Curcumin, quercetin and atorvastatin protected against the hepatic fibrosis by activating AMP-activated protein kinase

A role for curcumin in preventing liver fibrosis in animals: a systematic review and meta-analysis

Objective

This meta-analysis aimed to determine the efficacy of curcumin in preventing liver fibrosis in animal models.

Methods

A systematic search was conducted on studies published from establishment to November 2023 in PubMed, Web of Science, Embase, Cochrane Library, and other databases. The methodological quality was assessed using Sycle's RoB tool. An analysis of sensitivity and subgroups were performed when high heterogeneity was observed. A funnel plot was used to assess publication bias.

Results

This meta-analysis included 24 studies involving 440 animals with methodological quality scores ranging from 4 to 6. The results demonstrated that curcumin treatment significantly improved Aspartate aminotransferase (AST) [standard mean difference (SMD) = -3.90, 95% confidence interval (CI) (-4.96, -2.83), p < 0.01, I2 = 85.9%], Alanine aminotransferase (ALT)[SMD = - 4.40, 95% CI (-5.40, -3.40), p < 0.01, I2 = 81.2%]. Sensitivity analysis of AST and ALT confirmed the stability and reliability of the results obtained. However, the funnel plot exhibited asymmetry. Subgroup analysis based on species and animal models revealed statistically significant differences among subgroups. Furthermore, curcumin therapy improved fibrosis degree, oxidative stress level, inflammation level, and liver synthesis function in animal models of liver fibrosis.

Conclusion

Curcumin intervention not only mitigates liver fibrosis but also enhances liver function, while concurrently modulating inflammatory responses and antioxidant capacity in animal models. This result provided a strong basis for further large-scale animal studies as well as clinical trials in humans in the future. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42024502671.

Functional Food Chemical Ingredient Strategies for Non-alcoholic Fatty Liver Disease (NAFLD) and Hepatic Fibrosis: Chemical Properties, Health Benefits, Action, and Application

PURPOSE OF REVIEW

The liver is an important digestive gland in the body. Lifestyle and dietary habits are increasingly damaging our liver, leading to various diseases and health problems. Non-alcoholic fatty liver disease (NAFLD) has become one of the most serious liver disease problems in the world. Diet is one of the important factors in maintaining liver health. Functional foods and their components have been identified as novel sources of potential preventive agents in the prevention and treatment of liver disease in daily life. However, the effects of functional components derived from small molecules in food on different types of liver diseases have not been systematically summarized.

RECENT FINDINGS

The components and related mechanisms in functional foods play a significant role in the development and progression of NAFLD and liver fibrosis. A variety of structural components are found to treat and prevent NAFLD and liver fibrosis through different mechanisms, including flavonoids, alkaloids, polyphenols, polysaccharides, unsaturated fatty acids, and peptides. On the other hand, the relevant mechanisms include oxidative stress, inflammation, and immune regulation, and a large number of literature studies have confirmed a close relationship between the mechanisms. The purpose of this article is to examine the current literature related to functional foods and functional components used for the treatment and protection against NAFLD and hepatic fibrosis, focusing on chemical properties, health benefits, mechanisms of action, and application in vitro and in vivo. The roles of different components in the biological processes of NAFLD and liver fibrosis were also discussed.

AMP-activated protein kinase: An energy sensor and survival mechanism in the reinstatement of metabolic homeostasis

Cells are programmed to favorably respond towards the nutrient availability by adapting their metabolism to meet energy demands. AMP-activated protein kinase (AMPK) is a highly conserved serine/threonine energy-sensing kinase. It gets activated upon a decrease in the cellular energy status as reflected by an increased AMP/ATP ratio, ADP, and also during the conditions of glucose starvation without change in the adenine nucelotide ratio. AMPK functions as a centralized regulator of metabolism, acting at cellular and physiological levels to circumvent the metabolic stress by restoring energy balance. This review intricately highlights the integrated signaling pathways by which AMPK gets activated allosterically or by multiple non-canonical upstream kinases. AMPK activates the ATP generating processes (e.g., fatty acid oxidation) and inhibits the ATP consuming processes that are non-critical for survival (e.g., cell proliferation, protein and triglyceride synthesis). An integrated signaling network with AMPK as the central effector regulates all the aspects of enhanced stress resistance, qualified cellular housekeeping, and energy metabolic homeostasis. Importantly, the AMPK mediated amelioration of cellular stress and inflammatory responses are mediated by stimulation of transcription factors such as Nrf2, SIRT1, FoxO and inhibition of NF-κB serving as main downstream effectors. Moreover, many lines of evidence have demonstrated that AMPK controls autophagy through mTOR and ULK1 signaling to fine-tune the metabolic pathways in response to different cellular signals. This review also highlights the critical involvement of AMPK in promoting mitochondrial health, and homeostasis, including mitophagy. Loss of AMPK or ULK1 activity leads to aberrant accumulation of autophagy-related proteins and defective mitophagy thus, connecting cellular energy sensing to autophagy and mitophagy.

Thymoquinone and quercetin protect against hepatic steatosis in association with SIRT1/AMPK stimulation and regulation of autophagy, perilipin-2, and cytosolic lipases

BACKGROUND

We sought to investigate thymoquinone (TQ)/quercetin combination in preventing hepatic steatosis (HS).

MATERIALS AND METHODS

The included rat groups; (1) Control, (2) HS model, (3) HS treated with TQ 10 mg.kg^-1.d^-1, (4) HS treated with quercetin 50 mg.kg^-1.d^-1, and (5) HS treated with both compounds for 4 weeks.

RESULTS

TQ/quercetin co-treatment augmented the anti-steatosis potential of each ingredient. The results revealed more (p < 0.001) sirtuin (SIRT1)/AMP-activated protein kinase (p-AMPK) upregulation compared to each treatment in line with autophagy protein Atg7 enhancement, and suppressed pro-inflammatory and oxidation markers. They diminished the hepatic lipogenic enzymes and perilipin-2 and activated the cytosolic lipases adipose triglyceride lipase (ATGL). Histological and Biochemical analysis revealed diminished lipid deposition and improved liver enzymes (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) compared to the data of separate treatments.

CONCLUSION

TQ and quercitin effectively upregulated SIRT1/p-AMPK and regulated hepatic perilipin-2/ATGL, inflammation and oxidative stress, preserved liver structure and function. TQ/quercetin combination additively prevents HS.

Evaluation of statins as a new therapy to alleviate chronotropic dysfunction in cirrhotic rats

AIMS

Liver cirrhosis defines by regenerative nodules and fibrotic septa, causing a complication called cirrhotic cardiomyopathy (CCM) with chronotropic hypo-responsiveness. In addition to lowering cholesterol levels, statins yield antioxidant and anti-inflammatory effects. In liver diseases animal models, statins have been shown to decrease hepatic inflammation, fibrogenesis, and portal pressure (PP). Therefore, we evaluated the atorvastatin effect on the heart in cirrhotic rats.

MATERIALS AND METHODS

Bile duct ligation (BDL) or sham operation performed on male Wistar rats and grouped as cirrhotic; BDL/Saline, BDL/Ator-7d(days) (Atorvastatin 15 mg/kg/day), and BDL/Ator-14d groups, or control; Sham/Saline, Sham/Ator-7d, and Sham/Ator-14d groups. Corrected QT interval (QTc interval), chronotropic responses, serum brain natriuretic peptides (BNP), heart tumor necrosis factor-α (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2), and malondialdehyde (MDA) levels were studied along with atrial Ras homolog family member A (RhoA) and endothelial nitric oxide synthase (eNOS) gene expression.

KEY FINDINGS

The chronotropic responses decreased in BDL/Saline and increased in BDL/Ator-7d group. The QTc interval, BNP, TNF-α, and MDA levels increased in BDL/Saline and decreased in BDL/Ator-14d group. The Nrf2 level did not change in BDL/Saline and increased in BDL/Ator-14d group. The liver inflammation and fibrosis increased in BDL/Saline and did not affect BDL/Ator-7d and BDL/Ator-14d groups. The RhoA expression was down-regulated in BDL/Saline, BDL/Ator-7d, and BDL/Ator-14d groups. The eNOS expression did not change in BDL/Saline and down-regulated in BDL/Ator-14d group.

SIGNIFICANCE

Atorvastatin alleviates the chronotropic hypo-responsiveness and down-regulates the atrial RhoA and eNOS gene expression along with anti-inflammatory, antioxidant, and anti-stress effects in CCM.

The construction of preclinical evidence for the treatment of liver fibrosis with quercetin: A systematic review and meta-analysis

Quercetin (3,3',4',5,7-pentahydroxyflavone), a flavonoid, is widely found in fruits and vegetables and exerts broad-spectrum pharmacological effects in the liver. Many studies have explored the bioactivity of quercetin in the treatment of liver fibrosis. Hence, through a systematic review and biological mechanism evaluation, this study aimed to construct a body of preclinical evidence for the treatment of liver fibrosis using quercetin. The literature used in this study was mainly obtained from four databases, and the SYRCLE list (10 items) was used to evaluate the quality of the included literature. A meta-analysis of HA, LN, and other indicators was performed via STATA 15.0 software. Subgroup analyses based on animal species and model protocol were performed to further obtain detailed results. Moreover, the therapeutic mechanism of quercetin was summarized in a directed network form based on a comprehensive search of the literature. After screening, a total of 14 articles (comprising 15 studies) involving 254 animals were included. The results from the analysis showed that the corresponding liver function indexes, such as the levels of HA and LN, were significantly improved in the quercetin group compared with the model group, and liver function, such as the levels of AST and ALT, were also improved in the quercetin group. The species- and model-based subgroup analyses of AST and ALT revealed that quercetin exerts a significant effect. The therapeutic mechanism of quercetin was shown to be related to multiple pathways involving anti-inflammatory and antioxidant activities and lipid accumulation, including regulation of the TGF-β, α-SMA, ROS, and P-AMPK pathways. The results showed that quercetin exerts an obvious effect on liver fibrosis, and more prominent improvement effects on liver function and liver fibrosis indicators were obtained with a dose of 5-200 mg during a treatment course ranging from 4 to 8 weeks. Quercetin might be a promising therapeutic for liver fibrosis.

Biological Potential of Polyphenols in the Context of Metabolic Syndrome: An Analysis of Studies on Animal Models

Metabolic syndrome (MetS) is a disease that has a complex etiology. It is defined as the co-occurrence of several pathophysiological disorders, including obesity, hyperglycemia, hypertension, and dyslipidemia. MetS is currently a severe problem in the public health care system. As its prevalence increases every year, it is now considered a global problem among adults and young populations. The treatment of choice comprises lifestyle changes based mainly on diet and physical activity. Therefore, researchers have been attempting to discover new substances that could help reduce or even reverse the symptoms when added to food. These attempts have resulted in numerous studies. Many of them have investigated the bioactive potential of polyphenols as a "possible remedy", stemming from their antioxidative and anti-inflammatory effects and properties normalizing carbohydrate and lipid metabolism. Polyphenols may be supportive in preventing or delaying the onset of MetS or its complications. Additionally, the consumption of food rich in polyphenols should be considered as a supplement for antidiabetic drugs. To ensure the relevance of the studies on polyphenols' properties, mechanisms of action, and potential human health benefits, researchers have used laboratory animals displaying pathophysiological changes specific to MetS. Polyphenols or their plant extracts were chosen according to the most advantageous mitigation of pathological changes in animal models best reflecting the components of MetS. The present paper comprises an overview of animal models of MetS, and promising polyphenolic compounds whose bioactive potential, effect on metabolic pathways, and supplementation-related benefits were analyzed based on in vivo animal models.

Curcumin exerts hepatoprotection via overexpression of Paraoxonase-1 and its regulatory genes in rats undergone bile duct ligation

OBJECTIVES

Curcumin is described as an antioxidant, hepato-protective and antifibrotic in liver fibrosis, although its mechanism is still not known. One of the models of the chronic liver disease stemming from oxidative stress and the generation of free radical has been considered to be bile duct ligation (BDL). Paraoxonase 1 (PON1) is a prominent antioxidant enzyme. Therefore, the objective of the present research is to assess the effects of curcumin on upregulation of PON1 in BDL rats.

METHODS

As predicted, the rats have been divided into the four groups of Sham, Sham + Cur (curcumin), BDL and BDL + Cur. We evaluated the efficacy of curcumin (100 mg/kg/day) on protein and gene expression of PON1 and regulatory genes contributed to the gene expression PON1 such as Sp1, PKCα, SREBP-2, AhR, JNK and regulation PON1 activity gene expression of Apo A1.

RESULTS

Curcumin attenuated alterations in liver histology, hepatic enzymes and the mRNA expression of fibrotic markers (p<0.05). In addition, curcumin increased significantly mRNA, protein expression of PON1 and mRNA of the genes that are contributed to the expression of PON1 such as Sp1, PKCα, SREBP-2, AhR, JNK and increased PON1 activity through upregulation of Apo A1 (p<0.05).

CONCLUSIONS

Cirrhosis progression may be inhibited by treatment with curcumin through the increased influence the expression and activity of PON1.

Combination of pomegranate extract and curcumin ameliorates thioacetamide-induced liver fibrosis in rats: impact on TGF-β/Smad3 and NF-κB signaling pathways

Protection against liver injury and its consequences is considered an essential issue to minimize the number of annual deaths caused by liver diseases. The present study was designed to evaluate the potential role of pomegranate extract (PE) and/or curcumin in the regression of thioacetamide (TAA)-induced liver fibrosis, focusing on their modulatory effects on Nrf2/HO-1, NF-κB, and TGF-β/Smad3 signaling pathways. Liver fibrosis was induced in male Wistar rats by intraperitoneal injection of TAA (100 mg/kg) three times a week, for 8 weeks. To assess the protective effects of PE and/or curcumin against TAA-induced liver fibrosis, rats were treated on a daily basis with oral doses of PE (200 mg/kg) and/or curcumin (200 mg/kg) for 8 weeks. The results indicated that PE and/or curcumin attenuated TAA-induced liver fibrogenesis, as evidenced by a significant improvement in the liver function tests (AST, ALT, ALP, and albumin), oxidative stress biomarkers (MDA, SOD, and GSH), and inflammatory biomarkers (NF-ĸB, TNF-α, IL-1β, iNOS, TGF-β, and MPO), compared to TAA group. Moreover, treatment with PE and/or curcumin exerted a significant upregulation of Nrf2/HO-1 gene expressions along with significant downregulation of NF-ĸB, TGF-β, and phospho-Smad3 protein expressions, as well as α-SMA and collagen-1 gene expressions. The histopathological examination has corroborated these findings. In conclusion, hepatoprotective activities of PE and/or curcumin could be linked to their abilities to modulate Nrf2/HO-1, NF-κB, and TGF-β/Smad3 signaling pathways. It is worth noting that the combination of PE and curcumin exerted superior hepatoprotective effects against TAA-induced liver fibrosis, as compared to monotherapy.

Therapeutic potential of a novel combination of Curcumin with Sulfamethoxazole against carbon tetrachloride-induced acute liver injury in Swiss albino mice

BACKGROUND

In the current study, we have investigated the effect of each of curcumin (CUR) and sulfamethoxazole (SMX) either separate or mixed together (CUR + SMX) on biochemical, hematological and histological alternations associated with carbon tetrachloride (CCl₄)-induced liver fibrosis in mice.

RESULTS

CCl_4, caused changes of several biomarkers, proving its hepatotoxic effects, such as an increase in aminotransferases liver enzymes alanine and aspartate transaminases (ALT, AST), malondialdehyde (MDA), and nitric oxide (NO) formation, with a decrease in superoxide dismutase (SOD), glutathione reductase (GSSG), total antioxidant capacity (TAO), glutathione (GSH), total protein, and albumin, compared to a negative control mice group. Compared to the CCl₄ group of mice, the CUR and SMX separate and/or together (CUR + SMX) treatments showed significance in (p < 0.001), ameliorated liver injury (characterized by an elevation of (ALT, AST) and a decrease (p < 0.001) in serum albumin and total protein), antioxidant (characterized by a decrease in (p < 0.001) MDA, NO; an increase (p < 0.001) SOD, GSSG, TAO; and reducing GSH), hematological changes (characterized by a decrease (p < 0.001) in white blood cells count and an increase (p < 0.001) in platelets count, hematocrit levels, hemoglobin concentration, and (p < 0.05) red blood cells count), SDS-PAGE electrophoresis with a decrease in protein synthesis and changes in histological examinations.

CONCLUSIONS

CUR and SMX either separate or together (SUR + SMX) may be considered promising candidates in the prevention and treatment of liver fibrosis.

Hypolipidemic Activities of Two Pentapeptides (VIAPW and IRWWW) from Miiuy Croaker (Miichthys miiuy) Muscle on Lipid Accumulation in HepG2 Cells through Regulation of AMPK Pathway

In this work, the hypolipidemic activities of two pentapeptides (VIAPW and IRWWW) from miiuy croaker (Miichthys miiuy) muscle on oleic acid (OA)-induced lipid accumulation in HepG2 cells were investigated. VIAPW and IRWWW could significantly inhibit lipid accumulation induced by OA and decreased intracellular levels of intracellular triglyceride (TG) and total cholesterol (TC) in a dose-effect dependence manner. At the concentration of 100 μm, the TG levels of VIAPW (0.201 ± 0.006 mm) and IRWWW (0.186 ± 0.005 mm) were very (p < 0.01) and extremely (p < 0.001) significantly lower than those (0.247 ± 0.004 mm) of the OA model group; the levels of TC of VIAPW (45.88 ± 0.74 μg/mg protein) and IRWWW (41.02 ± 0.14 μg/mg protein) were very (p < 0.01) and extremely (p < 0.001) significantly lower than that (53.45 ± 0.10μg/mg protein) of the OA model group (p < 0.01). The hypolipidemic mechanisms of VIAPW and IRWWW were to down-regulate the expression levels of genes of SREBP-1c, SREBP-2, FAS, ACC, and HMGR in lipid synthesis and to up-regulate the expression levels of genes of PPARα, ACOX-1, and CPT-1 in lipid oxidation. These results suggested that VIAPW and IRWWW could play their hypolipidemic activities in HepG2 cells through regulation of AMPK pathway and act as hypolipidemic nutrient ingredients applied in public healthy and functional foods.

Influence of Olive Extracts on the Expression of Genes Involved in Lipid Metabolism in Medaka Fish

Aims. To assess the possible effect of polyphenol-rich olive extracts on lipid metabolism in medaka fish by quantifying the expression of lipogenic and lipolytic genes. Materials and methods. Adult medaka fish were maintained in tanks for five days with five extracts at 0.01% in water, causing obesity through a diet rich in carbohydrates, with a control group maintained in water with a normal diet. The extracts contained polyphenols ranging between 7 and 116 mg/g (oleuropein, hydroxytyrosol) with an antioxidant power of 2-13 mmol of 2,4,6-tri(2-pyridyl)-1,3,5-triazine/100 g. After five days, the fish were sacrificed and the hepatic mRNA and its complementary DNA were extracted by reverse transcription. Complementary DNAs were quantified for three lipolytic and three lipogenic genes by real-time PCR. The relative gene expression was calculated from the amplification curves in reference to the control group. Results. The expression of genes involved in lipolysis, including peroxisome proliferator-activated receptor-±, acyl-CoA oxidase 1, and carnitine palmitoyltransferase 1, were clearly decreased in fish subjected to an obesogenic diet, and this situation could not be reversed in fish maintained with polyphenol-rich extracts. In contrast, lipogenic fatty acid synthase, acetyl-CoA carboxylase 1, and sterol regulatory element-binding protein 1 genes increased considerably with the obesogenic diet and reverted to the normal state with the olive extracts. The effect was not dependent on the total polyphenol content, the specific oleuropein or hydroxytyrosol concentration, or the antioxidant power, suggesting a synergistic effect. Conclusion. Olive polyphenols, acting as anti-lipogenic agents, have a positive effect on lipid metabolism, but their mechanism in each gene is different according to the extract, which supports synergistic mechanisms with the different proportions of polyphenols and accompanying phytochemicals in each extract.