathological cardiac hypertrophy evidenced by improving cardiac function, decreasing hypertrophic growth and reducing cardiac fibrosis. Also, we demonstrated that PPARγ was upregulated by CRP both in NRCMs and in hearts. Moreover, PPARγ inhibitor could abolish the inhibitory effects of CRP on Ang II-induced pathological cardiac hypertrophy.

Conclusions

CRP attenuates Ang II-induced pathological cardiac hypertrophy by activating PPARγ.

Metabolic Impact of Flavonoids Consumption in Obesity: From Central to Peripheral

The prevention and treatment of obesity is primary based on the follow-up of a healthy lifestyle, which includes a healthy diet with an important presence of bioactive compounds such as polyphenols. For many years, the health benefits of polyphenols have been attributed to their anti-oxidant capacity as free radical scavengers. More recently it has been described that polyphenols activate other cell-signaling pathways that are not related to ROS production but rather involved in metabolic regulation. In this review, we have summarized the current knowledge in this field by focusing on the metabolic effects of flavonoids. Flavonoids are widely distributed in the plant kingdom where they are used for growing and defensing. They are structurally characterized by two benzene rings and a heterocyclic pyrone ring and based on the oxidation and saturation status of the heterocyclic ring flavonoids are grouped in seven different subclasses. The present work is focused on describing the molecular mechanisms underlying the metabolic impact of flavonoids in obesity and obesity-related diseases. We described the effects of each group of flavonoids in liver, white and brown adipose tissue and central nervous system and the metabolic and signaling pathways involved on them.

Natural constituents from food sources as therapeutic agents for obesity and metabolic diseases targeting adipose tissue inflammation

Adipose tissue, an endocrine and paracrine organ, plays critical roles in the regulation of whole-body metabolic homeostasis. Obesity is accompanied with a chronic low-grade inflammation status in adipose tissue, which disrupts its endocrine function and results in metabolic derangements, such as type 2 diabetes. Dietary bioactive components, such as flavonoids, polyphenols and unsaturated fatty acids from fruits and vegetables, have been widely revealed to alleviate both systemic and adipose tissue inflammation, and improve metabolic disorders. Remarkably, some dietary bioactive components mitigate the inflammatory response in adipocytes, macrophages, and other immune cells, and modulate the crosstalk between adipocytes and macrophages or other immune cells, in adipose tissue. Epidemiological and preclinical studies related to these substances have indicated beneficial effects on adipose tissue inflammation. The main purpose of this review is to provide a comprehensive and up-to-date state of knowledge on dietary components targeting adipose tissue inflammation and their underlying mechanisms. These natural products have great potential to be developed as functional food or lead compounds for treating and/or preventing metabolic disorders.

Adipose tissue as a possible therapeutic target for polyphenols: A case for Cyclopia extracts as anti-obesity nutraceuticals

Obesity is a significant contributor to increased morbidity and premature mortality due to increasing the risk of many chronic metabolic diseases such as type 2 diabetes, cardiovascular disease and certain types of cancer. Lifestyle modifications such as energy restriction and increased physical activity are highly effective first-line treatment strategies used in the management of obesity. However, adherence to these behavioral changes is poor, with an increased reliance on synthetic drugs, which unfortunately are plagued by adverse effects. The identification of new and safer anti-obesity agents is thus of significant interest. In recent years, plants and their phenolic constituents have attracted increased attention due to their health-promoting properties. Amongst these, Cyclopia, an endemic South African plant commonly consumed as a herbal tea (honeybush), has been shown to possess modulating properties against oxidative stress, hyperglycemia, and obesity. Likewise, several studies have reported that some of the major phenolic compounds present in Cyclopia spp. exhibit anti-obesity effects, particularly by targeting adipose tissue. These phenolic compounds belong to the xanthone, flavonoid and benzophenone classes. The aim of this review is to assess the potential of Cyclopia extracts as an anti-obesity nutraceutical as underpinned by in vitro and in vivo studies and the underlying cellular mechanisms and biological pathways regulated by their phenolic compounds.

Flavonoids: Broad Spectrum Agents on Chronic Inflammation

Flavonoids are major plant constituents with numerous biological/pharmacological actions both in vitro and in vivo. Of these actions, their anti-inflammatory action is prominent. They can regulate transcription of many proinflammatory genes such as cyclooxygenase-2/inducible nitric oxide synthase and many cytokines/chemokines. Recent studies have demonstrated that certain flavonoid derivatives can affect pathways of inflammasome activation and autophagy. Certain flavonoids can also accelerate the resolution phase of inflammation, leading to avoiding chronic inflammatory stimuli. All these pharmacological actions with newly emerging activities render flavonoids to be potential therapeutics for chronic inflammatory disorders including arthritic inflammation, meta-inflammation, and inflammaging. Recent findings of flavonoids are summarized and future perspectives are presented in this review.

Antidiabetic Properties of Naringenin: A Citrus Fruit Polyphenol

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by insulin resistance and hyperglycemia and is associated with personal health and global economic burdens. Current strategies/approaches of insulin resistance and T2DM prevention and treatment are lacking in efficacy resulting in the need for new preventative and targeted therapies. In recent years, epidemiological studies have suggested that diets rich in vegetables and fruits are associated with health benefits including protection against insulin resistance and T2DM. Naringenin, a citrus flavanone, has been reported to have antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, immunomodulatory and antidiabetic properties. The current review summarizes the existing in vitro and in vivo animal studies examining the anti-diabetic effects of naringenin.

Beneficial Effects of Citrus Flavonoids on Cardiovascular and Metabolic Health

The prevalence of cardiovascular disease (CVD) is increasing over time. CVD is a comorbidity in diabetes and contributes to premature death. Citrus flavonoids possess several biological activities and have emerged as efficient therapeutics for the treatment of CVD. Citrus flavonoids scavenge free radicals, improve glucose tolerance and insulin sensitivity, modulate lipid metabolism and adipocyte differentiation, suppress inflammation and apoptosis, and improve endothelial dysfunction. The intake of citrus flavonoids has been associated with improved cardiovascular outcomes. Although citrus flavonoids exerted multiple beneficial effects, their mechanisms of action are not completely established. In this review, we summarized recent findings and advances in understanding the mechanisms underlying the protective effects of citrus flavonoids against oxidative stress, inflammation, diabetes, dyslipidemia, endothelial dysfunction, and atherosclerosis. Further studies and clinical trials to assess the efficacy and to explore the underlying mechanism(s) of action of citrus flavonoids are recommended.

Cardiovascular Effects of Flavonoids

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Cardiovascular Disease (CVD) is the major cause of death worldwide, especially in Western society. Flavonoids are a large group of polyphenolic compounds widely distributed in plants, present in a considerable amount in fruit and vegetable. Several epidemiological studies found an inverse association between flavonoids intake and mortality by CVD. The antioxidant effect of flavonoids was considered the main mechanism of action of flavonoids and other polyphenols. In recent years, the role of modulation of signaling pathways by direct interaction of flavonoids with multiple protein targets, namely kinases, has been increasingly recognized and involved in their cardiovascular protective effect. There are strong evidence, in in vitro and animal experimental models, that some flavonoids induce vasodilator effects, improve endothelial dysfunction and insulin resistance, exert platelet antiaggregant and atheroprotective effects, and reduce blood pressure. Despite interacting with multiple targets, flavonoids are surprisingly safe. This article reviews the recent evidence about cardiovascular effects that support a beneficial role of flavonoids on CVD and the potential molecular targets involved.

Phytochemicals That Influence Gut Microbiota as Prophylactics and for the Treatment of Obesity and Inflammatory Diseases

Gut microbiota (GM) plays several crucial roles in host physiology and influences several relevant functions. In more than one respect, it can be said that you “feed your microbiota and are fed by it.” GM diversity is affected by diet and influences metabolic and immune functions of the host's physiology. Consequently, an imbalance of GM, or dysbiosis, may be the cause or at least may lead to the progression of various pathologies such as infectious diseases, gastrointestinal cancers, inflammatory bowel disease, and even obesity and diabetes. Therefore, GM is an appropriate target for nutritional interventions to improve health. For this reason, phytochemicals that can influence GM have recently been studied as adjuvants for the treatment of obesity and inflammatory diseases. Phytochemicals include prebiotics and probiotics, as well as several chemical compounds such as polyphenols and derivatives, carotenoids, and thiosulfates. The largest group of these comprises polyphenols, which can be subclassified into four main groups: flavonoids (including eight subgroups), phenolic acids (such as curcumin), stilbenoids (such as resveratrol), and lignans. Consequently, in this review, we will present, organize, and discuss the most recent evidence indicating a relationship between the effects of different phytochemicals on GM that affect obesity and/or inflammation, focusing on the effect of approximately 40 different phytochemical compounds that have been chemically identified and that constitute some natural reservoir, such as potential prophylactics, as candidates for the treatment of obesity and inflammatory diseases.

Frontline Science: Rapid adipose tissue expansion triggers unique proliferation and lipid accumulation profiles in adipose tissue macrophages

Obesity-related changes in adipose tissue leukocytes, in particular adipose tissue macrophages (ATMs) and dendritic cells (ATDCs), are implicated in metabolic inflammation, insulin resistance, and altered regulation of adipocyte function. We evaluated stromal cell and white adipose tissue (WAT) expansion dynamics with high fat diet (HFD) feeding for 3-56 days, quantifying ATMs, ATDCs, endothelial cells (ECs), and preadipocytes (PAs) in visceral epididymal WAT and subcutaneous inguinal WAT. To better understand mechanisms of the early response to obesity, we evaluated ATM proliferation and lipid accumulation. ATMs, ATDCs, and ECs increased with rapid WAT expansion, with ATMs derived primarily from a CCR2-independent resident population. WAT expansion stimulated proliferation in resident ATMs and ECs, but not CD11c⁺ ATMs or ATDCs. ATM proliferation was unperturbed in Csf2- and Rag1-deficient mice with WAT expansion. Additionally, ATM apoptosis decreased with WAT expansion, and proliferation and apoptosis reverted to baseline with weight loss. Adipocytes reached maximal hypertrophy at 28 days of HFD, coinciding with a plateau in resident ATM accumulation and the appearance of lipid-laden CD11c⁺ ATMs in visceral epididymal WAT. ATM increases were proportional to tissue expansion and adipocyte hypertrophy, supporting adipocyte-mediated regulation of resident ATMs. The appearance of lipid-laden CD11c⁺ ATMs at peak adipocyte size supports a role in responding to ectopic lipid accumulation within adipose tissue. In contrast, ATDCs increase independently of proliferation and may be derived from circulating precursors. These changes precede and establish the setting in which large-scale adipose tissue infiltration of CD11c⁺ ATMs, inflammation, and adipose tissue dysfunction contributes to insulin resistance.

Food Bioactives and Their Effects on Obesity-Accelerated Inflammatory Bowel Disease

Current views support the concept that obesity is linked to a worsening of the course of inflammatory bowel diseases (IBDs). Gut microbiota and adipose tissue macrophage (ATM) are considered key mediators or contributors in obesity-associated intestinal inflammation. Dietary components can have direct or indirect effects on "normal" or "healthy" microbial composition and participate in adiposity and metabolic status with gut inflammation. In this perspective, we highlight food-derived bioactives that have a potential application in the prevention of obesity-exacerbated IBD, targeting energy metabolism, M1 (classical activated)-M2 (alternatively activated) macrophage polarization, and gut microbiota.

Extracts of citrus Sudachi peel attenuate body weight gain in C57BL/6 mice fed a high-fat diet

Citrus Sudachi is the special local product of Tokushima Prefecture, and over 98% of Sudachi consumed in Japan every year is produced in Tokushima Prefecture. In this study, we evaluated the function of sudachi peel extract (SPE) using an animal model of obesity. C57BL/6 mice were fed a high-fat diet containing 1% SPE powder. Treatment with SPE significantly decreased body weight compared to that of mice fed a high-fat diet. A significant difference in body weight was observed between the control and SPE groups from 7 weeks after the start of the experiment, the significant difference continued until the end of the 14-week experiment. Reduction of blood glucose levels following insulin administration in SPE-treated mice was grater than that in control mice. Determination of mRNA expression in adipose tissue showed that the expression level of TNF-α in the SPE group was significantly decreased compared to that on the control group. These results suggest that SPE potentially has the ability to attenuate body weight gain. J. Med. Invest. 64: 20-23, February, 2017.

Nanoliposome improves inhibitory effects of naringenin on nonalcoholic fatty liver disease in mice

Aim: To prepare naringenin nanoliposome (NRG-Nanolipo) and investigate its inhibitory effects on nonalcoholic fatty liver disease (NAFLD). Materials & methods: NRG-Nanolipo was prepared by thin-film rehydration method. Its characterizations and effects on NAFLD in mice induced by methionine choline deficient diet were investigated. Results: NRG-Nanolipo had high-drug loading percentage and showed a sustained release profile. The nanoliposome formulation significantly increased oral absorption of naringenin (NRG). NRG-Nanolipo showed comparable inhibitory effects as NRG crude drug at a dose fourfold lower than the crude drug on NAFLD. Conclusion: It is the first study to report the inhibitory effects of NRG on NAFLD, and the NRG-Nanolipo significantly improved oral absorption of NRG, thus improved liver protective effects of NRG on NAFLD.

Cinnamaldehyde in diabetes: A review of pharmacology, pharmacokinetics and safety

Cinnamaldehyde, one of the active components derived from Cinnamon, has been used as a natural flavorant and fragrance agent in kitchen and industry. Emerging studies have been performed over the past decades to evaluate its beneficial role in management of diabetes and its complications. This review highlights recent advances of cinnamaldehyde in its glucolipid lowering effects, its pharmacokinetics, and its safety by consulting the Pubmed, China Knowledge Resource Integrated, China Science and Technology Journal, National Science and Technology Library, Wanfang Data, and the Web of Science Databases. For the inquiries, keywords such as Cinnamon, cinnamaldehyde, property, synthesis, diabetes, obesity, pharmacokinetics, and safety were used in various combinations. Accumulating evidence supports the notion that cinnamaldehyde exhibits glucolipid lowering effects in diabetic animals by increasing glucose uptake and improving insulin sensitivity in adipose and skeletal muscle tissues, improving glycogen synthesis in liver, restoring pancreatic islets dysfunction, slowing gastric emptying rates, and improving diabetic renal and brain disorders. Cinnamaldehyde exerts these effects through its action on multiple signaling pathways, including PPARs, AMPK, PI3K/IRS-1, RBP4-GLUT4, and ERK/JNK/p38MAPK, TRPA1-ghrelin and Nrf2 pathways. In addition, cinnamaldehyde seems to regulate the activities of PTP1B and α-amylase. Furthermore, cinnamaldehyde has the potential of metalizing into cinnamyl alcohol and methyl cinnamate and cinnamic acid in the body. Finally, there is a potential toxicity concern about this compound. In summary, cinnamaldehyde supplementation is shown to improve glucose and lipid homeostasis in diabetic animals, which may provide a new option for diabetic intervention. To this end, further scientific evidences are required from clinical trials on its glucose regulating effects and safety.

The ominous triad of adipose tissue dysfunction: inflammation, fibrosis, and impaired angiogenesis

There are three dominant contributors to the pathogenesis of dysfunctional adipose tissue (AT) in obesity: unresolved inflammation, inappropriate extracellular matrix (ECM) remodeling and insufficient angiogenic potential. The interactions of these processes during AT expansion reflect both a linear progression as well as feed-forward mechanisms. For example, both inflammation and inadequate angiogenic remodeling can drive fibrosis, which can in turn promote migration of immune cells into adipose depots and impede further angiogenesis. Therefore, the relationship between the members of this triad is complex but important for our understanding of the pathogenesis of obesity. Here we untangle some of these intricacies to highlight the contributions of inflammation, angiogenesis, and the ECM to both "healthy" and "unhealthy" AT expansion.

Phytochemicals as novel agents for the induction of browning in white adipose tissue

Obesity and its associated metabolic syndrome continue to be a health epidemic in westernized societies and is catching up in the developing world. Despite such increases, little headway has been made to reverse adverse weight gain in the global population. Few medical options exist for the treatment of obesity which points to the necessity for exploration of anti-obesity therapies including pharmaceutical and nutraceutical compounds. Defects in brown adipose tissue, a major energy dissipating organ, has been identified in the obese and is hypothesized to contribute to the overall metabolic deficit observed in obesity. Not surprisingly, considerable attention has been placed on the discovery of methods to activate brown adipose tissue. A variety of plant-derived, natural compounds have shown promise to regulate brown adipose tissue activity and enhance the lipolytic and catabolic potential of white adipose tissue. Through activation of the sympathetic nervous system, thyroid hormone signaling, and transcriptional regulation of metabolism, natural compounds such as capsaicin and resveratrol may provide a relatively safe and effective option to upregulate energy expenditure. Through utilizing the energy dissipating potential of such nutraceutical compounds, the possibility exists to provide a therapeutic solution to correct the energy imbalance that underlines obesity.

Effects of flavonoids on intestinal inflammation, barrier integrity and changes in gut microbiota during diet-induced obesity

Diet-induced obesity is associated with low-grade inflammation, which, in most cases, leads to the development of metabolic disorders, primarily insulin resistance and type 2 diabetes. Although prior studies have implicated the adipose tissue as being primarily responsible for obesity-associated inflammation, the latest discoveries have correlated impairments in intestinal immune homeostasis and the mucosal barrier with increased activation of the inflammatory pathways and the development of insulin resistance. Therefore, it is essential to define the mechanisms underlying the obesity-associated gut alterations to develop therapies to prevent and treat obesity and its associated diseases. Flavonoids appear to be promising candidates among the natural preventive treatments that have been identified to date. They have been shown to protect against several diseases, including CVD and various cancers. Furthermore, they have clear anti-inflammatory properties, which have primarily been evaluated in non-intestinal models. At present, a growing body of evidence suggests that flavonoids could exert a protective role against obesity-associated pathologies by modulating inflammatory-related cellular events in the intestine and/or the composition of the microbiota populations. The present paper will review the literature to date that has described the protective effects of flavonoids on intestinal inflammation, barrier integrity and gut microbiota in studies conducted using in vivo and in vitro models.

Naringenin Ameliorated Kidney Injury through Let-7a/TGFBR1 Signaling in Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the most common complications of diabetes mellitus (DM). However, the exact mechanism is not clearly understood. In this study, our results showed that 24 h urinary protein, kidney index, and glomerular area were decreased, while creatinine clearance ratio was increased in DN rats when the rats were treated with NAR 50 mg/d for 6 weeks. Mesangial cell (MMCs) proliferation was inhibited in the NAR group by 3,(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), and the cell cycle analysis showed that cells stayed in G2 phase in NAR group. And NAR treatment attenuated the deposition of ECM in DN rats and MMCs. Moreover, our data showed that let-7a was downexpressed in both DN rats and MMCs under high glucose condition. Surprisingly, NAR affected the expressions of Col4 and FN through upregulating let-7a in MMCs. In addition, we found that let-7a negatively regulated the expression of transforming growth factor-β1 receptor 1 (TGFBR1), and TGFBR1 was required for the let-7a-mediated downregulation of TGF-β1/smad signaling. Interestingly, NAR inhibited TGF-β1/smads signaling activation by upregulating let-7a. Therefore, our findings indicated that NAR ameliorated kidney injury by regulating let-7a/TGFBR1 signaling.

Antidiabetic properties of dietary flavonoids: a cellular mechanism review

Background

Natural food products have been used for combating human diseases for thousands of years. Naturally occurring flavonoids including flavones, flavonols, flavanones, flavonols, isoflavones and anthocyanidins have been proposed as effective supplements for management and prevention of diabetes and its long-term complications based on in vitro and animal models.

Aim

To summarize the roles of dietary flavonoids in diabetes management and their molecular mechanisms.

Findings

Tremendous studies have found that flavonoids originated from foods could improve glucose metabolism, lipid profile, regulating the hormones and enzymes in human body, further protecting human being from diseases like obesity, diabetes and their complications.

Conclusion

In the current review, we summarize recent progress in understanding the biological action, mechanism and therapeutic potential of the dietary flavonoids and its subsequent clinical outcomes in the field of drug discovery in management of diabetes mellitus.

Naringenin protects cardiac hypercholesterolemia-induced oxidative stress and subsequent necroptosis in rats

BACKGROUND

In earlier studies, the supplementation of the natural compound Naringenin (NGEN), improved the liver oxidative and inflammatory status, which indicates its direct effect via inhibition of the nuclear factor κB pathway on high cholesterol-induced hepatic damages. In this regard, the present study highlights the mechanisms associated with the protective efficacy of NGEN in the heart tissue of hypercholesterolemic diet rats.

RESULTS

The animals exposed to a high cholesterol diet (HCD) for 90 days exhibited a significant increase in the levels of serum lactate dehydrogenase (LDH) and creatine kinase (CK) activities, nitric oxide (NO) levels, protein and lipid oxidative markers and cardiac lipids profile. Moreover, hypercholesterolemia decreased the levels of enzymatic and non enzymatic antioxidants associated with mitochondrial dysfunctions as proved by the decrease in the mitochondrial complexes in comparison to controls. Importantly, cholesterol-feeding significantly increased myocardial reactive oxygen species (ROS) and nuclear DNA damage and led to the activation of gene expression of the tumor necrosis factor-α (TNF-α) and receptor-interacting protein kinase 3 (RIP3) mRNA that contributed to the elucidation of cholesterol-induced necroptosis, a recently described type of programmed necrosis, in the cardiac tissue.

CONCLUSIONS

Our results show that the co-administration of NGEN (50 mg/kg/bw) in HCD rats improved all the altered parameters and provided insight into a possible molecular mechanism underlying NGEN suppression of necroptosis pathway in the heart.