Cyclocarya paliurus extract alleviates diabetic nephropathy by inhibiting oxidative stress and aldose reductase

Cyclocarya paliurus leaves alleviate high-sucrose diet-induced obesity by improving intestinal metabolic disorders

High-sucrose diets are common in daily life but harmful to human health. Cyclocarya paliurus leaves (CPL) are a kind of tea used to alleviate metabolic diseases and are widely used in China. However, the effects of CPL on high-sucrose-induced obesity are unknown. This study aimed to describe the changes in gut metabolism induced by a high-sucrose diet and to reveal the potential mechanisms through which CPL alleviate high-sucrose diet-induced obesity. A high-sucrose-induced obesity model was generated in C57BL/6J and KM mice. The effects of CPL on obese mice were evaluated, and changes in the gut microbiota and intestinal metabolites induced by CPL treatment were observed. Furthermore, the fecal microbiota transplantation (FMT) method was used to prove that the effects of CPL on high-sucrose induced obesity depend on the changes of gut microbiota. The results of the C57BL/6J mouse experiment revealed that high-sucrose intake induced fat deposition and altered the gut microbiota. CPL treatment decreased fat deposition and alleviated disorders of the gut microbiota. Furthermore, CPL treatment increased the utilization of amnio acids, long fatty acids and saccharides and produced more bile acids, indole derivatives and less trimethylamine (TMA). A confirmatory experiment in KM mice also revealed that CPL can alleviate obesity, ameliorate intestinal metabolic disorders, and upregulate the expression of tight junction proteins in the intestinal mucosa. These results demonstrated that CPL could prevent high sucrose-induced obesity and generate more beneficial intestinal microbial metabolites but less harmful intestinal microbial metabolites.

Sweet triterpenoid glycoside from Cyclocarya paliurus ameliorates obesity-induced insulin resistance through inhibiting the TLR4/NF-κB/NLRP3 inflammatory pathway

Our prophase studies have manifested that the sweet triterpenoid glycoside from the leaves of Cyclocarya paliurus (CPST) effectively improved the disorders of glucolipid metabolism in vitro and in patients. The current purpose was to further detect its mechanisms involved. The results demonstrated that CPST could ameliorate high-fat diet (HFD)-induced insulin resistance (IR), which was linked to reducing HFD-induced mice's body weight, serum glucose (GLUO), triglyceride (TG), total cholesterol (T-CHO) and low-density lipoprotein cholesterol (LDL-C), lowering the area under the oral glucose tolerance curve and insulin tolerance, elevating the percentage of brown adipose, high-density lipoprotein cholesterol (HDL-C), reducing fat droplets of adipocytes in interscapular brown adipose tissue (iBAT) and cross-sectional area of adipocytes. Further studies manifested that CPST obviously downregulated TLR4, MyD88, NLRP3, ASC, caspase-1, cleased-caspase-1, IL-18, IL-1β, TXNIP, and GSDMD protein expressions and p-NF-кB/NF-кB ratio in iBAT. These aforementioned findings demonstrated that CPST ameliorated HFD induced IR by regulating TLR4/NF-κB/NLRP3 signaling pathway, which in turn enhancing insulin sensitivity and glucose metabolism.

Cyclocarya paliurus leaves extracts alleviate metabolic phenotypes in Chinese T2DM patients by modulating gut microbiota and metabolites: a clinical randomized controlled trial

Objective

We aimed to investigate the effect of Cyclocarya paliurus leaves extracts (CP) on glucose and blood lipid metabolism and its relationship with intestinal flora in type 2 diabetes mellitus (T2DM) patients.

Methods

In this open-label, 84-day randomized controlled trial, a total of 38 T2DM patients were randomly assigned to the CP group or the Glipizide group (G group) in a 2:1 ratio. T2DM-associated metabolic phenotypes, gut microbiota and metabolites including short-chain fatty acids (SCFAs) and bile acids (BAs) were detected.

Results

At the end of intervention, CP, like Glipizide, significantly improved HbA1c level and other glucose metabolism parameters (fasting plasma glucose (FBG), 2-hour post-meal blood glucose (2hPBG), the area under curve of oral glucose tolerance test glucose (OGTT glucose AUC)). Moreover, CP also resulted in the significant improvement in the levels of blood lipid and blood pressure. Notably, the improvement in blood lipid(triglycerides (TG) and high-density lipoprotein cholesterol (HDL-c)) and blood pressure (diastolic blood pressure (DBP)) was significantly greater in the CP group compared with the G group. Furthermore, the liver and kidney function parameters did not significantly change in both CP group and the G group over the 84-day period. Additionally, the enrichment of potentially beneficial bacteria (Faecalibacterium and Akkermansia), SCFAs and unconjugated BAs and the depletion of potential pathogenic bacteria (Prevotella_9) and conjugated BAs were observed in the CP group, while the abundances of the gut microbial were kept stable in the G group after intervention.

Conclusion

CP displays a more beneficial effect in the alleviation of T2DM-associated metabolic phenotypes than glipizide by regulating gut microbiota and metabolites in T2DM patients, with no significant effects on liver and kidney function.

The phytochemicals and health benefits of Cyclocarya paliurus (Batalin) Iljinskaja

Cyclocarya paliurus (C. paliurus), a nutritional and nutraceutical resource for human and animal diets, has been constantly explored. The available biological components of C. paliurus were triterpenoids, polysaccharides, and flavonoids. Recent studies in phytochemical-phytochemistry; pharmacological-pharmacology has shown that C. paliurus performed medicinal value, such as antihypertensive, antioxidant, anticancer, antimicrobial, anti-inflammatory and immunological activities. Furthermore, C. paliurus and its extracts added to drinks would help to prevent and mitigate chronic diseases. This review provides an overview of the nutritional composition and functional applications of C. paliurus, summarizing the research progress on the extraction methods, structural characteristics, and biological activities. Therefore, it may be a promising candidate for developing functional ingredients in traditional Chinese medicine. However, a more profound understanding of its active compounds and active mechanisms through which they perform biological activities is required. As a result, the plant needs further investigation in vitro and in vivo.

A Review of Medicinal Plants with Renoprotective Activity in Diabetic Nephropathy Animal Models

Diabetic nephropathy (DN), also recognized as diabetic kidney disease, is a kidney malfunction caused by diabetes mellitus. A possible contributing factor to the onset of DN is hyperglycemia. Poorly regulated hyperglycemia can damage blood vessel clusters in the kidneys, leading to kidney damage. Its treatment is difficult and expensive because its causes are extremely complex and poorly understood. Extracts from medicinal plants can be an alternative treatment for DN. The bioactive content in medicinal plants inhibits the progression of DN. This work explores the renoprotective activity and possible mechanisms of various medicinal plant extracts administered to diabetic animal models. Research articles published from 2011 to 2022 were gathered from several databases including PubMed, Scopus, ProQuest, and ScienceDirect to ensure up-to-date findings. Results showed that medicinal plant extracts ameliorated the progression of DN via the reduction in oxidative stress and suppression of inflammation, advanced glycation end-product formation, cell apoptosis, and tissue injury-related protein expression.

Progress in Traditional Chinese Medicine on Treatment of Diabetic Retinopathy

Diabetic retinopathy (DR), a common and blinding diabetic microvascular complication, is a harmful metabolic effect caused by persistent hyperglycemia. Owing to the complex pathogenesis of DR, various clinical treatment methods cannot completely prevent its development and are accompanied by various complications. Therefore, there is an urgent need to identify new therapeutic drugs or complementary and alternative therapies. Traditional Chinese medicine (TCM) has the unique advantages of multi-level, multi-target, and minimal side effects. Accumulating evidence has proven that TCM may help delay or prevent the progression of DR. This paper reviews the effect and mechanism of representative TCMs (including extracts, identified compounds, and compound formulas) on DR in recent years and provides evidence for new drug development and clinical efficacy.

Advances on Cyclocarya paliurus polyphenols: Extraction, structures, bioactivities and future perspectives

Cyclocaryapaliurus (C. paliurus) is an edible and medicinal plant, distributed in southern China. As a kind of new food raw material, the leaves of C. paliurus are processed as tea products in daily life. C. paliurus is recognized as a good source to polyphenols, showing excellent bioactivities, which has attracted more and more attention. Polyphenols are important functional bioactive components in C. paliurus. C. paliurus polyphenols perform nutritional functions in anti-diabetes, anti-hyperlipidemic, anti-obesity, anti-oxidant, and other activities. In this review, we summarize the research progress of extraction technologies, structural characteristics, and bioactivities of C. paliurus polyphenols. Other potential functions of C. paliurus polyphenols are prospected. This review provides a reference for further research and applications of C. paliurus polyphenols in a field of functional food and medicines.

The Leaves of Cyclocarya paliurus: A Functional Tea with Preventive and Therapeutic Potential of Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) has become a universal and chronic global public health concern and causes multiple complex complications. In order to meet the rapidly growing demand for T2DM treatment, increased research has been focused on hypoglycemic drugs. Cyclocarya paliurus (Batal.) Iljinsk is the only living species of the genus Cyclocarya Iljinskaja, whose leaves have been extensively used as a functional tea to treat obesity and diabetes in China. An enormous amount of very recent pharmacological research on the leaves of C. paliurus has demonstrated that they carry out numerous biological activities, such as hypoglycemic, anti-inflammatory, and intestinal microbiota regulation. Multiple in vitro and in vivo studies have also shown that the extracts of C. paliurus leaves are innocuous and safe. This study aims to provide an up-to-date review of the botany, traditional uses, phytochemistry, pharmacological effects against diabetes, toxicology, and clinical studies of C. paliurus leaves, in hopes of promoting a better understanding of their role in the prevention and treatment of T2DM.

Cyclocarya paliurus (Batalin) Iljinskaja: Botany, Ethnopharmacology, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Cyclocarya paliurus (Batalin) Iljinskaja (C. paliurus) also known as Sweet tea tree, Money tree, Money willow, green money plum, mountain willow and shanhua tree, is a native rare monocotyledonous plant in Southern China. It possesses numerous traditional benefits, including clearing heat, detoxification, producing saliva, slake thirst, anti-inflammatory, insecticidal, dispelling wind and relieving itching. It is also effective in preventing and treating diabetes, hypertension, hyperlipidemia, dizziness and swelling and pain, as well as reducing cholesterol, and modulating the functions of the immune system. The stem, leaves and bark of this plant are all medicinal parts, but the leaves have the highest research value.

AIM OF THE STUDY

This article summarized the plant's botanical description, distribution, ethnopharmacology, phytochemical profiles and pharmacological for the first time, to provide possible directions for future development and research in brief.

MATERIAL AND METHODS

The literature for this current manuscript was obtained from reports published from 1992 to May 2021 in diverse databases such as the China Knowledge Resource Integrated databases (CNKI), SciFinder, Google Scholar, Baidu Scholar, Elsevier and Pub-Med. The domestic and foreign references published about C. paliurus over recent years were collected, analyzed and summarized.

RESULTS

The botanical characteristics of the fruits of C. paliurus are unique in having a central nutlet surrounded by a circular wing to distinguish the living genera of Juglandaceae. In traditional medicine, C. paliurus leaves are used by the local people of Southern China to make tea to prevent diabetes. More than 210 compounds have been isolated from C. paliurus. Among them, the characteristic 3,4-seco-dammaranes accounted for the most. Other compounds include dammarane tetracyclic triterpenoids, various pentacyclic triterpenoids, flavonoids, isosclerones, phenolic derivatives and polysaccharides. The plant extracts and compounds have been reported to exert various pharmacological activities, such as anti-hyperglycemic, anti-hyperlipidemic, anti-cancer, cytotoxic, anti-oxidative, anti-inflammatory, hepatoprotective, and anti-microbial activities.

CONCLUSIONS

Comprehensive literature analysis shows that C. paliurus extract and its compounds have a variety of biological activities for the treatment of various diseases. The current modern pharmacology research is mostly related to the records of ethnic pharmacology, mainly in vitro research, relatively few in vivo research. Therefore, future studies should focus on this aspect. In addition, we also would like to recommend further research should concentrate on toxicity studies and quality control of C. paliurus to fill the study gap, as well as to provide theoretical support for the further development of the potential functions and clinical applications of the plant.

Natural Compounds as Source of Aldose Reductase (AR) Inhibitors for the Treatment of Diabetic Complications: A Mini Review

BACKGROUND

Aldol reductase (AR) is the polyol pathway's main enzyme that portrays a crucial part in developing 'complications of diabetes' involving cataract, retinopathy, nephropathy, and neuropathy. These diabetic abnormalities are triggered tremendously via aggregation of sorbitol formation (catalyzed by AR) in the polyol pathway. Consequently, it represents an admirable therapeutic target and vast research was done for the discovery of novel molecules as potential AR inhibitors for diabetic complications.

OBJECTIVE

This review article has been planned to discuss an outline of diabetic complications, AR and its role in diabetic complications, natural compounds reported as AR inhibitors, and benefits of natural/plant derived AR inhibitors for the management of diabetic abnormalities.

RESULTS

The goal of AR inhibition remedy is to stabilize the increased flux of blood glucose and sorbitol via the 'polyol pathway' in the affected tissues. A variety of synthetic inhibitors of AR have been established such as tolrestat and sorbinil, but both of these face limitations including low permeability and health problems. Pharmaceutical industries and other scientists were also undertaking work to develop newer, active, and 'safe' AR inhibitors from natural sources. Therefore, several naturally found molecules were documented to possess a potent inhibitory action on AR activity.

CONCLUSION

Natural inhibitors of AR appeared as harmless pharmacological agents for controlling diabetic complications. The detailed literature throughout this article shows the significance of herbal extracts and phytochemicals as prospective useful AR inhibitors in treating diabetic complications.

Potential Role of Natural Plant Medicine Cyclocarya paliurus in the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a common chronic metabolic disease that has become increasingly prevalent worldwide. It poses a serious threat to human health and places a considerable burden on global social medical work. To meet the increasing demand for T2DM treatment, research on hypoglycemic drugs is rapidly developing. Cyclocarya paliurus (Batal.) Iljinskaja is a medicinal plant that grows in China. The leaves of C. paliurus contain polysaccharides, triterpenoids, and other chemical components, which have numerous health benefits. Therefore, the use of this plant has attracted extensive attention in the medical community. Over the past few decades, contemporary pharmacological studies on C. paliurus extracts have revealed that it has abundant biological activities. Multiple in vitro and in vivo experiments have shown that C. paliurus extracts are safe and can play a therapeutic role in T2DM through anti-inflammatory and antioxidation activities, and intestinal flora regulation. Its efficacy is closely related to many factors, such as extraction, separation, purification, and modification. Based on summarizing the existing extraction methods, this article further reviews the potential mechanism of C. paliurus extracts in T2DM treatment, and we aimed to provide a reference for future research on natural plant medicine for the prevention and treatment of T2DM and its related complications.

Effects of Cyclocarya paliurus Aqueous and Ethanol Extracts on Glucolipid Metabolism and the Underlying Mechanisms: A Meta-Analysis and Systematic Review

Background and Aims:Cyclocarya paliurus (CP) has been used as an herbal tea to treat diabetes mellitus and obesity for hundreds of years. Previous research suggests that CP specifically restores glucolipid metabolic homeostasis, and the two most studied preparations are aqueous and ethanol extracts. In order to verify the effect of CP on glucolipid metabolism in animal models with metabolic syndrome, a meta-analysis was performed, and the active components and underlying mechanisms were systematically reviewed.

Methods: Four databases: PubMed, Web of Science, Embase, and Cochrane Library were searched to identify potential literature. Data of blood glucose (BG) level, area under curve (AUC) of oral glucose tolerance test (OGTT), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels were extracted as indicators of the assessment of CP's effects. Follow-up analyses including subgroup analysis, meta-regressions, and publication bias were also conducted.

Results: A total of 96 papers were identified from the databases and 11 papers including 31 data reports were involved in the meta-analysis. CP had a positive effect in down-regulating BG, AUC of OGTT, TC, TG, and LDL, and up-regulating HDL (P < 0.001, 95% confidence interval of standard mean difference did not incorporate the null value 0).

Conclusion: CP showed definite activity of regulating glucolipid metabolism in animal models, and it exerted its function through multiple mechanisms including but not limited to: (1) improving insulin resistance; (2) protecting pancreatic β cells; (3) decreasing inflammatory infiltration; and (4) anti-oxidative stress.

Cyclocarya paliurus polysaccharides alleviate type 2 diabetic symptoms by modulating gut microbiota and short-chain fatty acids

BACKGROUND

Cyclocarya paliurus polysaccharide (CCPP), a primary active component in the leaves of Cyclocarya paliurus (Batal.) Iljinsk (C. paliurus), has the ability to treat type 2 diabetes mellitus (T2DM), but cannot be digested by our digestive system. Therefore, mechanisms of regulating the gut microbiota and intestinal metabolites might exist.

PURPOSE

To reveal the potential mechanism of CCPP treatment, this study aimed to investigate the alterations of the gut microbiota and intestinal metabolites especially short chain fatty acids (SCFAs) in type 2 diabetic rats.

STUDY DESIGN AND METHODS

Type 2 diabetic rat models were developed, and the therapeutic effects of CCPP were evaluated. Metagenomics analysis was utilized to analyze the alterations to the gut microbiota, and UHPLC-QTOF/MS-based untargeted metabolomics analysis of colon contents was used to identify the differential intestinal metabolites. GC/MS was used to measure the SCFAs in rat's colon contents and human fecal inoculums. Furthermore, the expression of SCFA receptors including GPR41, GPR43 and GPR109a was verified by qRT-PCR and the concentration of glucagon-like peptide-1(GLP-1) and peptide tyrosinetyrosine (PYY) was measured by Elisa.

RESULTS

Inhibition of the blood glucose levels and improvements in glucose tolerance and serum lipid parameters were observed after CCPP treatment. Eleven SCFA-producing species including Ruminococcus_bromii, Anaerotruncus_colihominis, Clostridium_methylpentosum, Roseburia_intestinalis, Roseburia_hominis, Clostridium_asparagiforme, Pseudoflavonifractor_capillosus, Intestinimonas_butyriciproducens, Intestinimonas_sp._GD2, Oscillibacter_valericigenes and Oscillibacter_ruminantium were clearly increased in the CCPP group. Furthermore, our study indicated that CCPP increases the production of SCFAs both in vivo and in vitro, and the gut microbiota are the key factor of this process. The SCFA receptors including GPR41, GPR43 and GPR109a, were significantly stimulated in the CCPP treated rats, which was accompanied by the upregulated expression of GLP-1 and PYY.

CONCLUSION

These results demonstrated that CCPP could alleviate type 2 diabetic symptoms by increasing the SCFA-producing bacteria, promoting the production of SCFAs and upregulating SCFA-GLP1/PYY associated sensory mediators.

Protective Effect and Possible Mechanisms of Astragaloside IV in Animal Models of Diabetic Nephropathy: A Preclinical Systematic Review and Meta-Analysis

Astragaloside IV (AS-IV) has a variety of biological activities and is widely used to treat kidney diseases. We conducted a systematic review of 24 animal studies including 424 animals to evaluate the efficacy of AS-IV for diabetic nephropathy (DN); all current possible mechanisms were summarized. A search strategy was applied to eight databases from inception to June 2020. The CAMARADES 10-item quality checklist and Rev-Man 5.3 software were used to analyze the risks of bias of each study and data regarding outcome measures, respectively. The mean study quality score was 5.4 points (range 3–8 points). Meta-analyses data and comparisons between groups showed that AS-IV significantly slowed the progression of pathological signs in the kidney including glomeruli and tubules, increasing creatinine clearance rate, decreasing blood urea nitrogen, serum creatinine, 24-h urinary neutrophil gelatinase-associated lipocalin and N-acetyl-β-D-glucosaminidase, 24-h urinary albumin, 24-h urinary microalbumin and HbA1c. There were no significant differences between experimental and control groups with respect to mortality or levels of alanine aminotransferase and aspartate aminotransferase. In terms of the possible mechanisms of treatment of DN, AS-IV acts through antifibrotic, antioxidant, and antiapoptotic mechanisms, thereby alleviating endoplasmic reticulum stress, inhibiting mitochondrial fission, and increasing autophagic activity. Taken together, our findings suggest that AS-IV is a multifaceted renoprotective candidate drug for DN.

Combination of Ginsenoside Rg1 and Astragaloside IV reduces oxidative stress and inhibits TGF-β1/Smads signaling cascade on renal fibrosis in rats with diabetic nephropathy

Introduction

Anti-oxidative stress and inhibition of TGF-β1/Smads signaling cascade are essential therapeutic strategies for diabetic nephropathy (DN). In this study, we aimed to explore the effect of combination of Ginsenoside Rg1 and Astragaloside IV on oxidative stress and TGF-β1/Smads signaling in DN rats.

Materials and methods

Wistar rats were divided into five groups: N group, M group (streptozotocin [STZ], intraperitoneally), G group (STZ rats with Ginsenoside Rg1, intragastrically [ig]), A group (STZ rats with Astragaloside IV, ig) and C group (STZ rats with Ginsenoside Rg1 and Astragaloside IV, ig). The levels of methane dicarboxylic aldehyde (MDA), catalase (CAT), glutathione peroxidase (GSH-PX), total anti-oxidative capacity (T-AOC), blood urea nitrogen (BUN), β₂-microglobulin (β₂-MG), serum creatinine (SCr) and urinary creatinine (UCr) were detected in all the groups. The left kidneys of the rats were harvested to detect the expression of TGF-β1, Smad2/3, Smad7 and CTGF by immunohistochemical staining, while the right kidneys were used to detect the mRNA expression of TGF-β1, Smad7 and CTGF by real-time PCR.

Results

Rats in G group, A group and C group had lower level of MDA but higher levels of CAT, GSH-PX and T-AOC compared with rats in M group. Rats in C group showed the best anti-oxidative stress level. G group, A group and C group treatments significantly decreased the levels of BUN, SCr, β₂-MG and UCr. In addition, C group treatment showed the best kidney protective effect. G group, A group and C group treatments significantly diminish ED both factor and mRNA overexpression of TGF-β1 and CTGF but increase Smad7 expression in kidney tissue.

Conclusion

The combination of Ginsenoside Rg1 and Astragaloside IV may potentially protect against DN by reducing oxidative stress and inhibiting TGF-β1/Smads signaling cascade.

DMP-1 attenuates oxidative stress and inhibits TGF-β activation in rats with diabetic kidney disease

Introduction: DMP-1 supplement has a satisfactory effect on diabetic kidney disease in patients with whether T1DM or T2DM. Oxidative stress and TGF-β signal pathway activation are essential in the pathogenesis of DKD. We aim to investigate the effect of DMP-1 on oxidative stress and TGF-β activation in rats with DKD.

Materials and methods: Male Wistar rats were enrolled and randomly allocated into five groups: Control group, STZ group (60 mg/kg, ip), DMP-1 low dose group (0.5 g/kg/day, ig), DMP-1 medium dose group (1.0 g/kg/day, ig) and DMP-1 high dose group (2.0 g/kg/day, ig). The levels of UREA, BUN, UCr, β₂-MG, mALB, NOS, CAT, MDA and T-AOC were measured after 8 weeks treatment. And rats’ left kidneys were harvested to detect the expression of TGF-β, Smad2/3 and Smad7 by immunohistochemical analysis.

Results: DMP-1 treatment has protective effects on kidney injury induced by STZ, which is demonstrated as following criteria: (1) a significant reduction in levels of UREA (p < 0.05), BUN (p < 0.05), UCr (p < 0.05), β2-MG (p < 0.05) and mALB (p < 0.05) in rats treated by DMP-1 compared with the ones injected with STZ only; (2) an apparent increment levels of NOS (p < 0.05), CAT (p < 0.05) and T-AOC (p < 0.05), while reduction in level of MDA (p < 0.05) in DMP-1 groups compared with STZ group; (3) a significant inhibition of TGF-β and Smad2/3 overexpression induced by STZ in kidney tissue. What’s more, DMP-1 can increase Smad7 expression.

Conclusion: DMP-1 could slow pathological process and protect kidney from DKD injury by decreasing oxidative stress and inhibiting TGF-β signal pathway activation in rats.