Mechanisms of Herbal Nephroprotection in diabetes mellitus

Iridoids modulate inflammation in diabetic kidney disease: A review

In recent years, preclinical research on diabetic kidney disease (DKD) has surged to the forefront of scientific and clinical attention. DKD has become a pervasive complication of type 2 diabetes. Given the complexity of its etiology and pathological mechanisms, current interventions, including drugs, dietary modifications, exercise, hypoglycemic treatments and lipid-lowering methods, often fall short in achieving desired therapeutic outcomes. Iridoids, primarily derived from the potent components of traditional herbs, have been the subject of long-standing research. Preclinical data suggest that iridoids possess notable renal protective properties; however, there has been no summary of the research on their efficacy in the management and treatment of DKD. This article consolidates findings from in vivo and in vitro research on iridoids in the context of DKD and highlights their shared anti-inflammatory activities in treating this condition. Additionally, it explores how certain iridoid components modify their chemical structures through the regulation of intestinal flora, potentially bolstering their therapeutic effects. This review provides a focused examination of the mechanisms through which iridoids may prevent or treat DKD, offering valuable insights for future research endeavors. Please cite this article as: Zhou TY, Tian N, Li L, Yu R. Iridoids modulate inflammation in diabetic kidney disease: A review. J Integr Med. 2024; 22(3): 210-222.

Ameliorative effect of traditional polyherbal formulation on TNF-α, IL-1β and Caspase-3 expression in kidneys of wistar rats against sodium fluoride induced oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

Sharbat-e-bazoori Motadil (SBM) is a polyherbal formulation that have been used for centuries as a part of the Unani system of medicine for renal disease.

AIM OF THE STUDY

The objective of this study was to explore and validate the nephroprotective potential of sugar-free SBM (SF-SBM) and its mechanisms of action against sodium fluoride (NaF)-induced nephrotoxicity in HEK-293 cells. Additionally, the study aimed to assess the quality control of SF-SBM and investigate its effects using an in vivo rat model with pattern recognition following oral administration of SF-SBM.

MATERIALS AND METHODS

The nephroprotective effect of SF-SBM was investigated using both an HEK-293 cell line and Wistar rats. Nephrotoxicity was induced in these models by administering NaF at a concentration of 600 ppm (parts per million) for a duration of seven days. The SF-SBM formulation was standardized using high-performance thin-layer chromatography (HPTLC) to assess the presence of marker compounds, namely gallic acid, quercetin, and ferulic acid. Metabolite characterization of SF-SBM was carried out using ultra-high-performance liquid chromatography mass spectrometry (UPLC-MS) with a monolithic capillary silica-based C18 column. This analytical technique allowed for the identification of bioactive substances and verification of the identified markers. Acute toxicity of SF-SBM was evaluated in Wistar rats by administering a single oral dose of 2000 mg/kg of SF-SBM. The nephroprotective efficacy of SF-SBM was further assessed at low (LD), medium (MD) and high (HD) doses of 32.1, 64.2, and 128.4 mg/kg, respectively, administered orally. Nephrotoxicity was induced in Wistar rats by adding NaF to their drinking water for seven days. Biochemical and urine markers were analyzed to evaluate the antioxidant, inflammatory, and apoptotic potential of SF-SBM. Additionally, histopathological analysis and immunohistochemical alterations in the expression of caspase-3 and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-4 (NOX-4) in kidney tissue were performed to confirm the findings of the in vivo experiments. Furthermore, in vivo pattern recognition of SF-SBM metabolites, identified through GC-MS metabolomics, and in-silico docking analysis of major metabolites in plasma were conducted to gain further insights.

RESULT

Phytochemical analysis using HPTLC, TLC-bioautography, and UPLC-MS revealed the presence of several bioactive constituents in SF-SBM, including ferulic acid, gallic acid (GA), ellagic acid, quercetin, and apigenin. These compounds exhibit diverse pharmacological properties. In vitro studies demonstrated the protective effect of SF-SBM on HEK-293 cell line against nephrotoxicity. The acute toxicity study of SF-SBM at a dose of 2000 mg/kg showed no mortality or signs of toxicity throughout the 14-day observation period. In the in vivo studies, administration of NaF resulted in significant elevation (P < 0.001) of biochemical and urine parameters, indicating oxidative, inflammatory, and apoptotic stress. Histopathological examination revealed severe depletion of Bowman's capsule, and immunohistochemistry demonstrated negative immunostaining for caspase-3 and reduced NOX-4 reactions. Pre-treatment with SF-SBM significantly attenuated the elevated biochemical and urine markers, restored the antioxidant enzyme levels (such as SOD, CAT, GSH, GPx and NO), and regulated the expression of inflammatory cytokines (TNF-α, IL-1β, CASP-3) in kidney tissue at doses of SF-SBM-MD (64.2 mg/kg) and SF-SBM-HD (128.4 mg/kg), showing comparable results to those of α-Ketoanalogue. Histopathological assessment demonstrated improvements in tissue damage. Pattern recognition analysis of SF-SBM identified the presence of 56 metabolites at different time intervals. Additionally, in-silico studies revealed strong interactions of SF-SBM with a binding energy of -6.5 and -5.6 kcal for 4C2N.

CONCLUSION

The phytoconstituents present in SF-SBM play a crucial role in its nephroprotective action by acting as potent antioxidants and reducing proinflammatory and apoptotic damage in rat cells. This indicates that SF-SBM has promising potential for the treatment of nephrotoxicity.

A review on the effect of garlic on diabetes, BDNF, and VEGF as a potential treatment for diabetic retinopathy

BACKGROUND

Garlic is one of the favorite herbs in traditional medicine that has been reported to have many medicinal features. The aim of the current study is to review the latest documents on the effect of garlic on diabetes, VEGF, and BDNF and, finally, to review the existing studies on the effect of garlic on diabetic retinopathy.

MAIN TEXT

The therapeutic effect of garlic on diabetes has been investigated in various studies. Diabetes, especially in advanced stages, is associated with complications such as diabetic retinopathy, which is caused by the alteration in the expression of molecular factors involved in angiogenesis, neurodegeneration, and inflammation in the retina. There are different in-vitro and in-vivo reports on the effect of garlic on each of these processes. Considering the present concept, we extracted the most related English articles from Web of Science, PubMed, and Scopus English databases from 1980 to 2022. All in-vitro and animal studies, clinical trials, research studies, and review articles in this area were assessed and classified.

RESULT AND CONCLUSION

According to previous studies, garlic has been confirmed to have beneficial antidiabetic, antiangiogenesis, and neuroprotective effects. Along with the available clinical evidence, it seems that garlic can be suggested as a complementary treatment option alongside common treatments for patients with diabetic retinopathy. However, more detailed clinical studies are needed in this field.

Nephroprotective plant species used in traditional Mayan Medicine for renal-associated diseases

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of kidney disease has increased rapidly in recent years and has emerged as one of the leading causes of mortality worldwide. Natural products have been suggested as valuable nephroprotective agents due to their multi-target and synergistic effects on modulating important proteins involved in kidney injury. There is a large number of plant species that have been used traditionally for kidney-related conditions in Mesoamerican medicine by different cultural groups that could provide a valuable source of nephroprotective therapeutic candidates and could lead to potential drug discovery.

AIM OF REVIEW

This review aims to provide an overview of the currently known efficacy of plant species used traditionally in Mesoamerica by Mayan groups to treat kidney-related conditions and to analyze the phytochemical, pharmacological, molecular, toxicological, and clinical evidence to contribute to public health efforts and for directing future research.

METHODS

Primary sources of plant use reports for traditional kidney-related disorders in Mesoamerica were searched systematically from library catalogs, theses, and scientific databases (PubMed, Google Scholar; and Science Direct), and were filtered according to usage frequency in Mayan groups and plant endemism. The database of traditional plants was further analyzed based on associations with published reports of the phytochemical, pharmacological, molecular, toxicological, and clinical evidence.

RESULTS

The most reported kidney-related conditions used traditionally in Mayan medicine involve reducing renal damage (a cultural interpretation that considers an inflammatory or infectious condition), cleaning or purifying the blood and kidney, reducing kidney pain, and eliminating kidney stones. A total of 208 plants used for kidney-related problems by 10 Mayan groups were found, representing 143 native species, where only 42 have reported pharmacological activity against kidney damage, mainly approached by in vitro and in vivo models of chemical- or drug-induced nephrotoxicity, diabetes nephropathy, and renal injury produced by hypertension. Nephroprotective effects are mainly mediated by reducing oxidative stress, inflammatory response, fibrosis mechanisms, and apoptosis in the kidney. The most common nephroprotective compounds associated with traditional Mayan medicine were flavonoids, terpenoids, and phenolic acids. The most widely studied traditional plants in terms of pharmacological evidence, bioactive compounds, and mechanisms of action, are Annona muricata L., Carica papaya L., Ipomoea batatas (L.) Lam., Lantana camara L., Sechium edule (Jacq.) Sw., Tagetes erecta L., and Zea mays L. Most of the plant species with reported pharmacological activity against kidney damage were considered safe in toxicological studies.

CONCLUSION

Available pharmacological reports suggest that several herbs used in traditional Mayan medicine for renal-associated diseases may have nephroprotective effects and consistent pharmacological evidence, nephroprotective compounds, and mechanisms of action in different models of kidney injury. However, more research is required to fully understand the potential of traditional Mayan medicine in drug discovery given the limited ethnobotanical studies and data available for most species with regards to identification on bioactive components, pharmacological mechanisms, and the scarce number of clinical studies.

Oxidative Stress and NRF2/KEAP1/ARE Pathway in Diabetic Kidney Disease (DKD): New Perspectives

Diabetes mellitus (DM) is one of the most debilitating chronic diseases worldwide, with increased prevalence and incidence. In addition to its macrovascular damage, through its microvascular complications, such as Diabetic Kidney Disease (DKD), DM further compounds the quality of life of these patients. Considering DKD is the main cause of end-stage renal disease (ESRD) in developed countries, extensive research is currently investigating the matrix of DKD pathophysiology. Hyperglycemia, inflammation and oxidative stress (OS) are the main mechanisms behind this disease. By generating pro-inflammatory factors (e.g., IL-1,6,18, TNF-α, TGF-β, NF-κB, MCP-1, VCAM-1, ICAM-1) and the activation of diverse pathways (e.g., PKC, ROCK, AGE/RAGE, JAK-STAT), they promote a pro-oxidant state with impairment of the antioxidant system (NRF2/KEAP1/ARE pathway) and, finally, alterations in the renal filtration unit. Hitherto, a wide spectrum of pre-clinical and clinical studies shows the beneficial use of NRF2-inducing strategies, such as NRF2 activators (e.g., Bardoxolone methyl, Curcumin, Sulforaphane and their analogues), and other natural compounds with antioxidant properties in DKD treatment. However, limitations regarding the lack of larger clinical trials, solubility or delivery hamper their implementation for clinical use. Therefore, in this review, we will discuss DKD mechanisms, especially oxidative stress (OS) and NRF2/KEAP1/ARE involvement, while highlighting the potential of therapeutic approaches that target DKD via OS.

p-Coumaric acid attenuates high-fat diet-induced oxidative stress and nephropathy in diabetic rats

The prevalence of persistent hyperglycaemia during diabetes, impair antioxidant defence system and generate reactive oxygen species, which majorly contribute to its progression and associated complications. Phytochemicals were suggested to scavenge-free radicals and exert antioxidant effects required to improve insulin sensitivity and reduce the occurrence of diabetes-associated complications. We hypothesise that a phenolic phytochemical p-coumaric can reduce diabetes-induced oxidative stress and improve diabetes-associated nephropathy in rats. The aim of this study is to analyse the protective effects of p-coumaric acid against diabetes-induced oxidative stress and nephropathy in high-fat diet-induced diabetic rats. The oral feeding of p-coumaric acid (20 mg/kg for 12 weeks) was found to significantly decrease the elevated levels of blood glucose in high-fat diet-induced type 2 diabetic rats. p-Coumaric acid treatment also decreases the kidney weight whilst increasing the total body weight of diabetic rats. Furthermore whilst evaluation of the different renal functioning tests, p-coumaric acid significantly improves histopathological changes and the levels of urea, creatinine and uric acid in serum of diabetic rats, which was otherwise elevated under diabetic conditions. Our results also highlight that p-coumaric acid is an efficient compound with antioxidant properties and improves the diabetes-induced change in lipid peroxidation and activities of antioxidant enzymes: catalase, glutathione-S-transferase and superoxide dismutase. p-Coumaric acid thus possesses the potential to prevent diabetic nephropathy by reducing oxidative stress and can thus serve as a potential drug target for pharmaceutical companies.

Targeting NRF2 in Type 2 diabetes mellitus and depression: Efficacy of natural and synthetic compounds

Evidence supports a strong bidirectional association between depression and Type 2 diabetes mellitus (T2DM). The harmful impact of oxidative stress and chronic inflammation on the development of both disorders is widely accepted. Nuclear factor erythroid 2-related factor 2 (NRF2) is a pertinent target in disease management owing to its reputation as the master regulator of antioxidant responses. NRF2 influences the expression of various cytoprotective phase 2 antioxidant genes, which is hampered in both depression and T2DM. Through interaction and crosstalk with several signaling pathways, NRF2 endeavors to contain the widespread oxidative damage and persistent inflammation involved in the pathophysiology of depression and T2DM. NRF2 promotes the neuroprotective and insulin-sensitizing properties of its upstream and downstream targets, thereby interrupting and preventing disease advancement. Standard antidepressant and antidiabetic drugs may be powerful against these disorders, but unfortunately, they come bearing distressing side effects. Therefore, exploiting the therapeutic potential of NRF2 activators presents an exciting opportunity to manage such bidirectional and comorbid conditions.

The Effects of Antioxidants from Natural Products on Obesity, Dyslipidemia, Diabetes and Their Molecular Signaling Mechanism

Obesity is a risk factor that leads to the development of other diseases such as dyslipidemia and diabetes. These three metabolic disorders can occur simultaneously, hence, the treatment requires many drugs. Antioxidant compounds have been reported to have activities against obesity, dyslipidemia and diabetes via several mechanisms. This review aims to discuss the antioxidant compounds that have activity against obesity, dyslipidemia and diabetes together with their molecular signaling mechanism. The literature discussed in this review was obtained from the PUBMED database. Based on the collection of literature obtained, antioxidant compounds having activity against the three disorders (obesity, dyslipidemia and diabetes) were identified. The activity is supported by various molecular signaling pathways that are influenced by these antioxidant compounds, further study of which would be useful in predicting drug targets for a more optimal effect. This review provides insights on utilizing one of these antioxidant compounds as opposed to several drugs. It is hoped that in the future, the number of drugs in treating obesity, dyslipidemia and diabetes altogether can be minimized consequently reducing the risk of side effects.

Dapagliflozin Reduces Urinary Albumin Excretion by Downregulating the Expression of cAMP, MAPK, and cGMP-PKG Signaling Pathways Associated Genes

Objective: Diabetic nephropathy (DN), the most severe complication of diabetes mellitus, is characterized by albuminuria and progressive loss of kidney function. Dapagliflozin (DAP), a sodium-glucose cotransporter inhibitor, is an oral medication that improves blood glucose control in diabetic patients. However, the effects and mechanisms of DAP on DN remain unclear. Materials and Methods: The effect of DAP was based on a retrospective cohort study of patients who underwent 2-year surveillance, and the concentration of urine albumin-to-creatinine ratio, glomerular filtration rate, and serum creatinine were collected after treatment with DAP. To investigate the underlying mechanisms through which DAP reduces urinary albumin excretion, we used RNA-sequencing (RNA-seq) to analyze gene expression in human kidney 2 (HK-2) cells treated with DAP. Results: The retrospective cohort analysis indicated that DAP could reduce the excretion rate of urinary albumin in patients with type 2 diabetes and renal impairment. The results of the RNA-seq experiments showed 349 differentially expressed genes between DAP-treated HK-2 cells and control cells. Gene ontology annotation enrichment analysis showed that DAP mainly affected the expression of integral component of membrane- and cell junction-related genes, while the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that DAP primarily downregulated the expression of gene clusters associated with cyclic adenosine monophosphate, mitogen-activated protein kinase, and cyclic guanosine monophosphate-protein kinase G signaling pathways, which play critical roles in the progression of DN. Conclusion: Our results shed light on the mechanism by which DAP controls DN progression and provide a theoretical basis for the clinical treatment of DN.

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

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

Lipidomics study of the therapeutic mechanism of Plantaginis Semen in potassium oxonate-induced hyperuricemia rat

BACKGROUND

Plantaginis Semen has been widely used as folk medicine and health care food against hyperuricemia (HUA) and gout, but its pharmacological mechanism remains unclear. This study investigated the therapeutic mechanism of Plantaginis Semen extract on potassium oxonate -induced HUA rats based on a lipidomics approach.

METHODS

A model of HUA was established by potassium oxonate intragastric administration. 42 Sprague-Dawley (SD) male rats were randomly divided into the control group, model group, benzbromarone group (10 mg/kg) and three Plantaginis Semen groups (n = 7). The Plantaginis Semen groups were treated orally with Plantaginis Semen, 0.9375, 1.875  or 3.75 g/kg for 28 days. The levels of serum uric acid (UA), creatinine (Cr), triacylglycerol (TG) and tumor necrosis factor-α (TNF-α) were  measured using enzyme-linked immunosorbent assay kits. Ultra performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-Q-TOF/MS) was used for the serum lipidomics analysis, multivariate statistical analysis and independent samples t-test were carried out for the pattern recognition and characteristic metabolites identification. The relative levels of critical regulatory factors were determined by quantitative real-time polymerase chain reaction (RT-qPCR).

RESULTS

Compared with the model group, the levels of serum UA, Cr, TG and TNF-α were significantly (p < 0.05) decreased in benzbromarone and three Plantaginis Semen groups. With lipidomics analysis, significant lipid metabolic perturbations were observed in HUA rats, 13 metabolites were identified as potential biomarkers and glycerophospholipid metabolism pathway was  most affected. These perturbations  were partially restored via treatment of benzbromarone and Plantaginis Semen. Additionally, the mRNA expression levels of urate anion transporter 1 (URAT1) and phosphatidylinositol 3-kinase/protein kinases B (PI3K/Akt) were significantly decreased (p < 0.01) after treatment with benzbromarone and high dose of Plantaginis Semen.

CONCLUSIONS

Plantaginis Semen had significant effects on anti-HUA, anti-inflammatory and renal protection. It attenuated potassium oxonate-induced HUA through regulation of lipid metabolism disorder.

Luteolin attenuates doxorubicin-induced derangements of liver and kidney by reducing oxidative and inflammatory stress to suppress apoptosis

Doxorubicin is an effective anti-neoplastic agent; the reported toxicities of DOX limit its use. Luteolin is a polyphenolic phytochemical that exhibits beneficial biological effects via several mechanisms. We investigate luteolin protective effects on hepatorenal toxicity associated with doxorubicin treatment in rats. For 2 weeks, randomly assigned rat cohorts were treated as follows: control, luteolin (100 mg/kg; per os), doxorubicin alone (2mg/kg; by intraperitoneal injection), co-treated cohorts received luteolin (50 and 100 mg/kg) in addition to doxorubicin. Treatment with doxorubicin alone significantly (p < 0.05) increased biomarkers of hepatorenal toxicities in the serum. Doxorubicin also reduced relative organ weights, antioxidant capacity, and anti-inflammatory cytokine interleukine-10. Doxorubicin also increased reactive oxygen and nitrogen species, lipid peroxidation, pro-inflammatory-interleukin-1β and tumour necrosis factor-α-cytokine, and apoptotic caspases-3 and -9). Morphological damage accompanied these biochemical alterations in the rat's liver and kidney treated with doxorubicin alone. Luteolin co-treatment dose-dependently abated doxorubicin-mediated toxic responses, improved antioxidant capacity and interleukine-10 level. Luteolin reduced (p < 0.05) lipid peroxidation, caspases-3 and -9 activities and marginally improved rats' survivability. Similarly, luteolin co-treated rats exhibited improvement in hepatorenal pathological lesions observed in rats treated with doxorubicin alone. In summary, luteolin co-treatment blocked doxorubicin-mediated hepatorenal injuries linked with pro-oxidative, inflammatory, and apoptotic mechanisms. Therefore, luteolin can act as a chemoprotective agent in abating toxicities associated with doxorubicin usage and improve its therapeutic efficacy.

Piperazine ferulate attenuates high glucose‑induced mesangial cell injury via the regulation of p66Shc

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes. Hyperglycemia-induced glomerular mesangial cells injury is associated with microvascular damage, which is an important step in the development of DN. Piperazine ferulate (PF) has been reported to exert protective effects against the progression of DN. However, whether PF prevents high glucose (HG)-induced mesangial cell injury remains unknown. The aim of the present study was to investigate the effects of PF on HG-induced mesangial cell injury and to elucidate the underlying mechanisms. Protein and mRNA expression levels were determined via western blot analysis and reverse transcription-quantitative PCR, respectively. IL-6 and TNF-α levels were measured using ELISA. Reactive oxygen species levels and NF-κB p65 nuclear translation were determined via immunofluorescence analysis. Apoptosis was assessed by measuring lactate dehydrogenase (LDH) release, as well as using MTT and flow cytometric assays. The mitochondrial membrane potential of mesangial cells was determined using the JC-1 kit. The results revealed that LDH release were increased; however, cell viability and mitochondrial membrane potential were decreased in the HG group compared with the control group. These changes were inhibited after the mesangial cells were treated with PF. Moreover, PF significantly inhibited the HG-induced production of inflammatory cytokines and the activation of NF-κB in mesangial cells. PF also attenuated the HG-induced upregulation of the expression levels of fibronectin and collagen 4A1. Furthermore, the overexpression of p66^{Src homology/collagen (Shc)} abolished the protective effect of PF on HG-induced mesangial cell injury. In vivo experiments revealed that PF inhibited the activation of inflammatory signaling pathways, glomerular cell apoptosis and mesangial matrix expansion in diabetic mice. Collectively, the present findings demonstrated that PF attenuated HG-induced mesangial cells injury by inhibiting p66^Shc.

A Network Pharmacology-Based Approach for Exploring Key Active Compounds and Pharmacological Mechanisms of Tangshen Formula for Treatment of Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the common and severe microvascular complications of diabetes mellitus (DM). The occurrence and development of DN are related to multiple factors in the human body, which makes DN a complex disease, and the pathogeneses of DN have not yet been fully illustrated. Furthermore, DN lacks effective drugs for treatment nowadays. Chinese herbal medicine (CHM) often shows the feature of multicomponents, multitargets, multipathways, and synergistic effects and shows a promising source of new therapeutic drugs for DN. As a CHM, Tangshen Formula (TSF) was used to treat DN patients in China. However, its bioactive compounds and holistic pharmacological mechanisms on DN are both unclear. A network pharmacology approach was firstly applied to explore multiple active compounds and multiple key pharmacological mechanisms for TSF treating DN by drug-targeted interaction databases, herb-compound-target network, protein-protein interaction network, compound-target-pathway network, and analysis methods. And the results showed that TSF have the characteristic of multicomponents, multitargets, multipathways, and synergistic effects for treating DN. The quercetin, naringenin, kaempferol, and isorhamnetin as key active compounds and the PI3K-Akt signaling pathway, TNF signaling pathway, nonalcoholic fatty liver disease (NAFLD), focal adhesion, rap1 signaling pathway, T cell receptor signaling pathway, MAPK signaling pathway, and insulin resistance as the key molecular mechanisms play important roles in TSF treating DN. Moreover, quercetin, naringenin, kaempferol, and isorhamnetin were successfully detected in TSF by the UHPLC-MS/MS analysis method. And their concentrations were 0.224, 8.295, 0.0564, and 0.0879 mg·kg-1, respectively. The present findings not only provide new insights for a deeper understanding of the constituent basis and pharmacology of TSF but also provide guidance for further pharmacological studies on TSF.