Therapeutic Effect of Melatonin on CCl4-Induced Fibrotic Liver Model by Modulating Oxidative Stress, Inflammation, and TGF-β1 Signaling Pathway in Pinealectomized Rats

The study aimed to determine the CCl4-induced liver fibrosis model in pinealectomized rats and biochemically, immunohistochemically, and histopathologically investigate the therapeutic effect of melatonin on liver fibrosis. The surgical procedure for pinealectomy was performed at the beginning of the study, and the sham and pinealectomized rats were administered CCl4 dissolved in corn oil (1:1) alone every other day to induce liver fibrosis or together with melatonin (10 mg/kg) therapy for 15 days. Melatonin is an essential therapeutic agent and offers an alternative therapeutic strategy in CCl4-induced liver fibrosis by suppressing inflammation, oxidative stress, and the TGF-β1 signaling pathway. Treatment with melatonin ameliorated CCl4-induced liver fibrosis by restoring hepatocellular damage and reducing plasma AST, ALT, and ALP values. Melatonin increases the activity of SOD and CAT, which are important enzymes for antioxidant defence, and raises GSH levels, which further enhances antioxidant function. Also, melatonin reduced hepatic inflammation (IL-6 and IL-1β) and oxidative stress indices. Moreover, histopathological changes and immunohistochemical expression of TGF-β1 were restored following melatonin supplementation in the CCl4-induced liver fibrosis model in pinealectomized rats. Our study shows that melatonin supplementation has a beneficial effect in protecting the liver fibrosis induced by CCl4 in pinealectomized rats.

Silymarin enriched gelatin methacrylamide bioink imparts hepatoprotectivity to 3D bioprinted liver construct against carbon tetrachloride induced toxicity

Three-dimensional liver bioprinting is an emerging technology in the field of regenerative medicine that aids in the creation of functional tissue constructs that can be used as transplantable organ substitutes. During transplantation, the bioprinted donor liver must be protected from the oxidative stress environment created by various factors during the transplantation procedure, as well as from drug-induced damage from medications taken as part of the post-surgery medication regimen following the procedure. In this study, Silymarin, a flavonoid with the hepatoprotective properties were introduced into the GelMA bioink formulation to protect the bioprinted liver against hepatotoxicity. The concentration of silymarin to be added in GelMA was optimised, bioink properties were evaluated, and HepG2 cells were used to bioprint liver tissue. Carbon tetrachloride (CCl4) was used to induce hepatotoxicity in bioprinted liver, and the effect of this chemical on the metabolic activities of HepG2 cells was studied. The results showed that Silymarin helps with albumin synthesis and shields liver tissue from the damaging effects of CCl4. According to gene expression analysis, CCl4 treatment increased TNF-α and the antioxidant enzyme SOD expression in HepG2 cells while the presence of silymarin protected the bioprinted construct from CCl4-induced damage. Thus, the outcomes demonstrate that the addition of silymarin in GelMA formulation protects liver function in toxic environments.

Zinc-loaded whey protein nanoparticles alleviate the oxidative damage and enhance the gene expression of inflammatory mediators in rats

BACKGROUND

Zinc (Zn) is an essential trace element required for the function of the immune system. However, Zn fortification of food has faced some challenges, although excess Zn may be induced obesity and other related. This study aimed to use Zn-loaded whey protein nanoparticles (Zn-WPNPs) to enhance the immunomodulatory activity of Zn in rats treated with CCl₄.

METHODS

Zn was loaded to WPNPs at a level of 14 mg/g. Four experimental groups of male albino Wistar rats were treated for 30 days including the control group, CCl₄-treated group (0.5 ml/100 g b.w), Zn plus CCl₄-treated group (50 mg/kg b.w), and CCl₄ plus Zn-WPNPs-treated group (50 mg/kg b.w). Blood and tissue samples were collected for different assays and histological examinations.

RESULTS

The results revealed that CCl₄ disturbs the serum biochemical, hematological, and immune indicators in different organs besides the liver as a target organ. Animals that received CCl₄ showed a significant increase in oxidative stress markers, cytokines, and the mRNA expression of inflammatory mediators in the lung and spleen accompanied by a significant decrease in the hepatic and renal antioxidant enzymes along with histological changes in the liver, kidney, spleen, and lung. Zn or Zn-WPNPs could improve these parameters and the histological picture of the tested organs and Zn-WPNPs were more effective than Zn alone.

CONCLUSION

WPNPs induced synergistic immune-modulating effects which may control Zn release and may be a suitable candidate to enhance the immune system during any pandemic or the exposure to any chemicals that affect the immune system.

Crocin attenuates CCl4-induced liver fibrosis via PPAR-γ mediated modulation of inflammation and fibrogenesis in rats

BACKGROUND

Liver fibrosis is a chronic pathological condition with a leading cause of liver-related mortality worldwide. In the present study, we have evaluated the antifibrotic effect of crocin, a carotenoid present in the stigma of Crocus sativus, and also explored its putative mechanism of action.

METHODS

Liver fibrosis was induced by intraperitoneal administration of 30% carbon tetrachloride (CCl₄). The crocin was administered orally at 20, 40 and 80 mg/kg body weight along with CCl₄ up to 8 weeks.

RESULTS

Chronic exposure to CCl₄ resulted in elevated levels of liver enzymes and reduced cytochrome P450 2E1 (CYP2E1) activity in the liver. The liver tissue showed cellular swelling, vacuolization, necrosis, infiltration of inflammatory cells and fibrotic changes. The crocin treatment significantly lowered the levels of liver enzymes in serum and improved the liver CYP2E1 mRNA levels. The pathological changes in the liver were also lowered by crocin treatment. The level of pro-inflammatory cytokines, nuclear factor-kappa B, interleukin-6 and tumor necrosis factor α and fibrogenic factor, transforming growth factor β, and α-smooth muscle actin were elevated by the CCl₄ in the liver tissue. However, crocin treatment at different doses significantly reduced the expression of these factors. The increased caspase 3/7 activity was also lowered by crocin. CCl₄ administration decreased the expression of peroxisome proliferator-activated receptor γ (PPAR-γ) in liver tissue. The improved PPAR-γ expression in the liver by crocin treatment indicates its role in the therapeutic effect of crocin.

CONCLUSIONS

Crocin attenuated the various events in the progression of liver fibrosis via PPAR-γ mediated modulation of inflammatory and fibrogenic pathways.