A standardized pomegranate fruit extract ameliorates thioacetamide-induced liver fibrosis in rats via AGE-RAGE-ROS signaling

Pathological role of RAGE underlying progression of various diseases: its potential as biomarker and therapeutic target

The receptor for advanced glycation end products (RAGE) is a multi-ligand receptor with several structural types, performing a myriad of molecular mechanisms. The RAGE-ligand interactions play important roles in maintaining latent chronic inflammation, and oxidative damage underlying various pathological conditions like metabolic syndrome (MetS), neurodegenerative diseases, stroke, cardiovascular disorders, pulmonary disorders, cancer and infections. RAGE is thoroughly explored in knockout animals and human trials, targeted by small molecule inhibitors, peptides, diet, and natural compounds. But it is yet to be incorporated in the mainstream management of any ailment. This review performs an appraisal of the pathological mechanisms influenced by RAGE to uncover its prospects as a biomarker while also assessing its power to become a promising therapeutic target.

Targeting angiogenic and proliferative mediators by montelukast & trimetazidine Ameliorates thioacetamide-induced liver fibrosis in rats

Liver fibrosis is a significant health complication with the potential to result in serious mortality and morbidity. However, there is no standard treatment due to its complex pathogenesis. The drug montelukast reversibly and selectively antagonizes the cysteinyl-leukotrienes-1 receptor and reduces inflammation; thus, it is used in the treatment of asthma. Trimetazidine, an anti-anginal agent, selectively inhibits the activity of mitochondrial long-chain 3-ketoacyl-CoA thiolase, inhibition of free fatty acid (FFA) oxidation. This study explores the efficacy of montelukast (5 and 10 mg/kg) and trimetazidine (10-20 mg/kg) against liver fibrosis induced by thioacetamide (TAA) in rats. Impaired liver function tests were significantly improved by montelukast and trimetazidine. The antioxidant and anti-inflammatory effects of montelukast and trimetazidine were proved by the inhibition of malondialdehyde (MDA) and nitric oxide (NO) accumulation, with elevation of glutathione (GSH) and superoxide dismutase activity, decreased heat shock protein (HSP-70) expression, and a decline in interleukin-6 (IL-6) and tumor necrosis factor (TNF-α) levels in liver tissue. Also, the antifibrotic effects were explored by reducing levels of hydroxyproline and alpha-smooth muscle actin (α-SMA) expression in liver tissue and attenuating hepatic expression of hepatic expression of angiogenic mediator vascular endothelium growth factor (VEGF) and proliferative mediator Antigen Kiel 67 (Ki-67).

PHB2 alleviates retinal pigment epithelium cell fibrosis by suppressing the AGE-RAGE pathway

Fibrosis is the primary cause of retinal detachment and visual decline. Here, we investigated the role of Prohibitin 2 (PHB2) in modulating fibrosis in ARPE-19 cells stimulated by transforming growth factor (TGF)-β2. The proliferation, migration, and apoptosis of ARPE-19 cells were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing, and flow cytometry assays, and levels of fibrosis-associated and pathway-related proteins were determined by performing western blotting. To examine the mechanisms underlying ARPE-19 cell fibrosis, we performed RNA sequencing, protein-protein interaction network, and enrichment analyses. We detected increases in the expression of the fibrosis-related proteins fibronectin and collagen I in response to TGF-β2 treatment, whereas the expression of PHB2 was downregulated. PHB2 overexpression suppressed the proliferation and migration of TGF-β2-stimulated ARPE-19 cells, promoted apoptosis, and inhibited fibrosis and Smad and non-Smad pathways. PHB2 overexpression inhibited the advanced glycation end-product (AGE)-receptor of advanced glycation end-product (RAGE) pathway activated by TGF-β2 treatment, which contributed to enhancing the effects of PHB2 on cellular processes, fibrosis, and Smad and non-Smad pathways. Conversely, exogenous application of AGE counteracted the effects of PHB2 overexpression. We conclude that by suppressing the AGE-RAGE pathway, PHB2 exerts an inhibitory effect on TGF-β2-induced fibrosis in ARPE-19 cells.

Hepatoprotective effects of the xanthine oxidase inhibitor Febuxostat against thioacetamide-induced liver injury in rats: The role of the Nrf2/ HO-1 and TLR4/ NF-κB pathways

Experimental models of liver injury have been established utilizing thioacetamide (TAA), a classic liver toxic chemical that causes organ damage via oxidative stress and inflammatory induction. This study examined the impact of Febuxostat (a xanthine oxidase inhibitor; Febu, 10-15 mg/kg, orally) against TAA (500 mg/kg, i.p.) -induced liver injury in rats. Febu significantly attenuated TAA-induced alterations in liver function parameters, in addition to promoting hepatic antioxidant effects through a significant elevation of Heme-oxygenase-1(HO-1), nuclear factor erythroid 2-related factor2 (Nrf2), reduced glutathione (GSH) and superoxide dismutase (SOD) levels and reduction in hepatic malondialdehyde (MDA) content. Moreover, Febu improved the hepatic anti-inflammatory status by increasing the anti-inflammatory cytokine Interleukin (IL-10) level and reducing the levels of the pro-inflammatory cytokines (Nuclear factor kappa B (NF-κB), IL-1β, high-mobility group box1 (HMGB1), receptor for advanced glycation end products (RAGE), and toll-like receptor4 (TLR4) levels, in addition to suppressing the increased protein and mRNA expression levels of tumor necrosis factor alpha (TNF-α) and IL-6, hepatic expression of TNF-α and activated mitogen-activated protein kinases (p-JNK/p-p38 MAPK). Histopathologically, Febu markedly normalized TAA-induced alteration in liver sections. In conclusion, Febu, in a dose-dependent fashion, refines TAA-induced hepatotoxicity by enhancing antioxidant capabilities and decreasing inflammatory signals.

The effects of pomegranate (Punica granatum) on nonalcoholic fatty liver disease: A systematic review of in vivo interventional studies

Nonalcoholic fatty liver disease (NAFLD) is a disorder in which excess fat accumulates in hepatocytes and can lead to serious complications. Oxidative stress is one of the leading causes of NAFLD. Pomegranates are considered antioxidant-rich fruit. This systematic review study was aimed to investigate the impact of pomegranate on NAFLD. PubMed, Scopus, and Google Scholar databases/search engines (from inception up to July 2023) were searched for interventional studies (human and animal) that examined the effects of supplementation with different parts of pomegranate including fruits, peels, seeds, or flower on NAFLD outcomes. A total of 222 articles were retrieved following the initial search. After excluding duplicates, the title and abstract of 114 articles were screened. Afterward, irrelevant articles were removed and the full texts of the remaining 27 articles were reviewed. Eventually, 19 articles (16 animal and three human interventional studies) that met the inclusion criteria, published between 2009 and 2023, were included in this systematic review. Our study indicates the potential beneficial effects of different parts of pomegranate on the improvement of NAFLD. However, given that the majority of the included articles were animal studies, further investigations in the form of human clinical trials are warranted to suggest a clinical indication of such interventions.

Silymarin and MSC-exosomes ameliorate thioacetamide-evoked renal fibrosis by inhibiting TGF-β/SMAD pathway in rats

BACKGROUND

TGF-β1 and SMAD3 are particularly pathogenic in the progression of renal fibrosis.

AIM

This study aimed to evaluate the kidney protective potentials of silymarin (SM) and exosomes of mesenchymal stem cells against the nephrotoxin thioacetamide (TAA) in rats.

METHODS

32 female rats were randomly assigned into four groups: the control group, the TAA group, the TAA + SM group, and the TAA + Exosomes group. The kidney homogenates from all groups were examined for expression levels of TGF-β receptors I and II using real-time PCR, expression levels of collagen type I and CTGF proteins using ELISA, and the expression levels of nuclear SMAD2/3/4, cytoplasmic SMAD2/3, and cytoplasmic SMAD4 proteins using the western blot technique.

RESULTS

Compared to the control group, the injection of TAA resulted in a significant increase in serum levels of urea and creatinine, gene expression levels of TβRI and TβRII, protein expression levels of both collagen I and CTGF proteins, cytoplasmic SMAD2/3 complex, and nuclear SMAD2/3/4 (p-value < 0.0001), with significantly decreased levels of the co-SMAD partner, SMAD4 (p-value < 0.0001). Those effects were reversed considerably in both treatment groups, with the superiority of the exosomal treatment regarding the SMAD proteins and the expression levels of the TβRI gene, collagen I, and CTGF proteins returning to near-control values (p-value > 0.05).

CONCLUSION

Using in vitro and in vivo experimental approaches, the research discovered a reno-protective role of silymarin and exosomes of BM-MSCs after thioacetamide-induced renal fibrosis in rats, with the advantage of exosomes.