Flavonoid subclasses and type 2 diabetes mellitus risk: a meta-analysis of prospective cohort studies

Microbial Fermentation-Derived Dihydroquercetin Derivatives Exhibit Superior Efficacy in Ameliorating Insulin Resistance via JNK/PI3K/AKT Pathway Regulation Compared to Dihydroquercetin

Insulin resistance (IR) is a complex metabolic disorder characterized by diminished insulin sensitivity, leading to impaired glucose uptake and a potential progression to hyperglycemia and diabetes. While lifestyle modifications are essential, the limitations of current pharmacological interventions highlight the need for natural products with therapeutic benefits. This study introduces two novel dihydroquercetin (DHQ) derivatives, 8-hydroxy-dihydroquercetin (H-DHQ) and dihydroquercetin-7-O-β-d-(4″-O-methyl)-glucoside (DHQ-MG), developed through microbial fermentation using Beauveria bassiana. Results indicated that H-DHQ and DHQ-MG significantly enhanced the alleviation of IR in a HepG2 cell model compared with DHQ, with no significant differences noticed between DHQ-MG and H-DHQ. Mechanistic analyses revealed that these derivatives effectively reduced inflammation, oxidative stress, and endoplasmic reticulum (ER) stress, thereby activating the JNK/PI3K/AKT signaling pathway to promote glycogen synthesis, suppress gluconeogenesis, and stimulate glucose transport. This research highlights the potential of H-DHQ and DHQ-MG as effective natural alternatives for managing IR, while also providing indirect evidence for the application of microbial fermentation as a strategy to modify natural flavonoids for this purpose.

Hydroxylation of dihydromyricetin via Beauveria bassiana fermentation enhances its efficacy in improving insulin signaling: Insights into inflammation, oxidative stress, and endoplasmic reticulum stress

Chronic metabolic diseases, particularly insulin resistance (IR) and diabetes, pose significant global health challenges. This study introduces a novel hydroxylated dihydromyricetin (DHM) derivative, 8-hydroxy-DHM (H-DHM), produced via microbial fermentation using Beauveria bassiana. Notably, hydroxylation significantly enhances the efficacy of DHM in glucose consumption, glycogen synthesis, and glucose transport, while inhibiting gluconeogenesis in an IR-HepG2 cell model. This indicates that hydroxylation of DHM can enhance its regulation of glucose metabolism. Mechanistic investigations reveal that H-DHM regulates the JNK/PI3K/AKT signaling pathway by reducing inflammation, oxidative stress, and endoplasmic reticulum stress. These findings highlight the potential of hydroxylated DHM as a promising candidate for dietary and clinical interventions in IR management. Furthermore, this research provides new insights into the modification of natural flavonoids through microbial fermentation, presenting an innovative strategy for managing and preventing chronic metabolic diseases.

Role of dietary and nutritional interventions in ceramide-associated diseases

Ceramides are important intermediates in sphingolipid metabolism and serve as signaling molecules with independent biological significance. Elevated cellular and circulating ceramide levels are consistently associated with pathological conditions including cardiometabolic diseases, neurological diseases, autoimmune diseases, and cancers. Although pharmacological inhibition of ceramide formation often protects against these diseases in animal models, pharmacological modulation of ceramides in humans remains impractical. Dietary interventions including the Mediterranean diet, lacto-ovo-vegetarian diet, calorie-restricted diet, restriction of dairy product consumption, and dietary supplementation with polyunsaturated fatty acids, dietary fibers, and polyphenols, all have beneficial effects on modulating ceramide levels. Mechanistic insights into these interventions are discussed. This article reviews the relationships between ceramides and disease pathogenesis, with a focus on dietary intervention as a viable strategy for lowering the concentration of circulating ceramides.

Pre- and post-polyphenol intake and ovarian cancer survival: evidence from a prospective cohort study

PURPOSE

Although (poly)phenols have shown potential in anti-cancer activities, their impact on improving ovarian cancer (OC) survival remains unknown. Therefore, we aim to first investigate the association between dietary polyphenol intake and OC survival, providing valuable insights into potential interventions.

METHODS

The prospective cohort recruited 560 patients with OC to assess the associations of polyphenol intake, not only pre- and post-diagnosis but also the change from pre- to post-diagnosis with OC survival. Dietary intakes of total (poly)phenols and their five classes (flavonoids, phenolic acids, lignans, stilbenes, and other polyphenols) were assessed using a validated 111-item food frequency questionnaire. Overall survival (OS) was tracked through active follow-up and medical records until February 16th, 2023. Cox proportional hazard regression models were applied to calculate the hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

During a median follow-up of 44.4 months, 211 all-cause deaths were identified. We observed significant associations between higher polyphenol intake with lower risk of mortality among patients with OC ((HR T3 vs. T1 = 0.55, 95%CI = 0.35-0.87 for pre-diagnosis; and HR T3 vs. T1 = 0.59, 95%CI = 0.39-0.90 for post-diagnosis). Consistently, an evident linear trend was observed for polyphenol and flavonoid intake with OC survival. Of note, compared to the stable group (change within 10%), the decreased intake (change of more than 10%) of total (poly)phenols and five polyphenol classes was significantly associated with worse OS.

CONCLUSION

Dietary (poly)phenols, as well as its five classes, have an inverse association with OC survival.

Investigating the Mechanism of Banxia Xiexin Decoction in Treating Gastritis and Diabetes Mellitus through Network Pharmacology and Molecular Docking Analysis

Background:

Banxia Xiexin decoration (BXD), a complex prescription in Traditional Chinese Medicine (TCM), clinically acts as a treatment for gastritis and diabetes while its mechanism of treatment remains unknown.

Objection:

This study aimed to explore the common mechanism of BXD in treating gastritis and diabetes based on network pharmacology and molecular docking technology.

Methods:

The seven Chinese herbal components and drug targets were collected from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) for gastritis and diabetes using GeneCards, DisGeNET, Comparative Toxicogenomics Database (CTD), and Online Mendelian Inheritance in Man (OMIM) databases. Common drug and disease targets were imported into the STRING data platform for protein-protein interaction (PPI) analysis, and Cytoscape 3.7.2 software for network topology analysis, and core targets were filtered.

Results:

There were 124 components, 249 targets, 449 targets for gastritis, and 4005 targets for diabetes. After mapping, 83 BXD targets for gastritis and diabetes were obtained, and the targets with high correlation were STAT 3, JUN, TNF, IL-6, etc. More relevant targets were involved in the cancer pathway, AGE-RAGE signaling pathway of diabetic complications, fluid shear stress, and atherosclerosis pathway.

Conclusion:

This study preliminarily reveals that BXD may play a role in the treatment of gastritis and diabetes mellitus through multi-components, multi-targets, and multi-pathways, and proposes some potential "component-target-pathway" hypotheses in light of previous reports.

Efficacy of Myricetin Supplementation on Glucose and Lipid Metabolism: A Systematic Review and Meta-Analysis of In Vivo Mice Studies

BACKGROUND/OBJECTIVES

Type 2 diabetes mellitus (T2DM) is a disorder characterized by insulin resistance, hyperglycemia, and dyslipidemia. Myricetin, a flavonoid found in various plants, has shown potential anti-diabetic effects in murine studies. This meta-analysis aimed to evaluate the impact of myricetin supplementation on glucose metabolism and lipid profiles in mouse models of metabolic diseases.

METHODS

A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines (PROSPERO: CRD42024591569). Studies involving mice with metabolic disease models and exclusively using myricetin supplementation were checked across four databases (Embase, Scopus, PubMed, and WoS) until 23rd September 2024. The primary outcomes assessed were blood glucose (BG), insulin levels, triacylglycerol (TAG), total cholesterol (TC), HDL, and LDL. A random-effects model was applied to estimate standardized mean differences (SMD), and SYRCLE's risk-of-bias tool for animal studies was used.

RESULTS

Twenty-one studies with 514 mice met the inclusion criteria. Myricetin supplementation significantly reduced BG (SMD = -1.45, CI: -1.91 to -0.99, p < 0.00001, I2 = 74%), insulin (SMD = -1.78, CI: -2.89 to -0.68, p = 0.002, I2 = 86%), TAG (SMD = -2.60, CI: -3.24 to -1.96, p < 0.00001, I2 = 81%), TC (SMD = -1.86, CI: -2.29 to -1.44, p < 0.00001, I2 = 62%), and LDL (SMD = -2.95, CI: -3.75 to -2.14, p < 0.00001, I2 = 74%). However, the effect on HDL was not statistically significant (SMD = 0.71, CI: -0.01 to 1.43, p = 0.05, I2 = 83%).

CONCLUSIONS

Myricetin supplementation improved glucose metabolism and lipid profiles in mouse models, suggesting its potential as a therapeutic agent for managing T2DM. However, further research is needed to confirm these findings in human studies.

Association between dietary (poly)phenol intake and the ATHLOS Healthy Ageing Scale in the Polish arm of the HAPIEE study

Inverse association between (poly)phenol intake and age-related disorders has been demonstrated; however, little is known whether they affect comprehensively assessed healthy aging. The aim of this study was to evaluate the associations between the intake of (poly)phenol (including selected classes and subclasses) and healthy aging scores related to biopsychosocial aspects of health and functioning. A cross-sectional study was performed using data on 9774 randomly selected citizens of Krakow (Poland) who were 45-69 years of age. Dietary (poly)phenol intake was evaluated using a food frequency questionnaire and matching food consumption data with the Phenol-Explorer database. The healthy aging scores were estimated from the ATHLOS Healthy Ageing Scale (HAS) developed by the Ageing Trajectories of Health-Longitudinal Opportunities and Synergies (ATHLOS) consortium. Beta coefficients were calculated using multivariable linear regression models. In multivariable adjusted models, there were significant positive associations between the ATHLOS HAS score and intake of total (poly)phenols (b per increase of 100 mg/day = 0.081; 95% CI, 0.050; 0.112) and among main classes of (poly)phenols with phenolic acids (b = 0.139; 95% CI, 0.098; 0.180). Intake of remaining classes of (poly)phenols (flavonoids, lignans, stilbenes, and others) was not related to the ATHLOS HAS score. Among individual classes studied, hydroxycinnamic acids, flavonols, flavones, and dihydrochalcones were associated with better healthy aging. The findings suggest the beneficial effect of total dietary (poly)phenol and some classes and subclasses of (poly)phenol intake in terms of healthy aging in Poland. These findings should be confirmed in other settings and with prospective data.

Association between consumption of flavonol and its subclasses and chronic kidney disease in US adults: an analysis based on National Health and Nutrition Examination Survey data from 2007-2008, 2009-2010, and 2017-2018

Background

There is little research on the relationship between flavonol consumption and chronic kidney disease (CKD). This study aimed to examine the link between flavonol consumption and the risk of CKD among US adults, using data from the 2007-2008, 2009-2010 and 2017-2018 National Health and Nutrition Examination Survey (NHANES).

Methods

A cross-sectional approach was used, drawing on data from three NHANES cycles. The flavonol consumption of the participants in this study was assessed using a 48 h dietary recall interview. CKD was diagnosed based on an estimated glomerular filtration rate below 60 mL/min/1.73 m2 or a urine albumin-to-creatinine ratio of 30 mg/g or higher.

Results

Compared to the lowest quartile of flavonol intake (Q1), the odds ratios for CKD were 0.598 (95% CI: 0.349, 1.023) for the second quartile (Q2), 0.679 (95% CI: 0.404, 1.142) for the third quartile (Q3), and 0.628 (95% CI: 0.395, 0.998) for the fourth quartile (Q4), with a p value for trend significance of 0.190. In addition, there was a significant trend in CKD risk with isorhamnetin intake, with the odds ratios for CKD decreasing to 0.860 (95% CI: 0.546, 1.354) in the second quartile, 0.778 (95% CI: 0.515, 1.177) in the third quartile, and 0.637 (95% CI: 0.515, 1.177) in the fourth quartile (p for trend = 0.013).

Conclusion

Our analysis of the NHANES data spanning 2007-2008, 2009-2010, and 2017-2018 suggests that high consumption of dietary flavonol, especially isorhamnetin, might be linked to a lower risk of CKD in US adults. These findings offer new avenues for exploring strategies for managing CKD.

Higher dietary flavonol and isoflavonoid intakes are associated with lower incidence of type 2 diabetes

Background: Adequate evidence supports beneficial effects of plant-derived phytochemicals against type 2 diabetes (T2D). Among phytochemicals, dietary flavonoids is one of the superb candidates. The whole studies are carried out in Western populations, so it is needed to investigate the risk of T2D by dietary flavonoid intakes in ethnic origins and other regions to confirm these relations. This study was conducted to investigate whether the daily consumption of total flavonoid and its subclasses can affect the incidence of type 2 diabetes (T2D) in the Iranian population. Methods: Eligible adults (n=6547) were selected from among participants of the Tehran lipid and glucose study with an average follow-up of 3.0 years. Dietary intakes were assessed using a valid and reliable 168-item semi-quantitative food frequency questionnaire. Multivariate Cox proportional hazard regression models were used to estimate the development of T2D in relation to total intake of flavonoids. Results: This study was conducted on 2882 men and 3665 women, aged 41.3±14.6 and 39.0±13.4 years, respectively. After adjustment for several potential confounders (age, sex, diabetes risk score, physical activity, energy, fiber and total fat intakes), risk of T2D decreased from tertiles 1 to 3 for flavonols (HR (95% CI): 1.00, 0.86 (0.64-1.16), 0.87 (0.63-0.93), Ptrend=0.01) and isoflavonoids (HR (95% CI): 1.00, 0.84 (0.62-1.13), 0.64 (0.46-0.88), Ptrend=0.02), whereas non-significant results were found for total flavonoid and other subclasses of flavonoid. Conclusion: These results emphasize the potential protective role of flavonols and isoflavonoids rich food (e.g. apple, tea, soy, and dark chocolate) in the prevention of T2D.

Dietary Flavonoids Consumption and Health: An Umbrella Review

SCOPE

The current evidence between dietary flavonoids consumption and multiple health outcomes is inadequate and inconclusive. To summarize and evaluate the evidence for dietary flavonoids consumption and multiple health outcomes, an umbrella review of meta-analyses and systematic reviews is conducted.

METHODS AND RESULTS

PubMed, Ovid-EMBASE, and the Cochrane Database of Systematic Reviews are searched up to January 2024. The study includes a total of 32 articles containing 24 unique health outcomes in this umbrella review. Meta-analyses are recalculated by using a random effects model. Separate analyses are performed based on the kind of different flavonoid subclasses. The study finds some unique associations such as flavonol and gastric cancer, isoflavone and uterine fibroids and endometrial cancer, total flavonoids consumption and lung cancer, ovarian cancer, and prostate cancer. Overall, the study confirms the negative associations between dietary flavonoids consumption and type 2 diabetes mellitus, cardiovascular diseases, breast cancer, colorectal cancer, lung cancer, and mortality, while positive associations are observed for prostate cancer and uterine fibroids.

CONCLUSION

Although dietary flavonoids are significantly associated with many outcomes, firm generalizable conclusions about their beneficial or harmful effects cannot be drawn because of the low certainty of evidence for most of outcomes. More well-designed primary studies are needed.

Higher habitual intakes of flavonoids and flavonoid-rich foods are associated with a lower incidence of type 2 diabetes in the UK Biobank cohort

AIM

To examine the associations of a diet high in flavonoid-rich foods, as reflected by a "Flavodiet Score" (FDS), the major individual food contributors to flavonoid intake, and flavonoid subclasses with type 2 diabetes (T2D) risk in the UK Biobank cohort.

MATERIALS AND METHODS

Flavonoid intakes were estimated from ≥2 dietary assessments among 113,097 study participants [age at enrolment: 56 ± 8 years; 57% female] using the U.S Department of Agriculture (USDA) databases. Multivariable Cox proportional hazards models were used to investigate associations between dietary exposures and T2D.

RESULTS

During 12 years of follow-up, 2628 incident cases of T2D were identified. A higher FDS (compared to lower [Q4 vs. Q1]), characterised by an average of 6 servings of flavonoid-rich foods per day, was associated with a 26% lower T2D risk [HR: 0.74 (95% CI: 0.66-0.84), ptrend = <0.001]. Mediation analyses showed that lower body fatness and basal inflammation, as well as better kidney and liver function partially explain this association. In food-based analyses, higher intakes of black or green tea, berries, and apples were significantly associated with 21%, 15%, and 12% lower T2D risk. Among individual flavonoid subclasses, 19-28% lower risks of T2D were observed among those with the highest, compared to lowest intakes.

CONCLUSIONS

A higher consumption of flavonoid-rich foods was associated with lower T2D risk, potentially mediated by benefits to obesity/sugar metabolism, inflammation, kidney and liver function. Achievable increases in intakes of specific flavonoid-rich foods have the potential to reduce T2D risk.

Integrated Analysis of Genomic and Genome-Wide Association Studies Identified Candidate Genes for Nutrigenetic Studies in Flavonoids and Vascular Health: Path to Precision Nutrition for (Poly)phenols

Flavonoids exert vasculoprotective effects in humans, but interindividual variability in their action has also been reported. This study aims to identify genes that are associated with vascular health effects of flavonoids and whose polymorphisms could explain interindividual variability in response to their intake. Applying the predetermined literature search criteria, we identified five human intervention studies reporting positive effects of flavonoids on vascular function together with global genomic changes analyzed using microarray methods. Genes involved in vascular dysfunction were identified from genome-wide association studies (GWAS). By extracting data from the eligible human intervention studies, we obtained 5807 differentially expressed genes (DEGs). The number of identified upstream regulators (URs) varied across the studies, from 227 to 1407. The search of the GWAS Catalog revealed 493 genes associated with vascular dysfunction. An integrative analysis of transcriptomic data with GWAS genes identified 106 candidate DEGs and 42 candidate URs, while subsequent functional analyses and a search of the literature identified 20 top priority candidate genes: ALDH2, APOE, CAPZA1, CYP11B2, GNA13, IL6, IRF5, LDLR, LPL, LSP1, MKNK1, MMP3, MTHFR, MYO6, NCR3, PPARG, SARM1, TCF20, TCF7L2, and TNF. In conclusion, this integrated analysis identifies important genes to design future nutrigenetic studies for development of precision nutrition for polyphenols.

Hesperetin promotes diabetic wound healing by inhibiting ferroptosis through the activation of SIRT3

Hesperetin (HST) is a flavonoid compound naturally occurring in citrus fruits and is widespread in various traditional medicinal herbs such as grapefruit peel, orange peel, and tangerine peel. These plant materials are commonly used in traditional Chinese medicine to prepare herbal remedies. The study aimed to investigate the potential molecular mechanisms through which HST reduces ferroptosis in human umbilical vein endothelial cells (HUVECs) and promotes angiogenesis and wound healing. We employed network pharmacology to predict the downstream targets affected by HST. The expression of markers related to ferroptosis was assessed through Western blot (WB) and polymerase chain reaction. Intracellular levels of ferroptosis-related metabolism were examined using glutathione/oxidized glutathione (GSH/GSSG) and malondialdehyde (MDA) assay kits. Mitochondrial status and iron levels within the cells were investigated through staining with Mitosox, FerroOrange, and JC1 staining. Potential downstream direct targets of HST were identified using molecular docking. Additionally, wound healing and neovascularization within the wound site were analyzed using various methods including HE staining, Masson's staining, immunohistochemistry, and Doppler hemodynamics assessment. HST effectively inhibits the elevated levels of intracellular ferroptosis stimulated by ERASTIN. Furthermore, we observed that HST achieves this inhibition of ferroptosis by activating SIRT3. In a diabetic rat wound model, HST significantly promotes wound healing, reducing levels of tissue ferroptosis, consistent with our in vitro findings. This study demonstrates that HST can inhibit the progression of ferroptosis and protect the physiological function of HUVECs by activating SIRT3. HST holds promise as a natural compound for promoting diabetic wound healing.

Flavonoid Metabolites in Serum and Urine after the Ingestion of Selected Tropical Fruits

The serum concentration and urinary excretion of flavonoids after the ingestion of guava, pineapple, and pomelo were determined using liquid chromatography-mass spectroscopy (LC-MS/MS). Each group of healthy volunteers was given 200 g of fresh fruit after overnight fasting and a 24-h flavonoid-free diet. The results demonstrate that only the glucuronic-conjugated metabolites of luteolin, quercetin, kaempferol, and myricetin were detected after fruit ingestion. The metabolites were first detected after 2 h, with the time to maximum concentration (Tmax) at 6 h. The most abundant metabolites for guava, pineapple, and pomelo were the glucuronide metabolites of quercetin (AUC0-8 5.4 ± 1.3 μg·h/mL), kaempferol (AUC0-8 9.9 ± 2.3 μg·h/mL), and luteolin (AUC0-8 6.4 ± 1.1 μg·h/mL), respectively. The flavonoids found in the 24-h urinary excretions were glucuronic- and mainly sulfate-conjugated metabolites. Quercetin metabolites were the most abundant after guava and pineapple ingestion, accounting for 900 and 700 μg, respectively. Luteolin metabolites were the most abundant after pomelo ingestion, accounting for 450 μg. The serum and urinary metabolite profiles suggested that guava and pineapple are good sources of quercetin, pineapple is a good source of kaempferol, and pomelo is a good source of luteolin. The study of flavonoid profiles may provide information for the selection of fruits as functional foods for their health benefits to help with various health conditions.

Ingredients, structure and reconstitution properties of instant powder foods and the potential for healthy product development: a comprehensive review

Instant foods are widely presented in powder forms across different food segments, which potentially can be formulated with functional or beneficial compounds to provide health benefits. Many reconstituted instant powder foods form colloidal suspensions with complex structures. However, designing instant powder food could be challenging due to the structural complexity and high flexibility in formulation. This review proposed a new classification method for instant powder foods according to the solubility of ingredients and the structure of the reconstituted products. Instant powder foods containing insoluble ingredients are discussed. It summarised challenges and current advances in powder treatments, reconstitution improvement, and influences on food texture and structure to facilitate product design in related industries. The characteristics and incorporation of the main ingredients and ingredients with health benefits in product development were reviewed. Different products vary significantly in the ratios of macronutrients. The macronutrients have limited solubility in water. After being reconstituted by water, the insoluble components are dispersed and swell to form colloidal dispersions with complex structures and textures. Soluble components, which dissolve in the continuous phase, may facilitate the dispersing process or influence the solution environment. The structure of reconstituted products and destabilising factors are discussed. Both particle and molecular structuring strategies have been developed to improve wettability and prevent the formation of lumps and, therefore, to improve reconstitution properties. Various types of instant food have been developed based on healthy or functional ingredients and exhibit positive effects on the prevention of non-communicable diseases and overall health. Less processed materials and by-products are often chosen to enhance the contents of dietary fibre and phenolic compounds. The enrichment of phenolic compounds, dietary fibres and/or probiotics tend to be simultaneous in plant-based products. The process of the ingredients and the formulation of products must be tailored to design the desired structure and to improve the reconstitution property.

Exploring the mechanism of Jingshen Xiaoke decoction in treating T2DM mice based on network pharmacology and molecular docking

BACKGROUND

Jingshen Xiaoke decoction (JS) was prepared by studying the classic prescriptions of famous scholars in the past dynasties to prevent and treat diabetes. The related mechanism of JS against hyperlipidemia has yet to be revealed.

OBJECTIVE

To investigate the mechanism of action of JS in treating diabetes mellitus by using bioinformatics methods.

METHODS

A database was used to search the active ingredients and targets of the JS and targets for type 2 diabetes mellitus (T2DM). The protein interaction between the intersection targets, and the constructed the PPI network diagram was analyzed using the STRING database. Furthermore, the gene annotation tool DAVID was used to enrich the intersecting targets for the Gene ontology (GO) function and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway. Finally, Maestro software was used for molecular docking to verify the binding ability of the active ingredients to the core target genes.

RESULTS

A total of 45 active ingredients in JS were screened out corresponding to 239 effective targets, of which 64 targets were potential targets for treating T2DM. The analysis of PPI network diagram analysis revealed that the ingredients' active components are quercetin, β-sitosterol, stigmasterol, luteolin, and 7-Methoxy-2-methyl isoflavone. GO functional enrichment analysis indicated 186 biological processes (BP), 23 molecular functions (MF) and 13 cellular components (CC). KEGG pathway enrichment analysis revealed the enrichment of 59 signal pathways. The molecular docking results demonstrated that the active ingredients and core targets had a good docking affinity with a binding activity less than -7 kcal/mol. Finally, the western blotting illustrated that JS could up-regulate the liver PI3K/AKT-signaling pathway.

CONCLUSION

JS can regulate glucolipid metabolism, reduce the inflammatory response, improve insulin resistance and modulate the immune response through PI3K/AKT signaling pathway treating of T2DM and its complications effects.

Organic food consumption and the incidence of type 2 diabetes mellitus in the Danish Diet, Cancer and Health cohort

AIM

To investigate the association between organic food consumption and the incidence of type 2 diabetes mellitus.

METHODS

Among 41,286 cohort participants, aged 50-65 years, organic food consumption of vegetables, fruits, dairy products, eggs, meat, and cereal products, was summarized into an organic food score evaluated as never, low, medium and high consumption and as continuous intake. During follow-up, 4,843 cases were identified in the National Diabetes Register. Organic food consumption was associated to the disease incidence in Cox regression models.

RESULTS

Organic food consumption was linearly associated with a lower incidence of type 2 diabetes mellitus (Women, HR: 0.94, 95% CI: 0.89-1.00, Men, HR: 0.95, 95% CI: 0.90-1.00). Organic food consumption frequency, compared to never consumption, showed HRs below 1.00 for both women (medium intake HR: 0.96, 95% CI: 0.84-1.10, high intake HR: 0.88, 95% CI: 0.74-1.05) and men (low intake, HR: 0.95, 95% CI: 0.85-1.05, medium intake, HR: 0.92, 95% CI: 0.83-1.03, high intake, HR: 0.89, 95% CI: 0.75-1.05) but were not statistically significant. Similar patterns were observed with consumption of the specific organic food groups for women, but not for men.

CONCLUSIONS

Organic food consumption was associated with a suggested lower incidence of type 2 diabetes mellitus.

Exploration of natural flavones' bioactivity and bioavailability in chronic inflammation induced-type-2 diabetes mellitus

Diabetes, being the most widespread illness, poses a serious threat to global public health. It seems that inflammation plays a critical role in the pathophysiology of diabetes. This review aims to demonstrate a probable link between type 2 diabetes mellitus (T2DM) and chronic inflammation during its development. Additionally, the current review examined the bioactivity of natural flavones and the possible molecular mechanisms by which they influence diabetes and inflammation. While natural flavones possess remarkable anti-diabetic and anti-inflammatory bioactivities, their therapeutic use is limited by the low oral bioavailability. Several factors contribute to the low bioavailability, including poor water solubility, food interaction, and unsatisfied metabolic behaviors, while the diseases (diabetes, inflammation, etc.) causing even less bioavailability. Throughout the years, different strategies have been developed to boost flavones' bioavailability, including structural alteration, biological transformation, and innovative drug delivery system design. This review addresses current advancements in improving the bioavailability of flavonoids in general, and flavones in particular. Clinical trials were also analyzed to provide insight into the potential application of flavonoids in diabetes and inflammatory therapies.

Dietary flavonoids prevent diabetes through epigenetic regulation: advance and challenge

The pathophysiology of diabetes has been studied extensively in various countries, but effective prevention and treatment methods are still insufficient. In recent years, epigenetics has received increasing attention from researchers in exploring the etiology and treatment of diabetes. DNA methylation, histone modifications, and non-coding RNAs play critical roles in the occurrence, maintenance, and progression of diabetes and its complications. Therefore, preventing or reversing the epigenetic alterations that occur during the development of diabetes may reduce the individual and societal burden of the disease. Dietary flavonoids serve as natural epigenetic modulators for the discovery of biomarkers for diabetes prevention and the development of alternative therapies. However, there is limited knowledge about the potential beneficial effects of flavonoids on the epigenetics of diabetes. In this review, the multidimensional epigenetic effects of different flavonoid subtypes in diabetes were summarized. Furthermore, it was discussed that parental flavonoid diets might reduce diabetes incidence in offspring, which represent a promising opportunity to prevent diabetes in the future. Future work will depend on exploring anti-diabetic effects of different flavonoids with different epigenetic regulation mechanisms and clinical trials.Highlights• "Epigenetic therapy" could reduce the burden of diabetic patients• "Epigenetic diet" ameliorates diabetes• Targeting epigenetic regulations by dietary flavonoids in the diabetes prevention• Dietary flavonoids prevent diabetes via transgenerational epigenetic inheritance.

Association of Dietary Flavonoid Intake with Serum Cotinine Levels in the General Adult Population

Cotinine, the primary metabolite of nicotine, can be utilized as a marker for active smoking and as an indicator of exposure to secondhand smoke. However, the direct relationship between dietary flavonoid intake and serum cotinine levels remains a subject of ongoing investigation. In this study, we utilized data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010 and 2017-2018 to assess the association between dietary flavonoid intake and serum cotinine levels in adults through multiple linear regression analysis. A weighted quantile sum (WQS) regression model was used to assess the association of the mixture of six dietary flavonoids with serum cotinine levels in adults, which could represent the overall effect of the mixture of six dietary flavonoids. We also conducted stratified analyses by smoke status to explore multiple linear regression associations between different flavonoid intake and serum cotinine levels. A total of 14,962 adults were included in the study. Compared to the group with the lowest dietary flavonoid intake, total flavonoid intake in the second (β = -0.29 [-0.44, -0.14]), third (β = -0.41 [-0.58, -0.24]), and highest groups (β = -0.32 [-0.49, -0.16]) was inversely related to the levels of serum cotinine after adjusting the full model. An RCS model showed that when the total dietary flavonoid intake was less than 99.61 mg/day, there was a negative linear association between dietary flavonoid intake and the serum cotinine. The WQS regression model also showed that the intake of a mixture of six dietary flavonoids was significantly negatively correlated with serum cotinine levels (β = -0.54 [-0.61, -0.46], p <0.01), with anthocyanins having the greatest effect (weights = 32.30%). Our findings imply a significant correlation between dietary flavonoid intake and serum cotinine levels among adults. The consumption of a combination of six dietary flavonoids was consistently linked to lower serum cotinine levels, with anthocyanins displaying the most pronounced impact.

Kaempferol regulates the thermogenic function of adipocytes in high-fat-diet-induced obesity via the CDK6/RUNX1/UCP1 signaling pathway

Activation of adipose tissue thermogenesis is a promising strategy in the treatment of obesity and obesity-related metabolic disorders. Kaempferol (KPF) is a predominant dietary flavonoid with multiple pharmacological properties, such as anti-inflammatory and antioxidant activities. In this study, we sought to characterize the role of KPF in adipocyte thermogenesis. We demonstrated that KPF-treated mice were protected from diet-induced obesity, glucose tolerance, and insulin resistance, accompanied by markedly increased energy expenditure, ex vivo oxygen consumption of white fat, and increased expression of proteins related to adaptive thermogenesis. KPF-promoted beige cell formation is a cell-autonomous effect, since the overexpression of cyclin-dependent kinase 6 (CDK6) in preadipocytes partially reversed browning phenotypes observed in KPF-treated cells. Overall, these data implicate that KPF is involved in promoting beige cell formation by suppressing CDK6 protein expression. This study provides evidence that KPF is a promising natural product for obesity treatment by boosting energy expenditure.

The associations between dietary flavonoid intake and the prevalence of diabetes mellitus: Data from the National Health and Nutrition Examination Survey 2007-2010 and 2017-2018

Background

Diabetes mellitus (DM) is a prominent health concern worldwide, leading to the high incidence of disability and mortality and bringing in heavy healthcare and social burden. Plant-based diets are reported associated with a reduction of DM risk. Plant-based diets are rich in flavonoids, which possess properties such as scavenging free radicals and exerting both anti-inflammatory and antioxidant effects.

Purpose

However, whether dietary flavonoids are associated with the prevalence of DM remains controversial. The potential reasons for contradictory epidemiological outcomes on the association between dietary flavonoids and DM prevalence have not been determined.

Methods

To address these limitations, we employed data from 22,481 participants in the National Health and Nutrition Examination Survey to explore the association between the intake of flavonoids and DM prevalence by weighted Logistic regression and weighted restricted cubic splines.

Results

We found that the prevalence of DM was inversely associated with the intake of total flavonoids in the second quartile [Odds Ratio (OR) 0.78 95% confidence interval (CI) (0.63, 0.97), p = 0.028], in the third quartile [0.76 (0.60, 0.97), p = 0.031], and in the fourth quartile [0.80 (0.65, 0.97), p = 0.027]. However, the p for trend was not significant [0.94 (0.88, 1.01), p = 0.096]. Moreover, the association between DM prevalence and the intake of total flavonoids was significantly influenced by race (p for interaction = 0.006). In Mexican Americans, there was a significant positive association between DM prevalence and total flavonoid intake within the third quartile [1.04 (1.02, 1.07), p = 0.003]. Total flavan-3-ol and subtotal catechin intake exhibited a non-linear U-shaped association with DM prevalence (p for non-linearity < 0.0001 and p for non-linearity < 0.0001, respectively). Compared to the first quartile of corresponding intakes, consumption within the third quartile of subtotal catechins [0.70 (0.55, 0.89), p = 0.005] and total flavan-3-ols [0.65 (0.50, 0.84), p = 0.002] was associated with a lower prevalence of DM.

Conclusion

Taken together, our study may provide preliminary research evidence for personalized improvement of dietary habits to reduce the prevalence of diabetes.

Are (poly)phenols contained in 100% fruit juices mediating their effects on cardiometabolic risk factors? A meta-regression analysis

Background

The consumption of 100% fruit juices has not been associated with substantial detrimental outcomes in population studies and may even contribute to improving the cardiometabolic profile if included in a healthy balanced diet. The main contributors to such potential beneficial effects include vitamins, minerals, and likely the (poly)phenol content. This study aimed to investigate whether the (poly)phenols contained in 100% fruit juices may mediate their effects on cardiometabolic risk factors based on published randomized controlled trials (RCT).

Methods

A systematic search in PubMed/MEDLINE and Embase, updated till the end of October 2022, was carried out to identify RCT providing quantitative data on (poly)phenol content in 100% fruit juices and used as an intervention to improve cardiometabolic parameters such as blood lipids, glucose, and blood pressure. Meta-regression analysis was performed to calculate the effect of the intervention [expressed as standardized mean difference and 95% confidence intervals (CI)] using the (poly)phenol content as moderator.

Results

A total of 39 articles on RCT investigating the effects of 100% fruit juices on cardiometabolic risk factors reporting data on total (poly)phenol and anthocyanin content were included in the analysis. Total (poly)phenol content was substantially unrelated to any outcome investigated. In contrast, each 100 mg per day increase in anthocyanins was related to 1.53 mg/dL decrease in total cholesterol (95% CI, -2.83, -0.22, p = 0.022) and 1.94 mg/dL decrease in LDL cholesterol (95% CI, -3.46, -0.42, p = 0.012). No other potential mediating effects of anthocyanins on blood triglycerides, glucose, systolic and diastolic pressure were found, while a lowering effect on HDL cholesterol after excluding one outlier study was observed.

Discussion

In conclusion, the present study showed that anthocyanins may mediate the potential beneficial effects of some 100% fruit juices on some blood lipids. Increasing the content of anthocyanins through specific fruit varieties or plant breeding could enhance the health benefits of 100% fruit juices.

Nanoformulations for the Delivery of Dietary Anthocyanins for the Prevention and Treatment of Diabetes Mellitus and Its Complications

Diabetes mellitus (DM) is a metabolic disease characterized by abnormal blood glucose levels-hyperglycemia, caused by a lack of insulin secretion, impaired insulin action, or a combination of both. The incidence of DM is increasing, resulting in billions of dollars in annual healthcare costs worldwide. Current therapeutics aim to control hyperglycemia and reduce blood glucose levels to normal. However, most modern drugs have numerous side effects, some of which cause severe kidney and liver problems. On the other hand, natural compounds rich in anthocyanidins (cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin) have also been used for the prevention and treatment of DM. However, lack of standardization, poor stability, unpleasant taste, and decreased absorption leading to low bioavailability have hindered the application of anthocyanins as therapeutics. Therefore, nanotechnology has been used for more successful delivery of these bioactive compounds. This review summarizes the potential of anthocyanins for the prevention and treatment of DM and its complications, as well as the strategies and advances in the delivery of anthocyanins using nanoformulations.

Polyphenols as novel interventions for depression: exploring the efficacy, mechanisms of action, and implications for future research

Numerous animal and human studies have assessed the relationship between polyphenols and outcomes related to depression. However, no comprehensive synthesis of the main findings has been conducted. The aim of this manuscript was to systematically review the available evidence from animal and human studies on the association and the effects of dietary polyphenols on depression and provide recommendations for future research. We based our review on 163 preclinical animal, 16 observational and 44 intervention articles assessing the relationship between polyphenols and outcomes related to depression. Most animal studies demonstrated that exposure to polyphenols alleviated behaviours reported to be associated with depression. However, human studies are less clear, with some studies reporting and inverse relationship between the intake of some polyphenols, and polyphenol rich foods and depression risk and symptoms, while others reporting no association or effect. Hence, while there has been extensive research conducted in animals and there is some supporting evidence in humans, further human studies are required, particularly in younger and clinical populations.

Targeting Wnt/β-Catenin Pathway by Flavonoids: Implication for Cancer Therapeutics

The Wnt pathway has been recognized for its crucial role in human development and homeostasis, but its dysregulation has also been linked to several disorders, including cancer. Wnt signaling is crucial for the development and metastasis of several kinds of cancer. Moreover, members of the Wnt pathway have been proven to be effective biomarkers and promising cancer therapeutic targets. Abnormal stimulation of the Wnt signaling pathway has been linked to the initiation and advancement of cancer in both clinical research and in vitro investigations. A reduction in cancer incidence rate and an improvement in survival may result from targeting the Wnt/β-catenin pathway. As a result, blocking this pathway has been the focus of cancer research, and several candidates that can be targeted are currently being developed. Flavonoids derived from plants exhibit growth inhibitory, apoptotic, anti-angiogenic, and anti-migratory effects against various malignancies. Moreover, flavonoids influence different signaling pathways, including Wnt, to exert their anticancer effects. In this review, we comprehensively evaluate the influence of flavonoids on cancer development and metastasis by focusing on the Wnt/β-catenin signaling pathway, and we provide evidence of their impact on a number of molecular targets. Overall, this review will enhance our understanding of these natural products as Wnt pathway modulators.

Polyphenol-Rich Beverages and Mental Health Outcomes

Emerging evidence suggests that diets rich in plant-based foods and beverages may exert plausible effects on human health tackling the risk of chronic diseases. Although the data are promising for numerous outcomes, including cardiovascular diseases, the data on mental health are limited. The aim of this study was to investigate the association between individual polyphenol-rich beverages intake and mental health outcomes, such as perceived stress, depressive symptoms, and sleep quality, among adult individuals living in the Mediterranean area. The demographic and dietary characteristics of a sample of 1572 adults living in southern Italy were analysed. Multivariate logistic regression analyses, controlling for confounding factors, were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of the association between individual polyphenol-rich and alcoholic beverages containing polyphenols and mental health outcomes. The multivariate model adjusted for background covariates and the Mediterranean diet showed that individuals with a moderate intake (up to 1 cup/glass per day) of coffee and tea were less likely to have high perceived stress (OR = 0.61, 95% CI: 0.45-0.84) and depressive symptoms (OR = 0.56, 95% CI: 0.39-0.80), respectively. Furthermore, regular coffee and moderate/regular red wine drinkers were less likely to have depressive symptoms (OR = 0.72, 95% CI: 0.54-0.95 and OR = 0.74, 95% CI: 0.54-0.99, respectively). No significant associations were retrieved for the intake of polyphenol-rich and alcoholic beverages and sleep quality. In conclusion, the results of the present study suggest that polyphenol-rich beverages may be associated with mental health, in terms of depressive symptoms and perceived stress. Nonetheless, further research exploring how the polyphenol-rich beverages impact brain health and what the optimal patterns of consumption are for different populations are warranted.

Targeting epigenetics in diabetic cardiomyopathy: Therapeutic potential of flavonoids

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

The protective effects of flavonoids and carotenoids against diabetic complications-A review of in vivo evidence

Diabetes mellitus is a chronic metabolic disorder caused either by inadequate insulin secretion, impaired insulin function, or both. Uncontrolled diabetes is characterized by hyperglycemia which over time leads to fatal damage to both macro-and microvascular systems, causing complications such as cardiovascular diseases, retinopathy and nephropathy. Diabetes management is conventionally delivered through modifications of diet and lifestyle and pharmacological treatment, using antidiabetic drugs, and ultimately insulin injections. However, the side effects and financial cost of medications often reduce patient compliance to treatment, negatively affecting their health outcomes. Natural phytochemicals from edible plants such as fruits and vegetables (F&V) and medicinal herbs have drawn a growing interest as potential therapeutic agents for treating diabetes and preventing the onset and progression of diabetic complications. Flavonoids, the most abundant polyphenols in the human diet, have shown antidiabetic effects in numerous in vitro and preclinical studies. The underlying mechanisms have been linked to their antioxidant, anti-inflammatory and immunomodulatory activities. Carotenoids, another major group of dietary phytochemicals, have also shown antidiabetic potential in recent in vitro and in vivo experimental models, possibly through a mechanism of action similar to that of flavonoids. However, scientific evidence on the efficacy of these phytochemicals in treating diabetes or preventing the onset and progression of its complications in clinical settings is scarce, which delays the translation of animal study evidence to human applications and also limits the knowledge on their modes of actions in diabetes management. This review is aimed to highlight the potential roles of flavonoids and carotenoids in preventing or ameliorating diabetes-related complications based on in vivo study evidence, i.e., an array of preclinical animal studies and human intervention trials. The current general consensus of the underlying mechanisms of action exerted by both groups of phytochemicals is that their anti-inflammatory action is key. However, other potential mechanisms of action are considered. In total, 50 in vivo studies were selected for a review after a comprehensive database search via PubMed and ScienceDirect from January 2002 to August 2022. The key words used for analysis are type-2 diabetes (T2DM), diabetic complications, flavonoids, carotenoids, antioxidant, anti-inflammatory, mechanisms of prevention and amelioration, animal studies and human interventions.

Association between flavonoid and subclasses intake and metabolic associated fatty liver disease in U.S. adults: Results from National Health and Nutrition Examination Survey 2017-2018

BACKGROUND

Metabolic associated fatty liver disease (MAFLD) formerly known as non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Flavonoid is considered a promising candidate for metabolic disease prevention although few studies have explored the relationship between flavonoid intake and MAFLD.

PURPOSE

To assess the relationship between flavonoid intake and MAFLD prevalence in the U.S. adult population.

MATERIALS AND METHODS

The data of this cross-sectional study was obtained from National Health and Nutrition Examination Survey (NHANES) and Food and Nutrient Database for Dietary Studies (FNDDS) 2017-2018. Flavonoid and subclasses intake was assessed by two 24h recalls. MAFLD was diagnosed according to the consensus definitions. Multivariate logistic regression model was performed to examine the association between flavonoid intake and MAFLD with adjustments for confounders.

RESULTS

A total of 4,431 participants were included in this cross-sectional analysis. MAFLD had a weighted prevalence of 41.93% and was not associated with total flavonoid intake. A higher anthocyanin and isoflavone intake, on the other hand, was associated with a lower prevalence of MAFLD. The protective effect of higher anthocyanin intake was significant among male, Non-Hispanic White, and Non-Hispanic Asia participants. Higher isoflavone intake was associated with a lower risk of MAFLD in participants of younger (age < 50), Non-Hispanic Black, Non-Hispanic Asia, and higher HEI-2015 scores compared with the lowest quartile of isoflavone intake. Stratified analysis showed that compared with the lowest quartile of anthocyanin intake, the effect of anthocyanin intake on MAFLD varied by racial groups (P _interaction = 0.02). A positive correlation existed between HDL and anthocyanidin intake (P = 0.03), whereas a negative correlation existed between FPG and isoflavone intake (P = 0.02).

CONCLUSION

MAFLD was adversely linked with flavonoid subclasses, anthocyanin and isoflavone. This modifiable lifestyle provides a potential opportunity to prevent MAFLD. These findings promote future research into the links and mechanisms between anthocyanin and isoflavone intake and MAFLD.

Total dietary flavonoid intake and risk of cardiometabolic diseases: A dose-response meta-analysis of prospective cohort studies

Several epidemiological studies have suggested that flavonoid intake is associated with a decreased risk of cardiometabolic disease. However, the results remained inconsistent and there is no dose-response meta-analysis for specific outcomes. We conducted a meta-analysis to synthesize the knowledge about their associations and to explore their dose-response relationships. We comprehensively searched the PubMed, Embase, and Web of Science databases for prospective cohort studies published up to December 1, 2021. Summary relative risks (RR) and 95% confidence intervals (CI) were pooled for the association between flavonoid intake and cardiometabolic disease. Evaluations of linear or nonlinear dose-response were presented by restricted cubic splines. We identified 47 articles, including 1,346 676 participants and 127,507 cases in this meta-analysis. The summary of RR per 500 mg/d increase in flavonoid intake was 0.93 (95% CI 0.88-0.98) for cardiovascular disease, 0.89 (95% CI 0.84-0.94) for diabetes, and 0.97 (95% CI 0.94-0.99) for hypertension, respectively. We also found a linearity dose-response association between total flavonoid intake and cardiovascular disease (p nonlinearity = 0.541), and diabetes (p nonlinearity = 0.077). Our finding based on quantitative data suggested that a higher level of flavonoid intake is beneficial for the prevention of cardiometabolic diseases.

Flavonoid subclasses and CHD risk: a meta-analysis of prospective cohort studies

Epidemiological studies have shown that higher intake of flavonoid is inversely associated with CHD risk. However, which flavonoid subclass could reduce CHD risk has remained controversial. The present meta-analysis of prospective cohort studies aimed to quantitatively assess the associations between flavonoid subclasses and CHD risk. A systematic literature search was implemented from PubMed and Web of Science databases up to March 2021, and eligible studies were identified. Multivariate-adjust relative risks (RR) with corresponding 95 % CI were pooled by using a random-effects model. A restricted cubic spline regression model was performed for non-linear dose-response analysis. A total of 19 independent prospective cohort studies with 894 471 participants and 34 707 events were included. The results showed that dietary intakes of anthocyanins (RR = 0·90; 95 % CI: 0·83, 0·98), proanthocyanidins (RR = 0·78; 95 % CI: 0·65, 0·94), flavonols (RR = 0·88; 95 % CI: 0·79, 0·98), flavones (RR = 0·94; 95 % CI: 0·89, 0·99) and isoflavones (RR = 0·90; 95 % CI: 0·83, 0·98) were negatively associated with CHD risk. Dose-response analysis showed that increment of 50 mg/d anthocyanins, 100 mg/d proanthocyanidins, 25 mg/d flavonols, 5 mg/d flavones and 0·5 mg/d isoflavones were associated with 5 % reduction in CHD risk, respectively. Sensitivity and subgroup analyses were used to further support these associations. The present results indicate that dietary intakes of fruits and vegetables abundant five flavonoid subclasses, namely anthocyanins, proanthocyanidins, flavonols, flavones and isoflavones, are associated with a lower risk of CHD.

Isoflavone Protects the Renal Tissue of Diabetic Ovariectomized Rats via PPARγ

Diabetes associated with post-menopause is related to a worse condition of kidney disease. Taking into consideration that this disorder may be regulated by estrogenic mediators, we evaluated the renal protective effect of isoflavone. We investigated the role of the PPARγ in the pathogenesis of the disease. For this study, we used diabetic female rats in a postmenopausal model through ovariectomy. The animals were treated with isoflavone or 17β-estradiol. A dosage was administered to bring on blood glycemia, and through immunohistochemistry, we evaluated the immunoreactivity of PPARγ in the endometrium and renal tissue. We analyzed the immunoreactivity of renal injury molecule KIM-1 and the collagen and glycogen densities in the kidney. Through bioinformatics analysis, we observed PPARγ and COL1A1 gene expression under the influence of different glucose doses. In particular, we observed that isoflavone and 17β-estradiol regulate blood glycemia. Renal injury was inhibited by isoflavone, observed by a reduction in KIM-1, along with glycogen accumulation. These benefits of isoflavone may be associated with PPARγ overexpression in the kidneys and endometrium of diabetic ovariectomized rats.

Mutations that alter Arabidopsis flavonoid metabolism affect the circadian clock

Flavonoids are a well-known class of specialized metabolites that play key roles in plant development, reproduction, and survival. Flavonoids are also of considerable interest from the perspective of human health, as both phytonutrients and pharmaceuticals. RNA sequencing analysis of an Arabidopsis null allele for chalcone synthase (CHS), which catalyzes the first step in flavonoid metabolism, has uncovered evidence that these compounds influence the expression of genes associated with the plant circadian clock. Analysis of promoter-luciferase constructs further showed that the transcriptional activity of CCA1 and TOC1, two key clock genes, is altered in CHS-deficient seedlings across the day/night cycle. Similar findings for a mutant line lacking flavonoid 3'-hydroxylase (F3'H) activity, and thus able to synthesize mono- but not dihydroxylated B-ring flavonoids, suggests that the latter are at least partially responsible; this was further supported by the ability of quercetin to enhance CCA1 promoter activity in wild-type and CHS-deficient seedlings. The effects of flavonoids on circadian function were also reflected in photosynthetic activity, with chlorophyll cycling abolished in CHS- and F3'H-deficient plants. Remarkably, the same phenotype was exhibited by plants with artificially high flavonoid levels, indicating that neither the antioxidant potential nor the light-screening properties of flavonoids contribute to optimal clock function, as has recently also been demonstrated in animal systems. Collectively, the current experiments point to a previously unknown connection between flavonoids and circadian cycling in plants and open the way to better understanding of the molecular basis of flavonoid action.

Flavonoids for depression and anxiety: a systematic review and meta-analysis

Natural flavonoids are the most plentiful form of polyphenols. Given the anti-inflammatory and antioxidant properties of flavonoids, researchers discovered that it might be effective in treating depression and anxiety. The effect of flavonoids on depression and anxiety was investigated by a meta-analysis and systematic review. We searched PubMed, Embase, and Medline databases up to October 15, 2021. We selected 11 studies, among them, 10 studies were chosen to evaluate the depression effects of flavonoids and 7 studies were used to assess anxiety disorder. The meta-analysis showed that flavonoids have an overall significant effect on depression (p = 0.004, Hedge's g = -0.487, 95% CI -0.814 to -0.160) and anxiety (p = 0.006, Hedge's g = -0.741, 95% CI -1.266 to -0.217). Subgroup analysis indicated that the symptoms of depression were significantly improved in the studies when the dose of flavonoids was 50-100mg/day or the treatment duration was ≥8weeks. Anxiety symptoms were improved in the studies with the dose of flavonoids was ≥50mg/day. There was no evidence of publication bias. Our findings suggest that flavonoids might improve symptoms of depression and anxiety. However, a small number of participants and studies were included in this meta-analysis. Therefore, the results should be interpreted with caution.

Transcriptomic and Non-Targeted Metabolomic Analyses Reveal the Flavonoid Biosynthesis Pathway in Auricularia cornea

Flavonoids, which are abundant in plants, are recognized for their antioxidant and anticancer roles in clinical applications. However, little is known about the molecular basis of flavonoid biosynthesis in fungi. In this study, we found that inclusion of leachate of Korshinsk peashrub (Caragana korshinskii) in the fermentation medium increased the total flavonoid content of the edible fungus Auricularia cornea by 23.6% relative to that grown in a control medium. Combined transcriptomic and non-targeted metabolomic analysis of the flavonoid biosynthesis pathway in A. cornea illustrated that there are important metabolites in the phenylpropanoid, coumarin and isoflavonoid biosynthesis pathways. In addition, we found that certain homologous genes encode phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO) and chalcone isomerase (CHI) in these biosynthesis pathways. These results, in this study, provide a new line for studying the regulation of flavonoid production in edible fungi.

Comparison of Flavonoid Intake Assessment Methods Using USDA and Phenol Explorer Databases: Subcohort Diet, Cancer and Health-Next Generations-MAX Study

Flavonoids are bioactive plant compounds that are widely present in the human diet. Estimating flavonoid intake with a high degree of certainty is challenging due to the inherent limitations of dietary questionnaires and food composition databases. This study aimed to evaluate the degree of reliability among flavonoid intakes estimated using four different approaches based on the two most comprehensive flavonoid databases, namely, United States Department of Agriculture (USDA) and Phenol Explorer (PE). In 678 individuals from the MAX study, a subcohort of the Diet, Cancer and Health-Next Generations cohort, dietary data were collected using three 24-h diet recalls over 1 year. Estimates of flavonoid intake were compared using flavonoid food content from PE as (1) aglycones (chromatography with hydrolysis), (2) aglycones transformed (converted from glycosides by chromatography without hydrolysis), (3) as they are in nature (glycosides, aglycones, and esters), and 4) using flavonoid content from USDA as aglycones (converted). Spearman's intra-class correlation (ICC) coefficient and weighted kappa (K) coefficient were calculated for the reliability analysis. When comparing PE total aglycones to USDA total aglycones, there was a moderate reliability when a continuous variable was used [ICC: 0.73, 95% confidence interval (CI): 0.70-0.76] and an excellent reliability when flavonoid intake was modeled as a categorical variable (K: 0.89, 95% CI: 0.88-0.90). The degree of reliability among all methods of estimated flavonoid intakes was very similar, especially between database pairs, for the flavanol subclass, while larger differences were observed for flavone, flavonol, and isoflavone subclasses. Our findings indicate that caution should be taken when comparing the results of the associations between flavonoid intakes and health outcomes from studies, when flavonoid intakes were estimated using different methods, particularly for some subclasses.

The protective effects of dietary intake of flavonoids and its subclasses on metabolic syndrome incidence

This study aimed to evaluate the association between the intake of total flavonoids and flavonoid subclasses and metabolic syndrome (MetS) risk and to assess the modulating effects of lifestyle factors on these associations. A total of 1915 participants from the Tehran Lipid and Glucose Study were followed-up during 2006-2008 and 2016-2018. Their dietary intake was assessed by a food frequency questionnaire at baseline and within three-year intervals afterward. Moreover, the modifying effect of weight gain on the association between total flavonoids and MetS was assessed by Cox regression analysis. Participants in the highest tertile of flavonoid, flavonol, and flavone had a significantly lower MetS risk as compared to those in the lowest tertile. Also, in participants with weight gain <7%, all flavonoid subclasses had a more pronounced risk-reducing effect. Overall, the total flavonoid, flavonol, and flavone reduced the risk of MetS; this association could be modified by weight gain.

A meta-analysis of prospective cohort studies of flavonoid subclasses and stroke risk

Epidemiological studies indicate that higher intakes of flavonoids are associated with reduced stroke risk, however, which subtypes play significant roles to protect against stroke remain unclear. A systematic literature search in PubMed and Web of Science databases was performed up to Oct. 2021. Flavonoids or their subtypes (flavanol, flavanone, flavone, flavan-3-ol, isoflavone, or anthocyanin) were paired with stoke as the search term. Multivariate-adjusted relative risks (RRs) with 95% confidence intervals (CIs) for the highest versus the lowest category were pooled by using a random-effects model. Dose-response analysis was implemented by using a restricted cubic spline regression model. Ten independent prospective cohort studies with 387,076 participants and 9,564 events were included. Higher intakes of flavanones were inversely associated with stroke risk (RR = 0.85; 95%CI: 0.78, 0.93). Dose-response analysis showed that 50 mg/day increment of flavanones was associated with 11% reduction in stroke risk (RR = 0.89; 95%CI: 0.84, 0.94). Flavan-3-ols was marginally inversely associated with stroke risk (RR = 0.92; 95%CI: 0.82, 1.02). Dose-response analysis showed that 200 mg/day increment of flavan-3-ols was associated with 14% reduction in stroke risk (RR = 0.86; 95%CI: 0.75, 0.98). The non-significant association was observed with respect to other flavonoid subclasses. This study demonstrated higher intakes of flavanones and flavan-3-ols were associated with a lower risk of stroke. Dietary intakes of lemon and citrus rich in flavanones and flavan-3-ols might have beneficial functions for the protection against stroke. The findings of these associations of the present study need to be confirmed in other regions and ethnic origins.

Flavonoid constituents of Amomum tsao-ko Crevost et Lemarie and their antioxidant and antidiabetic effects in diabetic rats - in vitro and in vivo studies

Amomum tsao-ko Crevost et Lemarie (A. tsao-ko) is a well-known dietary spice and traditional Chinese medicine. This study aimed to identify the flavonoids in A. tsao-ko and evaluate their antioxidant and antidiabetic activities in in vitro and in vivo studies. A. tsao-ko methanol extracts possessed a high flavonoid content (1.21 mg QE per g DW) and a total of 29 flavonoids were identified by employing UPLC-MS/MS. In vitro, A. tsao-ko demonstrated antioxidant activity (ORAC value of 34276.57 μM TE/100 g DW, IC₅₀ of ABTS of 3.49 mg mL^-1 and FRAP value of 207.42 μM Fe²⁺ per g DW) and α-amylase and α-glucosidase inhibitory ability with IC₅₀ values of 14.23 and 1.76 mg mL^-1, respectively. In vivo, type 2 diabetes mellitus (T2DM) models were induced by a combined high-fat diet (HFD) and streptozotocin (STZ) injection in rats. Treatment with the A. tsao-ko extract (100 mg freeze-dried powder per kg bw) for 6 weeks could significantly improve impaired glucose tolerance, decrease the levels of fasting blood glucose (FBG), insulin, and malondialdehyde (MDA), and increase the superoxide dismutase (SOD) level. Histopathology revealed that the A. tsao-ko extract preserved the architecture and function of the pancreas. In conclusion, the flavonoid composition of A. tsao-ko exhibits excellent antioxidant and antidiabetic activity in vitro and in vivo. A. tsao-ko could be a novel natural material and developed as a related functional food and medicine in T2DM management.

Efficacy of flavonoids on biomarkers of type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials

A systematic review and meta-analysis of 28 randomized controlled trials (RCTs) to assess the efficacy of flavonoids intake on key biomarkers related to Type 2 diabetes mellitus was conducted. The mean difference (MD) with 95% confidence intervals (95% CI) was pooled using a random-effects model. Significant reduction in fasting glucose (MD: -0.22, 95% CI: -0.34 to -0.09, p = 0.0013), hemoglobin A1c (HbA1c) (MD: -0.26, 95% CI: -0.46 to -0.05, p = 0.021), homeostasis model assessment of insulin resistance (HOMA-IR) (MD: -0.40, 95% CI: -0.66 to -0.15, p = 0.0039), triglyceride (TG) (MD: -0.13, 95% CI: -0.21 to -0.05, p = 0.002), total cholesterol (TC) (MD: -0.14, 95% CI: -0.21 to -0.08, p = 0.0002), and low density lipoprotein-C (LDL-C) (MD: -0.15; 95% CI: -0.24 to -0.07, p = 0.0009) were observed in intervention group compare to placebo at the end of trial. Moreover, flavonoid intake had negative but non-significant effect on insulin (MD: -0.46), 2 h-postprandial glucose (2 h-PPG) (MD: -0.22), homeostasis model assessment of β-cell function (HOMA-β) (MD: -2.81), and insignificantly increased high-density lipoprotein-C (HDL-C) (MD: 0.03). In conclusion, flavonoid intake has modest but statistically significant benefits in glucose metabolism, insulin sensitivity, and lipid metabolism, especially for significantly lowing fasting blood glucose, HOMA-IR, HbA1c, TG, TC, and LDL-C.

Kaempferol, Myricetin and Fisetin in Prostate and Bladder Cancer: A Systematic Review of the Literature

Prostate and bladder cancer represent the two most frequently diagnosed genito-urinary malignancies. Diet has been implicated in both prostate and bladder cancer. Given their prolonged latency and high prevalence rates, both prostate and bladder cancer represent attractive candidates for dietary preventive measures, including the use of nutritional supplements. Flavonols, a class of flavonoids, are commonly found in fruit and vegetables and are known for their protective effect against diabetes and cardiovascular diseases. Furthermore, a higher dietary intake of flavonols was associated with a lower risk of both bladder and prostate cancer in epidemiological studies. In this systematic review, we gathered all available evidence supporting the anti-cancer potential of selected flavonols (kaempferol, fisetin and myricetin) against bladder and prostate cancer. A total of 21, 15 and 7 pre-clinical articles on bladder or prostate cancer reporting on kaempferol, fisetin and myricetin, respectively, were found, while more limited evidence was available from animal models and epidemiological studies or clinical trials. In conclusion, the available evidence supports the potential use of these flavonols in prostate and bladder cancer, with a low expected toxicity, thus providing the rationale for clinical trials that explore dosing, settings for clinical use as well as their use in combination with other pharmacological and non-pharmacological interventions.

Dietary Antioxidants and Brain Health: Focus on Cognitive and Affective Disorders

Today's society faces major global challenges, including the continuously increasing prevalence of mental disorders and neurodegenerative diseases, with different risk factors contributing to the trend [...].

Prevention and management of type II diabetes chronic complications: the role of polyphenols (Mini-Review)

The numerous complications of diabetes may be at least in part generated by the oxidative stress associated with the constant state of hyperglycemia. Polyphenols are plant based secondary metabolites that have high potentials in the prevention and treatment of some diseases, in particular those that involve oxidative stress, such as complications of diabetes. The purpose of this narrative review is to show the main evidence regarding the role of polyphenols in treating and preventing these complications. For the bibliographic research, the papers published up to March 15, 2021 were considered and the search terms included words relating to polyphenols, their classes and some more known compounds, in association with the complications of diabetes. There are numerous studies showing how polyphenols are active against endothelial damage induced by diabetes, oxidative stress and hyperinflammatory states that are at the origin of the complications of diabetes. Compounds such as flavonoids, but also anthocyanins, stilbenes or lignans slow the progression of kidney damage, prevent ischemic events and diabetic nephropathy. Many of these studies are preclinical, in cellular or animal models. The role of polyphenols in the prevention and treatment of diabetes complications is undoubtedly promising. However, more clinical trials need to be implemented to understand the real effectiveness of these compounds.

Metabolic functions of flavonoids: From human epidemiology to molecular mechanism

Dietary flavonoid intake is associated with the regulation of nutrient metabolism in the living body. Observational and cohort studies have reported a negative association between flavonoid intake and the risk of metabolic and cardiovascular diseases. Several intervention trials in humans have also supported the benefits of dietary flavonoids. In experimental studies using animal models, a daily diet rich in typical flavonoids such as catechins, anthocyanin, isoflavone, and quercetin was shown to improve whole-body energy expenditure, mitochondrial activity, and glucose tolerance. For some flavonoids, molecular targets for the metabolic modulations have been suggested. Although the effect of flavonoids on neurons has been unclear, several flavonoids have been shown to regulate thermogenesis and feeding behavior through modulating autonomic and central nervous systems. Based on epidemiological and experimental studies, this review summarizes the evidence on the metabolic benefits of flavonoids and their potential mechanism of action in metabolic regulation.