Isolated mangiferin and naringenin exert antidiabetic effect via PPARγ/GLUT4 dual agonistic action with strong metabolic regulation

Separation of Three Polar Compounds with Similar Polarities from Swertia mussotii by a Combination of Two Counter-Current Chromatography Modes

Separation of polar compounds especially with similar polarities is challenging. In the present study, three polar compounds with similar polarities, including gentiopicroside, sweroside and mangiferin, have been successfully separated from Swertia mussotii by a combination of two counter-current chromatography modes. With the selected solvent system of ethyl acetate/n-butanol/water (8/2/10, v/v), a continuous injection mode was firstly employed. As a result, 10.4 g of mangiferin with purity higher than 98% and 8 g of Peak I mainly composed of gentiopicroside and sweroside could be easily obtained from 24 g of the sample by counter-current chromatography through eight injections. Then, a recycling counter-current chromatography mode was introduced for the separation of gentiopicroside and sweroside. Through six cycles, 5.3 g of gentiopicroside and 0.8 g of sweroside with purity higher than 98% were obtained from 8 g of Peak I. The research provides a reference for the large-scale separation of polar compounds with similar polarities.

Mangiferin and EGCG Compounds Fight Against Hyperlipidemia by Promoting FFA Oxidation via AMPK/PPARα

Background: Hyperlipidemia is a critical risk factor for obesity, diabetes, cardiovascular diseases, and other chronic diseases. Our study was to determine the effects and mechanism of mangiferin (MF) and epigallocatechin gallate (EGCG) compounds on improving hyperlipidemia in HepG2 cells. Methods: HepG2 cells were treated with 0.25 mM palmitic acid (PA) and then incubated with MF (12.5, 25, and 50 μM) or EGCG (25, 50, and 100 μM) or MF:EGCG (0:0, 6.25:12.5, 25:50, and 50:100 μM:μM) for 24 h. The improvement of hyperlipidemia was verified by Oil Red O staining, changes in triglyceride (TG) and free fatty acid (FFA) levels, and the expression of lipid metabolizing proteins in western blotting. Results: MF (12.5, 25, and 50 μM) or EGCG (25, 50, and 100 μM) markedly lowered lipid accumulations by lipid index levels. Furthermore, we found that the optimum concentration of MF and EGCG compounds was 25:50 (μM:μM), which significantly reduced the FFA level, TG, and total cholesterol (TC) accumulations and increased FFA uptake in HepG2 cells, and the effect was better than that of single phytochemicals. The adenosine 5⁣'-monophosphate (AMP)-activated protein kinase (AMPK) protein and its downstream proteins sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor α (PPARα), and those involved in fatty acid translocase (CD36) and carnitine palmitoyltransferase 1 (CPT1) were also markedly increased in HepG2 cells. The upregulation of protein expression was reversed when AMPK-specific inhibitor Compound C was added. Conclusions: MF and EGCG (25:50 μM) compounds protect against hyperlipidemia by promoting the FFA oxidation, alleviating TG and TC accumulations via the AMPK/PPARα pathway in PA-treated HepG2 cells.

(Poly)phenols and diabetes: From effects to mechanisms by systematic multigenomic analysis

Diabetes is a chronic and multifactorial metabolic disease with increasing numbers of patients worldwide, characterized by loss of pancreatic β-cell mass and function with subsequent insulin deficiency. Thus, restoring functional β-cells could significantly impact disease management. The beneficial effects of natural compounds, namely (poly)phenols, in diabetes have gained increasing interest, due to their pleiotropic actions in several cellular processes, including in glucose homeostasis. These compounds are able to modulate nutri(epi)genomic mechanisms by interacting with cell signaling proteins and transcription factors (TFs). However, the underlying mechanisms of action, particularly of (poly)phenol metabolites resulting from digestion and colonic microbiota action, are yet to be elucidated. This study explored the multigenomic effects of (poly)phenols and their metabolites to uncover modulatory networks and mechanisms linked to diabetes. Published studies on gene expression alterations modulated by (poly)phenolic compounds or (poly)phenol-rich extracts were integrated, encompassing studies conducted on individuals with diabetes, animal models mimicking diabetes, and pancreatic β-cell lines. Bioinformatic analysis identified differentially expressed genes and potential regulatory factors, with roles in cell signaling pathways (FoxO, AMPK, p53), endocrine resistance, immune system pathways, apoptosis, and cellular senescence. Interestingly, in silico 3D docking analyses revealed potential interactions between key TFs (FOXO1, PPARG, SIRT1, and MAFA) and some metabolites. Apigenin, luteolin, and naringenin glucuronide forms showed the best binding capacity to SIRT1. The integrative analysis of (poly)phenol metabolites data highlights the potential of these molecules for nutraceutical/pharmaceutical development aimed at managing diabetes whose incidence increases with age.

Anti-depressant effect of Naringenin-loaded hybridized nanoparticles in diabetic rats via PPARγ/NLRP3 pathway

Naringenin (NAR) has various biological activities but low bioavailability. The current study examines the effect of Naringenin-loaded hybridized nanoparticles (NAR-HNPs) and NAR on depression induced by streptozotocin (STZ) in rats. NAR-HNPs formula with the highest in vitro NAR released profile, lowest polydispersity index value (0.21 ± 0.02), highest entrapment efficiency (98.7 ± 2.01%), as well as an acceptable particle size and zeta potential of 415.2 ± 9.54 nm and 52.8 ± 1.04 mV, respectively, was considered the optimum formulation. It was characterized by differential scanning calorimetry, examined using a transmission electron microscope, and a stability study was conducted at different temperatures to monitor its stability efficiency showing that NAR-HNP formulation maintains stability at 4 °C. The selected formulation was subjected to an acute toxicological test, a pharmacokinetic analysis, and a Diabetes mellitus (DM) experimental model. STZ (50 mg/kg) given as a single i.p. rendered rats diabetic. Diabetic rat groups were allocated into 4 groups: one group received no treatment, while the remaining three received oral doses of unloaded HNPs, NAR (50 mg/kg), NAR-HNPs (50 mg/kg) and NAR (50 mg/kg) + peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist, GW9662 (1mg/kg, i.p.) for three weeks. Additional four non-diabetic rat groups received: distilled water (normal), free NAR, and NAR-HNPs, respectively for three weeks. NAR and NAR-HNPs reduced immobility time in forced swimming test and serum blood glucose while increasing serum insulin level. They also reduced cortical and hippocampal 5-hydroxyindoeacetic acid, 3,4-Dihydroxy-phenylacetic acid, malondialdehyde, NLR family pyrin domain containing-3 (NLRP3) and interleukin-1beta content while raised serotonin, nor-epinephrine, dopamine and glutathione level. PPAR-γ gene expression was elevated too. So, NAR and NAR-HNPs reduced DM-induced depression by influencing brain neurotransmitters and exhibiting anti-oxidant and anti-inflammatory effects through the activation PPAR-γ/ NLRP3 pathway. NAR-HNPs showed the best pharmacokinetic and therapeutic results.

Discovery of New Dual-Target Agents Against PPAR-γ and α-Glucosidase Enzymes with Molecular Modeling Methods: Molecular Docking, Molecular Dynamic Simulations, and MM/PBSA Analysis

Type 2 diabetes mellitus (T2DM) has become a serious public health problem both in our country and worldwide, being the most prevalent type of diabetes. The combined use of drugs in the treatment of T2DM leads to serious side effects, including gastrointestinal problems, liver toxicity, hypoglycemia, and treatment costs. Hence, there has been a growing emphasis on drugs that demonstrate dual interactions. Several studies have suggested that dual-target agents for peroxisome proliferator-activated receptor-γ (PPAR-γ) and alpha-glucosidase (α-glucosidase) could be a potent approach for treating patients with diabetes. We aim to develop new antidiabetic agents that target PPAR-γ and α-glucosidase enzymes using molecular modeling techniques. These compounds show dual interactions, are more effective, and have fewer side effects. The molecular docking method was employed to investigate the enzyme-ligand interaction mechanisms of 159 newly designed compounds with target enzymes. Additionally, we evaluated the ADME properties and pharmacokinetic suitability of these compounds based on Lipinski and Veber's rules. Compound 70, which exhibited favorable ADME properties, demonstrated more effective binding energy with both PPAR-γ and α-glucosidase enzymes (-12,16 kcal/mol, -10.07 kcal/mol) compared to the reference compounds of Acetohexamide (-9.31 kcal/mol, -7.48 kcal/mol) and Glibenclamide (-11.12 kcal/mol, -8.66 kcal/mol). Further, analyses of MM/PBSA binding free energy and molecular dynamics (MD) simulations were conducted for target enzymes with compound 70, which exhibited the most favorable binding affinities with both enzymes. Based on this information, our study aims to contribute to the development of new dual-target antidiabetic agents with improved efficacy, reduced side effects, and enhanced reliability for diabetes treatment.

Clinical applications and mechanism insights of natural flavonoids against type 2 diabetes mellitus

Diabetes is a complex disease that affects a large percentage of the world's population, and it is associated with several risk factors. Self-management poses a significant challenge, but natural sources have shown great potential in providing effective glucose reducing solutions. Flavonoids, a class of bioactive substances found in different natural sources including medicinal plants, have emerged as promising candidates in this regard. Indeed, several flavonoids, including apigenin, arbutin, catechins, and cyanidin, have demonstrated remarkable anti-diabetic properties. The clinical effectiveness of these flavonoids is linked to their potential to decrease blood glucose concentration and increase insulin concentration. Thus, the regulation of certain metabolic pathways such as glycolysis and neoglycogenesis has also been demonstrated. In vitro and in vivo investigations revealed different mechanisms of action related to flavonoid compounds at subcellular, cellular, and molecular levels. The main actions reside in the activation of glycolytic signaling pathways and the inhibition of signaling that promotes glucose synthesis and storage. In this review, we highlight the clinical efficiency of natural flavonoids as well as the molecular mechanisms underlying this effectiveness.

Pharmacological properties of mangiferin: bioavailability, mechanisms of action and clinical perspectives

This review aims to provide an in-depth analysis of the pharmacological properties of mangiferin, focusing primarily on its bioavailability and mechanisms of action, and its potential therapeutic applications, especially in the context of chronic diseases. We conducted a comprehensive examination of in vitro and in vivo studies, as well as clinical trials involving mangiferin or plant extracts containing mangiferin. The primary source of mangiferin is Mangifera indica, but it's also found in other plant species from the families Anacardiaceae, Gentianaceae, and Iridaceae. Mangiferin has exhibited a myriad of therapeutic properties, presenting itself as a promising candidate for treating various chronic conditions including neurodegenerative disorders, cardiovascular diseases, renal and pulmonary diseases, diabetes, and obesity. Despite the promising results showcased in many in vitro studies and certain animal studies, the application of mangiferin has been limited due to its poor solubility, absorption, and overall bioavailability. Mangiferin offers significant therapeutic potential in treating a spectrum of chronic diseases, as evidenced by both in vitro and clinical trials. However, the challenges concerning its bioavailability necessitate further research, particularly in optimizing its delivery and absorption, to harness its full medicinal potential. This review serves as a comprehensive update on the health-promoting and therapeutic activities of mangiferin.

Acute Oral Toxicity, Antioxidant Activity and Molecular Docking Study of 2-(4-Bromo-phenoxy)-N-[6-chloro-4-(4-chlorophenyl)-3-cyano-4H-chromen- 2-yl]-acetamide

BACKGROUND

Several studies have been conducted on 4-H chromene compounds because of their intriguing pharmacological and biological properties. Various new natural compounds having a chromene foundation have been reported over the past 20 years.

OBJECTIVE

In the present study, we reported the acute oral toxicity, antioxidant activity, and molecular docking study of the most active 4H-chromene derivative2-(4-Bromo-phenoxy)-N-[6-chloro-4-(4- chlorophenyl)-3-cyano-4H-chromen-2-yl]-acetamide (A9).

METHOD

The acute oral toxicity was carried out as per OECD 423 guidelines. For investigating the antioxidant activity, various biochemical parameters in colon tissue like SOD, CAT, MDA, PC and GSH and also enzyme levels, such as ALT, AST, ALP, and LDH, were measured in this experiment.

RESULTS

Acute oral toxicity study indicated that the A9 ligand was found to be safer in animals. Additionally, the A9 ligand had significant antioxidant properties at various doses and was not found to be harmful to the liver. Due to its stronger binding energy and the appropriate interactions that induce inhibition, the A9 ligand's antioxidant function was also validated by additional molecular docking research.

CONCLUSION

This compound can be exploited as a lead molecule in further research.

Ethnomedicinal Knowledge of Plants Used in Nonconventional Medicine in the Management of Diabetes Mellitus in Kinshasa (Democratic Republic of the Congo)

Background

People with diabetes, herbalists, and traditional medicine practitioners (TMPs) from Kinshasa use plants to treat diabetes, but no study has inventoried the plants used by these populations. The present study was conducted to identify the plants used in Kinshasa to treat diabetes mellitus.

Methods

The survey conducted in the form of a semistructured interview between March 2005 and August 2006 made it possible to collect ethnobotanical information from people with diabetes (n = 126), herbalists (n = 80), and TMPs (n = 120).

Results

The 326 subjects consulted (sex ratio M/F = 0.6, age 51 ± 7 years, and experience: 17 ± 5 years) provided information on 71 plants, most of which are trees (35%), belonging to 38 families dominated by Fabaceae (19.7%) and indicated in 51 other cases of consultation dominated by malaria (12%). From these 71 plants derived, 86 antidiabetic recipes were administered orally, where the leaf is the most used part (>50%) and the decoction (>46%) is the most common mode of preparation. This study reports for the first time the antidiabetic use of 11 species, among which Tephrosia vogeliiX (0.08), Chromolaena corymbosaX (0.06), and Baphia capparidifoliaX (0.06) present the highest consensus indexes (CI) and Marsdenia latifoliaW (UVp = 0.08) and Rauvolfia manniiX (UVp = 0.06) present the highest UVs.

Conclusion

The results show that Kinshasa people treat diabetes using several plants. Some are specific to the ecological environment; others are used in other regions. Pharmacological studies are underway to assess the therapeutic efficacy of these plants.

Mangiferin for the Management of Liver Diseases: A Review

The liver is a digestive and metabolic organ, and several factors can induce liver damage, which is a severe threat to human health. As a natural polyphenolic compound, mangiferin belongs to xanthone glucoside and mainly exists in many plants, such as mango. It is notorious that mangiferin has remarkable pharmacological activities such as anti-inflammatory, anti-tumor, antioxidative stress, antiviral and so on. Emerging evidence indicates the therapeutic benefits of mangiferin against liver disease, including liver injury, nonalcoholic fatty liver disease, alcoholic liver disease, liver fibrosis, and hepatocellular carcinoma. This review aims to summarize the possible underlying signaling mediated by mangiferin in liver disease treatment and the available findings of mangiferin, which can be used to treat different liver diseases and may contribute to mangiferin as a therapeutic agent for liver disease in humans.

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.

Naringenin: A flavanone with anti-inflammatory and anti-infective properties

Although a growing body of research has recently shown how crucial inflammation and infection are to all major diseases, several of the medications currently available on the market have various unfavourable side effects, necessitating the development of alternative therapeutic choices. Researchers are increasingly interested in alternative medications or active components derived from natural sources. Naringenin is a commonly consumed flavonoid found in many plants, and since it was discovered to have nutritional benefits, it has been utilized to treat inflammation and infections caused by particular bacteria or viruses. However, the absence of adequate clinical data and naringenin's poor solubility and stability severely restrict its usage as a medicinal agent. In this article, we discuss naringenin's effects and mechanisms of action on autoimmune-induced inflammation, bacterial infections, and viral infections based on recent research. We also present a few suggestions for enhancing naringenin's solubility, stability, and bioavailability. This paper emphasizes the potential use of naringenin as an anti-inflammatory and anti-infective agent and the next prophylactic substance for the treatment of various inflammatory and infectious diseases, even though some mechanisms of action are still unclear, and offers some theoretical support for its clinical application.

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.

"Multiomics" Analyses Combined with Systems Pharmacology Reveal the Renoprotection of Mangiferin Monosodium Salt in Rats with Diabetic Nephropathy: Focus on Improvements in Renal Ferroptosis, Renal Inflammation, and Podocyte Insulin Resistance

We explored the protection of mangiferin monosodium salt (MGM) on kidney injury in rats with streptozotocin (STZ)-induced diabetic nephropathy (DN) by "multiomics" analysis combined with systems pharmacology, with a specific focus on ferroptosis, inflammation, and podocyte insulin resistance (IR) signaling events in kidneys. MGM treatment afforded renoprotective effects on rats with STZ-induced DN by alleviating systemic IR-induced renal inflammation and podocyte IR. These mechanisms were correlated mainly with the MGM treatment-induced inhibition of the mitogen-activated protein kinase/nuclear factor-kappa B axis and activation of the phosphorylated insulin receptor substrate 1(Tyr608)/phosphorylated phosphatidylinositol 3-kinase/phosphorylated protein kinase B axis in the kidneys of DN rats. MGM had an ameliorative function in renal ferroptosis in rats with STZ-induced DN by upregulating mevalonate-mediated antioxidant capacities (glutathione peroxidase 4 and ferroptosis suppressor protein 1/coenzyme Q10 axis) and weakening acyl-CoA synthetase long-chain family member 4-mediated proferroptotic generation of lipid drivers in kidneys. MGM may be a promising alternative strategy for the treatment of DN.

Effects of the synbiotic composed of mangiferin and Lactobacillus reuteri 1-12 on type 2 diabetes mellitus rats

Many synbiotics are effective for the prevention and treatment of type 2 diabetes mellitus (T2DM). In the treatment of T2DM, synbiotics often regulate the composition of intestinal flora, which autoinducer-2 (AI-2) may play an important role. Whether the changes of intestinal flora are related to AI-2 during synbiotics treatment of T2DM is a topic worth studying. We elucidated the effects of synbiotic composed of mangiferin and Lactobacillus reuteri 1-12 (SML) on T2DM rats. Male Spraque-Dawley rats were injected intraperitoneally with streptozotocin (STZ) and randomly grouped. After that, biochemical parameters, intestinal flora, fecal AI-2, and intestinal colonization of L. reuteri were detected. The results showed that SML had a hypoglycemic effect and mitigated the organ lesions of the liver and pancreas. Also, SML regulated biochemical parameters such as short chain fatty acids (SCFAs), lipopolysaccharides (LPS), intercellular cell adhesion molecule-1 (ICAM-1), and tumor necrosis factor-α (TNF-α). On the other hand, the proportion of probiotics, such as Lactobacillus acidophilus, L. reuteri, Bifidobacterium pseudolongum, Lactobacillus murinus, and Lactobacillus johnsonii, were elevated by the treatment of SML. In addition, SML promoted the colonization and proliferation of L. reuteri in the gut. Another thing to consider was that AI-2 was positively correlated with the total number of OTUs sequences and SML boosted AI-2 in the gut. Taken together, these results supported that SML may modulate intestinal flora through AI-2 to treat T2DM. This study provided a novel alternative strategy for the treatment of T2DM in future.

Urinary Metabolomics Study on the Protective Role of Cocoa in Zucker Diabetic Rats via 1H-NMR-Based Approach

Cocoa constitutes one of the richest sources of dietary flavonoids with demonstrated anti-diabetic potential. However, the metabolic impact of cocoa intake in a diabetic context remains unexplored. In this study, metabolomics tools have been used to investigate the potential metabolic changes induced by cocoa in type 2 diabetes (T2D). To this end, male Zucker diabetic fatty rats were fed on standard (ZDF) or 10% cocoa-rich diet (ZDF-C) from week 10 to 20 of life. Cocoa supplementation clearly decreased serum glucose levels, improved glucose metabolism and produced significant changes in the urine metabolome of ZDF animals. Fourteen differential urinary metabolites were identified, with eight of them significantly modified by cocoa. An analysis of pathways revealed that butanoate metabolism and the synthesis and degradation of branched-chain amino acids and ketone bodies are involved in the beneficial impact of cocoa on diabetes. Moreover, correlation analysis indicated major associations between some of these urine metabolites (mainly valine, leucine, and isoleucine) and body weight, glycemia, insulin sensitivity, and glycated hemoglobin levels. Overall, this untargeted metabolomics approach provides a clear metabolic fingerprint associated to chronic cocoa intake that can be used as a marker for the improvement of glucose homeostasis in a diabetic context.

Potential Therapeutic Mechanism of Traditional Chinese Medicine on Diabetes in Rodents: A Review from an NMR-Based Metabolomics Perspective

Traditional Chinese medicine (TCM) has been used to treat diabetes for a long time, but its application has not been widely accepted due to unstandardized product quality and complex pharmacological mechanisms. The modernization of TCM is crucial for its further development, and in recent years the metabolomics technique has largely driven its modernization. This review focuses on the application of NMR-based metabolomics in diabetic therapy using TCM. We identified a series of metabolic pathways that altered significantly after TCM treatment, providing a better understanding of the metabolic mechanisms of TCM for diabetes care.

Reno-protective effect of mangiferin against methotrexate-induced kidney damage in male rats: PPARγ-mediated antioxidant activity

Methotrexate (MTX) is an immunosuppressant used for the treatment of cancer and autoimmune diseases. MTX has a major adverse effect, acute kidney injury, which limits its use. Mangiferin (MF) is a natural bioactive xanthonoid used as a traditional herbal supplement to boost the immune system due to its potent anti-inflammatory and antioxidant activity. The present study evaluates the protective effect of MF against MTX-induced kidney damage. Male Wistar rats received MTX to induce nephrotoxicity or were pretreated with MF for 10 constitutive days before MTX administration. MF dose-dependently improved renal functions of MTX-treated rats and this activity was correlated with increased renal expression of PPARγ, a well-known transcriptional regulator of the immune response. Pretreating rats with PPARγ inhibitor, BADGE, reduced the reno-protective activity of MF. Furthermore, MF treatment significantly reduced MTX-induced upregulation of the pro-inflammatory (NFκB, interleukin-1ß, TNF-α, and COX-2), oxidative stress (Nrf-2, hemoxygenase-1, glutathione, and malondialdehyde), and nitrosative stress (nitric oxide and iNOS) markers in the kidney. Importantly, BADGE treatment significantly reduced the anti-inflammatory and antioxidant activity of MF. Therefore, our data suggest that the reno-protective effect of MF against MTX-induced nephrotoxicity is due to inhibition of inflammation and oxidative stress in a PPAR-γ-dependent manner.

Mechanistic exploration of the activities of poly(lactic-co-glycolic acid)-loaded nanoparticles of betulinic acid against hepatocellular carcinoma at cellular and molecular levels

The effectiveness of betulinic acid (B) and PLGA loaded nanoparticles of B (Bnp) against hepatocellular carcinoma (HCC) was established and reported earlier. In continuation of our previous report, the present study described the molecular mechanisms of their antineoplastic responses. In this context, the antineoplastic properties of both B and Bnp were evaluated on DEN-induced HCC rat model. The quantitative real-time polymerase chain reaction and western blot analyses revealed that HCC was developed through lower expressions of e-NOS, BAX, BAD, Cyt C and higher expressions of i-NOS, Bcl-xl, Bcl-2. B and Bnp normalised the expressions of these apoptogenic markers. Particularly, both activated i-NOS and e-NOS mediated Bcl-2 family proteins→CytC→Caspase 3 and 9 signalling cascades. The ¹H-NMR-based metabolomics study also demonstrated that the perturbed metabolites in DEN-induced rat serum restored to the normal level following both treatments. Moreover, the antineoplastic potential of Bnp was found to be comparable with the marketed product, 5-flurouracil.

Surface Functionalized Magnetic Nanoparticles as a Selective Sorbent for Affinity Fishing of PPAR-γ Ligands from Choerospondias axillaris

Coronary heart disease (CHD), which has developed into one of the major diseases, was reported to be treated by the target of peroxisome proliferators-activate receptor γ (PPAR-γ). As a natural medicine long used in the treatment of CHD, there are few studies on how to screen the target active compounds with high specific activity from Choerospondias axillaris. To advance the pace of research on target-specific active compounds in natural medicines, we have combined magnetic ligand fishing and functionalized nano-microspheres to investigate the active ingredients of PPAR-γ targets in Choerospondias axillaris. The PPAR-γ functionalized magnetic nano-microspheres have been successfully synthesized and characterized by vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The specificity, reusability, and reproducibility of the nano-microspheres were investigated with the help of the specific binding of rosiglitazone to PPAR-γ. In addition, the incubation temperature and the pH of the buffer solution in the magnetic ligand fishing were optimized to improve the specific adsorption efficiency of the analytes. Finally, with the aid of ultraperformance liquid chromatography plus Q-Exactive Orbitrap tandem mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS/MS), the 16 active ligands including 9 organic acids, 5 flavonoids, and 2 phenols were found in the ethanolic extracts of Choerospondias axillaris. Therefore, the study can provide a successful precedent for realizing the designated extraction and rapid isolation of target-specific active ingredient groups in the complex mixtures.

PPARβ mediates mangiferin-induced neuronal differentiation of neural stem cells through DNA demethylation

Adult hippocampal neurogenesis (AHN) is heavily implicated in the pathogenesis of various neuropsychiatric disorders. The mangiferin (MGF), a bioactive compound of the mango, reportedly produces biological effects on a variety of neuropsychiatric disorders. However, the function and underlying mechanisms of MGF in regulating hippocampal neurogenesis remain unknown. Here we discovered that the transcriptome and methylome of MGF-induced neural stem cells (NSCs) are distinct from the control. RNA-seq analysis revealed that the diferentially expressed genes (DEGs) were signifcantly enriched in the PPARs. Furthermore, we found that MGF enhanced neuronal differentiation and proliferation of neural stem cells (NSCs) via PPARβ but not PPARα and PPARγ. The combination of WGBS and RNA-seq analysis showed that the expression of some neurogenesis genes was negatively correlated with the DNA methylation level generally. We further found that PPARβ increased demethylation of Mash1 promoter by modulating the expressions of active and passive DNA demethylation enzymes in MGF-treated NSCs. Importantly, genetic deficiency of PPARβ decreased hippocampal neurogenesis in the adult mice, whereas the defective neurogenesis was notably rescued by Mash1 overexpression. Our findings uncover a model that PPARβ-mediated DNA demethylation of Mash1 contributes to MGF-induced neuronal genesis, and advance the concept that targeting PPARβ-TET1/DNMT3a-Mash1 axis regulation of neurogenesis might serve as a novel neurotherapeutic strategy.

Artemisia absinthium L. Aqueous and Ethyl Acetate Extracts: Antioxidant Effect and Potential Activity In Vitro and In Vivo against Pancreatic α-Amylase and Intestinal α-Glucosidase

Artemisia absinthium L. is one of the plants which has been used in folk medicine for many diseases over many centuries. This study aims to analyze the chemical composition of the Artemisia absinthium ethyl acetate and its aqueous extracts and to evaluate their effect on the pancreatic α-amylase enzyme and the intestinal α-glucosidase enzyme. In this study, the total contents of phenolic compounds, flavonoids, and condensed tannins in ethyl acetate and the aqueous extracts of Artemisia absinthium leaves were determined by using spectrophotometric techniques, then the antioxidant capacity of these extracts was examined using three methods, namely, the DPPH (2, 2-diphenyl-1picrylhydrazyl) free radical scavenging method, the iron reduction method FRAP, and the β-carotene bleaching method. The determination of the chemical composition of the extracts was carried out using high-performance liquid chromatography-the photodiode array detector (HPLC-DAD). These extracts were also evaluated for their ability to inhibit the activity of the pancreatic α-amylase enzyme, as well as the intestinal α-glucosidase enzyme, in vitro and in vivo, thus causing the reduction of blood glucose. The results of this study showed that high polyphenol and flavonoid contents were obtained in ethyl acetate extract with values of 60.34 ± 0.43 mg GAE/g and 25.842 ± 0.241 mg QE/g, respectively, compared to the aqueous extract. The results indicated that the aqueous extract had a higher condensed tannin content (3.070 ± 0.022 mg EC/g) than the ethyl acetate extract (0.987 ± 0.078 mg EC/g). Ethyl acetate extract showed good DPPH radical scavenging and iron reduction FRAP activity, with an IC₅₀ of 0.167 ± 0.004 mg/mL and 0.923 ± 0.0283 mg/mL, respectively. The β-carotene test indicated that the aqueous and ethyl acetate extracts were able to delay the decoloration of β-carotene with an inhibition of 48.7% and 48.3%, respectively, which may mean that the extracts have antioxidant activity. HPLC analysis revealed the presence of naringenin and caffeic acid as major products in AQE and EAE, respectively. Indeed, this study showed that the aqueous and ethyl acetate extracts significantly inhibited the pancreatic α-amylase and intestinal α-glucosidase, in vitro. To confirm this result, the inhibitory effect of these plant extracts on the enzymes has been evaluated in vivo. Oral intake of the aqueous extract significantly attenuated starch- and sucrose-induced hyperglycemia in normal rats, and evidently, in STZ-diabetic rats as well. The ethyl acetate extract had no inhibitory activity against the intestinal α-glucosidase enzyme in vivo. The antioxidant and the enzyme inhibitory effects may be related to the presence of naringenin and caffeic acid or their synergistic effect with the other compounds in the extracts.

The management of diabetes mellitus by mangiferin: advances and prospects

Diabetes mellitus has become one of the most challenging public health problems today. There are still various deficiencies that remain in existing therapeutic drugs. With increasing prevalence and mortality rates, more effective therapeutic agents are required for treatment clinically. As a kind of polyphenol and as a natural product, mangiferin has numerous pharmacological and excellent effects. In this review, the underlying mechanisms of mangiferin on diabetes mellitus and complications will be summarized. Moreover, mangiferin belongs to the BSC IV class and the clinical application and development of mangiferin are limited due to its poor aqueous solubility and fat solubility as well as low bioavailability. Our review also elaborated on improving the solubility of mangiferin by changing the dosage form and introduced the existing results, which hope to provide useful reference for mangiferin for further treating diabetes. In conclusion, mangiferin might be a potential adjuvant therapy for the treatment of diabetes mellitus and complications in the future.

Self-nanoemulsifying composition containing curcumin, quercetin, Ganoderma lucidum extract powder and probiotics for effective treatment of type 2 diabetes mellitus in streptozotocin induced rats

Liquid self-nanoemulsifying drug delivery system (L-SNEDDS) of curcumin and quercetin were prepared by dissolving them in isotropic mixture of Labrafil M1944CS®, Capmul MCM®, Tween-80® and Transcutol P®. The prepared L-SNEDDS were solidified using Ganoderma lucidum extract, probiotics and Aerosil-200® using spray drying. These were further converted into pellets using extrusion-spheronization. The mean droplet size and zeta potential of L-SNEDDS were found to be 63.46 ± 2.12 nm and - 14.8 ± 3.11 mV while for solid SNEDDS pellets, these were 72.46 ± 2.16 nm and -38.7 ± 1.34 mV, respectively. The dissolution rate for curcumin and quercetin each was enhanced by 4.5 folds while permeability was enhanced by 5.28 folds (curcumin) and 3.35 folds (quercetin) when loaded into SNEDDS pellets. The Cmax for curcumin and quercetin containing SNEDDS pellets was found 532.34 ± 5.64 ng/mL and 4280 ± 65.67 ng/mL, respectively. This was 17.55 and 3.48 folds higher as compared to their naïve forms. About 50.23- and 5.57-folds increase in bioavailability was observed for curcumin and quercetin respectively, upon loading into SNEDDS pellets. SNEDDS pellets were found stable at accelerated storage conditions. The developed formulation was able to normalize the levels of blood glucose, lipids, antioxidant biomarkers, and tissue architecture of pancreas and liver in streptozotocin induced diabetic rats as compared to their naïve forms.

A Multitarget Approach to Evaluate the Efficacy of Aquilaria sinensis Flower Extract against Metabolic Syndrome

Aquilaria sinensis (Lour.) Spreng is known for its resinous secretion (agarwood), often secreted in defense against injuries. We investigated the effects of A. sinensis flower extract (AF) on peroxisome proliferator-activated receptors alpha and gamma (PPARα and PPARγ), liver X receptor (LXR), glucose uptake, and lipid accumulation (adipogenesis). Activation of PPARα, PPARγ and LXR was determined in hepatic (HepG2) cells by reporter gene assays. Glucose uptake was determined in differentiated muscle (C2C12) cells using 2-NBDG (2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose). Adipogenesis was determined in adipocytes (3T3-L1 cells) by Oil red O staining. At a concentration of 50 µg/mL, AF caused 12.2-fold activation of PPARα and 5.7-fold activation of PPARγ, while the activation of LXR was only 1.7-fold. AF inhibited (28%) the adipogenic effect induced by rosiglitazone in adipocytes and increased glucose uptake (32.8%) in muscle cells at 50 μg/mL. It was concluded that AF acted as a PPARα/γ dual agonist without the undesired effect of adipogenesis and exhibited the property of enhancing glucose uptake. This is the first report to reveal the PPARα/γ dual agonistic action and glucose uptake enhancing property of AF along with its antiadipogenic effect, indicating its potential in ameliorating the symptoms of metabolic syndrome.

A Systematic Review of Orthosiphon stamineus Benth. in the Treatment of Diabetes and Its Complications

(1) Background: Orthosiphon stamineus Benth. is a traditional medicine used in the treatment of diabetes and chronic renal failure in southern China, Malaysia, and Thailand. Diabetes is a chronic metabolic disease and the number of diabetic patients in the world is increasing. This review aimed to systematically review the effects of O. stamineus in the treatment of diabetes and its complications and the pharmacodynamic material basis. (2) Methods: This systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), using the databases ScienceDirect, PubMed, and Web of Science. (3) Results: Thirty-one articles related to O. stamineus and diabetes were included. The mechanisms of O. stamineus in the treatment of diabetes and its complications mainly included inhibiting α-amylase and α-glucosidase activities, antioxidant and anti-inflammatory activities, regulating lipid metabolism, promoting insulin secretion, ameliorating insulin resistance, increasing glucose uptake, promoting glycolysis, inhibiting gluconeogenesis, promoting glucagon-likepeptide-1 (GLP-1) secretion and antiglycation activity. Phenolic acids, flavonoids and triterpenoids might be the main components for hypoglycemia effects in O. stamineus. (4) Conclusion: O. stamineus could be an antidiabetic agent to treat diabetes and its complications. However, it needs further study on a pharmacodynamic substance basis and the mechanisms of effective constituents.

Plant polyphenols mechanisms of action on insulin resistance and against the loss of pancreatic beta cells

Diabetes mellitus describes a group of metabolic disorders characterized by a prolonged period hyperglycemia with long-lasting detrimental effects on the cardiovascular and nervous systems, kidney, vision, and immunity. Many plant polyphenols are shown to have beneficial activity for the prevention and treatment of diabetes, by different mechanisms. This review article is focused on synthesizing the mechanisms by which polyphenols decrease insulin resistance and inhibit loss of pancreatic islet β-cell mass and function. To achieve the objectives, this review summarizes the results of the researches realized in recent years in clinical trials and in various experimental models, on the effects of foods rich in polyphenols, polyphenolic extracts, and commercially polyphenols on insulin resistance and β-cells death. Dietary polyphenols are able to reduce insulin resistance alleviating the IRS-1/PI3-k/Akt signaling pathway, and to reduce the loss of pancreatic islet β-cell mass and function by several molecular mechanisms, such as protection of the surviving machinery of cells against the oxidative insult; increasing insulin secretion in pancreatic β-cells through activation of the FFAR1; cytoprotective effect on β-cells by activation of autophagy; protection of β-cells to act as activators for anti-apoptotic pathways and inhibitors for apoptotic pathway; stimulating of insulin release, presumably by transient ATP-sensitive K⁺ channel inhibition and whole-cell Ca²⁺ stimulation; involvement in insulin release that act on ionic currents and membrane potential as inhibitor of delayed-rectifier K⁺ current (I_K(DR)) and activator of current. dietary polyphenols could be used as potential anti-diabetic agents to prevent and alleviate diabetes and its complications, but further studies are needed.

Antiproliferative, Antiangiogenic, and Antimetastatic Therapy Response by Mangiferin in a Syngeneic Immunocompetent Colorectal Cancer Mouse Model Involves Changes in Mitochondrial Energy Metabolism

In spite of the current advances and achievements in cancer treatments, colorectal cancer (CRC) persists as one of the most prevalent and deadly tumor types in both men and women worldwide. Drug resistance, adverse side effects and high rate of angiogenesis, metastasis and tumor relapse remain one of the greatest challenges in long-term management of CRC and urges need for new leads of anticancer drugs. We demonstrate that CRC treatment with the phytopharmaceutical mangiferin (MGF), a glucosylxanthone present in Mango tree stem bark and leaves (Mangifera Indica L.), induces dose-dependent tumor regression and decreases lung metastasis in a syngeneic immunocompetent allograft mouse model of murine CT26 colon carcinoma, which increases overall survival of mice. Antimetastatic and antiangiogenic MGF effects could be further validated in a wound healing in vitro model in human HT29 cells and in a matrigel plug implant mouse model. Interestingly, transcriptome pathway enrichment analysis demonstrates that MGF inhibits tumor growth, metastasis and angiogenesis by multi-targeting of mitochondrial oxidoreductase and fatty acid β-oxidation metabolism, PPAR, SIRT, NFκB, Stat3, HIF, Wnt and GP6 signaling pathways. MGF effects on fatty acid β-oxidation metabolism and carnitine palmitoyltransferase 1 (CPT1) protein expression could be further confirmed in vitro in human HT29 colon cells. In conclusion, antitumor, antiangiogenic and antimetastatic effects of MGF treatment hold promise to reduce adverse toxicity and to mitigate therapeutic outcome of colorectal cancer treatment by targeting mitochondrial energy metabolism in the tumor microenvironment.

Hypoglycemic and Hypolipidemic Effects of Malonyl Ginsenosides from American Ginseng (Panax quinquefolius L.) on Type 2 Diabetic Mice

American ginseng (Panax quinquefolius L.) is popularly consumed as traditional herbal medicine and health food for the treatment of type 2 diabetes mellitus (T2DM). Malonyl ginsenosides (MGR) are the main natural ginsenosides in American ginseng. However, whether the malonyl ginsenosides in P. quinquefolius (PQ-MGR) possess antidiabetic effects has not been explored yet. In this study, the antidiabetic effects and the underlying mechanism of PQ-MGR in high-fat diet/streptozotocin (HFD/STZ)-induced T2DM mice were investigated. The chemical composition was analyzed by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Our results showed that 14 malonyl ginsenosides were identified in the PQ-MGR. Among them, the content of m-Rb₁ represented about 77.4% of the total malonyl ginsenosides. After a 5-week experiment, the PQ-MGR significantly reduced the fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), nonesterified fatty acid (NEFA), alanine transaminase (ALT), and aspartate transaminase (AST) levels and improved glucose tolerance and insulin resistance. Furthermore, Western blot analysis demonstrated that the protein expressions of p-PI3K, p-AKT, p-AMPK, p-ACC, PPAR_γ, and GLUT4 in the liver and skeletal muscle were significantly upregulated after PQ-MGR treatment. In contrast, the protein expressions of p-IRS1 and p-JNK were significantly downregulated. Our results revealed that PQ-MGR could ameliorate glucose and lipid metabolism and insulin resistance in T2DM via regulation of the insulin receptor substrate-1/phosphoinositide3-kinase/protein-kinase B (IRS1/PI3K/Akt) and AMP-activated protein kinase/acetyl-CoA carboxylase (AMPK/ACC) pathways. These findings suggest that PQ-MGR may be used as an antidiabetic candidate drug for T2DM treatment.

Antiobesity and Antidiabetic Effects of Portulaca oleracea Powder Intake in High-Fat Diet-Induced Obese C57BL/6 Mice

This study investigated the hypothesis that Portulaca oleracea L. exerts antiobesity and antidiabetic effects by evaluating blood lipid profiles, blood glucose control factors, protein expression of lipid metabolism, and insulin sensitivity improvement. Three groups of high-fat diet (HFD) induced obese C57BL/6 mice (n = 8) received treatment with low (5%; HFD + PO5%) or high (10%; HFD + PO10%) concentrations of P. oleracea powder for 12 weeks or no treatment (HFD) and were compared with each other and a fourth control group. Weight gain was reduced by 34% in the HFD + PO10% group compared to the HFD group. Moreover, the perirenal and epididymal fat contents in the HFD + PO10% group were 6.3-fold and 1.5-fold, respectively, lower than those in the HFD group. The atherogenic index (AI) and cardiac risk factor (CRF) results in the P. oleracea-treated groups were significantly lower than those in the HFD group. The homeostasis model assessment of insulin resistance (HOMA-IR) levels was lower in the HFD + PO10% group than in the HFD group. The protein expression levels of the proliferator-activated receptor (PPAR)-α, glucose transporter (GLUT) 4 and PPAR-γ were upregulated in the HFD + PO10% group compared to the HFD group. However, the protein expression levels of tumor necrosis factor (TNF)-α were lower in the P. oleracea-treated groups than in the HFD group. Our results demonstrate that P. oleracea powder could be effectively used to treat and prevent obesity and diabetes-associated diseases through suppression of weight gain and reduction in body fat and blood glucose levels.

Naringenin Attenuates Non-Alcoholic Fatty Liver Disease by Enhancing Energy Expenditure and Regulating Autophagy via AMPK

Background: The prevalence of non-alcoholic fatty liver disease (NAFLD) keeps growing recently. Purpose: To investigate the effects and mechanisms of naringenin (NAR) on NAFLD. Methods: High-fat diet (HFD)-induced NAFLD rats were orally administered with NAR at 10, 30, and 90 mg/kg for 2 weeks. The serum level of triglyceride (TG), total cholesterol (TC), glutamic-oxaloacetic transaminase (AST), and glutamic-pyruvic transaminase (ALT) was measured. The hepatic histology was detected by H&E and oil red O staining. L02 and Huh-7 cells were induced by sodium oleate to establish a NAFLD cell model. The effects of NAR on lipid accumulation were detected by oil red O staining. The glucose uptake and ATP content of 3T3-L1 adipocytes and C2C12 myotubes were measured. The expression of proteins of the AMPK signaling pathway in 3T3-L1 adipocytes and C2C12 myotubes was assessed by Western blotting. The mitochondrial biogenesis of 3T3-L1 adipocytes and C2C12 myotubes was measured by mitotracker orange staining and Western blotting. The biomarkers of autophagy were detected by Western blotting and immunofluorescence. The binding of NAR to AMPKγ1 was analyzed by molecular docking. Chloroquine and compound C were employed to block autophagic flux and AMPK, respectively. Results: NAR alleviated HFD-induced NAFLD in rats at 10, 30, and 90 mg/kg. NAR attenuated lipid accumulation in L02 and Huh-7 cells at 0.7, 2.2, 6.7, and 20 μM. NAR increased glucose uptake, decreased the ATP content, activated the CaMKKβ/AMPK/ACC pathway, and enhanced the mitochondrial biogenesis in 3T3-L1 adipocytes and C2C12 myotubes. NAR increased autophagy and promoted the initiation of autophagic flux in 3T3-L1 preadipocytes and C2C12 myoblasts, while it inhibited autophagy in NAFLD rats, 3T3-L1 adipocytes, and C2C12 myotubes. Molecular docking showed that NAR binds to AMPKγ1. Compound C blocked effects of NAR on lipid accumulation and autophagy in L02 cells. Conclusion: NAR alleviates NAFLD by increasing energy expenditure and regulating autophagy via activating AMPK directly and indirectly. The direct binding of NAR and AMPKγ1 needs further validation.

A review of antidiabetic active thiosugar sulfoniums, salacinol and neokotalanol, from plants of the genus Salacia

During our studies characterizing functional substances from food resources for the prevention and treatment of lifestyle-related diseases, we isolated the active constituents, salacinol (1) and neokotalanol (4), and related thiosugar sulfoniums, from the roots and stems of the genus Salacia plants [Celastraceae (Hippocrateaceae)] such as Salacia reticulata Wight, S. oblonga Wall., and S. chinensis L., and observed their antidiabetic effects. These plant materials have been used traditionally in Ayurvedic medicine as a specific remedy at the early stage of diabetes, and have been extensively consumed in Japan, the United States, and other countries as a food supplement for the prevention of obesity and diabetes. Here, we review our studies on the antidiabetic effects of plants from the genus Salacia, from basic chemical and pharmacological research to their application and development as new functional food ingredients.

Natural products and analogs as preventive agents for metabolic syndrome via peroxisome proliferator-activated receptors: An overview

Natural products and synthetic analogs have drawn much attention as potential therapeutical drugs to treat metabolic syndrome. We reviewed the underlying mechanisms of 32 natural products and analogs with potential pharmacological effects in vitro, and especially in rodent models and/or patients, that usually act on the PPAR pathway, along with other molecular targets. Recent outstanding total syntheses or semisyntheses of these lead compounds are stated. In general, they can activate the transcriptional activity of PPARα, PPARγ, PPARα/γ, PPARβ/δ, PPARα/δ, PPARγ/δ and panPPAR as weak, partial agonists or selective PPARγ modulators (SPPARγM), which may be useful for managing obesity, type 2 diabetes (T2D), dyslipidemia and non-fatty liver disease (NAFLD). Terpenoids is the largest group of compounds that act as potential modulators on PPARs and are comprised from small lipophilic cannabinoids to lipophilic pentacyclic triterpenes and polar saponins. Shikimates-phenylpropanoids include polar heterocyclic flavonoids and phenolic compounds containing at least one C3-C6 unit and usually a double bond on the propyl chain. Quercetin (19), resveratrol (24) and curcumin (27), stand out from this group for exhibiting beneficial effects on patients. Alkaloids, the minor group of potential modulators on PPARs, include berberine (30), which has been widely explored in preclinical and clinical studies for its potential beneficial effects on T2D and dyslipidemia. However, large-scale clinical trials may be warranted for the promising compounds.

Herbal Resources to Combat a Progressive & Degenerative Nervous System Disorder- Parkinson's Disease

Parkinson's disease is one of the most common adult-onset, a chronic disorder involving neurodegeneration, which progressively leads to deprivation of dopaminergic neurons in substantia nigra, causing a subsequent reduction of dopamine levels in the striatum resulting in tremor, myotonia, and dyskinesia. Genetics and environmental factors are believed to be responsible for the onset of Parkinson's disease. The exact pathogenesis of Parkinson's disease is quite complicated and the present anti-Parkinson's disease treatments appear to be clinically insufficient. Comprehensive researches have demonstrated the use of natural products such as ginseng, curcumin, ashwagandha, baicalein, etc. for the symptomatic treatment of this disease. The neuroprotective effects exhibited by these natural products are mainly due to their ability to increase dopamine levels in the striatum, manage oxidative stress, mitochondrial dysfunction, glutathione levels, clear the aggregation of α- synuclein, induce autophagy and decrease the pro-inflammatory cytokines and lipid peroxidation. This paper reviews various natural product studies conducted by scientists to establish the role of natural products (both metabolite extracts as well as pure metabolites) as adjunctive neuroprotective agents.

Oral administration of mangiferin ameliorates diabetes in animal models: a meta-analysis and systematic review

Although mangiferin has a number of documented beneficial effects, there are no systematic reviews or meta-analyses of its effects in diabetic animal models. To investigate the effects of oral administration of mangiferin on blood glucose levels, body weight, and total cholesterol and triglycerides levels in diabetic animal models, a meta-analysis was conducted and the underlying mechanisms were reviewed. Studies from 6 databases (PubMed, Web of Science, Embase, Cochrane Library, and CNKI (China National Knowledge Infrastructure), and Wanfang Med) were searched from inception to April 2020. After article screening, a total of 19 articles were included in this meta-analysis. The meta-analysis was performed using RevMan 5.3 and STATA 14.0 software. The overall pooled estimate of standardized mean difference (SMD) of mangiferin's effect on blood glucose was -1.27 (95% confidence interval [CI]: -1.71, -0.82, P < .00001). Body weight increased in lean diabetic animals with an SMD of 1.41 (95% CI: 0.57, 2.25; P = .001), while it decreased in obese diabetic animals with an SMD of -0.92 (95% CI: -1.69, -0.14; P = .02). Mangiferin intake reduced serum total cholesterol and triglycerides levels with SMDs of -1.02 (95% CI: -1.43, -0.61; P < .001) and -1.24 (95% CI: -1.70, -0.79; P < .001), respectively. The meta-analysis suggests that oral intake of mangiferin has a significant antidiabetic effect in animal models, and the systematic review suggested that this function might be attributed to its anti-inflammatory and antioxidative properties, as well as to its function of improving glycolipid metabolism and enhancing insulin signaling.

Flavonoids: structure-function and mechanisms of action and opportunities for drug development

Flavonoids are polyphenolic phytochemicals produced in fruits, nuts and vegetables and dietary consumption of these structurally diverse compounds is associated with multiple health benefits including increased lifespan, decreased cardiovascular problems and low rates of metabolic diseases. Preclinical studies with individual flavonoids demonstrate that these compounds exhibit anti-inflammatory and anticancer activities and they enhance the immune system. Their effectiveness in both chemoprevention and chemotherapy is associated with their targeting of multiple genes/pathways including nuclear receptors, the aryl hydrocarbon receptor (AhR), kinases, receptor tyrosine kinases and G protein-coupled receptors. However, despite the remarkable preclinical activities of flavonoids, their clinical applications have been limited and this is due, in part, to problems in drug delivery and poor bioavailability and these problems are being addressed. Further improvements that will expand clinical applications of flavonoids include mechanism-based precision medicine approaches which will identify critical mechanisms of action of individual flavonoids with optimal activities that can be used in combination therapies.

Re-appraising the potential of naringin for natural, novel orthopedic biotherapies

Naringin is a naturally occurring flavonoid found in plants of the Citrus genus that has historically been used in traditional Chinese medical regimens for the treatment of osteoporosis. Naringin modulates signaling through numerous molecular pathways critical to musculoskeletal development, cellular differentiation, and inflammation. Administration of naringin increases in vitro expression of bone morphogenetic proteins (BMPs) and activation of the Wnt/β-catenin and extracellular signal-related kinase (Erk) pathways, thereby promoting osteoblastic proliferation and differentiation from stem cell precursors for bone formation. Naringin also inhibits osteoclastogenesis by both modifying RANK/RANKL interactions and inducing apoptosis in osteoclasts in vitro. In addition, naringin acts on the estrogen receptor in bone to mimic the native bone-preserving effects of estrogen, with few systemic side effects on other estrogen-sensitive tissues. The efficacy of naringin therapy in reducing the osteolysis characteristic of common musculoskeletal pathologies such as osteoporosis, degenerative joint disease, and osteomyelitis, as well as inflammatory conditions affecting bone such as diabetes mellitus, has been extensively demonstrated in vitro and in animal models. Naringin thus represents a naturally abundant, cost-efficient agent whose potential for use in novel musculoskeletal biotherapies warrants re-visiting and further exploration through human studies. Here, we review the cellular mechanisms of action that have been elucidated regarding the action of naringin on bone resident cells and the bone microenvironment, in vivo evidence of naringin’s osteostimulative and chondroprotective properties in the setting of osteolytic bone disease, and current limitations in the development of naringin-containing translational therapies for common musculoskeletal conditions.

Salacia chinensis exerts its antidiabetic effect by modulating glucose-regulated proteins and transcription factors in high-fat diet fed-streptozotocin-induced type 2 diabetic rats

This study aimed to investigate the properties of Salacia chinensis (Celastraceae, SC) and its molecular mechanism in the type 2 diabetic rats. Forty-two Wistar rats were divided into six groups (n = 7): control, SC (100 mg/kg, per os), high-fat diet (HFD), HFD + SC (100 mg/kg), HFD + streptozotocin (STZ, 40 mg/kg, i.p.), and HFD + STZ+SC. SC decreased serum glucose, insulin, triglycerides, free fatty acid, and malondialdehyde levels, but increased serum total antioxidant capacity (0.33 ± 0.02 versus. 0.79 ± 0.03), compared with the untreated group (p < .001). Additionally, SC elevated the expression of glucose-regulated proteins GLUT2, PPAR-ɣ, p-IRS, and Nrf2, but downregulated NF-κB in the liver and kidney (p < .001). In conclusion, SC could improve insulin resistance by modulation of glucose-regulated proteins and transcription factors in diabetic rats. PRACTICAL APPLICATIONS: Present data has contributed to the current ethnomedicinal benefits of SC, through which the SC intake regulated the carbohydrate metabolism and increased the antioxidant capacity. The balance of transcription factors can mediate these efficacies partially and various key proteins involved in energy metabolism, along with oxidative stress and insulin sensitivity.

Management of Type 2 Diabetes: Current Strategies, Unfocussed Aspects, Challenges, and Alternatives

Type 2 diabetes mellitus (T2DM) accounts for >90% of the cases of diabetes in adults. Resistance to insulin action is the major cause that leads to chronic hyperglycemia in diabetic patients. T2DM is the consequence of activation of multiple pathways and factors involved in insulin resistance and β-cell dysfunction. Also, the etiology of T2DM involves the complex interplay between genetics and environmental factors. This interplay can be governed efficiently by lifestyle modifications to achieve better management of diabetes. The present review aims at discussing the major factors involved in the development of T2DM that remain unfocussed during the anti-diabetic therapy. The review also focuses on lifestyle modifications that are warranted for the successful management of T2DM. In addition, it attempts to explain flaws in current strategies to combat diabetes. The employability of phytoconstituents as multitargeting molecules and their potential use as effective therapeutic adjuvants to first line hypoglycemic agents to prevent side effects caused by the synthetic drugs are also discussed.

Exploring Antioxidant and Enzymes (A-Amylase and B-Glucosidase) Inhibitory Activity of Morinda lucida and Momordica charantia Leaves from Benin

BACKGROUND

Momordica charantia Linn. (Cucurbitaceae), the wild variety of bitter melon and Morinda lucida Benth (Rubiaceae) were commonly used as a popular folk medicine in Benin. This research focused to measure the antioxidant and enzyme inhibitory effects of M. charantia and M. lucida leaves and their antidiabetic activity.

METHODS

Antioxidant activities were evaluated by micro-dilution technique using DPPH free radical scavenging activity and β-carotene-linoleate bleaching assay. The α-amylase inhibition assay was carried out utilizing the 3,5-dinitrosalicylic acid procedure, while β-glucosidase inhibition assay was demonstrated using as substrate p-nitrophenyl-β-D-glucopyranoside (PNPG). HPLC-DAD analysis was realized using a high-performance liquid chromatography systems with diode-array detector, L-3000.

RESULTS

Chlorogenic acid, epicatechin, daidzein, rutin, naringin, quercetin, naringenin and genistein were identified as polyphenol compounds in the both plants extract. Dichloromethane and ethyl acetate extracts showed a good α-amylase inhibitory activity (56.46 ± 1.96% and 58.76 ± 2.74% respectively). M. lucida methanolic extract has shown IC₅₀ of 0.51 ± 0.01 mg/mL, which is the lowest for DPPH scavenging activity. M. lucida dichloromethane extract showed the highest inhibitory capacity of β-glucosidase activity (82.11. ± 2.15%).

CONCLUSION

These results justify some traditional medicinal uses of both plants. The purified fractions could be used in future formulations, possibly incorporated in functional foods to combat certain diseases.

A Molecular Approach on the Protective Effects of Mangiferin Against Diabetes and Diabetes-related Complications

BACKGROUND

Diabetes and its related complications are now a global health problem without an effective therapeutic approach. There are many herbal medicines which have attracted much attention as potential therapeutic agents in the prevention and treatment of diabetic complications due to their multiple targets.

AIM

The aim of this study is to review available knowledge of mangiferin focusing on its mode of action.

METHODS

Mangiferin was extensively reviewed for its antidiabetic activity using online database like Scopus, PubMed, and Google Scholar as well as some offline textbooks. A critical discussion based on the mechanism of action and the future perspectives is also given in the present manuscript.

RESULTS

Mangiferin is a natural C-glucoside and mainly obtained from its primary source, the leaves of mango tree (Mangifera indica L.). Therapeutic and preventive properties of mangiferin include antimicrobial, anti-inflammatory, antioxidative, antiallergic, neuroprotective, and cognition-enhancing effects. It dissolves well in water, so it can be easily extracted into infusions and decoctions and hence, a number of researches have been made on the therapeutic effect of this molecule. Recently, mangiferin has been proved to be an effective remedy in diabetes and diabetes-related complications. It is a beneficial natural compound for type 2 diabetes mellitus as it improves insulin sensitivity, modulates lipid profile and reverts adipokine levels to normal.

CONCLUSION

This study concludes that mangiferin has the potential to treat diabetes and it can be developed as a therapeutic agent for diabetes and the complications caused by diabetes.

Mangiferin promotes macrophage cholesterol efflux and protects against atherosclerosis by augmenting the expression of ABCA1 and ABCG1

Mangiferin has been identified as a potent cardioprotective factor that enhances high-density lipoprotein cholesterol levels in plasma. The aim of this study was to investigate the impact of mangiferin on macrophage cholesterol efflux and the development of atherosclerosis. The results showed that mangiferin injection significantly decreased atherosclerotic plaque size, and reduced plasma levels of low-density lipoprotein cholesterol, triglyceride, and total cholesterol in apoE knockout mice, whereas reverse cholesterol transport efficiency and high-density lipoprotein cholesterol levels were enhanced. In vitro study showed that mangiferin prevented lipid accumulation and promoted [³H]-cholesterol efflux from acetylated LDL-loaded RAW264.7 macrophages with an increase in the expression of ATP binding cassette A1/G1 (ABCA1/G1), liver X receptor-α (LXRα) and peroxisome proliferator-activated receptor-γ (PPARγ). Moreover, transfection of PPARγ siRNA or LXRα siRNA markedly abolished the positive effects of mangiferin on ABCA1/G1 expression and cholesterol efflux. The opposite effects were observed after treatment with PPARγ agonist rosiglitazone or LXRα agonist T0901317. In conclusion, mangiferin may attenuate atherogenesis by promoting cholesterol efflux from macrophages via the PPARγ-LXRα-ABCA1/G1 pathway.

Advanced Glycation Endproducts (AGEs) in Food: Health Implications and Mitigation Strategies

Controversy remains over the impact of advanced glycation endproducts (AGEs), not only in their formation, but also whether they actually come directly from food products or are generated by the body in response to ingestion of certain foods. This final chapter will take a different approach to food contaminants and look at the health impact of AGEs, regardless of whether they are directly ingested from food, autogenerated by the body as a consequence of underlying disease conditions or contribute to the aetiology of disease. AGEs are formed from food components or as a consequence of some disease states, such as type II diabetes or cardiovascular disease (CVD). As such these compounds are inextricably linked to the Maillard reaction and cooking conditions. Furthermore, processing-derived chemical contaminants in cooked foods are of concern to consumers. This chapter examines new research into naturally derived plant extracts as inhibitory agents on new dietary AGE (dAGE) formation and introduces practical approaches for the reduction of dAGE consumption in the daily diet. Understanding the pathogenic mechanisms of AGEs is paramount to developing strategies against diabetic and cardiovascular complications.