Quercetin: an effective polyphenol in alleviating diabetes and diabetic complications

Underlying mechanisms of traditional Chinese medicine in the prevention and treatment of diabetic retinopathy: Evidences from molecular and clinical studies

As one of the most serious microvascular complications of diabetes mellitus (DM), diabetic retinopathy (DR) can cause visual impairment and even blindness. With the rapid increase in the prevalence of DM, the incidence of DR is also rising year by year. Preventing and effectively treating DR has become a major focus in the medical field. Traditional Chinese medicine (TCM) has a wealth of experience in treating DR and has achieved significant results with various herbs and TCM prescriptions. Traditional Chinese Medicine (TCM) provides a comprehensive therapeutic strategy for diabetic retinopathy (DR), encompassing anti-inflammatory and antioxidant actions, anti-neovascularization, neuroprotection, regulation of glucose metabolism, and inhibition of apoptosis. This review provides an overview of the current status of TCM treatment for DR in recent years, including experimental studies and clinical researches, to explore the clinical efficacy and the underlying modern mechanisms of herbs and TCM prescriptions. Besides, we also discussed the challenges TCM faces in treating DR, such as drug-drug interactions among TCM components and the lack of high-quality evidence-based medicine practice, which pose significant obstacles to TCM's application in DR.

Quercetin intervention mitigates small intestinal damage and immunologic derangement induced by polystyrene nanoplastics: Insights from multi-omics analysis in mice

Nanoplastics (NPs), which belong to emerging environmental pollutants, threaten environmental sustainability and human health. Despite recent studies have reported that NPs damage the gastrointestinal tract and immune homeostasis, the underlying mechanisms remain unclear. Polyphenols have been found to promote NPs excretion by interacting with intestinal flora (IF). However, the potential mechanisms and action targets of this are still poorly understood. To address these knowledge gaps, we investigated the impact of quercetin and three concentrations of polystyrene nanoplastics (PS-NPs) in mice using an integrated phenotypic and multi-omics analysis. Our findings demonstrated that PS-NPs accumulate within the intestine, resulting in impairments to intestinal tissue and barrier function, as well as disturbing the expression of immune-response small intestinal genes and composition of IF. Exposure to PS-NPs significantly elevate the level of intestinal IgG and CD20+ B cells, while inhibiting T cells activation. Furthermore, PS-NPs could induce systemic immune and serum insulin level disorders. Quercetin might mitigate PS-NPs-induced intestinal damage and immune disorders though reversing IF disorders, gene expression changes, and their interaction.

Quercetin supplementation in metabolic syndrome: nutrigenetic interactions with the Zbtb16 gene variant in rodent models

BACKGROUND

Quercetin is a promising phytochemical in treating abnormalities associated with metabolic syndrome (MetS). This study aimed to explore the morphometric, metabolic, transcriptomic, and nutrigenetic responses to quercetin supplementation using two genetically distinct MetS models that only differ in the variant of the MetS-related Zbtb16 gene (Zinc Finger And BTB Domain Containing 16).

RESULTS

Quercetin supplementation led to a significant reduction in the relative weight of retroperitoneal adipose tissue in both investigated strains. A decrease in visceral (epididymal) fat mass, accompanied by an increase in brown fat mass after quercetin treatment, was observed exclusively in the SHR strain. While the levels of serum triglycerides decreased within both strains, the free fatty acids levels decreased in SHR-Zbtb16-Q rats only. The total serum cholesterol levels were not affected by quercetin in either of the two tested strains. While there were no significant changes in brown adipose tissue transcriptome, quercetin supplementation led to a pronounced gene expression shift in white retroperitoneal adipose tissue, particularly in SHR-Zbtb16-Q.

CONCLUSION

Quercetin administration ameliorates certain MetS-related features; however, the efficacy of the treatment exhibits subtle variations depending on the specific variant of the Zbtb16 gene.

Mechanism of Yi-Qi-Bu-Shen Recipe for the Treatment of Diabetic Nephropathy Complicated with Cognitive Dysfunction Based on Network Pharmacology and Experimental Validation

Context

Diabetic nephropathy (DN) and cognitive dysfunction (CD) are common complications of diabetes. Yi-Qi-Bu-Shen Recipe (YQBS) can effectively reduce blood glucose, improve insulin resistance, and delay the progression of diabetic complications. The underlying mechanisms of its effects need to be further studied.

Objective

This study elucidates the mechanism of YQBS in DN with CD through network pharmacology and experimental validation.

Materials and Methods

Protein-protein interaction, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed. Male Sprague-Dawley (SD) rats were divided into 6 groups: model, YQBS (2, 4, 8 g/kg), positive control (metformin, 200 mg/kg), and control; the DN model was established by high sugar and high fat diet combined with intraperitoneal streptozotocin injection. After the DN model was established, the rats were gavaged for 10 weeks. Serum, kidneys, and hippocampus tissues were collected to measure the expression levels of TLR4, NF-κB, TNF-α, and IL-6.

Results

The network pharmacology analysis showed that quercetin and kaempferol were the main active components of YQBS. TNF and IL-6 were the key targets, and TLR4/NF-κB pathway was crucial to YQBS in treating DN complicated with CD. Experimental validation showed that the intervention of YQBS can reduce TNF-α and IL-6 in serum, and also significantly decreases the protein expression of TLR4 and NF-κB.

Conclusion

YQBS exerts anti-inflammatory effects on DN with CD through TLR4/NF-κB pathway. This study provides a biological basis for the scientific usage of YQBS in inflammation diseases and supplies experimental evidence for future traditional Chinese medicine development.

Layer by layer self-assembled hyaluronic acid nanoarmor for the treatment of ulcerative colitis

Natural compound-based treatments provide innovative ways for ulcerative colitis therapy. However, poor targeting and rapid degradation curtail its application, which needs to be addressed. Inspired by biomacromolecule-based materials, we have developed an orally administrated nanoparticle (GBP@HA NPs) using bovine serum albumin as a carrier for polyphenol delivery. The system synergizes galactosylated bovine serum albumin with two polyphenols, epigallocatechin gallate and tannic acid, which is then encased in "nanoarmor" of ε-Polylysine and hyaluronic acid to boost its stability and targeting. Remarkably, the nanoarmor demonstrated profound therapeutic effects in both acute and chronic mouse models of ulcerative colitis, mitigating disease symptoms via multiple mechanisms, regulating inflammation related factors and exerting a modulatory impact on gut microbiota. Further mechanistic investigations indicate that GBP@HA NPs may act through several pathways, including modulation of Keap1-Nrf2 and NF-κB signaling, as well as Caspase-1-dependent pyroptosis. Consequently, this novel armored nanotherapy promotes the way for enhanced polyphenol utilization in ulcerative colitis treatment research.

Genetic and therapeutic for oral lichen planus and diabetes mellitus: a comprehensive study

BACKGROUND

This study employed a bidirectional Mendelian Randomization (MR) approach to explore the causal relationships between Oral Lichen Planus (OLP), diabetes mellitus (DM), and glycemic control. It also aims to identify potential pharmacological and herbal treatments that effectively address both OLP and the metabolic dysfunctions associated with DM.

METHODS

This study employs a two-way MR approach to investigate the potential causal relationships between diabetes type and glycated hemoglobin (HbA1c) levels, and the risk of OLP. We analyzed differentially expressed genes from the OLP dataset in the Genomics Expression Omnibus (GEO) database, cross-referencing these with HbA1c-related genes for enrichment analysis. Additionally, the Drug-Gene Interaction Database (DGIdb) and Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) were utilized to assess the effectiveness of specific drugs, herbs, and ingredients in treating OLP while managing blood glucose levels.

RESULTS

The MR analysis revealed a significant association between Type 1 Diabetes mellitus (T1DM) and an increased risk of OLP, unlike Type 2 Diabetes mellitus (T2DM). This finding indicates a unique immunological interaction in T1DM that may predispose individuals to OLP. The drug prediction analysis focused on core targets linked to OLP and HbA1c, evaluating the therapeutic potential of retinoic acid, prednisone, and thalidomide for treating OLP and regulating blood glucose levels. Additionally, herbal medicines such as Ecliptae herbaand Amygdalus communis vas, along with herbal ingredients like quercetin, luteolin, and 17-beta-estradiol, were identified for their anti-inflammatory properties and potential to mitigate metabolic dysfunction in diabetes.

CONCLUSION

The study highlighted a complex interplay between diabetes and OLP, underscoring the efficacy of integrated therapeutic strategies that target both conditions. The findings suggest that both pharmaceutical and herbal treatments can effectively manage the clinical manifestations of OLP and associated metabolic challenges. This holistic approach to treatment could significantly enhance patient outcomes by addressing the interconnected aspects of these chronic conditions.

Metabolic effects of quercetin on inflammatory and autoimmune responses in rheumatoid arthritis are mediated through the inhibition of JAK1/STAT3/HIF-1α signaling

BACKGROUND

Rheumatoid arthritis, a chronic autoimmune disease, is characterized by synovial hyperplasia and cartilage erosion. Here, we investigated the potential mechanism of action of quercetin, the main component of flavonoids, in treating rheumatoid arthritis.

OBJECT

To examine the anti-arthritic effects of quercetin and elucidate the specific mechanisms that differentiate its metabolic effects on autoimmune and inflammatory responses at the synovial cell level.

METHODS

We created a collagen-induced arthritis (CIA) model in Wistar rats, which were administered quercetin (50 or 100 mg/kg) continuously for four weeks via stomach perfusion. The arthritis score, histopathological staining, radiological assessment, and serum biochemical parameters were used to study the impact of quercetin on disease improvement. Additionally, immunofluorescence was employed to detect JAK1/STAT3/HIF-1α expression in rat joints. Moreover, the effects of quercetin (20, 40, and 80 µmol/L) on the properties and behavior of synovial fibroblasts were evaluated in an in vitro MH7A cell model using flow cytometry, CCK8, and transwell assays. Further, the mRNA expression levels of inflammatory cytokines IL1β, IL6, IL17, and TNFα were assessed by quantitative real-time PCR. Glucose, lactate, lactate dehydrogenase, pyruvate, pyruvate dehydrogenase, and adenosine triphosphate assay kits were employed to measure the metabolic effects of quercetin on synovial fibroblasts. Finally, immunoblotting was used to examine the impact of quercetin on the JAK1/STAT3/HIF-1α signaling pathway in synovial fibroblasts.

RESULTS

In vivo experiments confirmed the favorable effects of quercetin in CIA rats, including an improved arthritis score and reduced ankle bone destruction, in addition to a decrease in the pro-inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α in serum. Immunofluorescence verified that quercetin may ameliorate joint injury in rats with CIA by inhibiting JAK1/STAT3/HIF-1α signaling. Various in vitro experiments demonstrated that quercetin effectively inhibits IL-6-induced proliferation of MH7A cells and reduces their migratory and invasive behavior, while inducing apoptosis and reducing the expression of the pro-inflammatory cytokines IL1β, IL6, IL17, and TNFα at the mRNA level. Quercetin caused inhibition of glucose, lactate, lactate dehydrogenase, pyruvate, and adenosine triphosphate and increased pyruvate dehydrogenase expression in MH7A cells. It was further confirmed that quercetin may inhibit energy metabolism and inflammatory factor secretion in MH7A cells through JAK1/STAT3/HIF-1α signaling.

CONCLUSIONS

Quercetin's action on multiple target molecules and pathways makes it a promising treatment for cartilage injury in rheumatoid arthritis. By reducing joint inflammation, improving joint metabolic homeostasis, and decreasing immune system activation energy, quercetin inhibits the JAK1/STAT3/HIF-1α signaling pathway to improve disease status.

Mechanochemically Reprogrammed Tantalum Interfaces Enhance Osseointegration Via Immunomodulation

Bone and tooth defects can considerably affect the quality of life and health of patients, and orthopedic implants remain the primary method of addressing such defects. However, implant materials cannot coordinate with the immune microenvironment because of their biological inertness, which may lead to implant loosening or failure. Motivated by the microstructure of nacre, we engineered a biomimetic micro/nanoscale topography on a tantalum surface using a straightforward method. This comprised an organized array of tantalum nanotubes arranged in a brick wall structure, with epigallocatechin gallate acting as "mortar." The coating improved the corrosion resistance, biocompatibility, and antioxidant properties. In vitro and in vivo evaluations further confirmed that coatings can create a favorable bone immune microenvironment through the synergistic effects of mechanochemistry and enhance bone integration. This research offers a new viewpoint on the creation of sophisticated functional implants, possessing vast potential for use in the regeneration and repair of bone tissue.

Liposomal quercetin: A promising strategy to combat hepatic insulin resistance and inflammation in type 2 diabetes mellitus

In type 2 diabetes mellitus, hepatic insulin resistance is intricately associated with oxidative stress and inflammation. Nonetheless, the lack of therapeutic interventions directly targeting hepatic dysfunction represents a notable gap in current treatment options. Flavonoids have been explored due to their potential antidiabetic effects. However, these compounds are associated with low bioavailability and high metabolization. In the present study, four flavonoids, kaempferol, quercetin, kaempferol-7-O-glucoside and quercetin-7-O-glucoside, were studied in a cellular model of hepatic insulin resistance using HepG2 cells. Quercetin was selected as the most promising flavonoid and incorporated into liposomes to enhance its therapeutic effect. Quercetin liposomes had a mean size of 0.12 µm, with an incorporation efficiency of 93 %. Quercetin liposomes exhibited increased efficacy in modulating insulin resistance. This was achieved through the modulation of Akt expression and the attenuation of inflammation, particularly via the NF-κB pathway, as well as the regulation of PGE2 and COX-2 expression. Furthermore, quercetin liposomes displayed a significant advantage over free quercetin in attenuating the production of reactive pro-oxidant species. These findings open new avenues for developing innovative therapeutic strategies to manage diabetes, emphasizing the potential of quercetin liposomes as a promising approach for targeting both hepatic insulin resistance and associated inflammation.

Phytonutrients in the promotion of healthspan: a new perspective

Considering a growing, aging population, the need for interventions to improve the healthspan in aging are tantamount. Diet and nutrition are important determinants of the aging trajectory. Plant-based diets that provide bioactive phytonutrients may contribute to offsetting hallmarks of aging and reducing the risk of chronic disease. Researchers now advocate moving toward a positive model of aging which focuses on the preservation of functional abilities, rather than an emphasis on the absence of disease. This narrative review discusses the modulatory effect of nutrition on aging, with an emphasis on promising phytonutrients, and their potential to influence cellular, organ and functional parameters in aging. The literature is discussed against the backdrop of a recent conceptual framework which describes vitality, intrinsic capacity and expressed capacities in aging. This aims to better elucidate the role of phytonutrients on vitality and intrinsic capacity in aging adults. Such a review contributes to this new scientific perspective-namely-how nutrition might help to preserve functional abilities in aging, rather than purely offsetting the risk of chronic disease.

Quercetin as one of the most abundant represented biological valuable plant components with remarkable chemoprotective effects - A review

As a consequence of environmental quality changes as well as changes in our population's lifestyle, there is rapidly increasing variability and many so-called lifestyle disorders, allergies, and food intolerances (also known as non-allergic food hypersensitivity). Unhealthy eating practices, an inappropriate food composition with an excessive energy intake, a high intake of saturated fats, simple sugars, and salt, as well as an inadequate intake of fibre, vitamins, and substances with preventive effects (such as antioxidants), are some of the factors causing this detrimental phenomenon. Enhanced consumption of plant foods rich in valuable secondary metabolites such as phenolic acids and flavonoids with the benefit on human health, food research focused on these components, and production of foods with declared higher content of biologically active and prophylactic substances are some ways how to change and improve this situation. A unique class of hydroxylated phenolic compounds with an aromatic ring structure are called flavonoids. One unique subclass of flavonoids is quercetin. This phytochemical naturally takes place in fruits, vegetables, herbs, and other plants. Quercetin and its several derivates are considered to be promising substances with significant antidiabetic, antibacterial, anti-inflammatory, and antioxidant effects, which could also act preventively against cardiovascular disease, cancer, or Alzheimer's disease.

Quercetin Alleviates Insulin Resistance and Repairs Intestinal Barrier in db/db Mice by Modulating Gut Microbiota

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease which seriously affects public health. Gut microbiota remains a dynamic balance state in healthy individuals, and its disorder may affect health status and even results in metabolic diseases. Quercetin, a natural flavonoid, has been shown to have biological activities that can be used in the prevention and treatment of metabolic diseases. This study aimed to explore the mechanism of quercetin in alleviating T2DM based on gut microbiota. db/db mice were adopted as the model for T2DM in this study. After 10 weeks of administration, quercetin could significantly decrease the levels of body weight, fasting blood glucose (FBG), serum insulin (INS), the homeostasis model assessment of insulin resistance (HOMA-IR), monocyte chemoattractant protein-1 (MCP-1), D-lactic acid (D-LA), and lipopolysaccharide (LPS) in db/db mice. 16S rRNA gene sequencing and untargeted metabolomics analysis were performed to compare the differences of gut microbiota and metabolites among the groups. The results demonstrated that quercetin decreased the abundance of Proteobacteria, Bacteroides, Escherichia-Shigella and Escherichia_coli. Moreover, metabolomics analysis showed that the levels of L-Dopa and S-Adenosyl-L-methionine (SAM) were significantly increased, but 3-Methoxytyramine (3-MET), L-Aspartic acid, L-Glutamic acid, and Androstenedione were significantly decreased under quercetin intervention. Taken together, quercetin could exert its hypoglycemic effect, alleviate insulin resistance, repair the intestinal barrier, remodel the intestinal microbiota, and alter the metabolites of db/db mice.

Polyphenols mediated attenuation of diabetes associated cardiovascular complications: A comprehensive review

Background

Diabetes mellitus is a common chronic metabolic disorder that is characterized by increased levels of glucose for prolonged periods of time. Incessant hyperglycemia leads to diabetic complications such as retinopathy, nephropathy, and neuropathy, and cardiovascular complications such as ischemic heart disease, peripheral vascular disease, diabetic cardiomyopathy, stroke, etc. There are many studies that suggest that various polyphenols affect glucose homeostasis and can help to attenuate the complications associated with diabetes.

Objective

This review focuses on the possible role of various dietary polyphenols in palliating diabetes-induced cardiovascular complications. This review also aims to give an overview of the interrelationship among ROS production (due to diabetes), inflammation, glycoxidative stress, and cardiovascular complications as well as the anti-hyperglycemic effects of dietary polyphenols.

Methods

Various scientific databases including Scopus, Web of Science, Google Scholar, PubMed, Science Direct, Springer Link, and Wiley Online Library were used for searching articles that complied with the inclusion and exclusion criteria.

Results

This review lists several polyphenols based on various pre-clinical and clinical studies that have anti-hyperglycemic potential as well as a protective function against cardiovascular complications.

Conclusion

Several pre-clinical and clinical studies suggest that various dietary polyphenols can be a promising intervention for the attenuation of diabetes-associated cardiovascular complications.

The development of nanocarriers for natural products

Natural bioactive compounds from plants exhibit substantial pharmacological potency and therapeutic value. However, the development of most plant bioactive compounds is hindered by low solubility and instability. Conventional pharmaceutical forms, such as tablets and capsules, only partially overcome these limitations, restricting their efficacy. With the recent development of nanotechnology, nanocarriers can enhance the bioavailability, stability, and precise intracellular transport of plant bioactive compounds. Researchers are increasingly integrating nanocarrier-based drug delivery systems (NDDS) into the development of natural plant compounds with significant success. Moreover, natural products benefit from nanotechnological enhancement and contribute to the innovation and optimization of nanocarriers via self-assembly, grafting modifications, and biomimetic designs. This review aims to elucidate the collaborative and reciprocal advancement achieved by integrating nanocarriers with botanical products, such as bioactive compounds, polysaccharides, proteins, and extracellular vesicles. This review underscores the salient challenges in nanomedicine, encompassing long-term safety evaluations of nanomedicine formulations, precise targeting mechanisms, biodistribution complexities, and hurdles in clinical translation. Further, this study provides new perspectives to leverage nanotechnology in promoting the development and optimization of natural plant products for nanomedical applications and guiding the progression of NDDS toward enhanced efficiency, precision, and safety. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Biomarkers and signaling pathways of diabetic nephropathy and peripheral neuropathy: possible therapeutic intervention of rutin and quercetin

Diabetic nephropathy and peripheral neuropathy are the two main complications of chronic diabetes that contribute to high morbidity and mortality. These conditions are characterized by the dysregulation of multiple molecular signaling pathways and the presence of specific biomarkers such as inflammatory cytokines, indicators of oxidative stress, and components of the renin-angiotensin system. In this review, we systematically collected and collated the relevant information from MEDLINE, EMBASE, ELSEVIER, PUBMED, GOOGLE, WEB OF SCIENCE, and SCOPUS databases. This review was conceived with primary objective of revealing the functions of these biomarkers and signaling pathways in the initiation and progression of diabetic nephropathy and peripheral neuropathy. We also highlighted the potential therapeutic effectiveness of rutin and quercetin, two plant-derived flavonoids known for their antioxidant and anti-inflammatory properties. The findings of our study demonstrated that both flavonoids can regulate important disease-promoting systems, such as inflammation, oxidative stress, and dysregulation of the renin-angiotensin system. Importantly, rutin and quercetin have shown protective benefits against nephropathy and neuropathy in diabetic animal models, suggesting them as potential therapeutic agents. These findings provide a solid foundation for further comprehensive investigations and clinical trials to evaluate the potential of rutin and quercetin in the management of diabetic nephropathy and peripheral neuropathy. This may contribute to the development of more efficient and comprehensive treatment approaches for diabetes-associated complications.

Therapeutic detoxification of quercetin for aflatoxin B1-related toxicity: Roles of oxidative stress, inflammation, and metabolic enzymes

Aflatoxins (AFTs), a type of mycotoxin mainly produced by Aspergillus parasiticus and Aspergillus flavus, could be detected in food, feed, Chinese herbal medicine, grain crops and poses a great threat to public health security. Among them, aflatoxin B1 (AFB1) is the most toxic one. Exposure to AFB1 poses various health risks to both humans and animals, including the development of chronic inflammatory diseases, cardiovascular diseases, neurodegenerative diseases, and cancer. The molecular mechanisms underlying these risks are intricate and dependent on specific contexts. This review primarily focuses on summarizing the protective effects of quercetin, a natural phenolic compound, in mitigating the toxic effects induced by AFB1 in both in vitro experiments and animal models. Additionally, the review explores the molecular mechanisms that underlie these protective effects. Quercetin has been demonstrated to not only have the direct inhibitory action on the production of AFTs from Aspergillus, both also possess potent ameliorative effects against AFB1-induced cytotoxicity, hepatotoxicity, and neurotoxicity. These effects are attributed to the inhibition of oxidative stress, mitochondrial dysfunction, mitochondrial apoptotic pathway, and inflammatory response. It could also directly target several metabolic enzymes (i.e., CYP3As and GSTA1) to reduce the production of toxic metabolites of AFB1 within cells, then reduce AFB1-induced cytotoxicity. In conclusion, this review highlights quercetin is a promising detoxification agent for AFB1. By advancing our understanding of the protective mechanisms offered by quercetin, we aim to contribute to the development of effective detoxification agents against AFB1, ultimately promoting better health outcomes.

Synergistic anti-diabetic effect of phloroglucinol and total procyanidin dimer isolated from Vitisvinifera methanolic seed extract potentiates via suppressing oxidative stress: in-vitro evaluation studies

Diabetes is often associated with increased oxidative stress caused by an imbalance between detoxification and ROS production. Unfortunately, many commercial drugs available today for treating this disease have adverse side effects and ultimately fail to restore glucose homeostasis. Therefore, finding a dietary anti-diabetic remedy that is safe, effective, and economical is crucial. In this study, GC-MS analysis, subsequent HPLC-assisted fractionation, and SPE-based purification led to identifying and purifying of key components such as phloroglucinol and total procyanidin dimer (procyanidin dimer and procyanidin dimer gallate) from methanolic seed extract of Vitis vinifera. In-vitro anti-diabetic screening of various fractions derived from methanolic extract along with individual components and their combinations revealed the potential synergistic behaviour of phloroglucinol and total procyanidin dimer with the lowest IC50 of 48.21 ± 3.54 µg/mL for α-glucosidase and 63.06 ± 5.38 µg/mL for α-amylase inhibition which is found to be superior to the effect shown by the standard Epigallocatechin gallate. Later Glucose utilization studies demonstrated the concentration-dependent effect of Phloroglucinol and total procyanidin dimer, and that has raised the glucose uptake by approximately 36-57% in HepG2 cells and 35-58% in L6 myocytes over a concentration of 50-100 µg/mL. The superior anti-diabetic effect of Phloroglucinol and total procyanidin dimer was proved by the suppression of oxidative stress with an IC50 of 7.92 ± 0.36 µg/mL for DPPH scavenging and 16.87 ± 1.24 µg/mL for SOD scavenging which is competent with the standard ascorbic acid. According to this study, suppressing ROS levels by phloroglucinol and total procyanidin dimer would be the underlying mechanism for the synergistic anti-diabetic effect of this combination.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03929-4.

Cell metabolism pathways involved in the pathophysiological changes of diabetic peripheral neuropathy

Diabetic peripheral neuropathy is a common complication of diabetes mellitus. Elucidating the pathophysiological metabolic mechanism impels the generation of ideal therapies. However, existing limited treatments for diabetic peripheral neuropathy expose the urgent need for cell metabolism research. Given the lack of comprehensive understanding of energy metabolism changes and related signaling pathways in diabetic peripheral neuropathy, it is essential to explore energy changes and metabolic changes in diabetic peripheral neuropathy to develop suitable treatment methods. This review summarizes the pathophysiological mechanism of diabetic peripheral neuropathy from the perspective of cellular metabolism and the specific interventions for different metabolic pathways to develop effective treatment methods. Various metabolic mechanisms (e.g., polyol, hexosamine, protein kinase C pathway) are associated with diabetic peripheral neuropathy, and researchers are looking for more effective treatments through these pathways.

Unveiling the Potential of Nelumbo nucifera-Derived Liensinine to Target The Myostatin Protein and to Counteract Muscle Atrophy

Muscle atrophy refers to a decline in muscle mass and function, which has become a global concern due to the aging population. Various clinical trials have investigated the inhibitors of myostatin (MSTN). They have shown promising improvements in muscle function and quality of life. However, there are no drugs specifically targeting MSTN that have been approved for clinical use. In this study, we virtually screened liensinine (LIE), a food (Nelumbo nucifera)-derived compound, with low toxicity, from over 1.1 million compounds. We subsequently identified it as a potential candidate that targets MSTN by a cellular thermal shift assay (CETSA) and drug affinity response target stability (DARTS) assay. Further validation through cellular and in vivo studies demonstrated its promising potential in combating muscle atrophy. The mechanism of action may involve hindering the interaction between MSTN and the activin receptor type IIB (ActRIIB) and downregulating the expression of downstream proteins, including the muscle RING-finger protein-1 (MuRF-1) and muscle atrophy F-box (MAFbx)/Atrogin-1, ultimately promoting muscle regeneration. These results provide a strong foundation for future studies to explore the therapeutic potential of LIE in clinical settings.

Antidiabetic Effect of Urolithin A in Cultured L6 Myotubes and Type 2 Diabetic Model KK-Ay/Ta Mice with Glucose Intolerance

Diabetes is caused by abnormal glucose metabolism, and muscle, the largest tissue in the human body, is largely involved. Urolithin A (UroA) is a major intestinal and microbial metabolite of ellagic acid and ellagitannins and is found in fruits such as strawberry and pomegranate. In this present study, we investigated the antidiabetic effects of UroA in L6 myotubes and in KK-Ay/Ta, a mouse model of type 2 diabetes (T2D). UroA treatment elevated the glucose uptake (GU) of L6 myotubes in the absence of insulin. This elevation in GU by UroA treatment was partially inhibited by the concurrent addition of LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K) which activates Akt (PKB: protein kinase B) or Compound C, an inhibitor of 5'-adenosine monophosphate-activated protein kinase (AMPK). Moreover, UroA was found to activate both pathways of Akt and AMPK, and then to promote translocation of glucose transporter 4 (GLUT4) from the cytosol to the plasma membrane in L6 myotubes. Based on these in vitro findings, an intraperitoneal glucose tolerance test (IPGTT) was performed after the oral administration of UroA for 3 weeks to KK-Ay/Ta mice with glucose intolerance. UroA was demonstrated to alleviate glucose intolerance. These results suggest that UroA is a biofactor with antihyperglycemic effects in the T2D state.

Therapeutic Potential of Quercetin in Diabetic Neuropathy and Retinopathy: Exploring Molecular Mechanisms

Diabetes mellitus poses a significant health challenge globally, often leading to debilitating complications, such as neuropathy and retinopathy. Quercetin, a flavonoid prevalent in fruits and vegetables, has demonstrated potential therapeutic effects in these conditions due to its antioxidant, anti-inflammatory, and neuroprotective properties. This review summarizes and provides a comprehensive understanding of the molecular mechanisms underlying the efficacy of quercetin in ameliorating diabetic neuropathy and retinopathy. A thorough search was carried out across scientific databases, such as SciFinder, PubMed, and Google Scholar, to gather pertinent literature regarding the effect of quercetin on diabetic neuropathy and retinopathy till February 2024. Preclinical studies indicate that quercetin mitigates neuropathic pain, sensory deficits, and nerve damage associated with diabetic neuropathy by improving neuronal function, reducing DNA damage, regulating pro-inflammatory cytokines, enhancing antioxidant enzyme levels and endothelial function, as well as restoring nerve injuries. In diabetic retinopathy, quercetin shows the potential to preserve retinal structure and function, inhibiting neovascularization, preventing retinal cell death, reducing pro-inflammatory cytokines, and increasing neurotrophic factor levels. Moreover, through modulating key signaling pathways, such as AMP-activated Protein Kinase (AMPK) activation, Glucose Transporter 4 (GLUT 4) upregulation, and insulin secretion regulation, quercetin demonstrates efficacy in reducing oxidative stress and inflammation, thereby protecting nerve and retinal tissues. Despite promising preclinical findings, challenges, such as limited bioavailability, necessitate further research to optimize quercetin's clinical application in order to establish its optimal dosage, formulation, and long-term efficacy in clinical settings.

Microenvironmental dynamics of diabetic wounds and insights for hydrogel-based therapeutics

The rising prevalence of diabetes has underscored concerns surrounding diabetic wounds and their potential to induce disability. The intricate healing mechanisms of diabetic wounds are multifaceted, influenced by ambient microenvironment, including prolonged hyperglycemia, severe infection, inflammation, elevated levels of reactive oxygen species (ROS), ischemia, impaired vascularization, and altered wound physicochemical properties. In recent years, hydrogels have emerged as promising candidates for diabetic wound treatment owing to their exceptional biocompatibility and resemblance to the extracellular matrix (ECM) through a three-dimensional (3D) porous network. This review will first summarize the microenvironment alterations occurring in the diabetic wounds, aiming to provide a comprehensive understanding of its pathogenesis, then a comprehensive classification of recently developed hydrogels will be presented, encompassing properties such as hypoglycemic effects, anti-inflammatory capabilities, antibacterial attributes, ROS scavenging abilities, promotion of angiogenesis, pH responsiveness, and more. The primary objective is to offer a valuable reference for repairing diabetic wounds based on their unique microenvironment. Moreover, this paper outlines potential avenues for future advancements in hydrogel dressings to facilitate and expedite the healing process of diabetic wounds.

Molecular targets and mechanisms of Jiawei Jiaotai Pill on diabetic cardiomyopathy based on network pharmacology

BACKGROUND

Jiawei Jiaotai Pill is commonly used in clinical practice to reduce apoptosis, increase insulin secretion, and improve blood glucose tolerance. However, its mechanism of action in the treatment of diabetic cardiomyopathy (DCM) remains unclear, hindering research efforts aimed at developing drugs specifically for the treatment of DCM.

AIM

To explore the pharmacodynamic basis and molecular mechanism of Jiawei Jiaotai Pill in DCM treatment.

METHODS

We explored various databases and software, including the Traditional Chinese Medicine Systems Pharmacology Database, Uniport, PubChem, GenCards, String, and Cytoscape, to identify the active components and targets of Jiawei Jiaotai Pill, and the disease targets in DCM. Protein-protein interaction network, gene ontology, and Kyoto Encyclopedia of Genes and Genomes analyses were used to determine the mechanism of action of Jiawei Jiaotai Pill in treating DCM. Molecular docking of key active components and core targets was verified using AutoDock software.

RESULTS

Total 42 active ingredients and 142 potential targets of Jiawei Jiaotai Pill were identified. There were 100 common targets between the DCM and Jiawei Jiaotai Pills. Through this screening process, TNF, IL6, TP53, EGFR, INS, and other important targets were identified. These targets are mainly involved in the positive regulation of the mitogen-activated protein kinase (MAPK) MAPK cascade, response to xenobiotic stimuli, response to hypoxia, positive regulation of gene expression, positive regulation of cell proliferation, negative regulation of the apoptotic process, and other biological processes. It was mainly enriched in the AGE-RAGE signaling pathway in diabetic complications, DCM, PI3K-Akt, interleukin-17, and MAPK signaling pathways. Molecular docking results showed that Jiawei Jiaotai Pill's active ingredients had good docking activity with DCM's core target.

CONCLUSION

The active components of Jiawei Jiaotai Pill may play a role in the treatment of DCM by reducing oxidative stress, cardiomyocyte apoptosis and fibrosis, and maintaining metabolic homeostasis.

Praeruptorin C alleviates cognitive impairment in type 2 diabetic mice through restoring PI3K/AKT/GSK3β pathway

Diabetic encephalopathy is a common consequence of diabetes mellitus that causes cognitive dysfunction and neuropsychiatric disorders. Praeruptorin C (Pra-C) from the traditional Chinese medicinal herb Peucedanum praeruptorum Dunn. is a potential antioxidant and neuroprotective agent. This study was conducted to investigate the molecular mechanisms underlying the effect of Pra-C on diabetic cognitive impairment. A novel object recognition test and the Morris water maze test were performed to assess the behavioral performance of mice. Electrophysiological recordings were made to monitor synaptic plasticity in the hippocampus. A protein-protein interaction network of putative Pra-C targets was constructed, and molecular docking simulations were performed to predict the potential mechanisms of the action of Pra-C. Protein expression levels were detected by western blotting. Pra-C administration significantly lowered body weight and fasting blood glucose levels and alleviated learning and memory deficits in type 2 diabetic mice. Network pharmacology and molecular docking results suggested that Pra-C affects the PI3K/AKT/GSK3β signaling pathway. Western blot analysis confirmed significant increases in phosphorylated PI3K, AKT, and GSK3β levels in vivo and in vitro upon Pra-C administration. Pra-C alleviated cognitive impairment in type 2 diabetic mice by activating PI3K/AKT/GSK3β pathway.

Genipin relieves diabetic retinopathy by down-regulation of advanced glycation end products via the mitochondrial metabolism related signaling pathway

BACKGROUND

Glycation is an important step in aging and oxidative stress, which can lead to endothelial dysfunction and cause severe damage to the eyes or kidneys of diabetics. Inhibition of the formation of advanced glycation end products (AGEs) and their cell toxicity can be a useful therapeutic strategy in the prevention of diabetic retinopathy (DR). Gardenia jasminoides Ellis (GJE) fruit is a selective inhibitor of AGEs. Genipin is an active compound of GJE fruit, which can be employed to treat diabetes.

AIM

To confirm the effect of genipin, a vital component of GJE fruit, in preventing human retinal microvascular endothelial cells (hRMECs) from AGEs damage in DR, to investigate the effect of genipin in the down-regulation of AGEs expression, and to explore the role of the CHGA/UCP2/glucose transporter 1 (GLUT1) signal pathway in this process.

METHODS

In vitro, cell viability was tested to determine the effects of different doses of glucose and genipin in hRMECs. Cell Counting Kit-8 (CCK-8), colony formation assay, flow cytometry, immunofluorescence, wound healing assay, transwell assay, and tube-forming assay were used to detect the effect of genipin on hRMECs cultured in high glucose conditions. In vivo, streptozotocin (STZ) induced mice were used, and genipin was administered by intraocular injection (IOI). To explore the effect and mechanism of genipin in diabetic-induced retinal dysfunction, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) assays were performed to explore energy metabolism and oxidative stress damage in high glucose-induced hRMECs and STZ mouse retinas. Immunofluorescence and Western blot were used to investigate the expression of inflammatory cytokines [vascular endothelial growth factor (VEGF), SCG3, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-18, and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing 3 (NLRP3)]. The protein expression of the receptor of AGEs (RAGE) and the mitochondria-related signal molecules CHGA, GLUT1, and UCP2 in high glucose-induced hRMECs and STZ mouse retinas were measured and compared with the genipin-treated group.

RESULTS

The results of CCK-8 and colony formation assay showed that genipin promoted cell viability in high glucose (30 mmol/L D-Glucose)-induced hRMECs, especially at a 0.4 μmol/L dose for 7 d. Flow cytometry results showed that high glucose can increase apoptosis rate by 30%, and genipin alleviated cell apoptosis in AGEs-induced hRMECs. A high glucose environment promoted ATP, ROS, MMP, and 2-NBDG levels, while genipin inhibited these phenotypic abnormalities in AGEs-induced hRMECs. Furthermore, genipin remarkably reduced the levels of the pro-inflammatory cytokines TNF-α, IL-1β, IL-18, and NLRP3 and impeded the expression of VEGF and SCG3 in AGEs-damaged hRMECs. These results showed that genipin can reverse high glucose induced damage with regard to cell proliferation and apoptosis in vitro, while reducing energy metabolism, oxidative stress, and inflammatory injury caused by high glucose. In addition, ROS levels and glucose uptake levels were higher in the retina from the untreated eye than in the genipin-treated eye of STZ mice. The expression of inflammatory cytokines and pathway protein in the untreated eye compared with the genipin-treated eye was significantly increased, as measured by Western blot. These results showed that IOI of genipin reduced the expression of CHGA, UCP2, and GLUT1, maintained the retinal structure, and decreased ROS, glucose uptake, and inflammation levels in vivo. In addition, we found that SCG3 expression might have a higher sensitivity in DR than VEGF as a diagnostic marker at the protein level.

CONCLUSION

Our study suggested that genipin ameliorates AGEs-induced hRMECs proliferation, apoptosis, energy metabolism, oxidative stress, and inflammatory injury, partially via the CHGA/UCP2/GLUT1 pathway. Control of advanced glycation by IOI of genipin may represent a strategy to prevent severe retinopathy and vision loss.

Polyphenolic profiles of a variety of wild berries from the Pacific Northwest region of North America

Polyphenols have been extensively profiled and quantified in commercially grown berries, but similar information is sparsely available for wild berries. Because polyphenolic contents are inherently associated with berries health benefits, determining phenolic profiles is an important step for strategizing potential uses by the industry and for health and nutrition outcomes. Here, we profiled phenolic compounds in wild berries commonly encountered and harvested in the Pacific Northwest region of North America. Huckleberries (Vaccinium membranaceum) of varying phenotypes were found to be comparable to related blueberries in terms of general phenolic classes composition. However, all huckleberries exhibited markedly high levels of cyanidins, and delphinidins or peonidins were also higher in specific phenotypes. Wild black elderberries (Sambucus nigra spp. Canadensis) were found to have remarkably high phenolic, especially anthocyanins, in line with reports from cultivated elderberries. Saskatoon serviceberries (Amelanchier alnifolia) were found to exhibit high polyphenol content, but with a less diverse profile dominated by quercetin. The most intriguing berry may be the Oregon grape (Mahonia Aquifolium) being the only one exhibiting more than one g of polyphenols per 100 g; as well as a remarkably even distribution of the different anthocyanin classes. All colored wild berries were found to have at minimum comparable total phenolic contents when compared to cultivated and other wild berries, suggesting they should exhibit comparable human health benefits such as antioxidant and metabolic syndrome preventative potential described for these other berries. Overall, our data represents a valuable resource to explore the potential to valorize wild berry species for their specific phenolic profiles and predicted nutritional and health properties. With repeated phenolic profiling to better understand the impact of the environment, the wild berries described here hold promises both as food ingredient applications as well as valuable complement for healthy dietary patterns.

Plant-Based Nutrition: Exploring Health Benefits for Atherosclerosis, Chronic Diseases, and Metabolic Syndrome-A Comprehensive Review

Atherosclerosis, chronic non-communicable diseases, and metabolic syndrome are highly interconnected and collectively contribute to global health concerns that reduce life expectancy and quality of life. These conditions arise from multiple risk factors, including inflammation, insulin resistance, impaired blood lipid profile, endothelial dysfunction, and increased cardiovascular risk. Adopting a plant-based diet has gained popularity as a viable alternative to promote health and mitigate the incidence of, and risk factors associated with, these three health conditions. Understanding the potential benefits of a plant-based diet for human health is crucial, particularly in the face of the rising prevalence of chronic diseases like diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. Thus, this review focused on the plausible advantages of consuming a type of food pattern for the prevention and/or treatment of chronic diseases, emphasizing the dietary aspects that contribute to these conditions and the evidence supporting the benefits of a plant-based diet for human health. To facilitate a more in-depth analysis, we present separate evidence for each of these three concepts, acknowledging their intrinsic connection while providing a specific focus on each one. This review underscores the potential of a plant-based diet to target the underlying causes of these chronic diseases and enhance health outcomes for individuals and populations.

Treatment of diabetic complications: do flavonoids holds the keys?

Diabetes mellitus (DM) is an endocrinological disorder in which blood sugar levels get elevated and if unmanaged, it leads to several critical complications. Existing therapies or drugs are not able to attain absolute control of DM. Moreover, associated side/adverse effects associated with pharmacotherapy further worsen the Quality of life of patients. Present review is focused on therapeutical potential of flavonoids in management of diabetes and diabetic complications. Plenteous literature has established significant potential of flavonoids in the treatment of diabetes and diabetic complications. A number of flavonoids are found to be effective in treatment of not only diabetes but progression of diabetic complication was also found to be attenuated with the use of flavonoids. Moreover, SAR studies of some flavonoids also indicated the that efficacy of flavonoids is increased with a change in functional group of flavonoids in the treatment of diabetes and diabetic complications. A number of clinical trials are into action to investigate the therapeutic potential of flavonoids as first-line drugs or as adjuvants for treatment of diabetes and diabetic complications.. Owing to their diverse mechanism of action, efficacy and safety, flavonoids may be conscripted as potential candidate for treatment of diabetic complications.

A Descriptive Review of the Action Mechanisms of Berberine, Quercetin and Silymarin on Insulin Resistance/Hyperinsulinemia and Cardiovascular Prevention

Insulin resistance (IR) and the associated hyperinsulinemia are early pathophysiological changes which, if not well treated, can lead to type 2 diabetes, endothelial dysfunction and cardiovascular disease. While diabetes care is fairly well standardized, the prevention and treatment of IR lacks a single pharmaceutical approach and many lifestyle and dietary interventions have been proposed, including a wide range of food supplements. Among the most interesting and well-known natural remedies, alkaloid berberine and the flavonol quercetin have particular relevance in the literature, while silymarin-the active principle of the Silybum marianum thistle-was traditionally used for lipid metabolism disorders and to sustain liver function. This review describes the major defects of insulin signaling leading to IR and the main properties of the three mentioned natural substances, their molecular targets and synergistic action mechanisms. The actions of berberine, quercetin and silymarin are partially superimposable as remedies against reactive oxygen intermediates generated by a high-lipid diet and by NADPH oxidase, which is triggered by phagocyte activation. Furthermore, these compounds inhibit the secretion of a battery of pro-inflammatory cytokines, modulate intestinal microbiota and are especially able to control the various disorders of the insulin receptor and post-receptor signaling systems. Although most of the evidence on the effects of berberine, quercetin and silymarin in modulating insulin resistance and preventing cardiovascular disease derive from experimental studies on animals, the amount of pre-clinical knowledge strongly suggests the need to investigate the therapeutic potential of these substances in human pathology.

Integration of molecular docking, molecular dynamics and network pharmacology to explore the multi-target pharmacology of fenugreek against diabetes

Fenugreek is an ancient herb that has been used for centuries to treat diabetes. However, how the fenugreek-derived chemical compounds work in treating diabetes remains unclarified. Herein, we integrate molecular docking and network pharmacology to elucidate the active constituents and potential mechanisms of fenugreek against diabetes. First, 19 active compounds from fenugreek and 71 key diabetes-related targets were identified through network pharmacology analysis. Then, molecular docking and simulations results suggest diosgenin, luteolin and quercetin against diabetes via regulation of the genes ESR1, CAV1, VEGFA, TP53, CAT, AKT1, IL6 and IL1. These compounds and genes may be key factors of fenugreek in treating diabetes. Cells results demonstrate that fenugreek has good biological safety and can effectively improve the glucose consumption of IR-HepG2 cells. Pathway enrichment analysis revealed that the anti-diabetic effect of fenugreek was regulated by the AGE-RAGE and NF-κB signalling pathways. It is mainly associated with anti-oxidative stress, anti-inflammatory response and β-cell protection. Our study identified the active constituents and potential signalling pathways involved in the anti-diabetic effect of fenugreek. These findings provide a theoretical basis for understanding the mechanism of the anti-diabetic effect of fenugreek. Finally, this study may help for developing anti-diabetic dietary supplements or drugs based on fenugreek.

Paliurus spina-christi Mill fruit extracts improve glucose uptake and activate the insulin signaling pathways in HepG2 insulin-resistant cells

BACKGROUND

Paliurus spina-christi Mill. (PSC) fruit is frequently used in the treatment of diabetes mellitus in Mediterranean regions. Here, we investigated the effects of various PSC fruit extracts (PSC-FEs) on glucose consumption and some key mediators of insulin signaling pathways in high glucose and high insulin-induced insulin-resistant HepG2 cells.

METHODS

The effects of methanolic, chloroform and total extracts on cell proliferation were assessed by the MTT assay. The potential of non-toxic extracts on glucose utilization in insulin-resistant HepG2 cells was checked using a glucose oxidase assay. AKT and AMP-activated protein kinase (AMPK) pathway activation and mRNA expression levels of insulin receptor (INSR), glucose transporter 1 (GLUT1), and glucose transporters 4 (GLUT4) were determined by western blotting and real-time PCR, respectively.

RESULTS

We found that high concentrations of methanolic and both low and high concentrations of total extracts were able to enhance glucose uptake in an insulin-resistant cell line model. Moreover, AKT and AMPK phosphorylation were significantly increased by the high strength of methanolic extract, while total extract raised AMPK activation at low and high concentrations. Also, GLUT 1, GLUT 4, and INSR were elevated by both methanolic and total extracts.

CONCLUSIONS

Ultimately, our results shed new light on methanolic and total PSC-FEs as sources of potential anti-diabetic medications, restoring glucose consumption and uptake in insulin-resistant HepG2 cells. These could be at least in part due to re-activating AKT and AMPK signaling pathways and also increased expression of INSR, GLUT1, and GLUT4. Overall, active constituents present in methanolic and total extracts of PCS are appropriate anti-diabetic agents and explain the use of these PSC fruits in traditional medicine for the treatment of diabetes.

Quercetin alleviates tubulointerstitial inflammation by inhibiting exosomes-mediated crosstalk between tubular epithelial cells and macrophages

BACKGROUND

Tubulointerstitial inflammation (TII) is a critical pathological feature of kidney disease leading to renal fibrosis, and its treatment remains a major clinical challenge. We sought to explore the role of quercetin, a potential exosomes inhibitor, in exosomes release and TII.

METHODS

The effects of quercetin on exosomes release and TII were examined by two TII mouse models: the unilateral ureteral obstruction (UUO) models and the LPS-induced mouse models. In vitro, exosomes-mediated crosstalk between tubular epithelial cells (TECs) and macrophages was performed to investigate the mechanisms by which quercetin inhibited exosomes and TII.

RESULTS

In this study, we found that exosomes-mediated crosstalk between TECs and macrophages contributed to the development of TII. In vitro, exosomes released from LPS-stimulated TECs induced increased expression of inflammatory cytokines and fibrotic markers in Raw264·7 cells and vice versa. Interestingly, heat shock protein 70 (Hsp70) or Hsp90 proteins could control exosomes release from TECs and macrophages both in vivo and in vitro. Importantly, quercetin, a previously recognized heat shock protein inhibitor, could significantly reduce exosomes release in TII models by down-regulating Hsp70 or Hsp90. Quercetin abrogated exosomes-mediated intercellular communication, which attenuated TII and renal fibrosis accordingly.

CONCLUSION

Quercetin could serve as a novel strategy for treatment of tubulointerstitial inflammation by inhibiting the exosomes-mediated crosstalk between tubules and macrophages.

Nanosuspension of Foeniculum Vulgare Promotes Accelerated Sensory and Motor Function Recovery after Sciatic Nerve Injury

The seed extract of Foeniculum vulgare (FV) was used for the preparation of a nanosuspension (NS) with an enhanced bioavailability of phytoconstituents. Subsequently, it was employed as a potent source of polyphenols, such as quercetin and kaempferol, to accelerate the regeneration and recovery of motor and sensory function in injured nerves. The NS was administered through daily gauging as NS1 (0.5 mg/mL) and NS2 (15 mg/mL), at a dose rate of 2 g/kg body weight until the end of the study. The NS-mediated retrieval of motor functions was studied by evaluating muscle grip strength and the sciatic functional index. The recovery of sensory functions was assessed by the hotplate test. Several well-integrated biochemical pathways mediate the recovery of function and the regeneration of nerves under controlled blood glucose and oxidative stress. Consequently, the NS-treated groups were screened for blood glucose, total antioxidant capacity (TAC), and total oxidant status (TOS) compared to the control. The NS administration showed a significant potential to enhance the recuperation of motor and sensory functions. Moreover, the oxidative stress was kept under check as a result of NS treatments to facilitate neuronal generation. Thus, the nanoformulation of FV with polyphenolic contents accelerated the reclamation of motor and sensory function after nerve lesion.

Targeting matrix metalloproteases in diabetic wound healing

Chronic inflammation participates in the progression of multiple chronic diseases, including obesity, diabetes mellitus (DM), and DM related complications. Diabetic ulcer, characterized by chronic wounds that are recalcitrant to healing, is a serious complication of DM tremendously affecting the quality of life of patients and imposing a costly medical burden on society. Matrix metalloproteases (MMPs) are a family of zinc endopeptidases with the capacity of degrading all the components of the extracellular matrix, which play a pivotal part in healing process under various conditions including DM. During diabetic wound healing, the dynamic changes of MMPs in the serum, skin tissues, and wound fluid of patients are in connection with the degree of wound recovery, suggesting that MMPs can function as essential biomarkers for the diagnosis of diabetic ulcer. MMPs participate in various biological processes relevant to diabetic ulcer, such as ECM secretion, granulation tissue configuration, angiogenesis, collagen growth, re-epithelization, inflammatory response, as well as oxidative stress, thus, seeking and developing agents targeting MMPs has emerged as a potential way to treat diabetic ulcer. Natural products especially flavonoids, polysaccharides, alkaloids, polypeptides, and estrogens extracted from herbs, vegetables, as well as animals that have been extensively illustrated to treat diabetic ulcer through targeting MMPs-mediated signaling pathways, are discussed in this review and may contribute to the development of functional foods or drug candidates for diabetic ulcer therapy. This review highlights the regulation of MMPs in diabetic wound healing, and the potential therapeutic ability of natural products for diabetic wound healing by targeting MMPs.

Niaoduqing alleviates podocyte injury in high glucose model via regulating multiple targets and AGE/RAGE pathway: Network pharmacology and experimental validation

Purpose: The aim of present study was to explore the pharmacological mechanisms of Niaoduqing granules on the treatment of podocyte injury in diabetic nephropathy (DN) via network pharmacology and experimental validation. Methods: Active ingredients and related targets of Niaoduqing, as well as related genes of podocyte injury, proteinuria and DN, were obtained from public databases. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) network analysis were performed to investigate the potential mechanisms. High glucose (HG) -induced MPC5 cell injury model was treated with the major core active ingredients of Niaoduqing and used to validate the predicted targets and signaling pathways. Results: Totally, 16 potential therapeutic targets were identified by intersecting the targets of Niaoduqing and disease, in which 7 of them were considered as the core targets via PPI network analysis. KEGG enrichment analysis showed that AGE-RAGE signaling pathway was identified as the most crucial signaling pathway. The results of in vitro experiments revealed that the treatment of Niaoduqing active ingredients significantly protected MPC5 cells from HG-induced apoptosis. Moreover, Niaoduqing could significantly attenuate the HG-induced activation of AGE-RAGE signaling pathway, whereas inhibited the over-expression of VEGF-A, ICAM-1, PTGS-2 and ACE in HG-induced MPC5 cells. Conclusion: Niaoduqing might protect against podocyte injury in DN through regulating the activity of AGE/RAGE pathway and expression of multiple genes. Further clinical and animal experimental studies are necessary to confirm present findings.

Quercetin and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a reproductive endocrine disease, and results to opsomenorrhea or amenorrhea, hairy, acne, acanthosis, infertility, abortion. In the long term, PCOS may also increase the risk of endometrial cancer, diabetes, hypertension, dyslipidemia and other diseases. Till now there is no specific drug for PCOS due to the unclearness of the cause and pathogenesis, as current treatments for PCOS only target certain symptoms. Quercetin (QUR) is a flavonoid drug widely found in Chinese herbal medicines, fruits, leaves, vegetables, seeds and plants roots. Studies on other diseases have found that QUR has anti-oxidant, anti-inflammatory, anti-insulin resistance, anti-cancer and other effects. Some studies have shown that serum testosterone (T), luteinizing hormone (LH), the LH/follicule-stimulating hormone (FSH) ratio, fasting glucose, fasting insulin, HOMA-IR and lipid levels are reduced in PCOS patients with QUR treatment. However, the mechanisms of QUR in PCOS patients have not been completely elucidated. In this review, we retrospect the basic characteristics of QUR, and in vitro studies, animal experiments and clinical trials of QUR and plant extracts containing QUR in the treatment of PCOS. We also summarized the effects and mechanism of QUR in ovarian cells in vitro and PCOS model rats, the changes in relevant parameters after QUR administration in PCOS patients, and its potentially therapeutic applications.

Single-cell analysis reveals that Jinwu Gutong capsule attenuates the inflammatory activity of synovial cells in osteoarthritis by inhibiting AKR1C3

Jinwu Gutong capsule (JGC) is a traditional Chinese medicine formula for the treatment of osteoarthritis (OA). Synovitis is a typical pathological change in OA and promotes disease progression. Elucidating the therapeutic mechanism of JGC is crucial for the precise treatment of OA synovitis. In this study, we demonstrate that JGC effectively inhibits hyperproliferation, attenuates inflammation, and promotes apoptosis of synovial cells. Through scRNA-seq data analysis of OA synovitis, we dissected two distinct cell fates that influence disease progression (one fate led to recovery while the other fate resulted in deterioration), which illustrates the principles of fate determination. By intersecting JGC targets with synovitis hub genes and then mimicking picomolar affinity interactions between bioactive compounds and binding pockets, we found that the quercetin-AKR1C3 pair exhibited the best affinity, indicating that this pair constitutes the most promising molecular mechanism. In vitro experiments confirmed that the expression of AKR1C3 in synovial cells was reduced after JGC addition. Further overexpression of AKR1C3 significantly attenuated the therapeutic efficacy of JGC. Thus, we revealed that JGC effectively treats OA synovitis by inhibiting AKR1C3 expression.

Research Progress on Mitochondrial Dysfunction in Diabetic Retinopathy

Diabetic Retinopathy (DR) is one of the most important microvascular complications of diabetes mellitus, which can lead to blindness in severe cases. Mitochondria are energy-producing organelles in eukaryotic cells, which participate in metabolism and signal transduction, and regulate cell growth, differentiation, aging, and death. Metabolic changes of retinal cells and epigenetic changes of mitochondria-related genes under high glucose can lead to mitochondrial dysfunction and induce mitochondrial pathway apoptosis. In addition, mitophagy and mitochondrial dynamics also change adaptively. These mechanisms may be related to the occurrence and progression of DR, and also provide valuable clues for the prevention and treatment of DR. This article reviews the mechanism of DR induced by mitochondrial dysfunction, and the prospects for related treatment.

Antidiabetic Actions of Ethanol Extract of Camellia sinensis Leaf Ameliorates Insulin Secretion, Inhibits the DPP-IV Enzyme, Improves Glucose Tolerance, and Increases Active GLP-1 (7-36) Levels in High-Fat-Diet-Fed Rats

Camellia sinensis (green tea) is used in traditional medicine to treat a wide range of ailments. In the present study, the insulin-releasing and glucose-lowering effects of the ethanol extract of Camellia sinensis (EECS), along with molecular mechanism/s of action, were investigated in vitro and in vivo. The insulin secretion was measured using clonal pancreatic BRIN BD11 β cells, and mouse islets. In vitro models examined the additional glucose-lowering properties of EECS, and 3T3L1 adipocytes were used to assess glucose uptake and insulin action. Non-toxic doses of EECS increased insulin secretion in a concentration-dependent manner, and this regulatory effect was similar to that of glucagon-like peptide 1 (GLP-1). The insulin release was further enhanced when combined with isobutylmethylxanthine (IBMX), tolbutamide or 30 mM KCl, but was decreased in the presence of verapamil, diazoxide and Ca²⁺ chelation. EECS also depolarized the β-cell membrane and elevated intracellular Ca²⁺, suggesting the involvement of a K_ATP-dependent pathway. Furthermore, EECS increased glucose uptake and insulin action in 3T3-L1 cells and inhibited dipeptidyl peptidase IV (DPP-IV) enzyme activity, starch digestion and protein glycation in vitro. Oral administration of EECS improved glucose tolerance and plasma insulin as well as inhibited plasma DPP-IV and increased active GLP-1 (7-36) levels in high-fat-diet-fed rats. Flavonoids and other phytochemicals present in EECS could be responsible for these effects. Further research on the mechanism of action of EECS compounds could lead to the development of cost-effective treatments for type 2 diabetes.

Polyphenols and inflammatory bowel disease: Natural products with therapeutic effects?

Inflammatory bowel disease (IBD) is a long-life disease with periods of recurrence and relief. Oxidative stress plays an important role in the pathogenesis of this disease. Recent years' studies in the field of IBD treatment mostly have focused on targeting cytokines and immune cell trafficking using antibodies and inhibitors, altering the composition of intestinal bacteria in the line of attenuation of inflammation using probiotics and prebiotics, and attenuating oxidative stress through antioxidant supplementation. Studies in animal models of IBD have shown that some polyphenolic compounds including curcumin, quercetin, resveratrol, naringenin, and epigallocatechin-3-gallate can affect almost all of the above aspects and are useful compounds in the treatment of IBD. Clinical studies performed on IBD patients have also confirmed the findings of animal model studies and have shown that supplementation with some of the above-mentioned polyphenolic compounds has positive effects in reducing disease clinical and endoscopic activity, inducing and maintaining remission, and improving quality of life. In this review article, in addition to a detailed reviewing the effects of the above-mentioned polyphenolic compounds on the events involved in the pathogenesis of IBD, the results of these clinical studies will also be reviewed.

Molecular Mechanistic Pathways Targeted by Natural Compounds in the Prevention and Treatment of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is one of the most common complications of diabetes, and its prevalence is still growing rapidly. However, the efficient therapies for this kidney disease are still limited. The pathogenesis of DKD involves glucotoxicity, lipotoxicity, inflammation, oxidative stress, and renal fibrosis. Glucotoxicity and lipotoxicity can cause oxidative stress, which can lead to inflammation and aggravate renal fibrosis. In this review, we have focused on in vitro and in vivo experiments to investigate the mechanistic pathways by which natural compounds exert their effects against the progression of DKD. The accumulated and collected data revealed that some natural compounds could regulate inflammation, oxidative stress, renal fibrosis, and activate autophagy, thereby protecting the kidney. The main pathways targeted by these reviewed compounds include the Nrf2 signaling pathway, NF-κB signaling pathway, TGF-β signaling pathway, NLRP3 inflammasome, autophagy, glycolipid metabolism and ER stress. This review presented an updated overview of the potential benefits of these natural compounds for the prevention and treatment of DKD progression, aimed to provide new potential therapeutic lead compounds and references for the innovative drug development and clinical treatment of DKD.