Catechin suppresses an array of signalling molecules and modulates alcohol-induced endotoxin mediated liver injury in a rat model

Stilbenes and anthocyanins reduce stress signaling in BV-2 mouse microglia

Blueberries contain an array of phytochemicals that may decrease both inflammatory and oxidative stress. This study determined if pterostilbene, resveratrol, and two anthocyanins commonly found in blueberries, delphinidin-3-O-glucoside and malvidin-3-O-glucoside, would be efficacious in protecting microglia from inflammatory-induced stress signaling. Microglia that were pretreated with blueberry extract (0.25, 0.5, 1, 2 mg/mL) or its components (1, 10, 20, 30 μM pterostilbene, resveratrol, delphinidin-3-O-glucoside, or malvidin-3-O-glucoside) prior to exposure to lipopolysaccharide (100 ng/mL) demonstrated concentration-dependent reductions in nitric oxide and tumor necrosis factor-alpha release and decreased expression of inducible nitric oxide synthase and cyclooxygenase-2. However, much higher concentrations of the individual components than those found in blueberries were needed to demonstrate the effects. For example, 1 mg/mL blueberry extract significantly reduced LPS-induced nitric oxide release; this concentration of blueberry extract contains 2.6 μM malvidin-3-O-glucoside, but when malvidin-3-O-glucoside was tested individually, 20 μM was necessary to observe a significant reduction in nitric oxide release. Therefore the protective effects of blueberries may not be due to any one component, but rather a synergism of the activity of the compounds tested and/or other blueberry compounds not tested here. These results lend further support that blueberry and its active components are able to combat some of the inflammatory mediators of aging at the cellular level.

Lymphocyte subsets in alcoholic liver disease

AIM

To compare lymphocyte subsets between healthy controls and alcoholics with liver disease.

METHODS

The patient cohort for this study included individuals who were suspected to have alcoholic liver disease (ALD) and who had undergone liver biopsy (for disease grading and staging, doubts about diagnosis, or concurrent liver disease; n = 56). Normal controls included patients who were admitted for elective cholecystectomy due to non-complicated gallstones (n = 27). Formalin-fixed, paraffin-embedded liver biopsy specimens were sectioned and stained with hematoxylin and eosin and Perls' Prussian blue. The non-alcoholic steatohepatitis score was used to assess markers of ALD. Lymphocyte population subsets were determined by flow cytometry. T lymphocytes were identified (CD3(+)), and then further subdivided into CD4(+) or CD8(+) populations. B lymphocytes (CD19(+)) and natural killer (NK) cell numbers were also measured. In addition to assessing lymphocyte subpopulation differences between ALD patients and controls, we also compared subsets of alcoholic patients without cirrhosis or abstinent cirrhotic patients to normal controls.

RESULTS

The patient cohort primarily consisted of older men. Active alcoholism was present in 66.1%. Reported average daily alcohol intake was 164.9 g and the average lifetime cumulative intake was 2211.6 kg. Cirrhosis was present in 39.3% of the patients and 66.1% had significant fibrosis (perisinusoidal and portal/periportal fibrosis, bridging fibrosis, or cirrhosis) in their liver samples. The average Mayo end-stage liver disease score was 7.6. No hereditary hemochromatosis genotypes were found. ALD patients (n = 56) presented with significant lymphopenia (1.5 × 10(9)/L ± 0.5 × 10(9)/L vs 2.1 × 10(9)/L ± 0.5 × 10(9)/L, P < 0.0001), due to a decrease in all lymphocyte subpopulations, except for NK lymphocytes: CD3(+) (1013.0 ± 406.2/mm(3) vs 1523.0 ± 364.6/mm(3), P < 0.0001), CD4(+) (713.5 ± 284.7/mm(3) vs 992.4 ± 274.7/mm(3), P < 0.0001), CD8(+) (262.3 ± 140.4/mm(3) vs 478.9 ± 164.6/mm(3), P < 0.0001), and CD19(+) (120.6 ± 76.1/mm(3) vs 264.6 ± 88.0/mm(3), P < 0.0001). CD8(+) lymphocytes suffered the greatest reduction, as evidenced by an increase in the CD4(+)/CD8(+) ratio (3.1 ± 1.3 vs 2.3 ± 0.9, P = 0.013). This ratio was associated with the stage of fibrosis on liver biopsy (r s = 0.342, P = 0.01) and with Child-Pugh score (r s = 0.482, P = 0.02). The number of CD8(+) lymphocytes also had a positive association with serum ferritin levels (r s = 0.345, P = 0.009). Considering only patients with active alcoholism but not cirrhosis (n = 27), we found similar reductions in total lymphocyte counts (1.8 × 10(9)/L ± 0.3 × 10(9)/L vs 2.1 × 10(9)/L ± 0.5 × 10(9)/L, P = 0.018), and in populations of CD3(+) (1164.7 ± 376.6/mm(3) vs 1523.0 ± 364.6/mm(3), P = 0.001), CD4(+) (759.8 ± 265.0/mm(3) vs 992.4 ± 274.7/mm(3), P = 0.003), CD8(+) (330.9 ± 156.3/mm(3) vs 478.9 ± 164.6/mm(3), P = 0.002), and CD19(+) (108.8 ± 64.2/mm(3) vs 264.6 ± 88.0/mm(3), P < 0.0001). In these patients, the CD4(+)/CD8(+) ratio and the number of NK lymphocytes was not significantly different, compared to controls. Comparing patients with liver cirrhosis but without active alcohol consumption (n = 11), we also found significant lymphopenia (1.3 × 10(9)/L ± 0.6 × 10(9)/L vs 2.1 × 10(9)/L ± 0.5 × 10(9)/L, P < 0.0001) and decreases in populations of CD3(+) (945.5 ± 547.4/mm(3) vs 1523.0 ± 364.6/mm(3), P = 0.003), CD4(+) (745.2 ± 389.0/mm(3) vs 992.4 ± 274.7/mm(3), P = 0.032), CD8(+) (233.9 ± 120.0/mm(3) vs 478.9 ± 164.6/mm(3), P < 0.0001), and CD19(+) (150.8 ± 76.1/mm(3) vs 264.6 ± 88.0/mm(3), P = 0.001). The NK lymphocyte count was not significantly different, but, in this group, there was a significant increase in the CD4(+)/CD8(+) ratio (3.5 ± 1.3 vs 2.3 ± 0.9, P = 0.01).

CONCLUSION

All patient subsets presented with decreased lymphocyte counts, but only patients with advanced fibrosis presented with a significant increase in the CD4(+)/CD8(+) ratio.

Herbal medicines for the prevention of alcoholic liver disease: a review

ETHNOPHARMACOLOGICAL RELEVANCE

Long-term excess alcohol exposure leads to alcoholic liver disease (ALD)-a global health problem without effective therapeutic approach. ALD is increasingly considered as a complex and multifaceted pathological process, involving oxidative stress, inflammation and excessive fatty acid synthesis. Over the past decade, herbal medicines have attracted much attention as potential therapeutic agents in the prevention and treatment of ALD, due to their multiple targets and less toxic side effects. Several herbs, such as Cnidium monnieri (L.) Cusson (Apiaceae), Curcuma longa L. (Zingiberaceae) and Pueraria lobata (Willd.) Ohwi (Leguminosae), etc., have been shown to be quite effective and are being widely used in China today for the treatment of ALD when used alone or in combination.

AIM OF THE REVIEW

To review current available knowledge on herbal medicines used to prevent or treat ALD and their underlying mechanisms.

MATERIALS AND METHODS

We used the pre-set searching syntax and inclusion criteria to retrieve available published literature from PUBMED and Web of Science databases, all herbal medicines and their active compounds tested on ALD induced by both acute and chronic alcohol ingestion were included.

RESULTS

A total of 40 experimental studies involving 34 herbal medicines and (or) active compounds were retrieved and reviewed. We found that all reported extracts and individual compounds from herbal medicines/natural plants could be beneficial to ALD, which might be attributed to regulate multiple critical targets involved in the pathways of oxidation, inflammation and lipid metabolism.

CONCLUSIONS

Screening chemical candidate from herbal medicine might be a promising approach to drug discovery for the prevention or treatment of ALD. However, further studies remain to be done on the systematic assessment of herbal medicines against ALD and the underlying mechanisms, as well as their quality control studies.

Antiproliferative effect of catechin in GRX cells

The phenolic compounds present in cocoa seeds have been studied regarding health benefits, such as antioxidant and anti-inflammatory activities. Fibrosis is a wound healing response that occurs in almost all patients with chronic liver injury. A large number of cytokines and soluble intercellular mediators are related to changes in the behavior and phenotype of the hepatic stellate cell (HSC) that develop a fibrogenic and contractile phenotype leading to the development of fibrosis. The objective of this study was to assess the catechin effect in GRX liver cells in activities such as cell growth and inflammation. The GRX cells treatment with catechin induced a significant decrease in cell growth. This mechanism does not occur by apoptosis or even by autophagy because there were no alterations in expression of caspase 3 and PARP (apoptosis), and LC3 (autophagy). The expression of p27 and p53 proteins, regulators of the cell cycle, showed increased expression, while COX-2 and IL-6 mRNA showed a significant decrease in expression. This study shows that catechin decreases cell growth in GRX cells and, probably, this decrease does not occur by apoptosis or autophagy but through an anti-inflammatory effect and cell cycle arrest. Catechin also significantly decreased the production of TGF-β by GRX cells, showing a significant antifibrotic effect.

Protective Effects of Total Flavonoids from Litsea coreana on Alcoholic Fatty Liver in Rats Associated with Down-Regulation Adipose Differentiation-Related Protein Expression

Alcoholic fatty liver (AFL) is a reversible condition, but it can potentiate the development of alcoholic hepatitis and even cirrhosis by increasing oxidant generation, which is one of the key pathogenic factors and could result in alcoholic liver disease (ALD). Total flavonoids from Litsea coreana (TFLC), an active component extracted from Litsea coreana leve, have been shown to have therapeutic effects on hyperlipidemia. The present study was to evaluate the protective effects of TFLC on alcoholic fatty liver (AFL) in rats, and investigate the potential mechanism. An AFL model in rats was established by intaking different doses of alcohol (concentration from 5% to 40%) over 12 weeks. Serum levels of TG, TC, LDL-C, HDL-C, TNF-α, insulin, and glucose were measured, histopathologic changes were determined, and expression of adipose differentiation-related protein (ADRP) in the liver were evaluated by Western blotting and immunohistochemistry, respectively. The results showed that treatment with TFLC resulted in decreased serum levels of TG, TC, LDL-C, TNF-α, glucose and insulin, as well as improved liver index. Morphological evaluation revealed rats in model group developed a severe steatosis, but the severities of liver steatosis were effectively ameliorated in TFLC (200 and 400 mg/kg) treated groups. Expression of hepatic ADRP were increased in model group, and suppressed in TFLC treated groups. These results suggest that TFLC had a protective effect on AFL rats; the mechanism may be involved in regulation serum lipid profiles via down-regulation of hepatic expression of ADRP in AFL rats.

Effect of tea catechins on regulation of cell proliferation and antioxidant enzyme expression in H2 O2 -induced primary hepatocytes of goat in vitro

Tea catechins (TC) are polyphenols that have potent antioxidant activity. The objectives of this study were to determine the effects of TC on antioxidant status of hepatocytes challenged with H2 O2 . Primary hepatocytes of goat were exposed to 1 mm H2 O2 without or with 5, 50 and 500 μg/ml TC. The cells were harvested at 48 h post-treatment to determine effects of TC on proliferation, apoptotic features and membrane integrity of cells, and expression of genes and activities of antioxidant enzymes. H2 O2 exposure caused damage to cells (p < 0.001). A lower concentration of TC (5 μg/ml) displayed a protective effect by inhibiting exorbitant cell proliferation and DNA degradation. Both H2 O2 exposure and TC pre-incubation affected expression of antioxidant enzymes at mRNA and protein levels (p < 0.001). The activities of catalase (CAT) (p = 0.027), CuZn-superoxide dismutase (CuZn-SOD) (p < 0.001) and glutathione peroxidase (GPx) (p < 0.001) increased with TC pre-incubation followed by H2 O2 challenge. Changes of CuZn-SOD activity induced by H2 O2 and TC basically paralleled the changes in the corresponding mRNA and protein levels, but the correlation in CAT and GPx expression displayed slightly different patterns at different concentrations of TC. These findings infer that oxidative stress can induce deleterious cellular responses and this unfavourable condition may be alleviated by treatment with TC.

Quince (Cydonia oblonga Miller) peel polyphenols modulate LPS-induced inflammation in human THP-1-derived macrophages through NF-κB, p38MAPK and Akt inhibition

Chronic inflammation is a hallmark of several pathologies, such as rheumatoid arthritis, gastritis, inflammatory bowel disease, atherosclerosis and cancer. A wide range of anti-inflammatory chemicals have been used to treat such diseases while presenting high toxicity and numerous side effects. Here, we report the anti-inflammatory effect of a non-toxic, cost-effective natural agent, polyphenolic extract from the Tunisian quince Cydonia oblonga Miller. Lipopolysaccharide (LPS) treatment of human THP-1-derived macrophages induced the secretion of high levels of the pro-inflammatory cytokine TNF-α and the chemokine IL-8, which was inhibited by quince peel polyphenolic extract in a dose-dependent manner. Concomitantly, quince polyphenols enhanced the level of the anti-inflammatory cytokine IL-10 secreted by LPS-treated macrophages. We further demonstrated that the unexpected increase in IL-6 secretion that occurred when quince polyphenols were associated with LPS treatment was partially responsible for the polyphenols-mediated inhibition of TNF-α secretion. Biochemical analysis showed that quince polyphenols extract inhibited the LPS-mediated activation of three major cellular pro-inflammatory effectors, nuclear factor-kappa B (NF-κB), p38MAPK and Akt. Overall, our data indicate that quince peel polyphenolic extract induces a potent anti-inflammatory effect that may prove useful for the treatment of inflammatory diseases and that a quince-rich regimen may help to prevent and improve the treatment of such diseases.