Protective effects of Astragaloside IV on endoplasmic reticulum stress-induced renal tubular epithelial cells apoptosis in type 2 diabetic nephropathy rats

Natural products derived from traditional Chinese medicines targeting ER stress for the treatment of kidney diseases

Various factors, both internal and external, can disrupt endoplasmic reticulum (ER) homeostasis and increase the burden of protein folding, resulting in ER stress. While short periods of ER stress can help cells return to normal function, excessive or prolonged ER stress triggers a complex signaling network that negatively affects cells. Numerous studies have demonstrated the significant role of ER stress in various kidney diseases, such as immune-related kidney injury, diabetic kidney diseases, renal ischemia reperfusion injury, and renal fibrosis. To date, there is a severe shortage of medications for the treatment of acute and chronic kidney diseases of all causes. Natural products derived from various traditional Chinese medicines (TCM), which are a major source of new drugs, have garnered considerable attention. Recent research has revealed that many natural products have renoprotective effects by targeting ER stress-mediated events, such as apoptosis, oxidative stress, inflammation, autophagy, and epithelial-mesenchymal transition. This article provides a comprehensive review of the current research progress on natural products targeting ER stress for the treatment of kidney diseases.

DMDD, isolated from Averrhoa carambola L., ameliorates diabetic nephropathy by regulating endoplasmic reticulum stress-autophagy crosstalk

BACKGROUND

Studies have shown that Averrhoa carambola L. possesses therapeutic potential for diabetes and related complications. However, the specific beneficial effects and molecular mechanisms of 2-dodecyl-6-meth-oxycyclohexa-2,5-diene-1,4-dione (DMDD) isolated from Averrhoa carambola L. on diabetic nephropathy (DN) require further investigation.

METHODS

80 C57BL/6 J male mice were subjected to a 1-week adaptive feeding, followed by a high-fat diet and intraperitoneal injection of 100 mg/kg streptozotocin (STZ) to construct an in vivo DN model. Additionally, human renal proximal tubular epithelial cells (HK-2) induced by high glucose (HG) were used as an in vitro DN model. The expression levels of epithelial-mesenchymal transition (EMT), endoplasmic reticulum stress (ERS), and autophagy-related proteins in renal tubular cells were detected by Western Blot, flow cytometry, immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) staining. Transcriptome analysis revealed was conducted to elucidate the specific mechanism of by which DMDD mitigates DN by inhibiting ERS and autophagy. HK-2 cells were transfected with IRE1α overexpression lentivirus to reveal the role of IRE1α overexpression in HG-induced HK-2.

RESULTS

The experimental data showed that DMDD significantly reduced blood glucose levels and improved renal pathological alterations in DN mice. Additionally, DMDD inhibited the calcium (Ca2+) pathway, manifested by decreased autophagosome formation and downregulation of LC3II/I, Beclin-1, and ATG5 expression. Moreover, in HG-induced HK-2 cells, DMDD suppressed the overexpression of GRP78, CHOP, LC3II/I, Beclin1, and ATG5. Notably, IRE1α overexpression significantly increased autophagy incidence; however, DMDD treatment subsequently reduced the expression of LC3II/I, Beclin1, and ATG5.

CONCLUSION

DMDD effectively inhibits excessive ERS and autophagy, thereby reducing renal cell apoptosis through the IRE1α pathway and Ca 2+ pathway.

A new strategy for Astragaloside IV in the treatment of diabetic kidney disease: Analyzing the regulation of ferroptosis and mitochondrial function of renal tubular epithelial cells

In China, the Astragalus membranaceus root is used to treat chronic kidney disease. Astragaloside IV (AS-IV), the primary bioactive compound, exhibits anti-inflammatory and antioxidative properties; however, its renoprotective mechanism in diabetic kidney disease (DKD) remains unclear. The study aimed to investigate the protective effects of AS-IV on DKD revealing the underlying mechanisms. We established an early diabetic rat model by feeding a high-fat diet and administering low-dose streptozotocin. Twelve weeks post-treatment, renal function was evaluated using functional assays, histological analyses, immunohistochemistry, western blotting, and transmission electron microscopy. HK-2 cells exposed to high glucose conditions were used to examine the effect of AS-IV on oxidative stress, iron levels, reactive oxygen species (ROS), and lipid peroxidation. Network pharmacology, proteomics, molecular docking, and molecular dynamics simulation techniques were employed to elucidate the role of AS-IV in DKD. The results revealed that AS-IV effectively enhanced renal function and mitigated disease pathology, oxidative stress, and ferroptosis markers in DKD rats. In HK-2 cells, AS-IV lowered the levels of lipid peroxides, Fe2+, and glutathione, indicating the repair of ferroptosis-related mitochondrial damage. AS-IV reduced mitochondrial ROS while enhancing mitochondrial membrane potential and ATP production, indicating its role in combating mitochondrial dysfunction. Overall, in silico analyses revealed that AS-IV interacts with HMOX1, FTH1, and TFR1 proteins, supporting its efficacy in alleviating renal injury by targeting mitochondrial dysfunction and ferroptosis. AS-IV may play a renoprotective role by regulating mitochondrial dysfunction and inhibiting. HMOX1/FTH1/TFR1-induced ferroptosis. Accordingly, AS-IV could be developed for the clinical treatment of DKD-related renal injury.

Evaluation of Phytochemistry and Antidiabetic Potential of an Astragalus Species (Astragalus kurdicus Boiss.)

Astragalus kurdicus Boiss. roots are used in folk medicine for antidiabetic purposes. Different Astragalus plant metabolites have a notable potential for antidiabetic activity through varying mechanisms. Herein, this study is designed to assess the antidiabetic activity of Astragalus kurdicus total (AKM: methanol extract, yield: 14.53 %) and sub-extracts (AKB: n-butanol, AKC: chloroform, AKW: water, AKH: hexane extracts), utilizing a range of diabetes-related in vitro methodologies, and to investigate the chemical composition of the plant. The highest astragaloside and saponin content was seen in AKB extract. Among the measured saponins, the abundance of Astragaloside IV (27.41 μg/mg in AKM) was the highest in high-performance thin-layer chromatography (HPTLC) analysis. Furthermore, flavonoid-rich AKC was found to be mostly responsible for the high antioxidant activity. According to the results of the activity tests, AKW was the most active extract in protein tyrosine phosphatase 1 B (PTP1B), dipeptidyl peptidase IV (DPP4), and α-amylase inhibition tests (percent inhibitions are: 87.17 %, 82.4 %, and 91.49 % respectively, at 1 mg/mL). AKM and AKW demonstrated the highest efficacy in stimulating the growth of prebiotic microorganisms and preventing the formation of advanced glycation end products (AGEs). Thus, for the first time, the antidiabetic activity of A. kurdicus was evaluated from various perspectives.

Renal tubular epithelial cell quality control mechanisms as therapeutic targets in renal fibrosis

Renal fibrosis is a devastating consequence of progressive chronic kidney disease, representing a major public health challenge worldwide. The underlying mechanisms in the pathogenesis of renal fibrosis remain unclear, and effective treatments are still lacking. Renal tubular epithelial cells (RTECs) maintain kidney function, and their dysfunction has emerged as a critical contributor to renal fibrosis. Cellular quality control comprises several components, including telomere homeostasis, ubiquitin-proteasome system (UPS), autophagy, mitochondrial homeostasis (mitophagy and mitochondrial metabolism), endoplasmic reticulum (ER, unfolded protein response), and lysosomes. Failures in the cellular quality control of RTECs, including DNA, protein, and organelle damage, exert profibrotic functions by leading to senescence, defective autophagy, ER stress, mitochondrial and lysosomal dysfunction, apoptosis, fibroblast activation, and immune cell recruitment. In this review, we summarize recent advances in understanding the role of quality control components and intercellular crosstalk networks in RTECs, within the context of renal fibrosis.

Astragaloside IV Alleviates Podocyte Injury in Diabetic Nephropathy through Regulating IRE-1α/NF-κ B/NLRP3 Pathway

OBJECTIVE

To investigate the effects of astragaloside IV (AS-IV) on podocyte injury of diabetic nephropathy (DN) and reveal its potential mechanism.

METHODS

In in vitro experiment, podocytes were divided into 4 groups, normal, high glucose (HG), inositol-requiring enzyme 1 (IRE-1) α activator (HG+thapsigargin 1 µmol/L), and IRE-1α inhibitor (HG+STF-083010, 20 µmol/L) groups. Additionally, podocytes were divided into 4 groups, including normal, HG, AS-IV (HG+AS-IV 20 µmol/L), and IRE-1α inhibitor (HG+STF-083010, 20 µmol/L) groups, respectively. After 24 h treatment, the morphology of podocytes and endoplasmic reticulum (ER) was observed by electron microscopy. The expressions of glucose-regulated protein 78 (GRP78) and IRE-1α were detected by cellular immunofluorescence. In in vivo experiment, DN rat model was established via a consecutive 3-day intraperitoneal streptozotocin (STZ) injections. A total of 40 rats were assigned into the normal, DN, AS-IV [AS-IV 40 mg/(kg·d)], and IRE-1α inhibitor [STF-083010, 10 mg/(kg·d)] groups (n=10), respectively. The general condition, 24-h urine volume, random blood glucose, urinary protein excretion rate (UAER), urea nitrogen (BUN), and serum creatinine (SCr) levels of rats were measured after 8 weeks of intervention. Pathological changes in the renal tissue were observed by hematoxylin and eosin (HE) staining. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the expressions of GRP78, IRE-1α, nuclear factor kappa Bp65 (NF-κBp65), interleukin (IL)-1β, NLR family pyrin domain containing 3 (NLRP3), caspase-1, gasdermin D-N (GSDMD-N), and nephrin at the mRNA and protein levels in vivo and in vitro, respectively.

RESULTS

Cytoplasmic vacuolation and ER swelling were observed in the HG and IRE-1α activator groups. Podocyte morphology and ER expansion were improved in AS-IV and IRE-1α inhibitor groups compared with HG group. Cellular immunofluorescence showed that compared with the normal group, the fluorescence intensity of GRP78 and IRE-1α in the HG and IRE-1α activator groups were significantly increased whereas decreased in AS-IV and IRE-1α inhibitor groups (P<0.05). Compared with the normal group, the mRNA and protein expressions of GRP78, IRE-1α, NF-κ Bp65, IL-1β, NLRP3, caspase-1 and GSDMD-N in the HG group was increased (P<0.05). Compared with HG group, the expression of above indices was decreased in the AS-IV and IRE-1α inhibitor groups, and the expression in the IRE-1α activator group was increased (P<0.05). The expression of nephrin was decreased in the HG group, and increased in AS-IV and IRE-1α inhibitor groups (P<0.05). The in vivo experiment results revealed that compared to the normal group, the levels of blood glucose, triglyceride, total cholesterol, BUN, blood creatinine and urinary protein in the DN group were higher (P<0.05). Compared with DN group, the above indices in AS-IV and IRE-1α inhibitor groups were decreased (P<0.05). HE staining revealed glomerular hypertrophy, mesangial widening and mesangial cell proliferation in the renal tissue of the DN group. Compared with the DN group, the above pathological changes in renal tissue of AS-IV and IRE-1α inhibitor groups were alleviated. Quantitative RT-PCR and Western blot results of GRP78, IRE-1α, NF-κ Bp65, IL-1β, NLRP3, caspase-1 and GSDMD-N were consistent with immunofluorescence analysis.

CONCLUSION

AS-IV could reduce ERS and inflammation, improve podocyte pyroptosis, thus exerting a podocyte-protective effect in DN, through regulating IRE-1α/NF-κ B/NLRP3 signaling pathway.

Astragaloside IV protects renal tubular epithelial cells against oxidative stress-induced injury by upregulating CPT1A-mediated HSD17B10 lysine succinylation in diabetic kidney disease

Tubular injury and oxidative stress are involved in the pathogenesis of diabetic kidney disease (DKD). Astragaloside IV (ASIV) is a natural antioxidant. The effects and underlying molecular mechanisms of ASIV on DKD have not been elucidated. The db/db mice and high-glucose-stimulated HK2 cells were used to evaluate the beneficial effects of ASIV in vivo and in vitro. Succinylated proteomics was used to identify novel mechanisms of ASIV against DKD and experimentally further validated. ASIV alleviated renal dysfunction and proteinuria, downregulated fasting blood glucose, and upregulated insulin sensitivity in db/db mice. Meanwhile, ASIV alleviated tubular injury, oxidative stress, and mitochondrial dysfunction in vivo and in vitro. Mechanistically, ASIV reversed downregulated 17beta-hydroxysteroid dehydrogenase type 10 (HSD17B10) lysine succinylation by restoring carnitine palmitoyl-transferase1alpha (Cpt1a or CPT1A) activity in vivo and in vitro. Molecular docking and cell thermal shift assay revealed that ASIV may bind to CPT1A. Molecular dynamics simulations demonstrated K99 succinylation of HSD17B10 maintained mitochondrial RNA ribonuclease P (RNase P) stability. The K99R mutation of HSD17B10 induced oxidative stress and disrupted its binding to CPT1A or mitochondrial ribonuclease P protein 1 (MRPP1). Importantly, ASIV restored the interaction between HSD17B10 and MRPP1 in vivo and in vitro. We also demonstrated that ASIV reversed high-glucose-induced impaired RNase P activity in HK2 cells, which was suppressed upon K99R mutation of HSD17B10. These findings suggest that ASIV ameliorates oxidative stress-associated proximal tubular injury by upregulating CPT1A-mediated K99 succinylation of HSD17B10 to maintain RNase P activity.

Saponin monomers: Potential candidates for the treatment of type 2 diabetes mellitus and its complications

Type 2 diabetes mellitus (T2DM), a metabolic disease with persistent hyperglycemia primarily caused by insulin resistance (IR), has become one of the most serious health challenges of the 21st century, with considerable economic and societal implications worldwide. Considering the inevitable side effects of conventional antidiabetic drugs, natural ingredients exhibit promising therapeutic efficacy and can serve as safer and more cost-effective alternatives for the management of T2DM. Saponins are a structurally diverse class of amphiphilic compounds widely distributed in many popular herbal medicinal plants, some animals, and marine organisms. There are many saponin monomers, such as ginsenoside compound K, ginsenoside Rb1, ginsenoside Rg1, astragaloside IV, glycyrrhizin, and diosgenin, showing great efficacy in the treatment of T2DM and its complications in vivo and in vitro. However, although the mechanisms of action of saponin monomers at the animal and cell levels have been gradually elucidated, there is a lack of clinical data, which hinders the development of saponin-based antidiabetic drugs. Herein, the main factors/pathways associated with T2DM and the comprehensive underlying mechanisms and potential applications of these saponin monomers in the management of T2DM and its complications are reviewed and discussed, aiming to provide fundamental data for future high-quality clinical studies and trials.

Nephroprotective effects of Aralia taibaiensis in a high-fat diet-streptozotocin rat model of diabetic nephropathy

Diabetic nephropathy (DN) has emerged as the foremost cause of end-stage renal disease (ESRD) globally. Endoplasmic reticulum (ER) stress plays a critical role in DN progression. Triterpenoid saponin from Aralia taibaiensis (sAT) has been reported to possess anti-diabetic and anti-oxidant effects. The aim of this study was to examine the influence of sAT on DN treatment and elucidate potential underlying mechanisms. A high-fat diet (HFD) and Streptozotocin (STZ) were employed to induce DN in male Sprague Dawley (SD) rats which were subsequently treated with varying concentrations of sAT for 8 weeks. Our findings reveal that different doses of sAT significantly mitigated hyperglycemia, reduced urinary albumin excretion, and decreased plasma creatinine and blood urea nitrogen levels in DN rats. Moreover, sAT administration improved body weight, alleviated renal fibrosis and histopathological changes in the diabetic kidneys. Notably, sAT treatment partially restored increased Bax expression and decreased Bcl-2 expression. Additionally, sAT inhibited ER stress-related proteins, including GRP78, p-PERK, ATF4 and CHOP in kidneys of DN rats. These results suggest that sAT ameliorated experimental diabetic nephropathy, at least in part, through ER stress pathway. These findings provide a scientific basis for the potential development of sAT as a therapeutic agent for DN treatment.

Astragaloside IV inhibits angiotensin II-induced atrial fibrosis and atrial fibrillation by SIRT1/PGC-1α/FNDC5 pathway

Aims and objectives

Astragaloside IV (AS-IV) has been found to possess anti-oxidative, anti-inflammatory, and anti-apoptotic properties, but its effect on atrial fibrosis is yet to be determined. This research investigates the protective role of AS-IV in angiotensin II (Ang II)-induced atrial fibrosis and atrial fibrillation (AF).

Methods

C57BL/6 male mice aged 8-10 weeks (n = 40) were subcutaneously administered Ang II (2.0 mg/kg/day) or saline, with AS-IV (80 mg/kg) intraperitoneally administered 2 h before Ang II infusion for 4 weeks. Biochemical, histological, and morphological analyses were carried out. Using transesophageal burst pacing, AF was generated in vivo.

Results

Here, we report that AS-IV treatment inhibited Ang II-induced AF development in mice (58 ± 5.86 vs 15.13 ± 2.16 %, p < 0.001). Ang II + AS-IV therapy was effective in reducing the atrial fibrotic area and decreasing the increase in smooth muscle alpha-actin (α-SMA)-positive myofibroblasts brought on by Ang II treatment (fibrotic area: 26.25 ± 3.81 vs 8.62 ± 1.83 %, p < 0.001 and α-SMA: 65.62 ± 10.63 vs 17.25 ± 1.78 %, p < 0.001). The reactive oxygen species (ROS) production was reduced by pretreatment with Ang II + AS-IV (9.20 ± 0.92 vs 2.63 ± 0.22 %/sec, p < 0.001). In addition, Ang II + AS-IV treatment suppressed oxidative stress in Ang II-induced atrial fibrosis (malondialdehyde: 701.78 ± 85.01 vs 504.07 ± 25.62 pmol/mg protein, p < 0.001; superoxide dismutase: 13.82 ± 1.25 vs 29.54 ± 2.45 U/mg protein, p < 0.001 and catalase: 11.43 ± 1.19 vs 20.83 ± 3.29 U/mg protein, p < 0.001, respectively). Moreover, Ang II + AS-IV decreased the expression of α-SMA, collagen III and collagen I (3.32 ± 0.53 vs 1.41 ± 0.20 fold, p < 0.001; 3.41 ± 0.55 vs 1.48 ± 0.18 fold, p < 0.001; 2.34 ± 0.55 vs 0.99 ± 0.17 fold, p < 0.001, respectively) while increasing the protein expression of sirtuin 1 (SIRT1), peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α), and fibronectin type III domain-containing protein 5 (FNDC5) in Ang II-treated mice (0.22 ± 0.02 vs 0.57 ± 0.08 fold, p < 0.001; 0.28 ± 0.04 vs 0.72 ± 0.05 fold, p < 0.001; 0.38 ± 0.03 vs 0.68 ± 0.06 fold, p < 0.001, respectively).

Conclusion

Our data led us to speculate that AS-IV may protect against Ang II-induced atrial fibrosis and AF via upregulation of the SIRT1/PGC-1α/FNDC5 pathway.

Liraglutide, a glucagon-like peptide-1 receptor agonist, inhibits bone loss in an animal model of osteoporosis with or without diabetes

Introduction

Liraglutide (Lrg), a novel anti-diabetic drug that mimics the endogenous glucagon-like peptide-1 to potentiate insulin secretion, is observed to be capable of partially reversing osteopenia. The aim of the present study is to further investigate the efficacy and potential anti-osteoporosis mechanisms of Lrg for improving bone pathology, bone- related parameters under imageology, and serum bone metabolism indexes in an animal model of osteoporosis with or without diabetes.

Methods

Eight databases were searched from their inception dates to April 27, 2024. The risk of bias and data on outcome measures were analyzed by the CAMARADES 10-item checklist and Rev-Man 5.3 software separately.

Results

Seventeen eligible studies were ultimately included in this review. The number of criteria met in each study varied from 4/10 to 8/10 with an average of 5.47. The aspects of blinded induction of the model, blinding assessment of outcome and sample size calculation need to be strengthened with emphasis. The pre-clinical evidence reveals that Lrg is capable of partially improving bone related parameters under imageology, bone pathology, and bone maximum load, increasing serum osteocalcin, N-terminal propeptide of type I procollagen, and reducing serum c-terminal cross-linked telopeptide of type I collagen (P<0.05). Lrg reverses osteopenia likely by activating osteoblast proliferation through promoting the Wnt signal pathway, p-AMPK/PGC1α signal pathway, and inhibiting the activation of osteoclasts by inhibiting the OPG/RANKL/RANK signal pathway through anti-inflammatory, antioxidant and anti-autophagic pathways. Furthermore, the present study recommends that more reasonable usage methods of streptozotocin, including dosage and injection methods, as well as other types of osteoporosis models, be attempted in future studies.

Discussion

Based on the results, this finding may help to improve the priority of Lrg in the treatment of diabetes patients with osteoporosis.

(+)-Catechin ameliorates diabetic nephropathy injury by inhibiting endoplasmic reticulum stress-related NLRP3-mediated inflammation

Endoplasmic reticulum (ER) stress and chronic sterile inflammation are associated with the pathogenesis of diabetic nephropathy (DN). Catechins are natural polyphenolic compounds found in green tea that possess some health benefits. However, whether (+)-catechin can reduce tubular injury in DN by regulating ER stress and NLRP3-associated inflammation remains uncertain. This study examined the effects of (+)-catechin on streptozotocin (STZ)-induced diabetic mice and on palmitic acid (PA)-treated HK-2 cells. In vivo, a DN mouse model was generated by injecting STZ. The biochemical indicators of serum and urine, as well as renal histopathology and ultrastructure were analysed. To predict the mechanisms associated with (+)-catechin, network pharmacology and molecular docking were used. Finally, quantitative real-time PCR (qPCR), western blot analysis and immunofluorescence analysis were performed to measure the mRNA and protein expressions of specific targets in the renal tissue of DN mice and PA-treated HK-2 cells to validate the predicted results. (+)-Catechin significantly ameliorated renal function and pathological changes associated with tubular injury by inhibiting ER stress by downregulating of GRP78, PEAK, CHOP, ATF6 and XBP1. In addition, (+)-catechin inhibited renal inflammation by suppressing NLRP3 associated inflammation, which was characterized by the downregulation of NLRP3, ASC, AIM2, Caspase1, IL-1β and IL-18 in DN mice and PA-treated HK-2 cells. Collectively, these findings suggested that (+)-catechin exerted a renoprotective effect against DN by inhibiting ER stress and NLRP3-related inflammation to ameliorate tubular injury, suggesting the therapeutic potential of (+)-catechin.

Astragaloside IV attenuates renal tubule injury in DKD rats via suppression of CD36-mediated NLRP3 inflammasome activation

Background

In recent years, diabetic kidney disease (DKD) has emerged as a prominent factor contributing to end-stage renal disease. Tubulointerstitial inflammation and lipid accumulation have been identified as key factors in the development of DKD. Earlier research indicated that Astragaloside IV (AS-IV) reduces inflammation and oxidative stress, controls lipid accumulation, and provides protection to the kidneys. Nevertheless, the mechanisms responsible for its protective effects against DKD have not yet been completely elucidated.

Purpose

The primary objective of this research was to examine the protective properties of AS-IV against DKD and investigate the underlying mechanism, which involves CD36, reactive oxygen species (ROS), NLR family pyrin domain containing 3 (NLRP3), and interleukin-1β (IL-1β).

Methods

The DKD rat model was created by administering streptozotocin along with a high-fat diet. Subsequently, the DKD rats and palmitic acid (PA)-induced HK-2 cells were treated with AS-IV. Atorvastatin was used as the positive control. To assess the therapeutic effects of AS-IV on DKD, various tests including blood sugar levels, the lipid profile, renal function, and histopathological examinations were conducted. The levels of CD36, ROS, NLRP3, Caspase-1, and IL-1β were detected using western blot analysis, PCR, and flow cytometry. Furthermore, adenovirus-mediated CD36 overexpression was applied to explore the underlying mechanisms through in vitro experiments.

Results

In vivo experiments demonstrated that AS-IV significantly reduced hyperglycemia, dyslipidemia, urinary albumin excretion, and serum creatinine levels in DKD rats. Additionally, it improved renal structural abnormalities and suppressed the expression of CD36, NLRP3, IL-1β, TNF-α, and MCP-1. In vitro experiments showed that AS-IV decreased CD36 expression, lipid accumulation, and lipid ROS production while inhibiting NLRP3 activation and IL-1β secretion in PA-induced HK-2 cells.

Conclusion

AS-IV alleviated renal tubule interstitial inflammation and tubule epithelial cell apoptosis in DKD rats by inhibiting CD36-mediated lipid accumulation and NLRP3 inflammasome activation.

A systematic review of astragaloside IV effects on animal models of diabetes mellitus and its complications

Context

Diabetes mellitus (DM) is one of the fastest-growing diseases worldwide; however, its pathogenesis remains unclear. Complications seriously affect the quality of life of patients in the later stages of diabetes, ultimately leading to suffering. Natural small molecules are an important source of antidiabetic agents.

Objective

Astragaloside IV (AS-IV) is an active ingredient of Astragalus mongholicus (Fisch.) Bunge. We reviewed the efficacy and mechanism of action of AS-IV in animal and cellular models of diabetes and the mechanism of action of AS-IV on diabetic complications in animal and cellular models. We also summarized the safety of AS-IV and provided ideas and rationales for its future clinical application.

Methods

Articles on the intervention in DM and its complications using AS-IV, such as those published in SCIENCE, PubMed, Springer, ACS, SCOPUS, and CNKI from the establishment of the database to February 2022, were reviewed. The following points were systematically summarized: dose/concentration, route of administration, potential mechanisms, and efficacy of AS-IV in animal models of DM and its complications.

Results

AS-IV has shown therapeutic effects in animal models of DM, such as alleviating gestational diabetes, delaying diabetic nephropathy, preventing myocardial cell apoptosis, and inhibiting vascular endothelial dysfunction; however, the potential effects of AS-IV on DM should be investigated.

Conclusion

AS-IV is a potential drug for the treatment of diabetes and its complications, including diabetic vascular disease, cardiomyopathy, retinopathy, peripheral neuropathy, and nephropathy. In addition, preclinical toxicity studies indicate that it appears to be safe, but the safe human dose limit is yet to be determined, and formal assessments of adverse drug reactions among humans need to be further investigated. However, additional formulations or structural modifications are required to improve the pharmacokinetic parameters and facilitate the clinical use of AS-IV.

Jianpi Gushen Huayu decoction ameliorated diabetic nephropathy through modulating metabolites in kidney, and inhibiting TLR4/NF-κB/NLRP3 and JNK/P38 pathways

BACKGROUND

Jianpi Gushen Huayu Decoction (JPGS) has been used to clinically treat diabetic nephropathy (DN) for many years. However, the protective mechanism of JPGS in treating DN remains unclear.

AIM

To evaluate the therapeutic effects and the possible mechanism of JPGS on DN.

METHODS

We first evaluated the therapeutic potential of JPGS on a DN mouse model. We then investigated the effect of JPGS on the renal metabolite levels of DN mice using non-targeted metabolomics. Furthermore, we examined the effects of JPGS on c-Jun N-terminal kinase (JNK)/P38-mediated apoptosis and the inflammatory responses mediated by toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain containing 3 (NLRP3).

RESULTS

The ameliorative effects of JPGS on DN mice included the alleviation of renal injury and the control of inflammation and oxidative stress. Untargeted metabolomic analysis revealed that JPGS altered the metabolites of the kidneys in DN mice. A total of 51 differential metabolites were screened. Pathway analysis results indicated that nine pathways significantly changed between the control and model groups, while six pathways significantly altered between the model and JPGS groups. Pathways related to cysteine and methionine metabolism; alanine, tryptophan metabolism; aspartate and glutamate metabolism; and riboflavin metabolism were identified as the key pathways through which JPGS affects DN. Further experimental validation showed that JPGS treatment reduced the expression of TLR4/NF-κB/NLRP3 pathways and JNK/P38 pathway-mediated apoptosis related factors.

CONCLUSION

JPGS could markedly treat mice with streptozotocin (STZ)-induced DN, which is possibly related to the regulation of several metabolic pathways found in kidneys. Furthermore, JPGS could improve kidney inflammatory responses and ameliorate kidney injuries in DN mice via the TLR4/NF-κB/NLRP3 pathway and inhibit JNK/P38 pathway-mediated apoptosis in DN mice.

Astragaloside IV Mitigated Diabetic Nephropathy by Restructuring Intestinal Microflora and Ferroptosis

SCOPE

To investigate the underlying mechanism of Astragaloside IV (AS-IV) in ameliorating diabetic nephropathy (DN) by regulating intestinal microbiota ecology and intestinal mucosal barrier.

METHODS AND RESULTS

Genetically db/db mice are used to establish DN mouse model to monitor the therapeutic effects of AS-IV and fecal microbiota transplantation (FMT) against DN. Supplementation with AS-IV dramatically attenuates several clinical indicators of DN in db/db mice. In addition, AS-IV markedly improves intestinal barrier function, modifies intestinal permeability, and reduces inflammation. Moreover, AS-IV treatment remarkably improves intestinal dysbiosis in db/db mice, characterized by an elevated abundance of Akkermansia, Ligilactobacillus, and Lactobacillus, indicating the fundamental role of the microbiome in DN progression. Furthermore, FMT derived from AS-IV-treated db/db mice is potentially efficient in antagonizing renal dysfunction, rebalancing gut microbiota, and improving intestinal permeability in recipient db/db mice. AS-IV-enriched Akkermansia muciniphila dramatically alleviates DN and intestinal mucosal barrier dysfunction in db/db mice. Intriguingly, AS-IV intervention dramatically diminishes ferroptosis in the kidney and colon tissues. CONCLUSION : Intestinal microbiome alterations and ferroptosis modulation by AS-IV may play instrumental roles in this mechanism, providing compelling evidence for the role of the gut-renal axis in DN.

Buyang Huanwu decoction ameliorates bleomycin-induced pulmonary fibrosis in rats by attenuating the apoptosis of alveolar type II epithelial cells mediated by endoplasmic reticulum stress

ETHNOPHARMACOLOGICAL RELEVANCE

According to the theory of traditional Chinese medicine, the pathogenesis of idiopathic pulmonary fibrosis (IPF) can be attributed to qi deficiency and blood stasis. Buyang Huanwu decoction (BHD), a representative Chinese herbal prescription for qi deficiency and blood stasis syndrome, is widely used to treat IPF in clinical practice. However, its potential mechanisms against IPF remain unclear.

AIMS OF THE STUDY

This study was carried out to explore the therapeutic effects and underlying mechanisms of BHD on bleomycin (BLM)-induced pulmonary fibrosis in rats.

MATERIALS AND METHODS

UPLC-MS/MS method was performed to identify the quality of BHD used in this study. Concurrently, a IPF rat model was established by single intratracheal injection of BLM. Pulmonary function test, H&E staining, Masson staining, hydroxyproline assay were conducted to evaluate the therapeutic effects of BHD on BLM-induced pulmonary fibrosis in rats, and the regulatory effect of BHD on endoplasmic reticulum stress (ERS)-mediated alveolar type II epithelial cells (AEC2s) apoptosis in rats was further investigated by TUNEL staining, Western blot, real-time fluorescence quantitative PCR and immunofluorescence co-staining to reveal the potential mechanisms of BHD against IPF.

RESULTS

The UPLC-MS/MS analysis showed that the BHD we used complied with the relevant quality control standards. The data from animal experiments confirmed that BHD administration ameliorated BLM-induced pulmonary function decline, lung fibrotic pathological changes and collagen deposition in rats. Further mechanism study revealed that BHD increased the Bcl-2 protein expression, decreased the Bax protein expression and inhibited the cleavage of CASP3 via suppressing the activation of PERK-ATF4-CHOP pathway under continuous ERS, thereby alleviating BLM-induced AEC2s apoptosis of rats.

CONCLUSION

This study demonstrated that BHD ameliorated BLM-induced pulmonary fibrosis in rats by suppressing ERS-mediated AEC2s apoptosis. Our findings can provide some fundamental research basis for the clinical application of BHD in the treatment of IPF.

Pharmacological potential of Astragali Radix for the treatment of kidney diseases

BACKGROUND

With the increasing prevalence of hypertension, diabetes, and obesity, the incidence of kidney diseases is also increasing, resulting in a serious public burden. Conventional treatments for kidney diseases have unsatisfactory effects and are associated with adverse reactions. Traditional Chinese medicines have good curative effects and advantages over conventional treatments for preventing and treating kidney diseases. Astragali Radix is a Chinese herbal medicine widely used to treat kidney diseases.

PURPOSE

To review the potential applications and molecular mechanisms underlying the renal protective effects of Astragali Radix and its components and to provide direction and reference for new therapeutic strategies and future research and development of Astragali Radix.

STUDY DESIGN AND METHODS

PubMed, Google Scholar, and Web of Science were searched using keywords, including "Astragali Radix," "Astragalus," "Astragaloside IV" (AS-IV), "Astragali Radix polysaccharide" (APS), and "kidney diseases." Reports on the effects of Astragali Radix and its components on kidney diseases were identified and reviewed.

RESULTS

The main components of Astragali Radix with kidney-protective properties include AS-IV, APS, calycosin, formononetin, and hederagenin. Astragali Radix and its active components have potential pharmacological effects for the treatment of kidney diseases, including acute kidney injury, diabetic nephropathy, hypertensive renal damage, chronic glomerulonephritis, and kidney stones. The pharmacological effects of Astragali Radix are manifested through the inhibition of inflammation, oxidative stress, fibrosis, endoplasmic reticulum stress, apoptosis, and ferroptosis, as well as the regulation of autophagy.

CONCLUSION

Astragali Radix is a promising drug candidate for treating kidney diseases. However, current research is limited to animal and cell studies, underscoring the need for further verifications using high-quality clinical data.

BM-MSCs alleviate diabetic nephropathy in male rats by regulating ER stress, oxidative stress, inflammation, and apoptotic pathways

Introduction: Diabetic nephropathy (DN), a chronic kidney disease, is a major cause of end-stage kidney disease worldwide. Mesenchymal stem cells (MSCs) have become a promising option to mitigate several diabetic complications. Methods: In this study, we evaluated the therapeutic potential of bone marrow-derived mesenchymal stem cells (BM-MSCs) in a rat model of STZ-induced DN. After the confirmation of diabetes, rats were treated with BM-MSCs and sacrificed at week 12 after treatment. Results: Our results showed that STZ-induced DN rats had extensive histopathological changes, significant upregulation in mRNA expression of renal apoptotic markers, ER stress markers, inflammatory markers, fibronectin, and intermediate filament proteins, and reduction of positive immunostaining of PCNA and elevated P53 in kidney tissue compared to the control group. BM-MSC therapy significantly improved renal histopathological changes, reduced renal apoptosis, ER stress, inflammation, and intermediate filament proteins, as well as increased positive immunostaining of PCNA and reduced P53 in renal tissue compared to the STZ-induced DN group. Conclusion: In conclusion, our study indicates that BM-MSCs may have therapeutic potential for the treatment of DN and provide important insights into their potential use as a novel therapeutic approach for DN.

METTL14 promotes the development of diabetic kidney disease by regulating m6A modification of TUG1

BACKGROUND

Diabetic kidney disease (DKD) is one of the most common diabetic complications. Endoplasmic reticulum stress (ERS) is an important step for renal tubular epithelial cell apoptosis during DKD progression. Herein, the role and regulatory mechanism of METTL14 in ERS during DKD progression were investigated.

METHODS

DKD animal and cell models were established by streptozotocin (STZ) and high glucose (HG), respectively. HE and Masson staining were performed to analyze renal lesions in DKD mouse. Cell viability and proliferation were determined by MTT and EdU staining, respectively. HK2 cell apoptosis was analyzed by flow cytometry. TUG1 m6A level was determined by Me-RIP. The interaction between TUG1, LIN28B and MAPK1 was analyzed by RIP and RNA pull-down assays.

RESULTS

HG stimulation promoted apoptosis and increased ERS marker proteins (GRP78, CHOP and caspase12) expression in HK2 cells, while these changes were reversed by METTL14 knockdown. METTL14 inhibited TUG1 stability and expression level in an m6A-dependent manner. As expected, TUG1 knockdown abrogated METTL14 knockdown's inhibition on HG-induced HK2 cell apoptosis and ERS. In addition, TUG1 inactivated MAPK1/ERK signaling by binding with LIN28B. And TUG1 overexpression's repression on HG-induced HK2 cell apoptosis and ERS was abrogated by MAPK1 signaling activation. Meanwhile, METTL14 knockdown or TUG1 overexpression protected against STZ-induced renal lesions and renal fibrosis in DKD mouse.

CONCLUSION

METTL14 promoted renal tubular epithelial cell apoptosis and ERS by activating MAPK/ERK pathway through m6A modification of TUG1, thereby accelerating DKD progression.

Could Cyclosiversioside F Serve as a Dietary Supplement to Prevent Obesity and Relevant Disorders?

Obesity is the basis of numerous metabolic diseases and has become a major public health issue due to its rapidly increasing prevalence. Nevertheless, current obesity therapeutic strategies are not sufficiently effective, so there is an urgent need to develop novel anti-obesity agents. Naturally occurring saponins with outstanding bio-activities have been considered promising drug leads and templates for human diseases. Cyclosiversioside F (CSF) is a paramount multi-functional saponin separated from the roots of the food-medicinal herb Astragali Radix, which possesses a broad spectrum of bioactivities, including lowering blood lipid and glucose, alleviating insulin resistance, relieving adipocytes inflammation, and anti-apoptosis. Recently, the therapeutic potential of CSF in obesity and relevant disorders has been gradually explored and has become a hot research topic. This review highlights the role of CSF in treating obesity and obesity-induced complications, such as diabetes mellitus, diabetic nephropathy, cardiovascular and cerebrovascular diseases, and non-alcoholic fatty liver disease. Remarkably, the underlying molecular mechanisms associated with CSF in disease therapy have been partially elucidated, especially PI3K/Akt, NF-κB, MAPK, apoptotic pathway, TGF-β, NLRP3, Nrf-2, and AMPK, with the aim of promoting the development of CSF as a functional food and providing references for its clinical application in obesity-related disorders therapy.

Biosynthesis and Pharmacological Activities of Flavonoids, Triterpene Saponins and Polysaccharides Derived from Astragalus membranaceus

Astragalus membranaceus (A. membranaceus), a well-known traditional herbal medicine, has been widely used in ailments for more than 2000 years. The main bioactive compounds including flavonoids, triterpene saponins and polysaccharides obtained from A. membranaceus have shown a wide range of biological activities and pharmacological effects. These bioactive compounds have a significant role in protecting the liver, immunomodulation, anticancer, antidiabetic, antiviral, antiinflammatory, antioxidant and anti-cardiovascular activities. The flavonoids are initially synthesized through the phenylpropanoid pathway, followed by catalysis with corresponding enzymes, while the triterpenoid saponins, especially astragalosides, are synthesized through the universal upstream pathways of mevalonate (MVA) and methylerythritol phosphate (MEP), and the downstream pathway of triterpenoid skeleton formation and modification. Moreover, the Astragalus polysaccharide (APS) possesses multiple pharmacological activities. In this review, we comprehensively discussed the biosynthesis pathway of flavonoids and triterpenoid saponins, and the structural features of polysaccharides in A. membranaceus. We further systematically summarized the pharmacological effects of bioactive ingredients in A. membranaceus, which laid the foundation for the development of clinical candidate agents. Finally, we proposed potential strategies of heterologous biosynthesis to improve the industrialized production and sustainable supply of natural products with pharmacological activities from A. membranaceus, thereby providing an important guide for their future development trend.

The role of Chinese herbal medicine in the treatment of diabetic nephropathy by regulating endoplasmic reticulum stress

Diabetic nephropathy (DN), a prevalent microvascular complication of diabetes mellitus, is the primary contributor to end-stage renal disease in developed countries. Existing clinical interventions for DN encompass lifestyle modifications, blood glucose regulation, blood pressure reduction, lipid management, and avoidance of nephrotoxic medications. Despite these measures, a significant number of patients progress to end-stage renal disease, underscoring the need for additional therapeutic strategies. The endoplasmic reticulum (ER) stress response, a cellular defense mechanism in eukaryotic cells, has been implicated in DN pathogenesis. Moderate ER stress can enhance cell survival, whereas severe or prolonged ER stress may trigger apoptosis. As such, the role of ER stress in DN presents a potential avenue for therapeutic modulation. Chinese herbal medicine, a staple in Chinese healthcare, has emerged as a promising intervention for DN. Existing research suggests that some herbal remedies may confer renoprotective benefits through the modulation of ER stress. This review explores the involvement of ER stress in the pathogenesis of DN and the advancements in Chinese herbal medicine for ER stress regulation, aiming to inspire new clinical strategies for the prevention and management of DN.

The beneficial effects of astragaloside IV on ameliorating diabetic kidney disease

Diabetic kidney disease (DKD) has become the major cause of chronic kidney disease or end-stage renal disease. There is still a need for innovative treatment strategies for preventing, arresting, treating, and reversing DKD, and a plethora of scientific evidence has revealed that Chinese herbal monomers can attenuate DKD in multiple ways. Astragaloside IV (AS-IV) is one of the active ingredients of Astragalus membranaceus and was selected as a chemical marker in the Chinese Pharmacopeia for quality control purposes. An increasing amount of studies indicate that AS-IV is a promising novel drug for the treatment of DKD. AS-IV has been shown to improve DKD by combating oxidative stress, attenuating endoplasmic reticulum stress, regulating calcium homeostasis, alleviating inflammation, improving vascular function, improving epithelial to mesenchymal transition and so on. This review briefly summarizes the pathogenesis of DKD, systematically reviews the mechanisms by which AS-IV improves DKD, and aims to facilitate related pharmacological research and development to promote the utilization of Chinese herbal monomers in DKD.

Astragaloside IV attenuates lipopolysaccharide induced liver injury by modulating Nrf2-mediated oxidative stress and NLRP3-mediated inflammation

Aims and objectives

Sepsis-associated liver injury is a common public health problem in intensive care units. Astragaloside IV (AS-IV) is an active component extracted from the Chinese herb Astragalus membranaceus, and has been shown to have anti-oxidation, anti-inflammation, and anti-apoptosis properties. The research aimed to investigate the protective effect of AS-IV in lipopolysaccharide (LPS)-induced liver injury.

Methods

Male C57BL/6 wild-type mice (6-8 week-old) were intraperitoneally injected with 10 mg/kg LPS for 24 h and AS-IV (80 mg/kg) 2 h before the LPS injection. Biochemical and histopathological analyses were carried out to assess liver injury. The RT-qPCR analyzed the mRNA expression of IL-1β, TNF-α, and IL-6. The mRNA and protein expression of SIRT1, nuclear Nrf2, Nrf2, and HO-1 were measured by Western blotting.

Results

Serum alanine/aspartate aminotransferases (ALT/AST) analysis, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) were showed that AS-IV protected against LPS-induced hepatotoxicity. The protection afforded by AS-IV was confirmed by pathological examination of the liver. Pro-inflammatory cytokines, including interleukin- 1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6), were observed to be reversed by AS-IV after exposure to LPS. Western blot analysis demonstrated that AS-IV enhanced the expression levels of Sirtuin 1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1).

Conclusions

AS-IV protects against LPS-induced Liver Injury and Inflammation by modulating Nrf2-mediated oxidative stress and NLRP3-mediated inflammation.

Anti-apoptotic effect of HeidihuangWan in renal tubular epithelial cells via PI3K/Akt/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Heidihuang Wan (HDHW) is a classic Chinese herbal formula, which was first recorded in the "Suwen Bingji Qiyi Baoming Collection" written by Liu Wansu during the Jin Dynasty (1115-1234 AD). It is commonly used clinically for the treatment of kidney diseases and its curative effect is stable. Previous animal experiments have confirmed that HDHW can effectively improve renal fibrosis. However, the underlying pharmacological mechanism remains unclear.

AIMS OF THIS STUDY

Renal tubular epithelial cell (RTEC) apoptosis is one of the main pathological features of renal fibrosis. This study aimed to observe the effect and underlying mechanism of HDHW on the apoptosis of RTECs to further explore the pathological mechanism of HDHW against renal fibrosis.

MATERIALS AND METHODS

We examined the HDHW composition in rat serum. In vitro, we first screened out the optimal intervention concentration of HDHW on RTECs using the MTT assay. Hypoxia/reoxygenation was then used to induce apoptosis of RTECs (H/R-RTECs), which were divided into H/R-RTEC, astragaloside IV (positive control), HDHW, and RTECs groups. After 48 h of drug intervention, apoptosis of RTECs was detected using flow cytometry and protein expression was detected by western blotting. The 5/6 nephrectomy rat model was constructed and divided into the normal control, 5/6 nephrectomy, HDHW, and astragaloside IV groups. After 8 weeks of treatment, TUNEL staining was used to detect cell apoptosis, and western blotting was used to detect protein expression.

RESULTS

HDHW downregulated the expression of pro-apoptotic proteins Bax and Caspase3, up-regulated the expression of anti-apoptotic protein Bcl-2, activated the PI3K/Akt/mTOR signaling pathway, and reversed the early apoptosis of RTECs, thereby resisting the apoptosis of RTECs.

CONCLUSION

HDHW inhibits apoptosis of RTECs by modulating the PI3K/Akt/mTOR signaling pathway. This study provides experimental evidence for the anti-fibrotic effect of HDHW on the kidneys and partially elucidates its pharmacological mechanism of action.

Role of renal tubular programed cell death in diabetic kidney disease

The pathogenic mechanism of diabetic kidney disease (DKD) is involved in various functions; however, its inadequate characterisation limits the availability of effective treatments. Tubular damage is closely correlated with renal function and is thought to be the main contributor to the injury observed in early DKD. Programed cell death (PCD) occurs during the biological development of the living body. Accumulating evidence has clarified the fundamental role of abnormalities in tubular PCD during DKD pathogenesis. Among PCD types, classical apoptosis, autophagic cell death, and pyroptosis are the most studied and will be the focus of this review. Our review aims to elucidate the current knowledge of the mechanism of DKD and the potential therapeutic potential of drugs targeting tubular PCD pathways in DKD.

Role of endoplasmic reticulum stress and autophagy in the transition from acute kidney injury to chronic kidney disease

Acute kidney injury (AKI) and chronic kidney disease (CKD) are global health concerns with increasing rates in morbidity and mortality. Transition from AKI-to-CKD is common and requires awareness in the management of AKI survivors. AKI-to-CKD transition is a main risk factor for the development of cardiovascular disease and progression to end-stage kidney disease. The mechanisms driving AKI-to-CKD transition are being explored to identify potential molecular and cellular targets for renoprotective drug interventions. Endoplasmic reticulum (ER) stress and autophagy are involved in the process of AKI-to-CKD transition. Excessive ER stress results in the persistent activation of unfolded protein response, which is an underneath cause of kidney cell death. Moreover, ER stress modulates autophagy and vice-versa. Autophagy is a degradation defensive mechanism protecting cells from malfunction. However, the underlying pathological mechanism involved in this interplay in the context of AKI-to-CKD transition is still unclear. In this review, we discuss the crosstalk between ER stress and autophagy in AKI, AKI-to-CKD transition, and CKD progression. In addition, we explore possible therapeutic targets that can regulate ER stress and autophagy to prevent AKI-to-CKD transition to improve the long-term prognosis of AKI survivors.

A natural products solution to diabetic nephropathy therapy

Diabetic nephropathy is one of the most common complications in diabetes. It has been shown to be the leading cause of end-stage renal disease. However, due to their complex pathological mechanisms, effective therapeutic drugs other than angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), which have been used for 20 years, have not been developed so far. Recent studies have shown that diabetic nephropathy is characterized by multiple signalling pathways and multiple targets, including inflammation, apoptosis, pyroptosis, autophagy, oxidative stress, endoplasmic reticulum stress and their interactions. It definitely exacerbates the difficulty of therapy, but at the same time it also brings out the chance for natural products treatment. In the most recent two decades, a large number of natural products have displayed their potential in preclinical studies and a few compounds are under invetigation in clinical trials. Hence, many compounds targeting these singals have been emerged as a comprehensive blueprint for treating strategy of diabetic nephropathy. This review focuses on the cellular and molecular mechanisms of natural prouducts that alleviate this condition, including preclinical studies and clinical trials, which will provide new insights into the treatment of diabetic nephropathy and suggest novel ideas for new drug development.

Astragalus Mongholicus: A review of its anti-fibrosis properties

Background: Fibrosis-related diseases (FRD) include cerebral fibrosis, pulmonary fibrosis, cardiac fibrosis, liver fibrosis, renal fibrosis, peritoneal fibrosis, etc. The effects of fibrosis can be severe, resulting in organ dysfunction, functional decline, and even organ failure, which can cause serious health problems.

Aim: Currently, there is no effective modern medicine for anti-fibrosis in the clinics; however, Chinese medicine has a certain beneficial effect on treating such diseases. Astragalus Mongholicus (AM) has rich medicinal value, and its anti-fibrosis effect has been recently investigated. In recent years, more and more experimental studies have been conducted on the intervention of astragaloside IV (AS-IV), astragalus polysaccharide (APS), astragalus flavone, cycloastragalus alcohol, astragalus water extract and other pharmacological components in fibrosis-related diseases, attracting the interest of researchers. We aim to provide ideas for future research by summarizing recent research advances of AM in treating fibrosis-related diseases.

Methods: A literature search was conducted from the core collections of electronic databases such as Baidu Literature, Sciencen.com, Google Scholar, PubMed, and Science Direct using the above keywords and the pharmacological and phytochemical details of the plant.

Results: AM can be used to intervene in fibrosis-disease progression by regulating inflammation, oxidative stress, the immune system, and metabolism.

Conclusion: AS-IV, APS, and astragalus flavone were studied and discussed in detail. These components have high potential anti-fibrosis activity. Overall, this review aims to gain insight into the AM’s role in treating fibro-related diseases.

Mitogen-activating protein kinase kinase kinase kinase-3, inhibited by Astragaloside IV through H3 lysine 4 monomethylation, promotes the progression of diabetic nephropathy by inducing apoptosis

Astragaloside IV (AS-IV) is a bioactive saponin extracted from the Astragalus root and has been reported to exert a protective effect on diabetic nephropathy (DN). However, the underlying mechanism remains unclear. Herein, we found that AS-IV treatment alleviated DN symptoms in DN mice accompanied by reduced metabolic parameters (body weight, urine microalbumin and creatinine, creatinine clearance, and serum urea nitrogen and creatinine), pathological changes, and apoptosis. Epigenetic histone modifications are closely related to diabetes and its complications, including H3 lysine 4 monomethylation (H3K4me1, a promoter of gene transcription). A ChIP-seq assay was conducted to identify the genes regulated by H3K4me1 in DN mice after AS-IV treatment and followed by a Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. The results showed that there were 16 common genes targeted by H3K4me1 in normal and AS-IV-treated DN mice, 1148 genes were targeted by H3K4me1 only in DN mice. From the 1148 genes, we screened mitogen-activating protein kinase kinase kinase kinase-3 (MAP4K3) for the verification of gene expression and functional study. The results showed that MAP4K3 was significantly increased in DN mice and high glucose (HG)-treated NRK-52E cells, which was reversed by AS-IV. MAP4K3 silencing reduced the apoptosis of NRK-52E cells under HG condition, as evidenced by decreased cleaved caspase 3 and Bax (pro-apoptotic factors), and increased Bcl-2 and Bcl-xl (anti-apoptotic factors). Collectively, AS-IV may downregulate MAP4K3 expression by regulating H3K4me1 binding and further reducing apoptosis, which may be one of the potential mechanisms that AS-IV plays a protective effect on DN.

Diosmin mitigates high glucose-induced endoplasmic reticulum stress through PI3K/AKT pathway in HK-2 cells

BACKGROUND

Diosmin has been reported to treat diabetes, but its role in diabetic nephropathy (DN) remains unclear. This research investigated the mechanism by which diosmin alleviated high glucose (HG)-induced HK-2 cell injury.

METHODS

First, we used CCK-8 to detect the effect of 0.1, 1, or 10 μg/mL diosmin on the viability of HK-2 cells treated with normal glucose or HG. Next, we used flow cytometry, automatic biochemical analyzer, ELISA, immunofluorescence, and colorimetric assay kit to examine the apoptosis, oxidative stress, inflammatory factors, and Caspase-3 expression in HK-2 cells. Thereafter, we used the western blot and qRT-PCR to examine the expression of the endoplasmic reticulum stress-, oxidative stress-, inflammation-, apoptosis-, and autophagy, and PI3K/AKT pathway-related factors.

RESULTS

Diosmin was non-cytotoxic to normal HK-2 cells and enhanced the HK-2 cell viability suppressed by HG. Meanwhile, diosmin restrained apoptosis, the contents of MDA, pro-inflammatory factors, and Caspase-3 but intensified the contents of SOD and CAT induced by HG. We further confirmed that diosmin blunted oxidative stress-, inflammation-, apoptosis-, and autophagy-related factors expression induced by HG via restraining the CHOP and GRP78 expressions. Further, we also discovered that PTEN level was restrained and the ratios of p-PI3K/PI3K and p-AKT/AKT were enhanced in HK-2 cells induced by HG, which was reversed by co-treatment of HG and diosmin.

CONCLUSIONS

Our study manifested that diosmin alleviated the HG-mediated endoplasmic reticulum stress injury in HK-2 cells via restraining the PI3K/AKT pathway.

Endoplasmic reticulum stress-dependent activation of TRB3-FoxO1 signaling pathway exacerbates hyperglycemic nephrotoxicity: Protection accorded by Naringenin

Endoplasmic reticulum (ER) dysfunction contributes greatly to the pathophysiology of hyperglycemic nephrotoxicity. This study unravels the critical role of Tribbles 3 (TRB3)-Forkhead box O1 (FoxO1) signaling pathway during hyperglycemic renal toxicity. It also uncovers the novel role of Naringenin, a flavanone, in regulating ER stress in proximal tubular cells, NRK 52E, and kidneys of streptozotocin/nicotinamide induced experimental diabetic Wistar rats. Results demonstrate that expression of ER stress marker proteins including phosphorylated protein kinase ER like kinase (p-PERK), phosphorylated eukaryotic Initiation Factor 2α (p-eIF2α), X Box Binding Protein 1 spliced (XBP1s), Activating Transcription Factor 4 (ATF4) and C/EBP Homologous Protein (CHOP) were upregulated in diabetic kidneys indicating the activation of ER stress response due to nephrotoxicity. Treatment with Naringenin reduced the expression of TRB3, an ER stress-inducible pseudokinase, both in vitro and in vivo. Gene silencing of TRB3 enhanced Akt and FoxO1 phosphorylation and alleviated FoxO1 mediated apoptosis during hyperglycemic nephrotoxicity. Notably, TRB3 gene silencing effects were comparable to the response with Naringenin treatment. Prevention of nuclear colocalization of ATF4 and CHOP in Naringenin treated cells was evident. Naringenin also reduced insulin resistance, apoptosis and glycogen accumulation along with enhancement of glucose tolerance in diabetic rats. Prevention of ultrastructural aberrations in the ER of hyperglycemic renal cells by Naringenin confirmed its anti-ER stress effects. These findings affirm that activation of TRB3-FoxO1 signaling is critical in the pathogenesis of hyperglycemia-induced renal toxicity and protective effect of Naringenin via modulation of ER stress may be exploited as a novel approach for its management.

NAD(P)H: quinone oxidoreductase 1 attenuates oxidative stress and apoptosis by regulating Sirt1 in diabetic nephropathy

Background

Diabetic nephropathy (DN) is one of the main complications of diabetes, and oxidative stress plays an important role in its progression. NAD(P)H: quinone oxidoreductase 1 (NQO1) protects cells from oxidative stress and toxic quinone damage. In the present study, we aimed to investigate the protective effects and underlying mechanisms of NQO1 on diabetes-induced renal tubular epithelial cell oxidative stress and apoptosis.

Methods

In vivo, the kidneys of db/db mice, which are a type 2 diabetes model, were infected with adeno-associated virus to induce NQO1 overexpression. In vitro, human renal tubular epithelial cells (HK-2 cells) were transfected with NQO1 pcDNA3.1(+) and cultured in high glucose (HG). Gene and protein expression was assessed by quantitative real-time PCR, western blotting, immunofluorescence analysis, and immunohistochemical staining. Reactive oxygen species (ROS) were examined by MitoSox red and flow cytometry. TUNEL assays were used to measure apoptosis.

Result

In vivo, NQO1 overexpression reduced the urinary albumin/creatinine ratio (UACR) and blood urea nitrogen (BUN) level in db/db mice. Our results revealed that NQO1 overexpression could significantly increase the ratio of NAD+/NADH and silencing information regulator 1 (Sirt1) expression and block tubular oxidative stress and apoptosis in diabetic kidneys. In vitro, NQO1 overexpression reduced the generation of ROS, NADPH oxidase 1 (Nox1) and Nox4, the Bax/Bcl-2 ratio and the expression of Cleaved Caspase-3 and increased NAD+/NADH levels and Sirt1 expression in HK-2 cells under HG conditions. However, these effects were reversed by the Sirt1 inhibitor EX527.

Conclusions

All these data suggest that NQO1 has a protective effect against oxidative stress and apoptosis in DN, which may be mediated by the regulation of Sirt1 through increasing intracellular NAD+/NADH levels. Therefore, NQO1 may be a new therapeutic target for DN.

Therapeutic potential of resveratrol in diabetic nephropathy according to molecular signaling

BACKGROUND

Diabetic nephropathy (DN) as a severe complication of diabetes mellitus (DM), is a crucial menace for human health and survival and remarkably elevates the healthcare systems' costs. Therefore, it is worth noting to identify novel preventive and therapeutic strategies to alleviate the disease conditions. Resveratrol, as a well-defined anti-diabetic/ antioxidant agent has capabilities to counteract diabetic complications. It has been predicted that resveratrol will be a fantastic natural polyphenol for diabetes therapy in the next few years.

OBJECTIVE

Accordingly, the current review aims to depict the role of resveratrol in the regulation of different signaling pathways that are involved in the reactive oxygen species (ROS) production, inflammatory processes, autophagy, and mitochondrial dysfunction, as critical contributors to DN pathophysiology.

RESULTS

The pathogenesis of DN can be multifactorial; hyperglycemia is one of the prominent risk factors of DN development that is closely related to oxidative stress. Resveratrol, as a well-defined polyphenol, has various biological and medicinal properties, including anti-diabetic, anti-inflammatory, and anti-oxidative effects.

CONCLUSION

Resveratrol prevents kidney damages that are caused by oxidative stress, enhances antioxidant capacity, and attenuates the inflammatory and fibrotic responses. For this reason, resveratrol is considered an interesting target in DN research due to its therapeutic possibilities during diabetic disorders and renal protection.

Jujuboside A ameliorates high fat diet and streptozotocin induced diabetic nephropathy via suppressing oxidative stress, apoptosis, and enhancing autophagy

Jujuboside A (JuA) is a triterpenoid saponins isolated from the seed of jujube (semen Ziziphi spinosae) with anti-oxidant, anti-inflammation and anti-apoptosis properties. The present study aimed to investigate the reno-protective effects of JuA on type II diabetes. JuA (20 mg/kg) and Metformin (Met, 300 mg/kg) were administrated to diabetic Sprague Dawley rat for 8 weeks daily. Our results showed that JuA reduced blood glucose and kidney function markers including 24 h urinary protein, urinary β-NAG/urinary creatinine, serum urea nitrogen, serum uric acid and serum creatinine, and relieved renal pathological changes. In addition, JuA decreased O₂^- and H₂O₂ level, enhanced SOD, CAT and GPx activities, decreased NOX4 expression and improved mitochondrial respiratory chain function through regulating respiratory chain complex expression. Moreover, JuA downregulated the expressions of mitochondrial apoptosis proteins: Bax, CytC, Apaf-1 and caspase 9. Apoptosis mediated by ER stress also been inhibited by JuA via downregulating p-PERK, p-IRE1, XBP1s, ATF4, p-CHOP and caspase 12 expressions. JuA also enhanced autophagy and mitophagy via regulating CaMKK2-AMPK-p-mTOR and PINK1/Parkin pathways. Collectively, these results indicated that JuA protected against type II diabetic nephropathy through inhibiting oxidative stress and apoptosis mediated by mitochondria and ER stress. In addition, autophagy and mitophagy was enhanced by JuA.

Astragaloside IV Attenuates Ocular Hypertension in a Mouse Model of TGFβ2 Induced Primary Open Angle Glaucoma

Elevated intraocular pressure (IOP) is a major risk factor in developing primary open angle glaucoma (POAG), which is the most common form of glaucoma. Transforming growth factor-beta 2 (TGFβ2) is a pro-fibrotic cytokine that plays an important role in POAG pathogenesis. TGFβ2 induced extracellular matrix (ECM) production, deposition and endoplasmic reticulum (ER) stress in the trabecular meshwork (TM) contribute to increased aqueous humor (AH) outflow resistance and IOP elevation. Drugs which alter the glaucomatous fibrotic changes and ER stress in the TM may be effective in reducing ocular hypertension. Astragaloside IV (AS.IV), a novel saponin isolated from the roots of Astragalus membranaceus, has demonstrated antifibrotic and ER stress lowering effects in various tissues during disease conditions. However, the effect of AS.IV on glaucomatous TM fibrosis, ER stress and ocular hypertension has not been studied. Primary human TM cells treated with AS.IV decreased TGFβ2 induced ECM (FN, Col-I) deposition and ER stress (KDEL, ATF4 and CHOP). Moreover, AS.IV treatment reduced TGFβ2 induced NF-κB activation and αSMA expression in TM cells. We found that AS.IV treatment significantly increased levels of matrix metalloproteases (MMP9 and MMP2) and MMP2 enzymatic activity, indicating that the antifibrotic effects of AS.IV are mediated via inhibition of NF-κB and activation of MMPs. AS.IV treatment also reduced ER stress in TM3 cells stably expressing mutant myocilin. Interestingly, the topical ocular AS.IV eye drops (1 mM) significantly decreased TGFβ2 induced ocular hypertension in mice, and this was associated with a decrease in FN, Col-1 (ECM), KDEL (ER stress) and αSMA in mouse TM tissues. Taken together, the results suggest that AS.IV prevents TGFβ2 induced ocular hypertension by modulating ECM deposition and ER stress in the TM.

Naringenin alleviates hyperglycemia-induced renal toxicity by regulating activating transcription factor 4-C/EBP homologous protein mediated apoptosis

Endoplasmic reticulum (ER) dysfunction plays a prominent role in the pathophysiology of diabetic nephropathy (DN). This study aimed to investigate the novel role of Naringenin (a flavanone mainly found in citrus fruits) in modulating ER stress in hyperglycemic NRK 52E cells and STZ/nicotinamide induced diabetes in Wistar rats. The results demonstrated that Naringenin supplementation downregulated the expression of ER stress marker proteins, including p-PERK, p-eIF2α, XBP1s, ATF4 and CHOP during hyperglycemic renal toxicity in vitro and in vivo. Naringenin abrogated hyperglycemia-induced ultrastructural changes in ER, evidencing its anti-ER stress effects. Interestingly, treatment of Naringenin prevented nuclear translocation of ATF4 and CHOP in hyperglycemic renal cells and diabetic kidneys. Naringenin prevented apoptosis in hyperglycemic renal cells and diabetic kidney tissues by downregulating expression of apoptotic marker proteins. Further, photomicrographs of TEM confirmed anti-apoptotic potential of Naringenin as it prevented membrane blebbing and formation of apoptotic bodies in hyperglycemic renal cells. Naringenin improved glucose tolerance, restored serum insulin level and reduced serum glucose level in diabetic rats evidencing its anti-hyperglycemic effects. Histopathological examination of kidney tissues also confirmed prevention of damage after 28 days of Naringenin treatment in diabetic rats. Additionally, Naringenin diminished oxidative stress and improved antioxidant defense response during hyperglycemic renal toxicity. Taken together, our study revealed a novel role of Naringenin in ameliorating ER stress during hyperglycemic renal toxicity along with prevention of apoptosis, cellular and tissue damage. The findings suggest that prevention of ER stress can be exploited as a novel approach for the management of hyperglycemic nephrotoxicity.

The therapeutic effect and mechanism of Qishen Yiqi dripping pills on cardiovascular and cerebrovascular diseases and diabetic complications

The alterations in vascular homeostasis is deeply involved in the development of numerous diseases, such as coronary heart disease, stroke, and diabetic complications. Changes in blood flow and endothelial permeability caused by vascular dysfunction are the common mechanisms for these three types of diseases. The disorders of glucose and lipid metabolism can result in changes of the energy production patterns in endothelium and surrounding cells which may consequently cause local energy metabolic disorders, oxidative stress and inflammatory responses. Traditional Chinese medicine (TCM) follows the principle of the "treatment by the syndrome differentiation". TCM considers of that coronary heart disease, stroke and diabetes complications all as the type of "Qi deficiency and Blood stasis" syndrome, which mainly happens to the vascular system. Therefore, the common pathogenesis of these three types of diseases suggests the treatment strategy by TCM should be in a close manner and named as "treating different diseases by the same treatment". Qishen Yiqi dripping pills is a modern Chinese herbal medicine which has been widely used for treatment of patients with coronary heart disease characterized as "Qi deficiency and blood stasis" in China. Recently, many clinical reports have demonstrated the potent therapeutic effects of Qishen Yiqi dripping pills on ischemic stroke and diabetic nephropathy. Based on these reports, we will summarize the clinical applications of Qishen Yiqi dripping pills on coronary heart disease, ischemic stroke and diabetic nephropathy, including the involved mechanisms with basic researches.

Endoplasmic Reticulum Stress in Diabetic Nephrology: Regulation, Pathological Role, and Therapeutic Potential

Recent progress has been made in understanding the roles and mechanisms of endoplasmic reticulum (ER) stress in the development and pathogenesis of diabetic nephropathy (DN). Hyperglycemia induces ER stress and apoptosis in renal cells. The induction of ER stress can be cytoprotective or cytotoxic. Experimental treatment of animals with ER stress inhibitors alleviated renal damage. Considering these findings, the normalization of ER stress by pharmacological agents is a promising approach to prevent or arrest DN progression. The current article reviews the mechanisms, roles, and therapeutic aspects of these findings.

Astragaloside IV ameliorates diabetic nephropathy in db/db mice by inhibiting NLRP3 inflammasome‑mediated inflammation

Diabetic nephropathy (DN) is a primary cause of end‑stage renal disease. Despite the beneficial effects of astragaloside IV (AS)‑IV on renal disease, the underlying mechanism of its protective effects against DN has not been fully determined. The aims of the present study were to assess the effects of AS‑IV against DN in db/db mice and to explore the mechanism of AS‑IV involving the NLR family pyrin domain containing 3 (NLRP3), caspase‑1 and interleukin (IL)‑1β pathways. The 8‑week‑old db/db mice received 40 mg/kg AS‑IV once a day for 12 weeks via intragastric administration. Cultured mouse podocytes were used to further confirm the underlying mechanism in vitro. AS‑IV effectively reduced weight gain, hyperglycemia and the serum triacylglycerol concentration in db/db mice. AS‑IV also reduced urinary albumin excretion, urinary albumin‑to‑creatinine ratio and creatinine clearance rate, as well as improved renal structural changes, accompanied by the upregulation of the podocyte markers podocin and synaptopodin. AS‑IV significantly inhibited the expression levels of NLRP3, caspase‑1 and IL‑1β in the renal cortex, and reduced the serum levels of tumor necrosis factor (TNF)‑α and monocyte chemoattractant protein‑1. In high glucose‑induced podocytes, AS‑IV significantly improved the expression levels of NLRP3, pro‑caspase‑1 and caspase‑1, and inhibited the cell viability decrease in a dose‑dependent manner, while NLRP3 overexpression eliminated the effect of AS‑IV on podocyte injury and the inhibition of the NLRP3 and caspase‑1 pathways. The data obtained from in vivo and in vitro experiments demonstrated that AS‑IV ameliorated renal functions and podocyte injury and delayed the development of DN in db/db mice via anti‑NLRP3 inflammasome‑mediated inflammation.

LncRNA TUG1 ameliorates diabetic nephropathy via inhibition of PU.1/RTN1 signaling pathway

Diabetic nephropathy (DN) is a leading cause of end-stage renal failure. The study aimed to investigate whether long noncoding RNA taurine-upregulated gene 1 (TUG1) can ameliorate the endoplasmic reticulum stress (ERS) and apoptosis of renal tubular epithelial cells in DN, and the underlying mechanism. The DN mouse model was established by streptozocin injection, and the human renal tubular epithelial cell line HK-2 was treated with high glucose (HG) to mimic DN in vitro. The molecular mechanism was explored through dual-luciferase activity assay, RNA pull-down assay, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (CHIP) assay. The expression of TUG1 was significantly decreased in the renal tubules of DN model mice. Overexpression of TUG1 reduced the levels of ERS markers and apoptosis markers by inhibiting reticulon-1 (RTN1) expression in HG-induced HK-2 cells. Furthermore, TUG1 down-regulated RTN1 expression by inhibiting the binding of transcription factor PU.1 to the RTN1 promoter, thereby reducing the levels of ERS markers and apoptosis markers. Meanwhile, TUG1-overexpression adenovirus plasmids injection significantly alleviated tubular lesions, and reduced RTN1 expression, ERS markers and apoptosis markers, whereas these results were reversed by injection of PU.1-overexpression adenovirus plasmids. TUG1 restrains the ERS and apoptosis of renal tubular epithelial cells and ameliorates DN through inhibition of transcription factor PU.1.

Ginsenoside Rg1 alleviates lipopolysaccharide-induced neuronal damage by inhibiting NLRP1 inflammasomes in HT22 cells

Lipopolysaccharide (LPS) is a toxic component of cell walls of Gram-negative bacteria that are widely present in gastrointestinal tracts. Increasing evidence showed that LPS plays important roles in the pathogeneses of neurodegenerative disorders, such as Alzheimer's disease (AD). NADPH oxidase s2 (NOX2) is a complex membrane protein that contributes to the production of reactive oxygen species (ROS) in several neurological diseases. The NLRP1 inflammasome can be activated in response to an accumulation of ROS in neurons. However, it is still unknown whether LPS exposure can deteriorate neuronal damage by activating NOX2-NLRP1 inflammasomes. Ginsenoside Rg1 (Rg1) has protective effects on neurons, although whether Rg1 alleviates LPS-induced neuronal damage by inhibiting NOX2-NLRP1 inflammasomes remains unclear. In the present study, the effect of concentration gradients and different times of LPS exposure on neuronal damage was investigated in HT22 cells, and further observed the effect of Rg1 treatment on NOX2-NLPR1 inflammasome activation, ROS production and neuronal damage in LPS-treated HT22 cells. The results demonstrated that LPS exposure significantly induced NOX2-NLRP1 inflammasome activation, excessive production of ROS, and neuronal damage in HT22 cells. It was also shown that Rg1 treatment significantly decreased NOX2-NLRP1 inflammasome activation and ROS production and alleviated neuronal damage in LPS-induced HT22 cells. The present data suggested that Rg1 has protective effects on LPS-induced neuronal damage by inhibiting NOX2-NLRP1 inflammasomes in HT22 cells, and Rg1 may be a potential therapeutic approach for delaying neuronal damage in AD.

A Review of Traditional Chinese Medicine in Treating Renal Interstitial Fibrosis via Endoplasmic Reticulum Stress-Mediated Apoptosis

Renal interstitial fibrosis (RIF) is the main pathological manifestation of end-stage renal disease. Recent studies have shown that endoplasmic reticulum (ER) stress is involved in the pathogenesis and development of RIF. Traditional Chinese medicine (TCM), as an effective treatment for kidney diseases, can improve kidney damage by affecting the apoptotic signaling pathway mediated by ER stress. This article reviews the apoptotic pathways mediated by ER stress, including the three major signaling pathways of unfolded protein response, the main functions of the transcription factor C/EBP homologous protein. We also present current research on TCM treatment of RIF, focusing on medicines that regulate ER stress. A new understanding of using TCM to treat kidney disease by regulating ER stress will promote clinical application of Chinese medicine and discovery of new drugs for the treatment of RIF.

Astragaloside IV alleviates liver injury in type 2 diabetes due to promotion of AMPK/mTOR‑mediated autophagy

Diabetic liver injury is a serious complication of type 2 diabetes mellitus (T2DM), which is often irreversible in the later stage, and affects the quality of life. Autophagy serves an important role in the occurrence and development of diabetic liver injury. For example, it can improve insulin resistance (IR), dyslipidaemia, oxidative stress and inflammation. Astragaloside IV (AS-IV) is a natural saponin isolated from the plant Astragalus membranaceus, which has comprehensive pharmacological effects, such as anti-oxidation, anti-inflammation and anti-apoptosis properties, as well as can enhance immunity. However, whether AS-IV can alleviate diabetic liver injury in T2DM and its underlying mechanisms remain unknown. The present study used high-fat diets combined with low-dose streptozotocin to induce a diabetic liver injury model in T2DM rats to investigate whether AS-IV could alleviate diabetic liver injury and to identify its underlying mechanisms. The results demonstrated that AS-IV treatment could restore changes in food intake, water intake, urine volume and body weight, as well as improve liver function and glucose homeostasis in T2DM rats. Moreover, AS-IV treatment promoted suppressed autophagy in the liver of T2DM rats and improved IR, dyslipidaemia, oxidative stress and inflammation. In addition, AS-IV activated adenosine monophosphate-activated protein kinase (AMPK), which inhibited mTOR. Taken together, the present study suggested that AS-IV alleviated diabetic liver injury in T2DM rats, and its mechanism may be associated with the promotion of AMPK/mTOR-mediated autophagy, which further improved IR, dyslipidaemia, oxidative stress and inflammation. Thus, the regulation of autophagy may be an effective strategy to treat diabetic liver injury in T2DM.

Anti-hyperuricemic potential of stevia (Stevia rebaudiana Bertoni) residue extract in hyperuricemic mice

Hyperuricemia (HUA) is considered a potent risk factor for the development of gout, renal failure, and cardiovascular disease. The current project was designed to use stevia (Stevia rebaudiana Bertoni) byproduct, named stevia residue extract (STVRE), for the treatment of HUA. Male Kunming mice were divided into six groups: normal control, model control, positive control (allopurinol, 5 mg per kg body weight [bw]), STVRE-1 (75 mg per kg bw), STVRE-2 (150 mg per kg bw), and STVRE-3 (300 mg per kg bw). HUA was induced by the administration of potassium oxonate (100 mg per kg bw), fructose (10% w/v), and yeast extract (100 mg per kg bw) for 8 weeks. STVRE significantly (p < 0.05) decreased uric acid (UA) production and ameliorated UA excretion by interacting with urate transporters. The STVRE remarkably attenuated oxidative stress mediated by UA and downregulated inflammatory-related response markers such as COX-2, NF-κB, PGE2, IL-1β, and TNF-α. Furthermore, STVRE also reversed HUA-induced abnormalities in kidneys compared with the MC group. The results of our study suggest that STVRE has potential to attenuate hyperuricemia and renal protective effects, and may be used as a natural supplement for the possible treatment of UA-related disorders.

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.

Astragaloside IV alleviates PM2.5-induced lung injury in rats by modulating TLR4/MyD88/NF-κB signalling pathway

OBJECTIVE

Astragaloside IV (AS IV) is antioxidant and anti-inflammatory product, which is extracted from the Chinese herb Astragalus membranaceus. It is widely used in a variety of inflammatory diseases. The research was to explored the protective effects of AS IV against lung injury induced by particulate matter 2.5 (PM2.5) in vivo.

SUBJECTS AND METHODS

Thirty-five male Sprague-Dawley rats were randomly divided into five groups (n=7 per group). (1) Normal saline group (NS), (2) AS IV group (AS) (100 mg/kg), (3) PM2.5 group (PM2.5), (4) PM2.5 + AS IV group (ASL) (50 mg/kg), and (5) PM2.5 + AS IVgroup (ASH) (100 mg/kg). Rats were pre-treated with AS IV intraperitoneally (50 and 100 mg/kg/day) for three days. Then, PM2.5 (7.5 mg/kg) was given by intratracheal instillation to induce lung injury. Six hours after PM2.5 stimulation, the rats were euthanized. Bronchoalveolar lavage fluid (BALF) was collected for assay of cytokines. Lung tissue was collected for oxidative stress, histology, immunohistochemistry, transmission electron microscope, and western blot analyses.

RESULTS

AS IV alleviated PM2.5-induced lung injury by decreasing lung dry-wet ratio, reducing the level of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) in BALF, and reduced oxidative stress response in lung tissue. Western blot results revealed that AS-IV regulated the expression of TLR4/MyD88/NF-κB pathway proteins in lung tissues.

CONCLUSION

AS IV mitigated PM2.5 induced lung injury by regulating the activity of TLR4/MyD88/NF-κB signalling pathway, reducing inflammatory and oxidative stress responses.