Centella asiatica Extract Attenuates Kidney Fibrosis Through Reducing Mesenchymal Transition and Inflammation in Ureteral Ligation Model in Mice

Advance on Chinese Medicine for Hypertensive Renal Damage: Focus on the Complex Molecular Mechanisms

Hypertensive renal damage (HRD) is a major cause of end-stage renal disease. Among the causes of end-stage renal disease, HRD accounts for nearly 34% of the total number of cases. Antihypertensive treatment is primarily drug-based, but therapeutic efficacy is less effective and can have serious side effects. Chinese medicine (CM) has significant advantages in the treatment of HRD. CM is rich in various active ingredients and has the property of targeting multiple targets and channels. Therefore, the regulatory network of CM on disease is complex. A large number of CM have been employed to treat HRD, either as single applications or as part of compound formulations. The key possible mechanisms of CM for HRD include regulation of the renin-angiotensin-aldosterone system, antioxidation, anti-inflammation, rescue of endothelial function, regulation of vasoactive substance secretion and obesity-related factors, etc. This review summarized and discussed the recent advance in the basic research mechanisms of CM interventions for HRD and pointed out the challenges and future prospects.

Centella asiatica ameliorates AlCl3 and D-galactose induced nephrotoxicity in rats via modulation of oxidative stress

Nephrotoxicity is a condition caused by toxic effects of medications and poisons resulting in the rapid decline of kidney function. Centella asiatica is a medicinal herb with antioxidative and anti-inflammatory characteristics that is used to treat a variety of ailments. The present study intends to explore the ability of Centella asiatica in preventing AlCl3 and D-Galactose-induced nephrotoxicity in rats. In this study 30 male albino Wistar rats were induced with nephrotoxicity using AlCl3 and D-galactose, and oral administration of Centella asiatica extract (100, 200, and 300mg/kg/day) was administered for 70 days. The kidneys were extracted after treatment and levels of oxidative and antioxidative enzymes, serum creatinine, and serum albumin were measured. The kidney's histopathological changes were studied. Administration of Centella asiatica extract significantly increased serum albumin, superoxide dismutase (SOD), and catalase levels in kidney homogenates while suppressing serum creatinine and malondialdehyde (MDA) levels and attenuating histopathological changes associated with nephrotoxicity. Centella asiatica extract lowered serum creatinine and oxidative stress levels in a drug-induced nephrotoxicity rat model, while simultaneously increasing serum albumin levels, as evidenced by mitigation of histological changes and normalisation of biomarkers of oxidative stress in the kidney.

Guben Xiezhuo Decoction inhibits M1 polarization through the Raf1/p-Elk1 signaling axis to attenuate renal interstitial fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Guben Xiezhuo Decoction (GBXZD) is an herbal compound used to treat chronic kidney disease (CKD) under the guidance of traditional Chinese medicine (TCM). Its main components are Astragalus membranaceus (Fisch.) Bunge, Codonopsis pilosula (Franch.) Nannf., Centella asiatica (L.) Urb., Salvia miltiorrhiza Bunge, Cuscuta chinensis Lam., and Rheum palmatum L.. Clinical studies have shown that it can relieve fatigue, nausea and other symptoms and improve kidney function in patients; however, its specific mechanism of action requires further study.

AIM OF THE STUDY

Renal interstitial fibrosis (RIF) is the ultimate characteristic manifestation of various CKD, that cannot be cured, and appropriate treatments to delay its progression require further exploration. GBXZD, widely used in clinical practice for RIF treatment, can effectively relieve the syndrome in patients with CKD. However, the specific mechanism of action of GBXZD in RIF is unknown and requires further study. This study aimed to explore the specific effects of GBXZD on RIF through the regulation of M1 macrophages.

MATERIALS AND METHODS

An in vivo RIF model was obtained through unilateral ureteral obstruction (UUO), and the Sprague-Dawley (SD) rats were randomly divided into sham operation, UUO, UUO + GBXZD-low dose (GBXZD-L) and UUO + GBXZD-high dose (GBXZD-H) groups. Pathological changes in rat kidney specimens were observed using hematoxylin and eosin (HE) and Masson staining. The expression of collagen I (COL I), fibronectin (FN), α-smooth muscle actin (α-SMA), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α) was detected using immunohistochemistry, and immunofluorescence was used to detect the expression of CD86 and inducible nitric-oxide synthase (iNOS) in kidney tissue. An in vitro experiment was performed using M1 polarization model in RAW264.7 macrophages induced by lipopolysaccharide (LPS). Cells were divided into control, LPS, LPS + GBXZD-low dose (GBXZD-L) and LPS + GBXZD-high dose (GBXZD-H) groups. The changes in expression of CD86, iNOS, IL-1β, IL-6, and TNF-α were measured using western blotting, flow cytometry, immunofluorescence and enzyme-linked immunosorbent assay (ELISA). We analyzed the action pathway of GBXZD in regulating M1 polarization of macrophages using antibody microarray and verified the results using western blotting.

RESULTS

Histopathological results showed that the UUO group exhibited significant fibrotic injury compared to the sham group. After GBXZD treatment, the degree of kidney injury, RIF, and inflammatory factor expression were lower than those in the UUO group. Compared with LPS-treated cells, the expression of the M1 markers CD86, iNOS, and pathway proteins Raf1 and p-Elk1 was down-regulated in RAW 264.7 cells treated with LPS and GBXZD. The secretion of the inflammatory factors IL-1β, IL-6, and TNF-α in the LPS group was more than that in the control group. However, the levels of these factors were significantly reduced in the GBXZD-H group compared to those in the LPS group.

CONCLUSIONS

This study indicates that GBXZD ameliorates RIF and inhibits the inflammatory response and macrophage M1 polarization by a potential mechanism related to the downregulation of Raf1 and p-Elk1. GBXZD therefore has therapeutic potential value for patients with CKD.

The Renoprotective Effect of Shikonin in a Rat Model of Diabetic Kidney Disease

BACKGROUND

In diabetes mellitus, diabetic nephropathy (DN) is a typical complication and pivotal cause of chronic kidney disease. The DN disease burden is among the highest in the world and is associated with high morbidity, mortality, and disease burden. Safe and effective medications are urgently needed for the treatment of DN. Interest has been increasing in Shikonin, extracted from the naphthoquinone plant, particularly in determining its renal protective effect.

METHODS

In this study, we explored Shikonin's effects and potential mechanisms on a streptozotocin (STZ)-induced DN experimental model. An STZ-induced rat diabetic model was established, and the rats were treated with different doses of Shikonin (10/50 mg/kg) for 4 weeks. Blood, urine, and renal tissue samples were collected after the last administration. Renal tissues were examined to detect each group's physiologic, biochemical, histopathologic, and molecular changes.

RESULTS

The results showed that Shikonin administration could significantly alleviate the STZ-induced elevation of blood urea nitrogen, serum creatinine, urinary protein content, and renal pathologic injury. Furthermore, Shikonin significantly decreased oxidative stress, inflammation, and Toll-like receptor 4/myeloid differentiation primary response 88/nuclear factor-κB expression levels in DN kidney tissues. Shikonin showed a dose-dependent effect, with the best outcome at 50 mg/kg.

CONCLUSION

Shikonin could effectively alleviate DN-related nephropathy damage and reveal the underlying pharmacologic mechanism. Based on the results, a Shikonin combination can be used in clinical treatment.

Acteoside alleviates UUO-induced inflammation and fibrosis by regulating the HMGN1/TLR4/TREM1 signaling pathway

PURPOSE

Acteoside (Act), a phenylethanoid compound that was first isolated from mullein, has been widely used for the investigation of anti-inflammatory and anti-fibrotic effect. However, the mechanism of Act against unilateral ureteral obstruction (UUO)-mediated renal injury is largely unknown. Therefore, this study aimed to explore the effects of Act on UUO rats and possible mechanisms.

METHODS

A total of 20 Sprague-Dawley (SD) rats were divided randomly into three groups (n ≥ 6): (i) sham-operated group (Sham); (ii) UUO group (UUO+Saline); and (iii) UUO + Act 40 mg/kg/day, (UUO+Act); Continuous gavage administration for 2 weeks postoperatively, while the rats in Sham and UUO+saline groups were given equal amounts of saline. All rats were sacrificed after 14 days, the urine and blood samples were collected for biochemical analysis, the renal tissues were collected for pathological staining and immunohistochemistry. Correlations between individual proteins were analyzed by Pearson correlation analysis.

RESULTS

The results of renal function indexes and histopathological staining showed that Act could improve renal function by reducing serum creatinine, blood urea nitrogen and urine protein at the same time, Act could alleviate renal inflammation and fibrosis. In addition, the results of immunohistochemistry showed that Act could reduce the expression of inflammation and kidney injury-related proteins F4/80, Mcp-1, KIM-1 proteins, as well as the expression of fibrosis-related protein α-SMA and β-catenin. More importantly, Act can also reduce the expression of HMGN1, TLR4 and TREM-1 proteins.

CONCLUSION

These data demonstrate that Act can ameliorate UUO-induced renal inflammation and fibrosis in rats probably through triggering HMGN1/TLR4/TREM-1 pathway.

Proteomic analysis exploring the mechanism of bladder fibrosis induced by ketamine using a rat model

Background

Long-term abuse of ketamine can cause irreversible bladder fibrosis, but the mechanism of bladder fibrosis is still under investigation. This study aims to explore the mechanism of bladder fibrosis utilizing proteomic analysis in a rat model.

Methods

After building a rat model, hematoxylin and eosin (HE) staining, Masson’s trichrome staining, and western blotting (WB) of collagen I were used to assess bladder pathology and fibrosis in a rat model. Next, protein expression changes in the rat bladder by proteomic technology were quantitatively detected, and reverse transcription-polymerase chain reaction (RT-PCR) and WB were used to verify the expression of proteins. Bioinformatic techniques and functional analysis were also performed.

Results

Compared to the control group, thinning of the bladder epithelium layer, infiltration of submucosal inflammatory cells, deposition of many collagen fibers, and an elevated expression of collagen I were observed in the experimental group. A total of 3,690 proteins were identified, of which 423 proteins were upregulated, and 304 proteins were down-regulated. Eight out of ten mRNA expressions and acyloxyacyl hydrolase (AOAH), mast cell (MC) protease 1 protein expressions were in line with the proteomic results. Sixty-five differential expression proteins (DEPs) were found to belong to the immune system, and 18 of them were involved in immune diseases, according to KEGG analysis.

Conclusions

We consider that MC protease 1 and platelet activation pathways may play an important role in ketamine-induced bladder fibrosis.