Research Progress of Chinese Herbal Medicine Intervention in Renal Interstitial Fibrosis

Advances in the study of key cells and signaling pathways in renal fibrosis and the interventional role of Chinese medicines

Renal fibrosis (RF) is a pathological process characterized by the excessive accumulation of extracellular matrix (ECM), which triggers a repair cascade in response to stimuli and pathogenic factors, leading to the activation of molecular signaling pathways involved in fibrosis. This article discusses the key cells, molecules, and signaling pathways implicated in the pathogenesis of RF, with a particular focus on tubular epithelial cells (TECs), cellular senescence, ferroptosis, autophagy, epithelial-mesenchymal transition (EMT), and transforming growth factor-β(TGF-β)/Smad signaling. These factors drive the core and regulatory pathways that significantly influence RF. A comprehensive understanding of their roles is essential. Through a literature review, we explore recent advancements in traditional Chinese medicine (TCM) aimed at reducing RF and inhibiting chronic kidney disease (CKD). We summarize, analyze, and elaborate on the important role of Chinese herbs in RF, aiming to provide new directions for their application in prevention and treatment, as well as scientific guidance for clinical practices.

Spatiotemporal delivery of multiple components of rhubarb-astragalus formula for the sysnergistic treatment of renal fibrosis

Purpose

Rhubarb (Rheum palmatum L.) and astragalus (Radix astragali) find widespread used in clinical formulations for treating chronic kidney disease (CKD). Notably, the key active components, total rhubarb anthraquinone (TRA) and total astragalus saponin (TAS), exhibit superiority over rhubarb and astragalus in terms of their clear composition, stability, quality control, small dosage, and efficacy for disease treatment. Additionally, astragalus polysaccharides (APS) significantly contribute to the treatment of renal fibrosis by modulating the gut microbiota. However, due to differences in the biopharmaceutical properties of these components, achieving synergistic effects remains challenging. This study aims to develop combined pellets (CPs) and evaluate the potential effect on unilateral ureteral obstruction (UUO)-induced renal fibrosis.

Methods

The CPs pellets were obtained by combining TRA/TAS-loaded SNEDDS pellets and APS-loaded pellets, prepared using the fluidized bed coating process. The prepared pellets underwent evaluation for morphology, bulk density, hardness, and flowing property. Moreover, the in vitro release of the payloads was evaluated with the CHP Type I method. Furthermore, the unilateral ureteral obstruction (UUO) model was utilized to investigate the potential effects of CPs pellets on renal fibrosis and their contribution to gut microbiota modulation.

Results

The ex-vivo study demonstrated that the developed CPs pellets not only improved the dissolution of TRA and TAS but also delivered TRA/TAS and APS spatiotemporally to the appropriate site along the gastrointestinal tract. In an animal model of renal fibrosis (UUO rats), oral administration of the CPs ameliorated kidney histological pathology, reduced collagen deposition, and decreased the levels of inflammatory cytokines. The CPs also restored the disturbed gut microbiota induced by UUO surgery and protected the intestinal barrier.

Conclusion

The developed CPs pellets represent a promising strategy for efficiently delivering active components in traditional Chinese medicine formulas, offering an effective approach for treating CKD.

Integrating network analysis and experimental validation to reveal the mechanism of si-jun-zi decoction in the treatment of renal fibrosis

Treating kidney diseases from the perspective of spleen is an important clinical method in traditional Chinese medicine (TCM) for anti-renal fibrosis (RF). Si-jun-zi decoction (SJZD), a classic formula for qi-invigorating and spleen-invigorating, has been reported to alleviate RF. This study aims to investigate the potential mechanism by which SJZD attenuates RF. The results demonstrated notable improvements in renal function levels, inflammation and fibrosis indices in UUO-mice following SJZD intervention. The main active ingredients identified were Quercetin, Kaempferol, Naringenin and 7-Methoxy-2-methyl isoflavone. Furthermore, STAT3, MAPK3, MYC were confirmed as key targets. Additionally, GO enrichment analysis demonstrated that SJZD delayed RF primarily by regulating oxidative stress and other biological mechanisms. KEGG enrichment analysis revealed the involvement of pathways such as Lipid and atherosclerosis signaling pathway, MAPK signaling pathway and other pathways in the reno-protective effects of SJZD. The molecular docking results revealed that the active ingredients of SJZD were well-bound and stable to the core targets. The experiments results revealed that Quercetin, Kaempferol, and Naringenin not only improved the morphology of TGF-β-induced HK-2 cells but also reversed the expression of α-SMA, COL1A1 and MAPK, thereby delaying the progression of RF. The anti-RF effects of SJZD were exerted through multi-components, multi-targets and multi-pathways.

Unlocking the Medicinal Potential of Plant-Derived Extracellular Vesicles: current Progress and Future Perspectives

Botanical preparations for herbal medicine have received more and more attention from drug researchers, and the extraction of active ingredients and their successful clinical application have become an important direction of drug research in major pharmaceutical companies, but the complexity of extracts, multiple side effects, and significant individual differences have brought many difficulties to the clinical application of herbal preparations. It is noteworthy that extracellular vesicles as active biomolecules extracted from medicinal plants are believed to be useful for the treatment of a variety of diseases, including cancer, inflammation, regenerative-restorative and degenerative diseases, which may provide a new direction for the clinical utilization of herbal preparations. In this review, we sort out recent advances in medicinal plant extracellular vesicles and discuss their potential as disease therapeutics. Finally, future challenges and research directions for the clinical translation of medicinal plant extracellular vesicles are also discussed, and we expect that continued development based on medicinal plant extracellular vesicles will facilitate the clinical application of herbal preparations.

Meta-analysis of traditional Chinese medicine on chronic kidney disease

OBJECTIVE

To explore the effect of traditional Chinese medicine (TCM) on the treatment of chronic kidney disease (CKD).

METHODS

Databases were used for literature research until 16 December 2022, including PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Embase. After full-text screening, data were extracted by two researchers independently. The Cochrane ROB tool was applied for quality assessment. The heterogeneity was tested using the Chi-squared-based Q statistic test and the I2 statistic.

RESULTS

The findings revealed that the use of TCM significantly improved the total effective rate (pooled odds ratio (OR) = 1.35, 95% confidence interval (CI) = [1.15, 1.57]), reduced the serum creatinine (SCr) level (pooled mean difference (MD) = -0.11, 95% CI = [-0.20, -0.03]), and increased the estimated glomerular filtration rate (eGFR, pooled MD = 3.76, 95% CI = [2.66, 4.87]) in patients with CKD, compared with non-TCM treatment. Meanwhile, TCM performed better effect on 24-h proteinuria (pooled MD = 0.17, 95% CI = [0.04, 0.31]) than non-TCM. No significant difference in the incidence of adverse events was found between TCM and non-TCM treatment (pooled OR = 0.63, 95% CI = [0.32, 1.24]). Sensitivity analysis demonstrated the stability of the pooled estimates.

CONCLUSION

TCM has the advantage over non-TCM treatment and is worth popularizing and applying in the prevention and cure of CKD.

PROSPERO REGISTRATION NUMBER

CRD42021279281.

Significance of methylation-related genes in diagnosis and subtype classification of renal interstitial fibrosis

BACKGROUND

RNA methylation modifications, such as N1-methyladenosine/N6-methyladenosine /N5-methylcytosine (m¹A/m⁶A/m⁵C), are the most common RNA modifications and are crucial for a number of biological processes. Nonetheless, the role of RNA methylation modifications of m¹A/m⁶A/m⁵C in the pathogenesis of renal interstitial fibrosis (RIF) remains incompletely understood.

METHODS

Firstly, we downloaded 2 expression datasets from the GEO database, namely GSE22459 and GSE76882. In a differential analysis of these datasets between patients with and without RIF, we selected 33 methylation-related genes (MRGs). We then applied a PPI network, LASSO analysis, SVM-RFE algorithm, and RF algorithm to identify key MRGs.

RESULTS

We eventually obtained five candidate MRGs (WTAP, ALKBH5, YTHDF2, RBMX, and ELAVL1) to forecast the risk of RIF. We created a nomogram model derived from five key MRGs, which revealed that the nomogram model may be advantageous to patients. Based on the selected five significant MRGs, patients with RIF were classified into two MRG patterns using consensus clustering, and the correlation between the five MRGs, the two MRG patterns, and the genetic pattern with immune cell infiltration was shown. Moreover, we conducted GO and KEGG analyses on 768 DEGs between MRG clusters A and B to look into their different involvement in RIF. To measure the MRG patterns, a PCA algorithm was developed to determine MRG scores for each sample. The MRG scores of the patients in cluster B were higher than those in cluster A.

CONCLUSIONS

Ultimately, we concluded that cluster A in the two MRG patterns identified on these five key m¹A/m⁶A/m⁵C regulators may be associated with RIF.

Protective effects and regulatory mechanisms of Shen-shuai-yi recipe on renal fibrosis in unilateral ureteral obstruction-induced mice

Renal fibrosis (RF) is a common pathological feature of chronic kidney disease (CKD), which remains a major public health problem. As now, there is still lack of chemical or biological drugs to reverse RF. Shen-shuai-yi Recipe (SSYR) is a classical Chinese herbal formula for the treatment of CKD. However, the effects and mechanisms of SSYR in treating RF are still not clear. In this study, the active constituents SSYR for treating RF were explored by UHPLC-Q-Orbitrap HRMS. Bioinformatics analyses were employed to analyze the key pharmacological targets and the core active constituents of SSYR in the treatment of RF. In experimental validation, vehicle or SSYR at doses of 2.12 g/kg/d and 4.25 g/kg/d were given by orally to unilateral ureteric obstruction (UUO) mice. 13 days after treatment, we detected the severity of renal fibrosis, extracellular collagen deposition and pre-fibrotic signaling pathways. Bioinformatics analysis suggested that signal transducer and activator of transcription 3 (STAT3) was the core target and lenticin, luteolin-7-O-rutinoside, hesperidin, kaempferol-3-O-rutinoside, and 3,5,6,7,8,3',4'-heptamethoxyflavone were the key constituents in SSYR for treating RF. SSYR significantly reduced the expressions of fibronectin (FN), α-smooth muscle actin (α-SMA), collagen-I and alleviated renal interstitial collagen deposition in UUO kidneys. In mechanism, SSYR potently blocked the phosphorylation of STAT3 and Smad3 and suppressed the expression of connective tissue growth factor (CTGF). Collectively, SSYR can ameliorate RF via inhibiting the phosphorylation of STAT3 and its downstream and reducing the collagen deposition, suggesting that SSYR can be developed as a novel medicine for treating RF.

Anti-Fibrotic Effect of Synthetic Noncoding Decoy ODNs for TFEB in an Animal Model of Chronic Kidney Disease

Despite emerging evidence suggesting that autophagy occurs during renal interstitial fibrosis, the role of autophagy activation in fibrosis and the mechanism by which autophagy influences fibrosis remain controversial. Transcription factor EB (TFEB) is a master regulator of autophagy-related gene transcription, lysosomal biogenesis, and autophagosome formation. In this study, we examined the preventive effects of TFEB suppression on renal fibrosis. We injected synthesized TFEB decoy oligonucleotides (ODNs) into the tail veins of unilateral ureteral obstruction (UUO) mice to explore the regulation of autophagy in UUO-induced renal fibrosis. The expression of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and collagen was decreased by TFEB decoy ODN. Additionally, TEFB ODN administration inhibited the expression of microtubule-associated protein light chain 3 (LC3), Beclin1, and hypoxia-inducible factor-1α (HIF-1α). We confirmed that TFEB decoy ODN inhibited fibrosis and autophagy in a UUO mouse model. The TFEB decoy ODNs also showed anti-inflammatory effects. Collectively, these results suggest that TFEB may be involved in the regulation of autophagy and fibrosis and that regulating TFEB activity may be a promising therapeutic strategy against kidney diseases.