Curcumin attenuates hepatic fibrosis and insulin resistance induced by bile duct ligation in rats

Protective role of curcumin in disease progression from non-alcoholic fatty liver disease to hepatocellular carcinoma: a meta-analysis

Background: Pathological progression from non-alcoholic fatty liver disease (NAFLD) to liver fibrosis (LF) to hepatocellular carcinoma (HCC) is a common dynamic state in many patients. Curcumin, a dietary supplement derived from the turmeric family, is expected to specifically inhibit the development of this progression. However, there is a lack of convincing evidence. Methods: The studies published until June 2023 were searched in PubMed, Web of Science, Embase, and the Cochrane Library databases. The SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) approach was used to evaluate the certainty of evidence. StataSE (version 15.1) and Origin 2021 software programs were used to analyze the critical indicators. Results: Fifty-two studies involving 792 animals were included, and three disease models were reported. Curcumin demonstrates a significant improvement in key indicators across the stages of NAFLD, liver fibrosis, and HCC. We conducted a detailed analysis of common inflammatory markers IL-1β, IL-6, and TNF-α, which traverse the entire disease process. The research results reveal that curcumin effectively hinders disease progression at each stage by suppressing inflammation. Curcumin exerted hepatoprotective effects in the dose range from 100 to 400 mg/kg and treatment duration from 4 to 10 weeks. The mechanistic analysis reveals that curcumin primarily exerts its hepatoprotective effects by modulating multiple signaling pathways, including TLR4/NF-κB, Keap1/Nrf2, Bax/Bcl-2/Caspase 3, and TGF-β/Smad3. Conclusion: In summary, curcumin has shown promising therapeutic effects during the overall progression of NAFLD-LF-HCC. It inhibited the pathological progression by synergistic mechanisms related to multiple pathways, including anti-inflammatory, antioxidant, and apoptosis regulation.

Metabolomics reveals that chronic restraint stress alleviates carbon tetrachloride-induced hepatic fibrosis through the INSR/PI3K/AKT/AMPK pathway

Hepatic fibrosis (HF) could be developed into liver cirrhosis or even hepatocellular carcinoma. Stress has an important role in the occurrence and development of various considerable diseases. However, the effect of a certain degree stress on HF is still controversial. In our study, stress was simulated with regular chronic restraint stress (CRS) and HF model was induced with CCl4 in mice. We found that CRS was able to attenuate CCl4-induced liver injury and fibrosis in mice. Surprisingly, behavioral analysis showed that the mice in the HF group exhibited depression-like behavior. Further, the metabolomic analysis revealed that 119 metabolites and 20 metabolic pathways were altered in mice liver, especially the betaine metabolism pathway. Combined with the results of Ingenuity Pathway Analysis (IPA), the key proteins INSR, PI3K, AKT, and p-AMPK were identified and verified, and the results showed that CRS could upregulate the protein levels and mRNA expression of INSR, PI3K, AKT, and p-AMPK in liver tissues of HF mice. It suggested that CRS alleviated CCl4-induced liver fibrosis in mice through upregulation of the INSR/PI3K/AKT/AMPK pathway. Proper stress might be a potential therapeutic strategy for the treatment of chronic liver disease, which provided new insights into the treatment of HF. KEY MESSAGES: Chronic restraint stress mitigated CCl4-induced liver injury and hepatic fibrosis. CCl4-induced liver fibrosis could cause depression-like behavior. Chronic restraint stress altered metabolomic profiles in hepatic fibrosis mice, especially the betaine metabolism pathway. Chronic restraint stress increased betaine levels in liver tissue. Chronic restraint stress regulated the INSR/PI3K/AKT/AMPK signaling pathway in hepatic fibrosis mice.

Curcumin inhibits the activity and induces apoptosis of activated hepatic stellate cell by suppressing autophagy

Curcumin, a kind of natural compound, has been previously proven to inhibit the autophagy in hepatic stellate cells (HSCs) and induce their apoptosis. However, it is not clear whether the enhanced apoptosis of activated HSCs (aHSCs) caused by curcumin depends on autophagy inhibition. We aim to verify this hypothesis and explore the potential mechanisms in this study. Immortalized human HSC line LX-2 was used as an experimental specimen and pretreated with transforming growth factor β1(TGF-β1) for 24 h to activate it before drug application. The levels of autophagy, apoptosis, cell activity, lipid metabolism, and the activity of the PI3K/Akt/mTOR signal pathway were evaluated by multiple methods, such as Western blotting, mcherry-EGFP-LC3B adenoviruses transfection, immunofluorescence, Nile Red staining, flow cytometry among others. Our results showed that rapamycin, an autophagy activator, could partly offset the effects of curcumin on autophagy and apoptosis of LX-2 cells, while 3-Methyladenine (3-MA), an autophagy inhibitor, could enhance these effects. Furthermore, curcumin could promote the activity of the PI3K/Akt/mTOR signal pathway in LX-2 cells, while PI3K inhibitor could partly offset this effect and increase the autophagy level. Overall, we demonstrated that curcumin could inhibit the activity and promote LX-2 cells apoptosis by suppressing autophagy by activating the PI3K/Akt/mTOR signal pathway. In addition, lipid recovery and energy deprivation due to autophagy inhibition may be the exact mechanism by which curcumin attenuates the pro-fibrotic activity of LX-2.

A biochemical, theoretical and immunohistochemical study comparing the therapeutic efficacy of curcumin and taurine on T-2 toxin induced hepatotoxicity in rats

Introduction: Foodborne trichothecene T-2 Toxin, is a highly toxic metabolite produced by Fusarium species contaminating animal and human food, causing multiple organ failure and health hazards. T-2 toxins induce hepatotoxicity via oxidative stress causing hepatocytes cytotoxicity and genotoxicity. In this study, curcumin and taurine were investigated and compared as antioxidants against T-2-provoked hepatotoxicity. Methods: Wistar rats were administrated T-2 toxin sublethal oral dose (0.1 mg/kg) for 2 months, followed by curcumin (80 mg/kg) and taurine (50 mg/kg) for 3 weeks. Biochemical assessment of liver enzymes, lipid profiles, thiobarbituric acid reactive substances (TBARs), AFU, TNF-α, total glutathione, molecular docking, histological and immunohistochemical markers for anti-transforming growth factor-β1 (TGFβ1), double-strand DNA damage (H2AX), regeneration (KI67) and apoptosis (Active caspase3) were done. Results and Discussion: Compared to T-2 toxin, curcumin and taurine treatment significantly ameliorated hepatoxicity as; hemoglobin, hematocrit and glutathione, hepatic glycogen, and KI-67 immune-reactive hepatocytes were significantly increased. Although, liver enzymes, inflammation, fibrosis, TGFβ1 immunoexpressing and H2AX and active caspase 3 positive hepatocytes were significantly decreased. Noteworthy, curcumin's therapeutic effect was superior to taurine by histomorphometry parameters. Furthermore, molecular docking of the structural influence of curcumin and taurine on the DNA sequence showed curcumin's higher binding affinity than taurine. Conclusion: Both curcumin and taurine ameliorated T-2 induced hepatotoxicity as strong antioxidative agents with more effectiveness for curcumin.

The role of curcumin in the liver-gut system diseases: from mechanisms to clinical therapeutic perspective

Natural products have provided abundant sources of lead compounds for new drug discovery and development over the past centuries. Curcumin is a lipophilic polyphenol isolated from turmeric, a plant used in traditional Asian medicine for centuries. Despite the low oral bioavailability, curcumin exhibits profound medicinal value in various diseases, especially liver and gut diseases, bringing an interest in the paradox of its low bioavailability but high bioactivity. Several latest studies suggest that curcumin's health benefits may rely on its positive gastrointestinal effects rather than its poor bioavailability solely. Microbial antigens, metabolites, and bile acids regulate metabolism and immune responses in the intestine and liver, suggesting the possibility that the liver-gut axis bidirectional crosstalk controls gastrointestinal health and diseases. Accordingly, these pieces of evidence have evoked great interest in the curcumin-mediated crosstalk among liver-gut system diseases. The present study discussed the beneficial effects of curcumin against common liver and gut diseases and explored the underlying molecular targets, as well as collected evidence from human clinical studies. Moreover, this study summarized the roles of curcumin in complex metabolic interactions in liver and intestine diseases supporting the application of curcumin in the liver-gut system as a potential therapeutic option, which opens an avenue for clinical use in the future.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

Effect of Curcumin on Interleukin-6 Expression and Malondialdehyde Levels in Liver Fibrosis

BACKGROUND: Chronic inflammation and excessive oxidative stress are the main mechanisms causing liver fibrosis. It releases anti-inflammatory cytokines, namely, interleukin 6 (IL-6), nitric oxide, and malondialdehyde (MDA). Curcumin acts as an anti-inflammatory, antioxidant, and antifibrotic. AIM: This study is aimed to analyze differences in IL-6 expression and MDA levels in (Deutschland, Denken, and Yoken) DDY mice with liver fibrosis after common bile duct ligation between the curcumin-treated and control groups. METHODS: This research is an experimental study with a post-test-only control group design. Seventy-five male DDY mice 20–30g were used in this study (n = 5). Mice were randomly divided into five groups, each consisting of 15 mice. The first group healthy control (HC) was the HC group given phosphate-buffered saline (PBS) solution and did not perform the CBDL. The second group negative control (NC) was a NC group given PBS solution and completed the CBDL. The third group positive control (PC) was a PC group given oral ursodeoxycholic acid (UDCA) and performed CBDL. The fourth group (P1) was assigned oral curcumin and performed the CBDL. The fifth group (P2) was given oral curcumin and UDCA and performed the CBDL. Seven, fourteen, and 21 days after ligation, liver samples were taken to examine IL-6 expression and MDA levels. RESULTS: There was a significant difference between the NC and PC groups (p = 0.00), NC and P1 (p = 0.00), NC with P2 (p = 0.00), PC with P1 (p = 0.04), PC with P2 (p = 0.04), on day 21 between the NC and PC groups (p = 0.00), NC with P1 (p = 0.00), and PC with P2 (p = 0.00). Statistical analysis of the comparison of MDA levels on days 7 and 14 found no significant difference. On day 21, there was a substantial difference between the NC group and P1 (p = 0.02). CONCLUSION: This study concluded that curcumin effectively reduced IL-6 expression and MDA levels in liver fibrosis.

Therapeutic Screening of Herbal Remedies for the Management of Diabetes

The study of diabetes mellitus (DM) patterns illustrates increasingly important facts. Most importantly, they include oxidative stress, inflammation, and cellular death. Up to now, there is a shortage of drug therapies for DM, and the discovery and the development of novel therapeutics for this disease are crucial. Medicinal plants are being used more and more as an alternative and natural cure for the disease. Consequently, the objective of this review was to examine the latest results on the effectiveness and protection of natural plants in the management of DM as adjuvant drugs for diabetes and its complex concomitant diseases.

Curcumin protects against inflammation and lung injury in rats with acute pulmonary embolism with the involvement of microRNA-21/PTEN/NF-κB axis

This study was intended to investigate the effect of Curcumin on acute pulmonary embolism (APE) via microRNA-21 (miR-21)/PTEN/NF-κB axis. APE model was induced on rats and administrated with Curcumin. Western blot analysis and RT-qPCR manifested the downregulation of Sp1, miR-21 and NF-κB, but the upregulation of PTEN in Curcumin-treated APE rats. Blood gas analysis, ELISA, and weighing of wet weight/dry weight (W/D) ratio indicated that Curcumin diminished mPAP and RVSP levels, W/D ratio, thrombus volume, and inflammatory factors in the lungs of APE rats. Further mechanical analysis was conducted by dual-luciferase reporter assays and ChIP assay, which showed that Sp1 increased miR-21 expression by binding to the miR-21 promoter, and that PTEN was targeted by miR-21. The APE rats were injected with adenovirus to evaluate the effect of Sp1, miR-21, or PTEN on lung injury and inflammation. It was observed that downregulation of miR-21 or Sp1, or upregulation of PTEN diminished mPAP and RVSP levels, W/D ratio, thrombus volume, and inflammatory factors in the lungs of APE rats. In summary, Curcumin decreased miR-21 expression by downregulating Sp1 to upregulate PTEN and to impair the NF-κB signaling pathway, thus suppressing lung injury and inflammation in APE rats.

Toward Regulatory Effects of Curcumin on Transforming Growth Factor-Beta Across Different Diseases: A Review

Immune response, proliferation, migration and angiogenesis are juts a few of cellular events that are regulated by transforming growth factor-β (TGF-β) in cells. A number of studies have documented that TGF-β undergoes abnormal expression in different diseases, e.g., diabetes, cancer, fibrosis, asthma, arthritis, among others. This has led to great fascination into this signaling pathway and developing agents with modulatory impact on TGF-β. Curcumin, a natural-based compound, is obtained from rhizome and roots of turmeric plant. It has a number of pharmacological activities including antioxidant, anti-inflammatory, anti-tumor, anti-diabetes and so on. Noteworthy, it has been demonstrated that curcumin affects different molecular signaling pathways such as Wnt/β-catenin, Nrf2, AMPK, mitogen-activated protein kinase and so on. In the present review, we evaluate the potential of curcumin in regulation of TGF-β signaling pathway to corelate it with therapeutic impacts of curcumin. By modulation of TGF-β (both upregulation and down-regulation), curcumin ameliorates fibrosis, neurological disorders, liver disease, diabetes and asthma. Besides, curcumin targets TGF-β signaling pathway which is capable of suppressing proliferation of tumor cells and invading cancer cells.

Curcumin prevents cognitive deficits in the bile duct ligated rats

RATIONALE

Bile duct ligation (BDL) in rodents can cause impaired liver function and cognition deficits. Curcumin has shown a preventive and therapeutic role in memory impairment.

OBJECTIVES

Therefore, this study aimed to explore the effect of curcumin on the performance of male adult Wistar rats that underwent BDL, a model of hepatic encephalopathy (HE) in the Morris water maze (MWM).

METHODS

Four weeks after surgery, sham (manipulation of common bile duct without ligation) and BDL rats underwent the MWM test.

RESULTS

The representative data showed that BDL rats exhibited impairments in spatial learning and reference memory in the MWM compared with the sham rats. Treatment of BDL rats with curcumin (40 mg/kg, i.p., for 4 weeks) prevented these impairments, while it did not affect spatial learning and memory in the sham rats, by itself. Curcumin increased expression levels of the pro-survival B cell lymphoma extra-large (Bcl-xL) gene and two genes involved in mitochondrial function, peroxisome proliferative-activated receptor-γ co-activator 1α (PGC-1α) and mitochondrial transcription factor A (TFAM), in the hippocampus of BDL rats compared with the vehicle-treated sham or BDL rats, while it decreased the pro-apoptotic Bcl-2-associated X protein (Bax) gene expression level. BDL up-regulated Bax and down-regulated TFAM, by itself. Furthermore, curcumin reduced the mRNA level of Bax, while it increased Bcl-2 and TFAM mRNA levels.

CONCLUSIONS

These findings demonstrate the beneficial effect of curcumin on cognitive function in BDL rats of the HE model. The curcumin effect may be related to mitochondrial function improvement in the HE.

A Comprehensive Review of Natural Products against Liver Fibrosis: Flavonoids, Quinones, Lignans, Phenols, and Acids

Liver fibrosis resulting from continuous long-term hepatic damage represents a heavy burden worldwide. Liver fibrosis is recognized as a complicated pathogenic mechanism with extracellular matrix (ECM) accumulation and hepatic stellate cell (HSC) activation. A series of drugs demonstrate significant antifibrotic activity in vitro and in vivo. No specific agents with ideally clinical efficacy for liver fibrosis treatment have been developed. In this review, we summarized the antifibrotic effects and molecular mechanisms of 29 kinds of common natural products. The mechanism of these compounds is correlated with anti-inflammatory, antiapoptotic, and antifibrotic activities. Moreover, parenchymal hepatic cell survival, HSC deactivation, and ECM degradation by interfering with multiple targets and signaling pathways are also involved in the antifibrotic effects of these compounds. However, there remain two bottlenecks for clinical breakthroughs. The low bioavailability of natural products should be improved, and the combined application of two or more compounds should be investigated for more prominent pharmacological effects. In summary, exploration on natural products against liver fibrosis is becoming increasingly extensive. Therefore, natural products are potential resources for the development of agents to treat liver fibrosis.