Pretreatment with the total flavone glycosides of Flos Abelmoschus manihot and hyperoside prevents glomerular podocyte apoptosis in streptozotocin-induced diabetic nephropathy

Astragalus polysaccharide attenuates diabetic nephropathy by reducing apoptosis and enhancing autophagy through activation of Sirt1/FoxO1 pathway

OBJECTIVE

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in diabetic patients. Astragalus polysaccharide (APS) is a natural active ingredient in Astragalus membranaceus with anti-hypertensive and anti-oxidative properties. This study aimed to explore the protective roles of APS and its underlying mechanisms in DN.

METHODS

After the establishment of a rat model of DN by a high-fat diet and treatment with 30 mg/kg streptozotocin (STZ), the effects of 100 mg/kg APS on the levels of serum creatinine, blood urea nitrogen, blood glucose, and urinary albumin-to-creatinine ratio were measured. Histopathological alterations in renal tissues, renal cell apoptosis, renal inflammation, and oxidative stress were examined. The impacts of 0-200 μg/mL APS on the viability and apoptosis in high glucose (HG)-stimulated podocytes were measured by Cell Counting Kit-8 assays and flow cytometry, respectively. The expression of genes was tested by immunoblotting, quantitative real-time PCR, and immunofluorescence staining.

RESULTS

APS enhanced the expression of podocin and nephrin, increased viability, and reduced apoptosis in HG-induced podocytes. APS treatment abrogated high glucose-mediate suppression of autophagy in podocytes by activating the Sirt1/FoxO1 pathway. The Sirt1 inhibitor EX-527 eliminated the ameliorative effects of APS on renal dysfunction and renal tissue damage, as well as the inhibitory effects of APS on oxidative stress, inflammation, and apoptosis in DN rats. Moreover, EX-527 inhibited APS-induced autophagy activation in DN rats.

CONCLUSION

APS mitigated DN under hyperglycemic conditions by activating the Sirt1/FoxO1 autophagy pathway, suggesting that APS is a promising agent for DN treatment.

Therapeutic approaches for cholestatic liver diseases: the role of nitric oxide pathway

Cholestasis describes bile secretion or flow impairment, which is clinically manifested with fatigue, pruritus, and jaundice. Neutrophils play a crucial role in many diseases such as cholestasis liver diseases through mediating several oxidative and inflammatory pathways. Data have been collected from clinical, in vitro, and in vivo studies published between 2000 and December 2021 in English and obtained from the PubMed, Google Scholar, Scopus, and Cochrane libraries. Although nitric oxide plays an important role in the pathogenesis of cholestatic liver diseases, excessive levels of NO in serum and affected tissues, mainly synthesized by the inducible nitric oxide synthase (iNOS) enzyme, can exacerbate inflammation. NO induces the inflammatory and oxidative processes, which finally leads to cell damage. We found that natural products such as baicalin, curcumin, resveratrol, and lycopene, as well as chemical likes ursodeoxycholic acid, dexamethasone, rosuvastatin, melatonin, and sildenafil, are able to markedly attenuate the NO production and iNOS expression, mainly through inducing the nuclear factor κB (NF-κB), Janus kinase and signal transducer and activator of transcription (JAK/STAT), and toll like receptor-4 (TLR4) signaling pathways. This study summarizes the latest scientific data about the bile acid signaling pathway, the neutrophil chemotaxis recruitment process during cholestasis, and the role of NO in cholestasis liver diseases. Literature review directed us to propose that suppression of NO and its related pathways could be a therapeutic option for preventing or treating cholestatic liver diseases.

The therapeutic effect of wine-processed Corni Fructus on chronic renal failure in rats through the interference with the LPS/IL-1-mediated inhibition of RXR function

ETHNOPHARMACOLOGICAL RELEVANCE

Corni Fructus, derived from the fruit of Cornus officinalis Sieb. et Zucc, is a widely utilized traditional Chinese medicine (TCM) with established efficacy in the treatment of diverse chronic kidney diseases. Crude Corni Fructus (CCF) and wine-processed Corni Fructus (WCF) are the main processed forms of Corni Fructus. Generally, TCM is often used after processing (paozhi). Despite the extensive use of processed TCM, the underlying mechanisms of processing for most TCMs have been unclear so far.

AIM OF THE STUDY

In this study, an integrated strategy combined renal metabolomics with proteomics was established and investigated the potential processing mechanisms of CCF or WCF on chronic renal failure (CRF) models.

MATERIALS AND METHODS

Firstly, the differences in biochemical parameters and pathological histology were compared to evaluate the effects of CCF and WCF on CRF model rats. Then, the tissue differential metabolites and proteins between CCF and WCF on CRF model rats were screened based on metabolomics and proteomics technology. Concurrently, a combined approach of metabolomics and proteomics was employed to investigate the underlying mechanisms associated with these marker metabolic products and proteins.

RESULTS

Compared to the MG group, there were 27 distinct metabolites and 143 different proteins observed in the CCF-treatment group, while the WCF-treatment group exhibited 24 distinct metabolites and 379 different proteins. Further, the integration interactions analysis of the protein and lipid metabolite revealed that both WCF and CCF improved tryptophan degradation and LPS/IL-1-mediated inhibition of RXR function. WCF inhibited RXR function more than CCF via the modulation of LPS/IL-1 in the CRF model. Experimental results were validated by qRT-PCR and western blotting. Notably, the gene expression amount and protein levels of FMO3 and CYP2E1 among 8 genes influenced by WCF were higher compared to CCF.

CONCLUSION

The results of this study provide a theoretical basis for further study of Corni Fructus with different processing techniques in CRF. The findings also offer guidance for investigating the mechanism of action of herbal medicines in diseases employing diverse processing techniques.

Identification of the main flavonoids of Abelmoschus manihot (L.) medik and their metabolites in the treatment of diabetic nephropathy

Introduction: Huangkui capsule (HKC) is made from the ethanol extract of Abelmoschus manihot (L.) Medik [Malvaceae; abelmoschi corolla] and received approval from the China Food and Drug Administration (Z19990040) in 1999. Currently, HKC is used for treatment of the patients with diabetic nephropathy (DN) in China. The bioactive chemical constituents in HKC are total flavonoids of A. manihot (L.) Medik (TFA). The present study aims to identify the primary flavonoid metabolites in HKC and TFA and their metabolism fates in db/db mice, the animal model for the study of type 2 diabetes and DN. Methods: HKC (0.84 g/kg/d) and TFA (0.076 g/kg/d) or vehicle were respectively administered daily via oral gavage in db/db mice for 4 weeks. The metabolism fate of the main metabolites of HKC in serum, liver, kidney, heart, jejunum, colon, jejunal contents, colonic contents, and urine of db/db mice were analyzed with a comprehensive metabolite identification strategy. Results and Discussion: In db/db mice administered with HKC and TFA, 7 flavonoid prototypes and 38 metabolites were identified. The related metabolic pathways at Phases I and II reactions included dehydroxylation, deglycosylation, hydrogenation, methylation, glucuronidation, sulphation, and corresponding recombined reactions. Quercetin, isorhamnetin, quercetin sulphate, quercetin monoglucuronide, and isorhamnetin monoglucuronide presented a high exposure in the serum and kidney of db/db mice. Thereby, the present study provides a pharmacodynamic substance basis for better understanding the mechanism of A. manihot (L.) Medik for medication of DN.

Traditional Chinese medicine for the treatment of immune-related nephropathy: A review

Immune-related nephropathy (IRN) refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure. The pathogenesis of IRN is not fully understood; therefore, treatment is challenging. Traditional Chinese medicines (TCMs) have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy, lupus nephropathy, and diabetic nephropathy. The underlying mechanisms mainly include its inhibition of inflammation; improvements to renal interstitial fibrosis, oxidative stress, autophagy, apoptosis; and regulation of immunity. In this review, we summarize the clinical symptoms of the three IRN subtypes and the use of TCM prescriptions, herbs, and bioactive compounds in treating IRN, as well as the potential mechanisms, intending to provide a reference for the future study of TCM as IRN treatments.

Phytochemicals and their Potential Mechanisms against Insulin Resistance

Insulin's inception dates back to 1921 and was unveiled through a momentous revelation. Diabetes is a dangerous, long-term disease in which the body fails to generate enough insulin or utilize the insulin it creates adequately. This causes hyperglycemia, a state of high blood sugar levels, which can even put a person into a coma if not managed. Activation of the insulin receptor corresponds to two crucial metabolic functions, i.e., uptake of glucose and storage of glycogen. Type 2 diabetes mellitus (T2DM) exists as one of the most challenging medical conditions in the 21st century. The sedentary lifestyle and declining quality of food products have contributed to the rapid development of metabolic disorders. Hence, there is an urgent need to lay some reliable, significant molecules and modalities of treatment to combat and manage this epidemic. In this review, we have made an attempt to identify and enlist the major phytoconstituents along with the associated sources and existing mechanisms against insulin resistance. The conducted study may offer potential sustainable solutions for developing and formulating scientifically validated molecules and phytoconstituents as formulations for the management of this metabolic disorder.

m6A epitranscriptomic modification in diabetic microvascular complications

N6-methyladenosine (m6A) modifications are modulated by m6A methyltransferases, m6A demethylases, and m6A-binding proteins. The dynamic and reversible patterns of m6A modification control cell fate programming by regulating RNA splicing, translation, and decay. Emerging evidence demonstrates that m6A modification of coding and noncoding RNAs exerts crucial effects that influence the pathogenesis of diabetic microvascular complications that include diabetic cardiomyopathy, diabetic nephropathy, diabetic retinopathy, diabetic neuropathy, and diabetic dermatosis. In this review, we summarize the roles of m6A modification and m6A modification-related enzymes in diabetic microvascular complications and discuss potential m6A modification-related enzyme-targeting therapeutic strategies.

Total flavone of flowers of Abelmoschus manihot (L.) Medic inhibits the expression of adhesion molecules in primary mesenteric arterial endothelial cells and ameliorates dextran sodium sulphate-induced ulcerative colitis in mice

BACKGROUND

Flowers of Abelmoschus manihot (L.) medic (AM) is a traditional Chinese medicine used to treat chronic nephritis, nephrotic syndrome, diabetic nephropathy, and colonic inflammation.

PURPOSE

This study aimed to explore the influence of the total flavone of AM flowers (TFA) on acute ulcerative colitis (UC) and the potential underlying mechanism.

METHODS

Efficacy of TFA (30, 60, 120 mg/kg) on UC was evaluated in a dextran sodium sulphate (DSS)-induced colonic inflammatory mouse model by analyzing disease activity index (DAI), histopathological score, colon length, and cytokine expression. Expression levels of critical adhesion molecules and nuclear factor kappa B (NF-κB) were examined by qRT-PCR, Western blotting, or immunofluorescence labeling. Myeloperoxidase activity was examined using ELISA. In vitro THP-1 adhesion assay was used to evaluate monocyte adhesion.

RESULTS

TFA significantly reduced DAI score, prevented colon shortening, and ameliorated histological injuries of colons in DSS-treated mice. TFA inhibited the expression of cytokines (IL-1β and TNF-α) and adhesion molecules (ICAM-1, VCAM-1, and MAdCAM-1) in colon tissues of DSS mice. In vitro studies on mesenteric arterial endothelial cells (MAECs) showed that TFA attenuated TNF-α-induced upregulation of ICAM-1, VCAM-1, and MAdCAM-1, as well as THP-1 cell adhesion to MAECs. TFA also suppressed the phosphorylation and nuclear translocation of NF-κB in MAECs.

CONCLUSION

TFA efficaciously ameliorates UC possibly by inhibiting monocyte adhesion through blocking TNF-α-induced NF-κB activation, which in turn suppresses the upregulation of adhesive molecules in colon endothelial cells. Inhibiting the expression of adhesion molecule in MAECs may represent a useful strategy for therapeutic development to treat UC, with TFA being a safe and efficacious therapeutic agent.

Neuroprotective Effect of Abelmoschus manihot Flower Extracts against the H2O2-Induced Cytotoxicity, Oxidative Stress and Inflammation in PC12 Cells

The progression of neurodegenerative diseases is associated with oxidative stress and inflammatory responses. Abelmoschus manihot L. flower (AMf) has been shown to possess excellent antioxidant and anti-inflammatory activities. This study investigated the protective effect of ethanolic extract (AME), water extract (AMW) and supercritical extract (AMS) of AMf on PC12 neuronal cells under hydrogen peroxide (H2O2) stimulation. This study also explored the molecular mechanism underlying the protective effect of AME, which was the best among the three extracts. The experimental results showed that even at a concentration of 500 μg/mL, neither AME nor AMW showed toxic effects on PC12 cells, while AMS caused about 10% cell death. AME has the most protective effect on apoptosis of PC12 cells stimulated with 0.5 mM H2O2. This is evident by the finding when PC12 cells were treated with 500 μg/mL AME; the viability was restored from 58.7% to 80.6% in the Treatment mode (p < 0.001) and from 59.1% to 98.1% in the Prevention mode (p < 0.001). Under the stimulation of H2O2, AME significantly up-regulated the expression of antioxidant enzymes, such as catalase, glutathione peroxidase and superoxide dismutase; promoted the production of the intracellular antioxidant; reduced glutathione; and reduced ROS generation in PC12 cells. When the acute inflammation was induced under the H2O2 stimulation, AME significantly down-regulated the pro-inflammatory cytokines and mediators (e.g., TNF-α, IL-1β, IL-6, COX-2 and iNOS). AME pretreatment could also greatly promote the production of nucleotide excision repair (NER)-related proteins, which were down-regulated by H2O2. This finding indicates that AME could repair DNA damage caused by oxidative stress. Results from this study demonstrate that AME has the potential to delay the onset and progression of oxidative stress-induced neurodegenerative diseases.

Therapeutic potential of dietary flavonoid hyperoside against non-communicable diseases: targeting underlying properties of diseases

Non-communicable diseases (NCDs) are a global epidemic with diverse pathogenesis. Among them, oxidative stress and inflammation are the most fundamental co-morbid features. Therefore, multi-targets and multi-pathways therapies with significant anti-oxidant and anti-inflammatory activities are potential effective measures for preventing and treating NCDs. The flavonol glycoside compound hyperoside (Hyp) is widely found in a variety of fruits, vegetables, beverages, and medicinal plants and has various health benefits, especially excellent anti-oxidant and anti-inflammatory properties targeting nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB) signaling pathways. In this review, we summarize the pathogenesis associated with oxidative stress and inflammation in NCDs and the biological activity and therapeutic potential of Hyp. Our findings reveal that the anti-oxidant and anti-inflammatory activities regulated by Hyp are associated with numerous biological mechanisms, including positive regulation of mitochondrial function, apoptosis, autophagy, and higher-level biological damage activities. Hyp is thought to be beneficial against organ injuries, cancer, depression, diabetes, and osteoporosis, and is a potent anti-NCDs agent. Additionally, the sources, bioavailability, pharmacy, and safety of Hyp have been established, highlighting the potential to develop Hyp into dietary supplements and nutraceuticals.

Total extract of Abelmoschus manihot L. alleviates uric acid-induced renal tubular epithelial injury via inhibition of caspase-8/caspase-3/NLRP3/GSDME signaling

Purpose: The incidence of uric acid (UA)-induced kidney injury is increasing owing to the high incidence of hyperuricemia in recent years. The flower of Abelmoschus manihot (Linneus) Medik is a traditional Chinese medicinal herb widely used in the treatment of some kidney diseases. In our previous study, we reported that the total extract of A. manihot L. flower (TEA) attenuated adriamycin-induced renal tubular cell injury. In this study, we aimed to evaluate the role of TEA in UA-induced tubular cell injury.

Methods: Normal rat proximal epithelial NRK-52E cells were incubated with UA to mimic hyperuricemia conditions. The role of TEA in the renal tubular cells was also assessed. The cellular morphology was observed using phase-contrast microscopy, and cell viability was analyzed using the Cell Counting kit-8. Living and dead cells were stained using a Calcein-AM/PI double stain kit. The release of lactate dehydrogenase (LDH) was analyzed by LDH cytotoxicity Assay Kit. The expression of target proteins was analyzed using western blot analysis.

Results: UA triggered NRK-52E cell injury, as evidenced by morphological changes, detachment of cells from the bottom, cell swelling, large bubbles blowing from cell membrane and loss of cell viability. UA increased release of LDH. UA induced the expression of p-ERK1/2 and the subsequent activation of caspase-8, caspase-3, and NLRP3 inflammasomes. Pyroptosis was elicited by UA after gasdermin E N-terminal (GSDME-NT) was cleaved from gasdermin E (GSDME). Z-DEVD-FMK, a caspase-3 inhibitor, suppressed the expression of both NLRP3 and GSDME-NT, but not that of caspase-8. INF39, an NLRP3 inhibitor, altered the expression of GSDME-NT expression, but not that caspase-3 and caspase-8. TEA alleviated UA-induced cell injury by suppressing ERK1/2/caspase-8/caspase-3/NLRP3/GSDME signaling.

Conclusion: GSDME-mediated pyroptosis was involved in UA-induced renal tubular cell injury. This is the first study to report that TEA protects renal tubular epithelial cells against UA by inhibiting the ERK/1/2/caspase-8/caspase-3/NLRP3/GSDME pathway.

Hyperoside as a Potential Natural Product Targeting Oxidative Stress in Liver Diseases

Hyperoside (Hyp), also known as quercetin-3-O-galactoside or 3-O-β-D-galactopyranosyl, is a well-known flavonol glycoside that is abundant in various fruits, vegetables, and medicinal plants. Hyp has been suggested to exhibit a wide range of biological actions, including cardiovascular, renal, neuroprotective, antifungal, antifibrotic, and anticancer effects. Accumulating evidence supports the pharmacological activities of Hyp in improving liver pathophysiology. Hence, the present literature review aims to summarize preclinical data suggesting the beneficial effects and underlying mechanisms of Hyp. In addition, our study focuses on hepatic antioxidant defense signaling to assess the underlying mechanisms of the biological actions of Hyp that are closely associated with liver diseases. Experimental findings from an up-to-date search showed that Hyp possesses hepatoprotective, antiviral, antisteatotic, anti-inflammatory, antifibrotic, and anticancer activities in cellular and animal models related to liver dysfunction by enhancing antioxidant responses. In particular, hepatocellular antioxidant defense via activation of erythroid-related nuclear factor 2 by Hyp chiefly explains how this compound acts as a therapeutic agent in liver diseases. Thus, this review emphasizes the therapeutic potential of Hyp as a strong antioxidative substance that plays a crucial role in the regulation of various liver disorders during their pathogenesis.

Evidence construction of Huangkui capsule against chronic glomerulonephritis: A systematic review and network pharmacology

BACKGROUND

Chronic glomerulonephritis (CGN) is a relatively common primary glomerular disease. Huangkui capsule (HKC) combined with angiotensin receptor blocker (ARB) for CGN is frequently used in clinical practice, however, there is still lack of high-quality evidence-based evidence and network pharmacology to clarify the therapeutic efficacy and pharmacological mechanisms.

PURPOSE

Integrating evidence-based medicine and network pharmacology to explain the therapeutic efficacy and pharmacological mechanisms of ARB combined with HKC for CGN.

METHODS

Studies matching the topic were searched from PubMed, Web of Science, Embase database, the Cochrane Library, Chinese National Knowledge Infrastructure, CBM databases, the VIP medicine information system and the Wanfang database and screened according to inclusion and exclusion criteria. The data of the included studies were meta-analyzed by blood urea nitrogen (BUN), serum creatinine (SCR), 24-h urine protein (24hUP) and effective rate (ER). A meta-analysis of the data from the included studies was performed. Then, based on the network pharmacology, the chemical ingredients in HKC and their targets of action, disease targets, common targets and other relevant information were screened, and the key pathways were relevantly annotated based on bioinformatics technology to explore the potential mechanisms of HKC and ARB for CGN.

RESULTS

The results showed that SCR index (p < 0.05), 24hUP index (p < 0.001) in the group treated with HKC and ARB were significantly lower than those in the control group. BUN index in the group treated with HKC and VAL were significantly lower than those in the control group (p < 0.001). Effective rate index in the group treated with HKC and ARB was significantly higher than those in the control group (p < 0.001). There was no significant difference in BUN treated with IRB, LOS, and TEL (p = 0.181; p = 0.811; p = 0.067). Based on network pharmacology, the results were as follows: The PPI network indicated that STAT3, AKT1, MAPK1, TP53 and JUN were key target proteins. The results of KEGG analysis suggested that the pharmacological mechanisms were mainly associated with AGE-RAGE signaling pathway in diabetic complications.

CONCLUSION

The combination of ARB and HKC can achieve better therapeutic effects in the treatment of CGN, meanwhile, ARB and HKC have a significant improved effectiveness in the treatment of CGN compared with ARB or HKC alone. In addition, HKC and ARB synergistically treated CGN through a multi-pathway network.

Hyperoside: A review on its sources, biological activities, and molecular mechanisms

Hyperoside is a natural flavonol glycoside in various plants, such as Crataegus pinnatifida Bge, Forsythia suspensa, and Cuscuta chinensis Lam. Medical research has found that hyperoside possesses a broad spectrum of biological activities, including anticancer, anti-inflammatory, antibacterial, antiviral, antidepressant, and organ protective effects. These pharmacological properties lay the foundation for its use in treating multiple diseases, such as sepsis, arthritis, colitis, diabetic nephropathy, myocardial ischemia-reperfusion, pulmonary fibrosis, and cancers. Hyperoside is obtained from the plants and chemical synthesis. This study aims to provide a comprehensive overview of hyperoside on its sources and biological activities to provide insights into its therapeutic potential, and to provide a basis for high-quality studies to determine the clinical efficacy of this compound.

Efficacy and safety of Abelmoschus manihot in treating chronic kidney diseases: A multicentre, open-label and single-arm clinical trial

RATIONALE AND OBJECTIVE

The efficacy of Abelmoschus manihot (AM) in treating of chronic kidney disease (CKD) has been confirmed by prior trials. AM is also commonly combined to other medicines among CKD patients in clinic. This trial aimed at evaluating the safety of AM combination application, and further verifying the efficacy of AM in treating various types of CKD.

STUDY DESIGN

A multicentre, prospective, open-label, single-arm trial SETTING AND PARTICIPANTS: Approximately 2000 CKD patients with proteinuria (≥ 150 mg/d), from 105 centres across China INTERVENTIONS: AM was administered to patients three times per day for 24 weeks: the daily dose was based on age (> 12 years old: 2.5 g tid; 6∼12 years old: 1.5 g tid; 2∼6 years old: 1 g tid) OUTCOMES: The efficacy outcomes were the change in 24-hour proteinuria and estimated glomerular filtration rate (eGFR) from baseline to week 24. Safety outcomes included adverse events and laboratory tests.

RESULTS

2054 CKD patients from 105 centres were enrolled in this trial, with 1843 (89.7%) completing the 24-week follow-up. The participants' median age was 44 years old and 44.6% were female. Compared to baseline, 24-hour proteinuria decreased 471 mg (95% confident interval, 367 to 575, p < 0.001) at week 24. eGFR did not change significantly relative to baseline with the mean increase as 1.7 ml/min/1.73 m2 (95% confident interval, -0.3 to 3.7, p = 0.09). 902 (43.9%) participants combined medication to AM during follow-up. The total incidence of adverse events was 12.9%; and the most common adverse events were hyperlipidaemia (4.1%), abnormal liver function (2.3%), upper respiratory infection (1.8%), and hyperglycaemia (1.1%). Combined medications did not change the risk for hyperlipidaemia and upper respiratory infection. The combination application with antiplatelet reagents increased the risk of abnormal liver function, and with calcium channel blockers increased the risk of hyperglycaemia.

LIMITATIONS

Single-arm clinical trial and short observation time CONCLUSION: We have provided safety information of AM on various types of CKD in a large trial, especially when combination to medications most commonly prescribed to CKD patients. AM also showed to decrease proteinuria with stable kidney function during follow up. AM is a promising treatment for CKD patients.

Quercetin Attenuates Podocyte Apoptosis of Diabetic Nephropathy Through Targeting EGFR Signaling

Podocytes injury is one of the leading causes of proteinuria in patients with diabetic nephropathy (DN), and is accompanied by podocytes apoptosis and the reduction of podocyte markers such as synaptopodin and nephrin. Therefore, attenuation of podocyte apoptosis is considered as an effective strategy to prevent the proteinuria in DN. In this study, we evaluated the anti-podocyte-apoptosis effect of quercetin which is a flavonol compound possessing an important role in prevention and treatment of DN and verified the effect by using db/db mice and high glucose (HG)-induced mouse podocytes (MPs). The results show that administration of quercetin attenuated the level of podocyte apoptosis by decreasing the expression of pro-apoptotic protein Bax, cleaved caspase 3 and increasing the expression of anti-apoptotic protein Bcl-2 in the db/db mice and HG-induced MPs. Furthermore, epidermal growth factor receptor (EGFR) was predicted to be the potential physiological target of quercetin by network pharmacology. In vitro and vivo experiments confirmed that quercetin inhibited activation of the EGFR signaling pathway by decreasing phosphorylation of EGFR and ERK1/2. Taken together, this study demonstrates that quercetin attenuated podocyte apoptosis through inhibiting EGFR signaling pathway, which provided a novel approach for further research of the mechanism of quercetin in the treatment of DN.

Molecular Mechanistic Pathways Targeted by Natural Antioxidants in the Prevention and Treatment of Chronic Kidney Disease

Chronic kidney disease (CKD) is the progressive loss of renal function and the leading cause of end-stage renal disease (ESRD). Despite optimal therapy, many patients progress to ESRD and require dialysis or transplantation. The pathogenesis of CKD involves inflammation, kidney fibrosis, and blunted renal cellular antioxidant capacity. In this review, we have focused on in vitro and in vivo experimental and clinical studies undertaken to investigate the mechanistic pathways by which these compounds exert their effects against the progression of CKD, particularly diabetic nephropathy and kidney fibrosis. The accumulated and collected data from preclinical and clinical studies revealed that these plants/bioactive compounds could activate autophagy, increase mitochondrial bioenergetics and prevent mitochondrial dysfunction, act as modulators of signaling pathways involved in inflammation, oxidative stress, and renal fibrosis. The main pathways targeted by these compounds include the canonical nuclear factor kappa B (NF-κB), canonical transforming growth factor-beta (TGF-β), autophagy, and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid factor 2-related factor 2 (Nrf2)/antioxidant response element (ARE). This review presented an updated overview of the potential benefits of these antioxidants and new strategies to treat or reduce CKD progression, although the limitations related to the traditional formulation, lack of standardization, side effects, and safety.

New Insights Into the Effects of Individual Chinese Herbal Medicines on Chronic Kidney Disease

The clinical and experimental study into the effects of Chinese herbal medicines on chronic kidney disease has evolved over the past 40 years with new insight into their mechanism and evidence of their clinical effects. Among the many traditional Chinese herbs examined in chronic renal disease, five were found to have evidence of sufficient clinical efficacy, high frequency of use, and well-studied mechanism. They are: Abelmoschus manihot and Huangkui capsule, Salvia miltiorrhiza and its components (tanshinone II A, salvianolic acid A and B); Rhizoma coptidis and its monomer berberine; Tripterygium wilfordii and its components (triptolide, tripterygium glycosides); Kudzu root Pueraria and its monomer Puerarin. These Chinese herbal medications have pharmaceutical effects against fibrosis, inflammation and oxidative stress and also promote renal repair and regeneration. This article reviews their clinical efficacy, anti-fibrotic effects in animal models, and molecular mechanism of action.

Deciphering nutritional interventions for podocyte structure and function

Despite increasing awareness and therapeutic options chronic kidney disease (CKD) is still and important health problem and glomerular diseases constitute and important percentage of CKD. Proteinuria/albuminuria is not just a marker; but it also plays a direct pathogenic role in renal disease progression of CKD. Glomerular filtration barrier (GFB) which consists of fenestrated endothelial cells, fused basal membrane and interdigitating podocyte foot process and filtration slits between foot process is the major barrier for proteinuria/albuminuria. Many glomerular diseases are characterized by disruption of GFB podocytes, foot process and slit diaphragm. Many proteinuric diseases are non-specifically targeted by therapeutic agents such as steroids and calcineurin inhibitors with systemic side effects. Thus, there is unmet need for more efficient and less toxic therapeutic options to treat glomerular diseases. In recent years, modification of dietary intake, has been gained to treat pathologic processes introducing the concept of 'food as a medicine'. The effect of various nutritional products on podocyte function and structure is also trending, especially in recent years. In the current review, we summarized the effect of nutritional interventions on podocyte function and structure.

Total Flavones of Abelmoschus manihot Ameliorates Podocyte Pyroptosis and Injury in High Glucose Conditions by Targeting METTL3-Dependent m6A Modification-Mediated NLRP3-Inflammasome Activation and PTEN/PI3K/Akt Signaling

Background: The total flavones of Abelmoschus manihot (TFA), a compound that is extracted from Abelmoschus manihot, has been widely used in China to reduce podocyte injury in diabetic kidney disease (DKD). However, the mechanisms underlying the therapeutic action of this compound have yet to be elucidated. Podocyte pyroptosis is characterized by activation of the NLRP3 inflammasome and plays an important role in inflammation-mediated diabetic kidneys. Regulation of the PTEN/PI3K/Akt pathway is an effective strategy for improving podocyte damage in DKD. Previous research has also shown that N6-methyladenosine (m6A) modification is involved in DKD and that m6A-modified PTEN regulates the PI3K/Akt pathway. In this study, we investigated whether TFA alleviates podocyte pyroptosis and injury by targeting m6A modification-mediated NLRP3-inflammasome activation and PTEN/PI3K/Akt signaling. Methods: We used MPC-5 cells under high glucose (HG) conditions to investigate the key molecules that are involved in podocyte pyroptosis and injury, including activation of the NLRP3 inflammasome and the PTEN/PI3K/Akt pathway. We detected alterations in the levels of three methyltransferases that are involved in m6A modification. We also investigated changes in the levels of these key molecules in podocytes with the overexpression or knockdown of methyltransferase-like (METTL)3. Results: Analysis showed that TFA and MCC950 protected podocytes against HG-induced pyroptosis and injury by reducing the protein expression levels of gasdermin D, interleukin-1β, and interleukin-18, and by increasing the protein expression levels of nephrin, ZO-1, WT1 and podocalyxin. TFA and 740Y-P inhibited activation of the NLRP3 inflammasome via the PI3K/Akt pathway by inhibiting the protein levels of NIMA-related kinase7, NLRP3, ASC, and caspase-1, and by increasing the protein expression levels of p-PI3K and p-Akt. TFA improved pyroptosis and injury in HG-stimulated podocytes by regulating METTL3-dependent m6A modification. Conclusion: Collectively, our data indicated that TFA could ameliorate pyroptosis and injury in podocytes under HG conditions by adjusting METTL3-dependent m6A modification and regulating NLRP3-inflammasome activation and PTEN/PI3K/Akt signaling. This study provides a better understanding of how TFA can protect podocytes in DKD.

Total Flavone of Abelmoschus manihot Ameliorates Stress-Induced Microbial Alterations Drive Intestinal Barrier Injury in DSS Colitis

Purpose

Total flavone of Abelmoschus manihot (TFA), the effective constituents extracted from Flos Abelmoschus Manihot, has been reported to inhibit inflammation. However, the effect of TFA on ulcerative colitis (UC) progression in patients with depression is unknown. The purpose of our research was to explore the anti-UC effects of TFA in the context of depression in mice with UC by regulating the gut microbiota to drive the intestinal barrier.

Methods

In this study, chronic stress (CS) and dextran sodium sulfate (DSS) were used to induce depression and UC, respectively, in C57BL/6J mice. Fecal microbiota transplantation (FMT) was used to evaluate how treating mice modeling UC and depression with TFA effected their gut microbiota.

Results

Our results showed that TFA effectively improved UC aggravated by CS. In addition, TFA treatment improved the depression-like phenotype, the disturbed gut microbiota, and the intestinal barrier function in CS mice. It is worth noting that FMT from the CS mice to the receptor group further aggravated the damage of the intestinal barrier and the disturbance of the gut microbiota in the recipient DSS mice, thus further aggravating UC, however, treatment of the intervention of TFA in the CS fecal microbiota transplant with TFA also played its therapeutic outcome.

Conclusion

Taken together, our results show that CS disrupts the gut microbiota, triggers intestinal barrier injury and aggravates DSS colitis, while TFA is a promising drug for the treatment of UC in patients with depression.

Hyperoside ameliorates diabetic nephropathy induced by STZ via targeting the miR-499-5p/APC axis

Diabetic nephropathy is a serious complication of diabetes. Hyperoside has been widely reported to ameliorate diabetes-associated disease. The current study is designed to explore the mechanism of hyperoside in diabetic nephropathy. In the present study, high glucose was used to treat podocytes. Diabetic nephropathy mice models were established by high-fat feeding followed by multiple low dose injections of streptozocin. Western blot analysis was conducted for detection of extracellular matrix accumulation, inflammatory response and cell apoptosis. We found out that hyperoside improved high glucose-induced cell injury. Additionally, hyperoside prevented mice with diabetic nephropathy from diabetic symptoms and renal dysfunction. Mechanistically, hyperoside inhibited the mRNA and protein expression of APC. MiR-499-5p was found to be an upstream negative mediator of APC, and hyperoside induced the upregulation of miR-499-5p. MiR-499-5p bound with the 3' untranslated region of APC to inhibit its expression. Finally, rescue assays revealed that the suppressive effects of miR-499-5p overexpression on renal dysfunction were rescued by upregulation of APC in mice with diabetic nephropathy. In conclusion, these findings indicated that hyperoside ameliorates diabetic nephropathy via targeting the miR-499-5p/APC axis, suggesting that hyperoside may offer a potential tactic for diabetic nephropathy treatment.

Hyperoside regulates its own biosynthesis via MYB30 in promoting reproductive development and seed set in okra

Flavonoids are secondary metabolites that play important roles in fruit and vegetable development. Here, we examined the function of hyperoside, a unique flavonoid in okra (Abelmoschus esculentus), known to promote both flowering and seed set. We showed that the exogenous application of hyperoside significantly improved pollen germination rate and pollen tube growth by almost 50%, resulting in a 42.7% increase in the seed set rate. Of several genes induced by the hyperoside treatment, AeUF3GaT1, which encodes an enzyme that catalyzes the last step of hyperoside biosynthesis, was the most strongly induced. The transcription factor AeMYB30 enhanced AeUFG3aT1 transcription by directly binding to the AeUFG3aT1 promoter. We studied the effect of the hyperoside application on the expression of 10 representative genes at four stages of reproductive development, from pollination to seed maturity. We firstly developed an efficient transformation system that uses seeds as explants to study the roles of AeMYB30 and AeUFG3aT1. Overexpression of AeMYB30 or AeUF3GaT1 promoted seed development. Moreover, exogenous application of hyperoside partially restored the aberrant phenotype of AeUF3GaT1 RNA-interference plants. Thus, hyperoside promotes seed set in okra via a pathway involving AeUF3GaT and AeMYB30, and the exogenous application of this flavonoid is a simple method that can be used to improve seed quality and yield in okra.

Mechanisms and Efficacy of Chinese Herbal Medicines in Chronic Kidney Disease

As the current treatment of chronic kidney disease (CKD) is limited, it is necessary to seek more effective and safer treatment methods, such as Chinese herbal medicines (CHMs). In order to clarify the modern theoretical basis and molecular mechanisms of CHMs, we reviewed the knowledge based on publications in peer-reviewed English-language journals, focusing on the anti-inflammatory, antioxidative, anti-apoptotic, autophagy-mediated and antifibrotic effects of CHMs commonly used in kidney disease. We also discussed recently published clinical trials and meta-analyses in this field. Based on recent studies regarding the mechanisms of kidney disease in vivo and in vitro, CHMs have anti-inflammatory, antioxidative, anti-apoptotic, autophagy-mediated, and antifibrotic effects. Several well-designed randomized controlled trials (RCTs) and meta-analyses demonstrated that the use of CHMs as an adjuvant to conventional medicines may benefit patients with CKD. Unknown active ingredients, low quality and small sample sizes of some clinical trials, and the safety of CHMs have restricted the development of CHMs. CHMs is a potential method in the treatment of CKD. Further study on the mechanism and well-conducted RCTs are urgently needed to evaluate the efficacy and safety of CHMs.

Traditional Uses, Chemical Constituents, Biological Properties, Clinical Settings, and Toxicities of Abelmoschus manihot L.: A Comprehensive Review

Abelmoschus manihot, an annual herbal flowering plant, is widely distributed throughout eastern Europe and in temperate and subtropical regions of Asia. Its flowers have been traditionally used for the treatment of chronic kidney disease in China. Currently, more than 128 phytochemical ingredients have been obtained and identified from the flowers, seeds, stems, and leaves of A. manihot. The primary components are flavonoids, amino acids, nucleosides, polysaccharides, organic acids, steroids, and volatile oils. A. manihot and its bioactive constituents possess a plethora of biological properties, including antidiabetic nephropathy, antioxidant, antiadipogenic, anti-inflammatory, analgesic, anticonvulsant, antidepressant, antiviral, antitumor, cardioprotective, antiplatelet, neuroprotective, immunomodulatory, and hepatoprotective activities, and have effects on cerebral infarction, bone loss, etc. However, insufficient utilization and excessive waste have already led to a rapid reduction of resources, meaning that a study on the sustainable use of A. manihot is urgent and necessary. Moreover, the major biologically active constituents and the mechanisms of action of the flowers have yet to be elucidated. The present paper provides an early and comprehensive review of the traditional uses, chemical constituents, pharmacological activities, and pharmaceutical, quality control, toxicological, and clinical settings to emphasize the benefits of this plant and lays a solid foundation for further development of A. manihot.

The Flower Extract of Abelmoschus manihot (Linn.) Increases Cyclin D1 Expression and Activates Cell Proliferation

Abelmoschus manihot (Linn.) is a medicinal herbal plant that is commonly used to treat chronic kidney disease and hepatitis. However, its effect on cell proliferation has not been clearly revealed. In this report, we sought to determine the effect of the flower extract of A. manihot (FA) on cell proliferation. Based on our findings, FA increased the proliferation of human diploid fibroblast (HDF) and HEK293 cells. Through cell cycle analysis, FA was found to increase the number of HDF cells in the S phase and G2/M phase. FA also increased the expression of cyclin D1 and enhanced the migration of HDF cells. By administering FA to HDF cells with ≥30 passages, a decrease in the number of senescence-associated β galactosidase-positive cells was observed, thereby indicating that FA can ameliorate cellular senescence. Collectively, our findings indicate that FA increases cyclin D1 expression and regulates cell proliferation.

Hyperoside Ameliorates Diabetic Retinopathy via Anti-Oxidation, Inhibiting Cell Damage and Apoptosis Induced by High Glucose

Background

Hyperoside (Hyp) is a flavonoid substance extracted from plants, which has the functions of anti-cancer, anti-inflammatory, and anti-oxidation. In the previous study, we found that Hyp reduced the injury of rat retinal vascular endothelial cells (RVECs) induced by H₂O₂.

Method

In the present research, we evaluated the protective effect of Hyp on the pathological damage of retina caused by high glucose of diabetes mellitus (DM) in in vitro and in vivo experiments. The effect of Hyp on cell viability, oxidative stress level, and apoptosis of RVECs was assessed.

Results

Hyp significantly reduced the of RVECs damage, oxidative stress level, and cell apoptosis induced by high glucose in vitro. In DM model rats, Hyp treatment could significantly reduce blood glucose levels and the pathological damage of retina caused by DM and increase the proliferation of RVECs while exerting the inhibition on apoptotic activity. Furthermore, Hyp treatment decreased the expressions of apoptotic proteins including caspase-3, caspase-9, and Bax in RVECs of DM rats, while increased the expression of anti-apoptotic protein Bcl-2.

Conclusion

Hyp may have protective effect on diabetes-induced retinopathy by reducing oxidative stress, inhibiting cell damage, and apoptosis induced by high glucose.

Ethyl Vanillin Protects against Kidney Injury in Diabetic Nephropathy by Inhibiting Oxidative Stress and Apoptosis

Diabetes-induced oxidative stress and apoptosis is regarded as a critical role in the pathogenesis of diabetic nephropathy (DN). Treating diabetes-induced kidney damage and renal dysfunction has been thought a promising therapeutic option to attenuate the development and progression of DN. In this study, we investigated the renoprotective effect of ethyl vanillin (EVA), an active analogue of vanillin isolated from vanilla beans, on streptozotocin- (STZ-) induced rat renal injury model and high glucose-induced NRK-52E cell model. The EVA treatment could strongly improve the deterioration of renal function and kidney cell apoptosis in vivo and in vitro. Moreover, treating with EVA significantly decreased the level of MDA and reactive oxygen species (ROS) and stabilized antioxidant enzyme system in response to oxidative stress by enhancing the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in vivo and in vitro. Furthermore, EVA also markedly suppressed cleaved caspase-3, Bax, and nuclear transcription factor erythroid 2-related factor (Nrf2) expression in STZ-induced rats. Therefore, these results of our investigation provided that EVA might protect against kidney injury in DN by inhibiting oxidative stress and cell apoptosis.

Silencing of long noncoding RNA PVT1 inhibits podocyte damage and apoptosis in diabetic nephropathy by upregulating FOXA1

The number of patients with diabetic nephropathy (DN) is still on the rise worldwide, and this requires the development of new therapeutic strategies. Recent reports have highlighted genetic factors in the treatment of DN. Herein, we aimed to study the roles of long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) and histone 3 lysine 27 trimethylation (H3K27me3) in DN. A model of DN was established by inducing diabetes in mice with streptozotocin. Mouse podocyte clone 5 (MPC5) podocytes and primary podocytes were cultured in normal and high glucose media to observe cell morphology and to quantify PVT1 expression. The roles of PVT1 and enhancer of zeste homolog 2 (EZH2) were validated via loss-of-function and gain-of-function in vitro experiments to identify the interactions among PVT1, EZH2, and forkhead box A1 (FOXA1). The podocyte damage and apoptosis due to PVT1 and FOXA1 were verified with in vivo experiments. PVT1 was highly expressed in MPC5 and primary podocytes in DN patients and in cultures grown in high glucose medium. A large number of CpG (C-phosphate-G) island sites were predicted at the FOXA1 promoter region, where PVT1 recruited EZH2 to promote the recruitment of H3K27me3. The silencing of PVT1 or the overexpression of FOXA1 relieved the damage and inhibited the apoptosis of podocytes in DN, as was evidenced by the upregulated expression of synaptopodin and podocin, higher expression of Bcl-2, and lower expression of Bax and cleaved caspase-3. The key findings of this study collectively indicate that the suppression of lncRNA PVT1 exerts inhibitory effects on podocyte damage and apoptosis via FOXA1 in DN, which is of clinical significance.

Targeting an RNA molecule responsible for disrupting metabolic protein levels in diabetic kidney disease may improve treatment. Diabetic nephropathy (DN) can affect people with type I or type II diabetes, and results in functional deterioration and the need for regular dialysis. DN incidence is rising worldwide, but existing treatments are only partially effective. Zhang-Suo Liu at Zhengzhou University, China, and co-workers examined the role of a long noncoding RNA molecule known as PVT1, which has been recently associated with kidney disease. The team collected serum samples from 32 patients with DN, and also generated a DN mouse model. They found that PVT1 expression was significantly higher in DN, and that this inhibited the expression of a key metabolic protein, FOXA1. Silencing PVT1 restored FOXA1 levels, limiting damage and cell death in kidney cells.

Quercetin improves lipid metabolism via SCAP-SREBP2-LDLr signaling pathway in early stage diabetic nephropathy

Purpose: Quercetin, the most widely distributed flavonoid, has been shown to have multiple properties and beneficial effects on various metabolic diseases. Thus, our aim was to investigate the underlying mechanism whereby quercetin regulates renal lipid accumulation and ameliorates early diabetic renal injuries in Leprdb/Leprdb (db/db) mice, a model of type 2 diabetes. Methods: db/db mice were administered either 50 mg/kg or 100 mg/kg quercetin by oral gavage once a day to evaluate its effects on early stage diabetic nephropathy; mice were sacrificed at the end of the 10th week after intervention; a similar number of db/db and db/m mice were used as controls. During the experimental study, the general status of the animals was observed daily; body weight and blood glucose concentrations were measured at bi-weekly intervals. Biochemical parameters of lipid metabolism were measured by automatic biochemical analyzer. Renal function parameters were performed using commercial kits. Early renal histological changes and lipid accumulation were demonstrated by H&E staining and Oil-Red-O staining, respectively. Moreover, the expression of key proteins in the low-density lipoprotein receptors (LDLr)-SREBP-2-SREBP cSCAP signaling pathway in the kidneys of diabetic mice was detected by Western blot assay. Results: Compared with diabetic controls, quercetin not only ameliorated albuminuria and urinary albumin-to-creatinine ratio, but also decreased blood urea nitrogen and glucose, serum cholesterol, triglycerides, and low-density lipoprotein cholesterol, whereas it had no remarkable effect on the high-density lipoprotein cholesterol in diabetic db/db mice. Additionally, the evidently down regulated expression of LDLr, HMGCR, SREBP-2, and SCAP subsequently attenuated the renal lipid profile change and lipid droplet accumulation, resulting in the alleviation of renal injury of db/db mice. Conclusion: Quercetin safely and efficiently alleviates early diabetic renal injuries, possibly through improving the lipid metabolism via SCAP-SREBP2-LDLr signaling pathway.

Total Extracts of Abelmoschus manihot L. Attenuates Adriamycin-Induced Renal Tubule Injury via Suppression of ROS-ERK1/2-Mediated NLRP3 Inflammasome Activation

Abelmoschus manihot (L.) Medik. (Malvaceae) is a herb used in traditional Chinese medicine to treat some kidney diseases. To date, the detailed mechanisms by which A. manihot improves some kinds of renal disease are not fully understood. In this study, we established Adriamycin-induced NRK-52E cells, the normal rat kidney epithelial cell line, injury, and Sprague-Dawley rats with Adriamycin-induced nephropathy to evaluate the role and mechanisms of total extracts of A. manihot flower (TEA) both in vitro and in vivo. We found that TEA ameliorated Adriamycin-induced cellular morphological changes, cell viability, and apoptosis through the suppression of protein oxidation and ERK1/2 signaling. However, this anti-oxidative stress role of TEA was independent of ROS inhibition. Adriamycin activated ERK1/2 signaling followed by activation of NLRP3 inflammasomes. TEA suppressed NLRP3 inflammasomes via inhibition of ERK1/2 signal transduction; decreased proteinuria and attenuated renal tubule lesions; and inhibited the expression of NLRP3 in tubules in rats with Adriamycin nephropathy. Collectively, TEA protects renal tubular cells against Adriamycin-induced tubule injury via inhibition of ROS-ERK1/2-NLRP3 inflammasomes.

Abelmoschus manihot for Diabetic Nephropathy: A Systematic Review and Meta-Analysis

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). Many trials have shown that Abelmoschus manihot could further improve proteinuria and protect kidney function in patients with DN when added to a renin-angiotensin system (RAS) blocker. A systematic assessment of the efficacy and safety of A. manihot in DN is essential. Eight electronic databases were searched to identify eligible trials published from inception to December 2017. The Cochrane Risk of Bias Tool was used to evaluate the methodological quality of eligible studies. Seventy-two studies with 5,895 participants were identified. The methodological quality of included studies was generally low. The results indicated that, compared to a RAS blocker, combined treatment of A. manihot with a RAS blocker was more effective for 24h urinary protein (24h UP) (mean difference [MD], -0.39 [95% confidence interval [CI], -0.46 to -0.33] g/d; P<0.00001), urinary albumin excretion rate (UAER)(MD, -19.90 [95% CI, -22.62 to -17.18] μg/min; P<0.00001), 24h UP reduction rate (risk ratio [RR], 1.43; 95% CI, 1.26-1.63; P<0.00001), normalization of UAER (RR, 1.48; 95% CI, 1.29-1.70; P<0.00001), and serum creatinine (SCr) (MD, -7.35 [95% CI, -9.95 to -4.76] umol/L; P<0.00001). None of these trials reported the ESRD rate. No statistically significant difference occurred between A. manihot combined with a RAS blocker and a RAS blocker alone in estimated glomerular filtration rate (eGFR) (MD, 4.43 [95% CI, -1.68 to 10.54] mL/min; P=0.16). A. manihot did not increase the rates of adverse drug events. A. manihot in addition to a RAS blocker was effective and safe to further improve proteinuria and protect kidney function in patients with DN. However, due to the generally low methodological quality, significant heterogeneity, and publication bias, high-quality randomized controlled trials are required to confirm these findings before the routine use of A. manihot can be recommended.

Renoprotective Effect of Yiqi Yangyin Huayu Tongluo Formula against Diabetic Nephropathy in Diabetic Rats

Diabetic nephropathy is developed in 20-40% of patients with diabetes mellitus, and patients with diabetic nephropathy require dialysis and renal transplantation. Traditional Chinese medicine has been widely used in treating patients with diabetic nephropathy in China. However, the detailed mechanisms of traditional Chinese medicine remain unclear. Yiqi Yangyin Huayu Tongluo formula (ZY formula) is a traditional Chinese medicinal formula. Here, we demonstrated kidney protective effect of ZY formula on the rats with diabetic nephropathy. The therapeutic effect of ZY formula on the diabetic nephropathy was almost the same as that of Irbesartan, which proved to have excellent curative effects on diabetic nephropathy. We also demonstrated the mechanism of ZY formula effect on the diabetic nephropathy. First, we validated that the activation of ROS-JNK signaling pathway in diabetic rats could be reduced by ZY. Furthermore, collagen I expression could be downregulated by ZY formula treatment. Meanwhile, cell apoptosis in the kidney of diabetic rats could be alleviated by ZY formula.

Supplementation of Abelmoschus manihot Ameliorates Diabetic Nephropathy and Hepatic Steatosis by Activating Autophagy in Mice

Diabetic nephropathy (DN) is a diabetic complication marked by albuminuria and a decline of the glomerular filtration rate. Diabetic kidneys are defective in the autophagy process and mitochondrial function and their enhancement of activity alleviates the pathology. In this paper, we developed a mouse model of DN by a combined treatment of a high-fat diet and streptozotocin after unilateral nephrectomy and supplementation with flower or leaf extracts of Abelmoschus manihot (AM) were tested. The preventive effects of the extracts on DN pathology and changes on autophagy and mitochondrial proteins were investigated. DN mice showed a significant increase in fasting blood glucose, plasma creatinine, blood urea nitrogen, and urinary albumin levels. Periodic acid–Schiff and Sirius red staining of the diabetic kidney presented a significant change in glomerular and tubular structures that was associated with podocyte loss and fibrotic protein accumulation. These changes were attenuated by AM extract treatment in DN mice. In addition, hepatic injury, proinflammatory cytokines, and lipid accumulation were decreased by AM extracts in DN mice. As a protective mechanism, AM extracts significantly increased the expression of proteins by regulating autophagy and mitochondrial dynamics, which potentially prevented the kidney and liver from accumulating pathogenic proteins and dysfunctional mitochondria, which alleviated the progression of DN.

Icariin modulates mitochondrial function and apoptosis in high glucose-induced glomerular podocytes through G protein-coupled estrogen receptors

Podocyte apoptosis in glomerular lesions has been found to have a dominant role in the progression of diabetic nephropathy. The present research aimed to explore the beneficial effect of icariin on diabetic podocytes by interfering in the process of apoptosis. Podocyte apoptosis was significantly exacerbated after high glucose treatment, with the level of reactive oxygen species (ROS) increasing simultaneously. Here, we demonstrated that icariin, which is a G protein-coupled estrogen receptor 1 (GPER) agonist, inhibited podocyte apoptosis by reducing ROS, maintaining the integrity of mitochondrial membranes. Moreover, the stabilization of mitochondria by icariin was reversed when GPER was knocked down in podocytes. Meanwhile, icariin inhibited the caspase cascade in podocyte apoptosis by promoting Bcl-2 expression and mitochondrial translocation. The above findings at least partly elucidated the mechanism by which icariin stabilized podocytes by inducing the mitochondrial Bcl-2 translocation and therefore preventing downstream apoptosis.

Antioxidant and Antiapoptotic effect of aqueous extract of Pueraria tuberosa (Roxb. Ex Willd.) DC. On streptozotocin-induced diabetic nephropathy in rats

BACKGROUND

Oxidative stress and renal apoptosis play a significant role in the progression of diabetic nephropathy. The tubers of Pueraria tuberosa (Roxb. ex Willd.) DC. has been traditionally used as anti-ageing and health promotive tonic. The purpose of this study was to investigate its nephroprotective effect and mechanism via antioxidant and antiapoptotic potential in Streptozotocin-induced diabetic nephropathy (DN) in rats.

METHODS

The chemical composition of aqueous extract of Pueraria tuberosa (PTY-2r) was analyzed by gas chromatography-mass spectrometry (GC-MS). Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) (55 mg/kg body weight) in rats. After 60 days, the rats were randomly divided into 3 groups (n = 6/each group), namely DN control (DN) group-2, DN rats treated with PTY-2r at the dose of 50 mg/100 g, group-3 and 100 mg/100 g, group-4 p.o. for 20 days. The normal rats were chosen as a normal control (NC) group-1. PTY-2r was orally given to the rats for 20 days. Reactive oxygen species (ROS), lipid peroxidation (LPO) and the activity of ROS-scavenging enzymes - superoxide dismutase (SOD), catalase (CAT) & glutathione peroxidase (GPx) were determined in the kidney tissue of DN rats. The expression of apoptosis-related proteins was measured by immunofluorescence.

RESULTS

GC-MS analysis of PTY-2r indicated the presence of 37 compounds among them 5-Hydroxymethylfurfural (17.80%), 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (17.03%), n-Hexadecanoic acid (5.18%) and 9-Octadecenoic acid (Z) - (6.69%) were found in the higher amount. A significant increase in ROS and LPO was observed along with the decreased activity of antioxidant enzymes, responsible for oxidative stress in the kidney of DN rats. Since, high oxidative stress induces apoptosis in target cells, as shown by significantly decreased expression of Bcl-2 along with increased expression of Bax, active Caspase-3 & cleaved PARP-1 in DN control rats, suggesting apoptosis. The PTY-2r treatment significantly raised the activity of antioxidant enzymes, suppressed oxidative stress and apoptosis thus, prevented urinary albumin excretion in a dose-dependent manner.

CONCLUSIONS

The findings suggest that PTY-2r exerted the nephroprotective potential against STZ induced DN rats via suppressing oxidative stress and apoptosis due to the presence of different bioactive compounds. ᅟ.

Total Flavones of Abelmoschus manihot Exhibits Pro-Angiogenic Activity by Activating the VEGF-A/VEGFR2-PI3K/Akt Signaling Axis

Angiogenesis is a process of new blood vessel formation from pre-existing vessels. Vascular endothelial growth factor-A (VEGF-A) binds to VEGF receptor-2 (VEGFR2) and thus activation of phosphatidylinositol 3-kinase (PI3K)/Akt pathway play a central role in angiogenesis. Total flavones of Abelmoschus manihot (TFA), the major active component of the traditional Chinese herb Abelmoschus manihot, display novel pro-angiogenic activity. However, little information concerning its underlying mechanism is available. Here we investigate the pro-angiogenesis of TFA with the aim of understanding its mechanism of action. Human umbilical vein endothelial cells (HUVECs) and the chick chorioallantoic membrane (CAM) model were used to evaluate pro-angiogenesis of TFA using cell viability, wounding healing, transwell invasion, tube formation, RT-qPCR and Western blot methods. LY294002, a PI3K inhibitor, was used to interfere with PI3K/Akt pathway signal for assessing the underlying mechanism. Results in vitro indicated TFA obviously promoted HUVECs proliferation, migration, invasion and tube formation. Furthermore, TFA markedly augmented PI3K and Akt phosphorylation and up-regulated VEGF-A and VEGFR2 expression in HUVECs. However, pre-treatment with LY294002 not only markedly attenuated TFA-induced cells proliferation, migration, invasion and tube formation, but also significantly abolished TFA-induced VEGF-A and VEGFR2 over-expression as well as PI3K and Akt phosphorylation. Experiments in CAM model showed TFA significantly promoted the formation of branched blood vessels and was dramatically suppressed by LY294002. Taken together, TFA promoted angiogenesis both in vitro and in vivo which, however, were counteracted by LY294002, suggesting at least in part, TFA exhibits pro-angiogenic activity by activating the VEGF-A/VEGFR2-PI3K/Akt signaling axis.

Anti-hypoglycemic and hepatocyte-protective effects of hyperoside from Zanthoxylum bungeanum leaves in mice with high-carbohydrate/high-fat diet and alloxan-induced diabetes

The development of diabetes mellitus (DM) is accompanied by hyperglycemia-induced oxidative stress. Hyperoside is a major bioactive component in Zanthoxylum bungeanum leaves (HZL) and is a natural antioxidant. However, the effects of HZL on DM and its mechanisms of action remain undefined. The present study evaluated the anti-hypoglycemic and hepatocyte-protective effects of HZL in mice with diabetes induced by a high-carbohydrate/high-fat diet (HFD) and alloxan. We also aimed to eludicate the underlying mechanisms. Our resutls demonstrated that the administration of HZL significantly reduced body weight gain, serum glucose levels and insulin levels in diabetic mice compared with the vehicle-treated mice. In addition, the levels of dyslipidemia markers including total cholesterol, triglyceride and low-density lipoprotein cholesterol in the HFD-treated mice were markedly decreased. Further experiments using hepatocytes from mice revealed that HZL significantly attenuated liver injury associated with DM compared with vehicle treatment, as evidenced by lower levels of alanine aminotransferase and aspartate aminotransferase in serum and by lower levels of lipid peroxidation, nitric oxide content and inducible nitric oxide synthase activity in liver tissues. Nuclear factor-κB (NF-κB) and mitogen-associated protein kinase (MAPK) signaling pathways were investigated to elucidate the molecular mechanisms responsible for the protective effects of HZL against diabetic liver injury. The results indicated that HZL inhibited the phosphorylation of p65/NF-κB, MAPK (including p38, JNK and ERK1/2) and activating transcription factor 3 protein expression, with an additional suppression of Bax, cytochrome c, caspase-9 and caspase-3 in the liver tissues of diabetic mice. Taken together, our findings suggest that HZL, which was effective in inhibiting oxidative stress-related pathways may be beneficial for use in the treatment of DM.

Hyperoside pre-treatment prevents glomerular basement membrane damage in diabetic nephropathy by inhibiting podocyte heparanase expression

Glomerular basement membrane (GBM) damage plays a pivotal role in pathogenesis of albuminuria in diabetic nephropathy (DN). Heparan sulfate (HS) degradation induced by podocyte heparanase is the major cause of GBM thickening and abnormal perm-selectivity. In the present study, we aimed to examine the prophylactic effect of hyperoside on proteinuria development and GBM damage in DN mouse model and the cultured mouse podocytes. Pre-treatment with hyperoside (30 mg/kg/d) for four weeks could significantly decrease albuminuria, prevent GBM damage and oxidative stress in diabetes mellitus (DM) mice. Immunofluorescence staining, Real time PCR and Western blot analysis showed that decreased HS contents and increased heparanase expression in DN mice were also significantly improved by hyperoside pre-treatment. Meanwhile, transmission electron microscope imaging showed that hyperoside significantly alleviated GBM thickening in DN mice. In addition, hyperoside pre-treatment inhibited the increased heparanase gene (HPR1) promoter activity and heparanase expression induced by high glucose or reactive oxidative species (ROS) in cultured podocytes. Our data suggested that hyperoside has a prophylactic effect on proteinuria development and GBM damage in DM mice by decreasing podocyte heparanase expression.

Hyperglycemia-induced oxidative stress and heart disease-cardioprotective effects of rooibos flavonoids and phenylpyruvic acid-2-O-β-D-glucoside

Diabetic patients are at an increased risk of developing heart failure when compared to their non-diabetic counter parts. Accumulative evidence suggests chronic hyperglycemia to be central in the development of myocardial infarction in these patients. At present, there are limited therapies aimed at specifically protecting the diabetic heart at risk from hyperglycemia-induced injury. Oxidative stress, through over production of free radical species, has been hypothesized to alter mitochondrial function and abnormally augment the activity of the NADPH oxidase enzyme system resulting in accelerated myocardial injury within a diabetic state. This has led to a dramatic increase in the exploration of plant-derived materials known to possess antioxidative properties. Several edible plants contain various natural constituents, including polyphenols that may counteract oxidative-induced tissue damage through their modulatory effects of intracellular signaling pathways. Rooibos, an indigenous South African plant, well-known for its use as herbal tea, is increasingly studied for its metabolic benefits. Prospective studies linking diet rich in polyphenols from rooibos to reduced diabetes associated cardiovascular complications have not been extensively assessed. Aspalathin, a flavonoid, and phenylpyruvic acid-2-O-β-D-glucoside, a phenolic precursor, are some of the major compounds found in rooibos that can ameliorate hyperglycemia-induced cardiomyocyte damage in vitro. While the latter has demonstrated potential to protect against cell apoptosis, the proposed mechanism of action of aspalathin is linked to its capacity to enhance the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression, an intracellular antioxidant response element. Thus, here we review literature on the potential cardioprotective properties of flavonoids and a phenylpropenoic acid found in rooibos against diabetes-induced oxidative injury.

Dynamic changes of flavonoids in Abelmoschus manihot different organs at different growth periods by UPLC-MS/MS

Abelmoschus manihot (Linn.) Medicus has been clinically used to treat chronic kidney disease, oral ulcers, burns, and dysmenorrhea in China for many centuries. The major pharmacologically-active components of A. manihot are flavonoids. In this study, a rapid and highly sensitive UPLC-MS/MS analysis method was established and successfully applied to the simultaneous determination of five major flavonoids (rutin, hyperoside, isoquercitrin, quercetin, and myricetin) in different parts of A. manihot harvested at ten growth periods. Under the optimized chromatographic conditions, good separation for five target components was obtained on an Acquity UPLC BEH C18 column within 18min. The total contents of the five investigated flavonoids in A. manihot roots, stems, leaves and flowers ranged from 2.86 to 123.7μg/g, 46.39 to 141.0μg/g, 929.4 to 3096μg/g, and 10,150 to 19,390μg/g, respectively, indicating that the total flavonoids in the four parts could be mainly arranged in a decreasing order as flower>leaf>stem>root. The peak of total flavonoids in flowers and leaves appeared at G8 and G9, respectively. These results will be helpful for the determination of the suitable harvest time of A. manihot and the improvement of the utility value of the disused parts.

Chemical Composition, Antioxidant and α-Glucosidase-Inhibiting Activities of the Aqueous and Hydroethanolic Extracts of Vaccinium myrtillus Leaves

Vaccinium myrtillus (bilberry) leaf is traditionally used in southeastern Europe for the treatment of diabetes. In the present study, the ability of bilberry leaf extracts to inhibit carbohydrate-hydrolyzing enzymes and restore glutathione concentration in Hep G2 cells subjected to glucose-induced oxidative stress was investigated. A comprehensive analysis of the antioxidant activity of two bilberry leaf extracts was performed. The aqueous extract showed excellent total antioxidant and chelating activity. Its antioxidant activity in the β-carotene-linoleic acid assay was very good, reaching the activity of the antioxidant standard BHA (93.4 ± 2.3% vs. 95.1 ± 2.4%, respectively). The hydroethanolic extract (ethanol/H₂O, 8:2, v/v), on the other hand, was a better radical scavenger and Fe²⁺ reducing agent. Furthermore, the aqueous extract was able to efficiently increase glutathione concentration in Hep G2 cells subjected to glucose-induced oxidative stress and restore it to the levels observed in non-hyperglycaemic cells. The hydroethanolic extract strongly inhibited α-glucosidase, with the IC₅₀ statistically equal to the antidiabetic drug acarbose (0.29 ± 0.02 mg/mL vs. 0.50 ± 0.01 mg/mL, respectively). Phytochemical analysis revealed the presence of quercetin and kaemferol derivatives, as well as chlorogenic and p-coumaric acid. The study results indicate that V. myrtillus leaf may have promising properties as a supporting therapy for diabetes.

Polydatin impairs mitochondria fitness and ameliorates podocyte injury by suppressing Drp1 expression

Polydatin (PD), a resveratrol glycoside, has been shown to protect renal function in diabetic nephropathy (DN), but the underlying molecular mechanism remains unclear. This study demonstrates that PD stabilize the mitochondrial morphology and attenuate mitochondrial malfunction in both KKAy mice and in hyperglycemia (HG)‐induced MPC5 cells. We use Western blot analysis to demonstrate that PD reversed podocyte apoptosis induced by HG via suppressing dynamin‐related protein 1 (Drp1). This effect may depend on the ability of PD to inhibit the generation of cellular reactive oxygen species (ROS). In conclusion, we demonstrate that PD may be therapeutically useful in DN, and that, podocyte apoptosis induced by HG can be reversed by PD through suppressing Drp1 expression.

Treatment of chronic kidney disease using a traditional Chinese medicine, Flos Abelmoschus manihot (Linnaeus) Medicus (Malvaceae)

The flowers of Abelmoschus manihot (Linnaeus) Medicus (Malvaceae; Flos A. manihot) have been used in China for many centuries as a traditional Chinese medicine for the treatment of chronic kidney disease. The Huangkui capsule is a single-plant drug extracted from the dry corolla of Flos A. manihot that has been approved by China's State Food and Drug Administration for the treatment of chronic glomerulonephritis. The purpose of this paper is to review briefly some of the past experiences in rapid filtration and to present more fully a few facts brought out in recent studies. The primary chemical constituents of Flos A. manihot are flavonoids. In vivo, the flavonoids can be transformed into glucuronide-sulphate conjugates, which are the major metabolites of Flos A. manihot and could contribute to the renoprotective effects in vivo. Flos A. manihot can ameliorate proteinuria, podocyte apoptosis, glomerulosclerosis and mesangial proliferation. The renoprotective effects of Flos A. manihot are related to inhibition of caspase-3 and caspase-8 overexpression, reduction of the infiltration of ED1(+) and ED3(+) macrophages, downregulation of oxidative stress, inhibition of the p38 mitogen-activated protein kinase and serine/threonine kinase pathways and suppression of transforming growth factor-β1 and tumour necrosis factor-α expression. Recently, a multicentre randomized controlled trial demonstrated that Flos A. manihot was more effective than the angiotensin-receptor blocker losartan in reducing proteinuria in patients with primary glomerular disease. Because Flos A. manihot is generally preferred by Chinese patients and clinicians, high-quality trials to test the efficacy and safety of Flos A. manihot are urgently needed.

Chinese medicines in the treatment of experimental diabetic nephropathy

Diabetic nephropathy (DN) is a severe micro vascular complication accompanying diabetes mellitus that affects millions of people worldwide. End-stage renal disease occurs in nearly half of all DN patients, resulting in large medical costs and lost productivity. The course of DN progression is complicated, and effective and safe therapeutic strategies are desired. While the complex nature of DN renders medicines with a single therapeutic target less efficacious, Chinese medicine, with its holistic view targeting the whole system of the patient, has exhibited efficacy for DN management. This review aims to describe the experimental evidence for Chinese medicines in DN management, with an emphasis on the underlying mechanisms, and to discuss the combined use of herbs and drugs in DN treatment.

Review of Herbal Traditional Chinese Medicine for the Treatment of Diabetic Nephropathy

Diabetic nephropathy (DN) is the most serious chronic complications of diabetes; 20-40% of diabetic patients develop into end stage renal disease (ESRD). However, exact pathogenesis of DN is not fully clear and we have great difficulties in curing DN; poor treatment of DN led to high chances of mortality worldwide. A lot of western medicines such as ACEI and ARB have been demonstrated to protect renal function of DN but are not enough to delay or retard the progression of DN; therefore, exploring exact and feasible drug is current research hotspot in medicine. Traditional Chinese medicine (TCM) has been widely used to treat and control diabetes and its complications such as DN in a lot of scientific researches, which will give insights into the mechanism of DN, but they are not enough to reveal all the details. In this paper, we summarize the applications of herbal TCM preparations, single herbal TCM, and/or monomers from herbal TCM in the treatment of DN in the recent 10 years, depicting the renal protective effects and the corresponding mechanism, through which we shed light on the renal protective roles of TCM in DN with a particular focus on the molecular basis of the effect and provide a beneficial supplement to the drug therapy for DN.