The synergic renoprotective effect of Rehmanniae Radix Preparata and Corni Fructus on adenine-induced chronic kidney disease rats based on integrated plasma metabolomics and network pharmacology approach

Screening of ESR2-targeted anti-postmenopausal osteoporosis chemistry from Rehmanniae Radix Preparata based on affinity ultrafiltration with UPLC-QE-Orbitrap-MS

Rehmanniae Radix Preparata, a processed form of the traditional Chinese medicinal plant Rehmannia glutinosa Libosch, has long been valued for its medicinal properties and use as a food. It is notably effective in treating postmenopausal osteoporosis. This study utilized C18 to separate and purify different concentrations of its eluent streams. MC3T3-E1 cells were utilized to identify the optimal ESR2 activity fraction from various concentrations of Rehmanniae Radix Preparata, using osteoprotegerin (OPG) as an indicator. A single-target affinity ultrafiltration method was created, combining ESR2 affinity ultrafiltration with liquid chromatography-mass spectrometry (LC-MS). Molecular docking validated the interaction mechanism between small molecule ligands and ESR2 protein. These ligands were then tested in MC3T3-E1 cells to assess survival rate, OPG content, and alkaline phosphatase (ALP) activity, an osteogenic differentiation marker. The study showed that Radix Rehmanniae Praeparata effectively combats PMOP, and the combined method of single-target-affinity ultrafiltration-LC-MS with molecular docking offers a robust approach for identifying its anti-PMOP compounds.

Analysis of non-targeted serum metabolomics in patients with chronic kidney disease and hyperuricemia

Hyperuricemia (HUA) is a common complication of chronic kidney disease (CKD). Conversely, HUA can promote the disease progression of CKD. However, the molecular mechanism of HUA in CKD development remains unclear. In the present study, we applied ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to analyze the serum metabolite profiling of 47 HUA patients, 41 non-hyperuricemic CKD (NUA-CKD) patients, and 51 CKD and HUA (HUA-CKD) patients, and then subjected to multivariate statistical analysis, metabolic pathway analysis and diagnostic performance evaluation. Metabolic profiling of serums showed that 40 differential metabolites (fold-change threshold (FC) > 1.5 or<2/3, variable importance in projection (VIP) > 1, and p < 0.05) were screened in HUA-CKD and HUA patients, and 24 differential metabolites (FC > 1.2 or<0.83, VIP>1, and p < 0.05) were screened in HUA-CKD and NUA-CKD patients. According to the analysis of metabolic pathways, significant changes existed in three metabolic pathways (compared with the HUA group) and two metabolic pathways (compared with the HUA-CKD group) in HUA-CKD patients. Glycerophospholipid metabolism was a significant pathway in HUA-CKD. Our findings show that the metabolic disorder in HUA-CKD patients was more serious than that in NUA-CKD or HUA patients. A theoretical basis is provided for HUA to accelerate CKD progress.

Integrating network pharmacology, molecular docking, and experimental validation to reveal the mechanism of Radix Rehmanniae in psoriasis

BACKGROUND

Radix Rehmanniae (RR) plays an important role in treating psoriasis. However, the active compounds of RR and potential mechanisms are unclear. The current study was designed to investigate the potential active ingredients, targets, and mechanisms of RR in treating psoriasis through network pharmacology, molecular docking, and vitro experiments.

METHODS

Initially, the TCMSP database and literature retrieval were used to access the active ingredients of RR. The psoriasis target proteins were obtained from Therapeutic Target Database, OMIM, GeneCards, and DrugBank databases. The target proteins were then converted into target genes using Uniprot. Secondly, overlapping genes were obtained through Venn online tool. Then, protein-protein interactions network diagram is finished by STRING database. Next, Cytoscape software was used to acquire the top 10 hub proteins; gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis were then used to predict possible mechanisms. Afterwards, molecular docking validation of the active ingredients with the main targets was performed by AutoDock software. Finally, lipopolysaccharides induced RAW264.7, to assess the effects and molecular mechanisms by MTT, RT-qPCR, and Western blot assays.

RESULTS

Overall, there are 20 effective compounds and 33 targets involved in biological processes including apoptosis, intracellular signaling, vasodilation, and mitogen-activated protein kinase (MAPK) signaling cascade. The docking results showed strong binding capacity between the active ingredients and targets. We verified aucubin as the key active ingredient, tumor necrosis factor α, and IL6 as the core targets, and focused on the p38MAPK protein pathway. Cellular experiments showed that aucubin down-regulated the phosphorylated p38MAP protein and reduced the expression of tumor necrosis factor α mRNA, IL6 mRNA, and IL1βmRNA.

CONCLUSION

In summary, RR is featured with multicomponent, multi-target, and multi-pathway in treating psoriasis; the preliminary mechanism may be associated with the down-regulation of p38MAPK phosphorylation and curbing the expression of inflammatory factor by aucubin. This paper provides the scientific basis for Traditional Chinese medicine treating psoriasis.

Progress of research into the pharmacological effect and clinical application of the traditional Chinese medicine Rehmanniae Radix

The traditional Chinese medicine (TCM) Rehmanniae Radix (RR) refers to the fresh or dried root tuber of the plant Rehmannia glutinosa Libosch of the family Scrophulariaceae. As a traditional Chinese herbal medicine (CHM), it possesses multiple effects, including analgesia, sedation, anti-inflammation, antioxidation, anti-tumor, immunomodulation, cardiovascular and cerebrovascular regulation, and nerve damage repair, and it has been widely used in clinical practice. In recent years, scientists have extensively studied the active components and pharmacological effects of RR. Active ingredients mainly include iridoid glycosides (such as catalpol and aucuboside), phenylpropanoid glycosides (such as acteoside), other saccharides, and unsaturated fatty acids. In addition, the Chinese patent medicine (CPM) and Chinese decoction related to RR have also become major research subjects for TCM practitioners; one example is the Bolus of Six Drugs, which includes Rehmannia, Lily Bulb and Rehmannia Decoction, and Siwu Decoction. This article reviews recent literature on RR; summarizes the studies on its chemical constituents, pharmacological effects, and clinical applications; and analyzes the progress and limitations of current investigations to provide reference for further exploration and development of RR.

Nutraceuticals and network pharmacology approach for acute kidney injury: A review from the drug discovery aspect

Acute kidney injury (AKI) has become a global health issue, with ~12 million reports yearly, resulting in a persistent increase in morbidity and mortality rates. AKI pathophysiology is multifactorial involving oxidative stress, mitochondrial dysfunction, epigenetic modifications, inflammation, and eventually, cell death. Hence, therapies able to target multiple pathomechanisms can aid in AKI management. To change the drug discovery framework from "one drug, one target" to "multicomponent, multitarget," network pharmacology is evolving as a next-generation research approach. Researchers have used the network pharmacology approach to predict the role of nutraceuticals against different ailments including AKI. Nutraceuticals (herbal products, isolated nutrients, and dietary supplements) belong to the pioneering category of natural products and have shown protective action against AKI. Nutraceuticals have recently drawn attention because of their ability to provide physiological benefits with less toxic effects. This review emphasizes the nutraceuticals that exhibited renoprotection against AKI and can be used either as monotherapy or adjuvant with conventional therapies to boost their effectiveness and lessen the adverse effects. Additionally, the study sheds light on the application of network pharmacology as a cost-effective and time-saving approach for the therapeutic target prediction of nutraceuticals against AKI.

Fufang Shenhua tablet inhibits renal fibrosis by inhibiting PI3K/AKT

BACKGROUND

Fufang Shenhua tablet (SHT), a traditional Chinese medicine compound, has been utilized in the clinical management of chronic kidney disease (CKD) for a long time. Nevertheless, the fundamental active constituents and potential mechanism of action remain unclear. Thus, the objective of this study was to investigate the renoprotective effect of SHT on residual renal tissue in CKD model rats and to explore its primary efficacious components and their underlying mechanism.

METHODS

After a 12-week period of SHT treatment through gavage in a 5/6 nephrectomized animal model of CKD, we evaluated the body weight, renal function, and renal pathological changes. Furthermore, the expression levels of fibronectin (FN), collagen I (COL-1), α-smooth muscle actin (α-SMA), and vimentin in renal tissues were assessed. In addition, network pharmacology analysis and molecular docking were utilized to predict the primary active components, potential therapeutic targets, and intervention pathways through which SHT could potentially exert its anti-kidney fibrosis effects. Subsequently, these predictions were validated in renal tissues of rats with CKD and in transforming growth factor β1 (TGF-β1)-induced HK-2 cells.

RESULTS

SHT significantly improved renal function and reduced renal pathological damage and fibrosis in CKD model rats. Network pharmacological analysis identified 62 active components in SHT, with quercetin ranked first, and 105 protein targets shared by SHT and CKD. Based on the protein‒protein interaction network (PPI) and the SHT-CKD-pathway network, AKT1, MYC, IL2, and VEGFA were identified as key targets. Furthermore, GO and KEGG pathway enrichment analyses indicated that the renoprotective effect of SHT on CKD was closely associated with the PI3K/AKT signaling pathway. Molecular docking results demonstrated that the main active components of SHT had a strong binding affinity to the hub genes. During experimental validation, SHT hindered the activity of the PI3K/AKT signaling pathway in the renal tissue of CKD model rats. Furthermore, activation of the PI3K/AKT signaling pathway was correlated with a modified fibrotic phenotype in rats with 5/6 nephrectomy-induced CKD and TGF-β1-induced HK-2 cells. Conversely, SHT and quercetin curtailed the activation of the PI3K/AKT signaling pathway and inhibited the formation of renal fibrosis, thus indicating that the PI3K/AKT signaling pathway is the basis of the antifibrotic effects of SHT. Ultimately, administration of the PI3K/AKT agonist 740Y-P counteracted the fibrotic phenotype of TGF-β1-induced HK-2 cells induced by SHT.

CONCLUSIONS

In this investigation, we employed a fusion of systems pharmacology and in vivo and in vitro experiments to elucidate the mechanism of SHT's antifibrotic properties via obstruction of the PI3K/AKT signaling pathway. Additionally, we surmised that AKT may be the principal target of SHT for the management of CKD and that quercetin may be its efficacious component. We have thus identified SHT as a promising drug for the amelioration of renal fibrosis and the progression of CKD.

Soluble guanylate cyclase agonist, isoliquiritigenin attenuates renal damage and aortic calcification in a rat model of chronic kidney failure

AIMS

Chronic kidney disease (CKD) is a growing fatal health problem worldwide associated with vascular calcification. Therapeutic approaches are limited with higher costs and poor outcomes. Adenine supplementation is one of the most relevant CKD models to human. Insufficient Nitric Oxide (NO)/ cyclic Guanosine Monophosphate (cGMP) signaling plays a key role in rapid development of renal fibrosis. Natural products display proven protection against CKD. Current study therefore explored isoliquiritigenin, a bioflavonoid extracted from licorice roots, potential as a natural activator for soluble Guanylate Cyclase (sGC) in a CKD rat model.

MATERIALS AND METHODS

60 male Wistar rats were grouped into Control group (n = 10) and the remaining rats received adenine (200 mg/kg, p.o) for 2 wk to induce CKD. They were equally sub-grouped into: Adenine untreated group and 4 groups orally treated by isoliquiritigenin low or high dose (20 or 40 mg/kg) with/without a selective sGC inhibitor, ODQ (1-H(1,2,4)oxadiazolo(4,3-a)-quinoxalin-1-one, 2 mg/kg, i.p) for 8 wk.

KEY FINDINGS

Long-term treatment with isoliquiritigenin dose-dependently and effectively amended adenine-induced chronic renal and endothelial dysfunction. It not only alleviated renal fibrosis and apoptosis markers but also aortic calcification. Additionally, this chalcone neutralized renal inflammatory response and oxidative stress. Isoliquiritigenin beneficial effects were associated with up-regulation of serum NO, renal and aortic sGC, cGMP and its dependent protein kinase (PKG). However, co-treatment with ODQ antagonized isoliquiritigenin therapeutic impact.

SIGNIFICANCE

Isoliquiritigenin seems to exert protective effects against CKD and vascular calcification by activating sGC, increasing cGMP and its downstream PKG.

Integrating strategies of metabolomics, network pharmacology, and experiment validation to investigate the processing mechanism of Epimedium fried with suet oil to warm kidney and enhance yang

Introduction: Epimedium, a traditional Chinese medicine (TCM) commonly used in ancient and modern China, is one of the traditional Chinese medicines clinically used to treat kidney yang deficiency syndrome (KYDS). There are differences in the efficacy of Epimedium before and after processing, and the effect of warming the kidney and enhancing yang is significantly enhanced after heating with suet oil. However, the active compounds, corresponding targets, metabolic pathways, and synergistic mechanism of frying Epimedium in suet oil to promote yang, remain unclear. Methods: Herein, a strategy based on comprehensive GC-TOF/MS metabolomics and network pharmacology analysis was used to construct an "active compounds-targets-metabolic pathways" network to identify the active compounds, targets and metabolic pathways involved. Subsequently, the targets in kidney tissue were further validated by real-time quantitative polymerase chain reaction (RT-qPCR). Histopathological analysis with physical and biochemical parameters were performed. Results: Fifteen biomarkers from urine and plasma, involving five known metabolic pathways related to kidney yang deficiency were screened. The network pharmacology results showed 37 active compounds (13 from Epimedium and 24 from suet oil), 159 targets, and 267 pathways with significant correlation. Importantly, integrated metabolomics and network pharmacologic analysis revealed 13 active compounds (nine from Epimedium and four from suet oil), 7 corresponding targets (ALDH2, ARG2, GSTA3, GSTM1, GSTM2, HPGDS, and NOS2), two metabolic pathways (glutathione metabolism, arginine and proline metabolism), and two biomarkers (Ornithine and 5-Oxoproline) associated with improved kidney yang deficiency by Epimedium fried with suet oil. Discussion: These finds may elucidate the underlying mechanism of yang enhancement via kidney warming effects. Our study indicated that the mechanism of action mainly involved oxidative stress and amino acid metabolism. Here, we demonstrated the novel strategies of integrating metabolomics and network pharmacology in exploring of the mechanisms of traditional Chinese medicines.

Natural products from plants and microorganisms: Novel therapeutics for chronic kidney disease via gut microbiota regulation

Dysbiosis of gut microbiota plays a fundamental role in the pathogenesis and development of chronic kidney disease (CKD) and its complications. Natural products from plants and microorganisms can achieve recognizable improvement in renal function and serve as an alternative treatment for chronic kidney disease patients with a long history, yet less is known on its beneficial effects on kidney injury by targeting the intestinal microbiota. In this review, we summarize studies on the effects of natural products from plants and microorganisms, including herbal medicines and their bioactive extracts, polysaccharides from plants and microorganisms, and phytochemicals, on the prevention and treatment of chronic kidney disease through targeting gut microflora. We describe the strategies of these anti-CKD effects in animal experiments including remodulation of gut microbiota structure, reduction of uremic toxins, enhancement of short-chain fatty acid (SCFA) production, regulation of intestinal inflammatory signaling, and improvement in intestinal integrity. Meanwhile, the clinical trials of different natural products in chronic kidney disease clinical practice were also analyzed and discussed. These provide information to enable a better understanding of the renoprotective effects of these effective natural products from plants and microorganisms in the treatment of chronic kidney disease. Finally, we propose the steps to prove the causal role of the intestinal microflora in the treatment of chronic kidney disease by natural products from plants and microorganisms. We also assess the future perspective that natural active products from plants and microorganisms can beneficially delay the onset and progression of kidney disease by targeting the gut flora and highlight the remaining challenges in this area. With the continuous deepening of studies in recent years, it has been proved that gut microbiota is a potential target of natural active products derived from plants and microorganisms for chronic kidney disease treatment. Fully understanding the functions and mechanisms of gut microbiota in these natural active products from plants and microorganisms is conducive to their application as an alternative therapeutic in the treatment of chronic kidney disease.

Corni Fructus Alleviates UUO-Induced Renal Fibrosis via TGF-β/Smad Signaling

Renal fibrosis is a type of chronic kidney disease (CKD) induced by infiltration of inflammatory cells, myofibroblast accumulation, and ECM production in the kidney. From a long time ago, Corni Fructus (CF) is known to supplement the liver and kidney with its tepid properties. In this study, we investigated the renal protective mechanism of CF, which is known to supplement the kidney, in rat model of unilateral ureteral obstruction (UUO). After inducing UUO through surgery, the group was separated ( $n=8$ ) and the drug was administered for 2 weeks; normal rats (normal), water-treated UUO rats (control), CF 100 mg/kg-treated UUO rats (CF100), and CF 200 mg/kg-treated UUO rats (CF200). As a result of histopathological examination of kidney tissue with H&E, MT, and PAS staining, it was confirmed that the infiltration of inflammatory cells and the erosion of collagen were relatively decreased in the kidneys treated with CF. Also, CF significantly reduced the levels of MDA and BUN in serum. As a result of confirming the expression of the factors through western blotting, CF treatment significantly reduced the expression of NADPH oxidase and significantly regulated the AMPK/LKB1/NF-κB pathway associated with inflammation. In addition, it downregulated the expression of major fibrotic signaling factors, such as α-SMA, collagen I, MMP-2, and TIMP-1, and significantly regulated the TGF-β1/Smad pathway, which is known as a major regulator of renal fibrosis. Taken together, these findings indicate that CF can alleviate renal fibrosis by regulating the TGF-β1/Smad pathway through inhibition of oxidative stress in UUO.

Changes in the Chemical Components of Processed Rehmanniae Radix Distillate during Different Steaming Times

Distillate was obtained in different processing cycles of processed Rehmanniae Radix (PRR). In this study, we investigated the chemical compositions of distillates 1 (Dis1) to 9 (Dis9) via GC-MS and LC-MS. Differences between Dis1–Dis9 were noticeable. A total of 13 and 21 compounds were detected via GC-MS and LC-MS, respectively, including organic acids, furans, alcohols, iridoid glycosides, phenylpropanoid glycosides, and saccharides. The relative contents of compound 2,5-hydroxymethylfurfural and furans all gradually increased with steaming time. Other compounds, however, exhibited a negative trend or fluctuated. Of these compounds, iridoid glycosides and phenylpropanoid glycosides were unstable and easily degraded, which led to a gradually decreasing concentration with increased steaming times. In addition, the degradation products were mainly derived from catalpol and acteoside, among which catalpol mainly existed as aglycone and its rearranged products. However, acteoside was converted into verbasoside through the removal of caffeoyl. Some volatile alcohols, such as phenylethyl alcohol, hydroxyphenyl ethanol, and 3-hydroxy-4-methoxybenzoic acid, were also likely from the degradation of acteoside and its homologs. These results provide an important reference basis for the processing methods, quality evaluation, and rational clinical application of PRR and its distillate.