Stewed Rhubarb Decoction Ameliorates Adenine-Induced Chronic Renal Failure in Mice by Regulating Gut Microbiota Dysbiosis

Huang Gan Formula Alleviates Systemic Inflammation and Uremia in Adenine-Induced Chronic Kidney Disease Rats May Associate with Modification of Gut Microbiota and Colonic Microenvironment

Purpose

This study aims to investigate the effects of Huang Gan formula (HGF), a Chinese herbal prescription used for chronic kidney disease (CKD), on the regulation of the gut microbiota and colonic microenvironment of CKD.

Methods

CKD rats were induced by 150 mg/kg adenine gavage for 4 weeks, then orally treated with or without 3.6 g/kg or 7.2 g/kg of HGF for 8 weeks. The renal function and structure were analyzed by biochemical detection, hematoxylin and eosin, Masson's trichrome, Sirius red and immunochemical staining. Average fecal weight and number in the colon were recorded to assess colonic motility. Further, the changes in the gut microbiota and colonic microenvironment were evaluated by 16S rRNA sequencing, RT-PCR or immunofluorescence. The levels of inflammatory cytokines, uremic toxins, and NF-κB signaling pathway were detected by RT-PCR, ELISA, chloramine-T method or Western blotting. Redundancy analysis biplot and Spearman's rank correlation coefficient were used for correlation analysis.

Results

HGF significantly improved renal function and pathological injuries of CKD. HGF could improve gut microbial dysbiosis, protect colonic barrier and promote motility of colonic lumens. Further, HGF inhibited systemic inflammation through a reduction of TNF-α, IL-6, IL-1β, TGF-β1, and a suppression of NF-κB signaling pathway. The serum levels of the selected uremic toxins were also reduced by HGF treatment. Spearman correlation analysis suggested that high-dose HGF inhibited the overgrowth of bacteria that were positively correlated with inflammatory factors (eg, TNF-α) and uremic toxins (eg, indoxyl sulfate), whereas it promoted the proliferation of bacteria belonging to beneficial microbial groups and was positively correlated with the level of IL-10.

Conclusion

Our results suggest that HGF can improve adenine-induced CKD via suppressing systemic inflammation and uremia, which may associate with the regulations of the gut microbiota and colonic microenvironment.

Sesamolin Attenuates Kidney Injury, Intestinal Barrier Dysfunction, and Gut Microbiota Imbalance in High-Fat and High-Fructose Diet-Fed Mice

This study investigated the effects of sesamolin on kidney injury, intestinal barrier dysfunction, and gut microbiota imbalance in high-fat and high-fructose (HF-HF) diet-fed mice and explored the underlying correlations among them. The results indicated that sesamolin suppressed metabolic disorders and increased renal function parameters. Histological evaluation showed that sesamolin mitigated renal epithelial cell degeneration and brush border damage. Meanwhile, sesamolin inhibited the endotoxin-mediated induction of the Toll-like receptor 4-related IKKα/NF-κB p65 pathway activation. Additionally, sesamolin mitigated intestinal barrier dysfunction and improved the composition of gut microbiota. The correlation results further indicated that changes in the dominant phyla, including Firmicutes, Deferribacterota, Desulfobacterota, and Bacteroidota, were more highly correlated with a reduction in endotoxemia and metabolic disorders, as well as decreases in intestinal proinflammatory response and related renal risk biomarkers. The results of this study suggest that sesamolin attenuates kidney injuries, which might be associated with its effects on the reduction of endotoxemia and related metabolic disorders through the restoration of the intestinal barrier and the modulation of gut microbiota. Thus, sesamolin may be a potential dietary supplement for protection against obesity-associated kidney injury.

Clinical effect of rhubarb on the treatment of chronic renal failure: A meta-analysis

Objective: 1) To evaluate the effificacy of rhubarb in the treatment of chronic renal failure (CRF); 2) To explore the safety for rhubarb-based therapy on chronic renal failure. Methods: The randomized and semi randomized controlled trials of Rhubarb in the treatment of chronic renal failure in medical electronic databases (up to September 2021) were searched, and meta-analysis was carried out by revman 5.3 software. Results: A total of 2,786 patients were included in 34 literatures, including 1,474 cases in the treatment group and 1,312 cases in the control group. The results of meta-analysis showed that Serum creatinine (SCR) [MD = 123.57, 95% Cl (111.59, 131.96)], Blood urea nitrogen (BUN) [MD = -3.26, 95% Cl (-4.22,-2.31)], Creatinine clearance rate (CCR) [MD = 3.95, 95% Cl (-0.03, 7.93)], Hemoglobin (Hb) [MD = 7.70, 95% Cl (-0.18, 15.58)] and Uric acid (UA) [MD = -42.79, 95% CI (-66.29, -19.29)]. The total effective rate of improving symptoms and signs in chronic renal failure patients [Peto or = 4.14, 95% Cl (3.32, 5.16)]. Conclusion: This systematic review and meta-analysis demonstrated that rhubarb has a positive therapeutic effect, which may provide confifidence and some theoretical reference for clinical application to a certain extent. Compared with the control group, rhubarb alone or traditional Chinese medicine compound containing Rhubarb can significantly reduce Serum creatinine, Blood urea nitrogen and Uric acid, increase Creatinine clearance rate, and improve the total effective rate of symptoms and signs. However, there is no evidence that rhubarb is more effective than the control group in increasing hemoglobin. In addition, due to the low quality of research methodology in the included literature, it is necessary to further study high-quality literature to evaluate its efficacy and safety. Systematic Review Registration: https://inplasy.com/inplasy-2021-10-0052/, identifier INPLASY2021100052.

Emodin ameliorates renal injury and fibrosis via regulating the miR-490-3p/HMGA2 axis

Renal fibrosis is a major pathological feature of chronic kidney disease (CKD). While emodin is reported to elicit anti-fibrotic effects on renal injury, little is known about its effects on microRNA (miRNA)-modulated mechanisms in renal fibrosis. In this study, we established a unilateral ureteral obstruction (UUO) model and a transforming growth factor (TGF)-β1-induced normal rat renal tubular epithelial cell line (NRK-52E) model to investigate the protective effects of emodin on renal fibrosis and its miRNA/target gene mechanisms. Dual-luciferase assay was performed to confirm the direct binding of miRNA and target genes in HEK293 cells. Results showed that oral administration of emodin significantly ameliorated the loss of body weight and the increase in physicochemical parameters, including serum uric acid, creatinine, and urea nitrogen in UUO mice. Inflammatory cytokines, including tumor necrosis factor-α, monocyte chemoattractant protein-1, and interleukin (IL)-1β, but not IL-6, were down-regulated by emodin administration. Emodin decreased the expression levels of TGF-β1 and fibrotic-related proteins, including alpha-smooth muscle actin, Collagen IV, and Fibronectin, and increased the expression of E-cadherin. Furthermore, miR-490-3p was decreased in UUO mice and negatively correlated with increased expression of high migration protein A2 (HMGA2). We further confirmed HMGA2 was the target of miR-490-3p. Transfection of miR-490-3p mimics decreased, while transfection of miR-490-3p inhibitors increased fibrotic-related proteins and HMGA2 expression levels in TGF-β1-induced NRK-52E cells. Furthermore, transfection of miR-490-3p mimics enhanced the anti-fibrotic effects of emodin, while transfection of miR-490-3p inhibitors abolished the protective effects of emodin. Thus, as a novel target of emodin that prevents renal fibrosis in the HMGA2-dependent signaling pathway, miR-490-3p has potential implications in CKD pathology.