Theaphenon E prevents fatty liver disease and increases CD4+ T cell survival in mice fed a high-fat diet.

BACKGROUND & AIMS: Obesity is a major cause of non-alcoholic fatty liver disease (NAFLD). NAFLD is an epidemic affecting nearly 34% of the adult population in the US. As a chronic inflammatory disease, NAFLD influences the immune system by dysregulating T-cell activity. Remedies for the adverse effects on the immune system are urgently needed. We studied Theaphenon E (TE), a standardized formulation of green tea extract, on the adverse effects of NAFLD in C57BL/6J mice fed a high fat diet (HFD). METHODS: Mice received HFD, low fat diet (LFD) or HFD+2% TE for 35 weeks. Hepatic lipid accumulation, cell proliferation, apoptosis and CD4+T lymphocytes were measured throughout the bioassay. The hepatic composition of fatty acids was determined. The effects of epigallocatechin gallate (EGCG) metabolites on lipid accumulation in mouse and primary human liver cells were studied. RESULTS: Unlike mice receiving HFD, mice on HFD+2% TE maintained normal liver to body weight ratios with low levels of alanine and aspartate aminotransferase (ALT and AST). Hepatic lipid accumulation was observed in HFD mice, accompanied by increased proliferation, reduced apoptosis and loss of CD4+ T lymphocytes. TE significantly inhibited lipid accumulation, decreased proliferation, induced apoptosis and increased CD4+ T cell survival in HFD mice. It was found that the EGCG metabolite EGC-M3 reduced lipid accumulation in mouse and human hepatocytes. Linoleic acid showed the largest increase (2.5-fold) in livers of mice on a HFD and this increase was significantly suppressed by TE. CONCLUSIONS: Livers of HFD-fed mice showed lipid accumulation, increased proliferation, reduced apoptosis, elevated linoleic acid and loss of CD4+ T cells. TE effectively ameliorated all of these adverse effects.

Detection of a lipid peroxidation-induced DNA adduct across liver disease stages.

BACKGROUND: Oxidative stress and chronic inflammation can increase cellular levels of reactive oxygen species and lipid peroxidation (LPO) when associated with the pathogenesis of hepatocellular carcinoma (HCC), which can develop following the progression of steatosis, fibrosis and cirrhosis. Using a monoclonal antibody for cyclic γ-hydroxy-1, N2 -propanodeoxyguanosine (γ-OHPdG), a promutagenic DNA adduct formed endogenously by LPO, we examined its formation across liver disease stages to understand it's potential role in HCC development. METHODS: Formalin-fixed paraffin embedded (FFPE) liver tissue samples from 49 patients representing normal, steatosis, fibrosis, cirrhosis and HCC were stained for γ-OHPdG and 8-hydroxydeoxyguanosine (8-oxo-dG), an oxidative damage biomarker. Quantification of immunohistochemical (IHC) staining was performed using histological scoring of intensity and distribution. Using primary human hepatocytes (HH) and a stellate cell (SC) co-culture, immunocytochemical staining of γ-OHPdG and Nile Red was performed to determine if the formation of γ-OHPdG was consistent between the clinical sample disease stages and the in vitro steatotic and fibrotic conditions. RESULTS: γ-OHPdG levels varied significantly between the stages of normal and steatosis, steatosis and fibrosis, and steatosis and cirrhosis (P≤0.005). There was a trend, although not significant, of increased levels of γ-OHPdG in HCC compared to the other groups. A strong correlation was observed (Pearson's, R2 =0.85) between levels of γ-OHPdG and 8-oxo-dG across the disease spectrum. The increase of γ-OHPdG in steatosis and decrease in fibrosis was a pattern confirmed in an in vitro model using primary HH co-cultured with human SCs. CONCLUSIONS: γ-OHPdG was detected in FFPE liver tissues of patients with different stages of liver disease and in vitro studies, demonstrating that its formation is consistent with LPO in early stages of liver disease and suggesting that it may be a source of mutagenic DNA damage in liver disease progression.

α-Synuclein-mediated inhibition of ATF6 processing into COPII vesicles disrupts UPR signaling in Parkinson's disease.

The unfolded protein response (UPR) monitors the folding environment within the endoplasmic reticulum (ER). Accumulation of misfolded proteins within the ER activates the UPR resulting in the execution of adaptive or non-adaptive signaling pathways. α-Synuclein (α-syn) whose accumulation and aggregation define the pathobiology of Parkinson's disease (PD) has been shown to inhibit ER-Golgi transit of COPII vesicles. ATF6, a protective branch of the UPR, is processed via COPII mediated ER-Golgi transit following its activation via ER stress. Using cellular PD models together with biochemical reconstitution assays, we showed that α-syn inhibited processing of ATF6 directly through physical interactions and indirectly through restricted incorporation into COPII vesicles. Impaired ATF6 signaling was accompanied by decreased ER-associated degradation (ERAD) function and increased pro-apoptotic signaling. The mechanism by which α-syn inhibits ATF6 signaling expands our understanding of the role ER stress and the UPR play in neurodegenerative diseases such as PD.

Acupuncture blocks cold stress-induced increases in the hypothalamus-pituitary-adrenal axis in the rat.

Electroacupuncture (EA) is used to treat chronic stress; however, its mechanism(s) of action in allaying stress remains unclear. The interplay of stress hormones of the hypothalamus-pituitary-adrenal axis (HPA) and the sympathetic nervous system (SNS) is critical in the stress response. Our objective was to determine whether EA at acupoint, stomach 36 (EA St36) is effective in preventing chronic cold stress-induced increased hormone levels in the rat by examining four groups of animals, three of which were exposed to cold and one of which was a non-treatment control group. Before exposure to the cold, two groups were treated with either EA St36, or Sham-EA, before 10 days of cold stress. The EA St36 animals demonstrated a significant decrease in peripheral HP hormones (ACTH and CORT) compared with stress animals (P<0.05). These effects were specific; rats receiving Sham-EA had elevation of these hormones, similar to the stress-only animals. These effects were mirrored centrally in the brain; CRH levels were significantly (P<0.05) reduced in EA St36 animals compared with the other animals. Finally, EA effect on peripheral and adrenal SNS hormones (norepinephrine (NE) and neuropeptide Y (NPY) respectively) was examined, with no significant difference noted in adrenal tyrosine hydroxylase or circulating NE in any of the groups. However, EA St36 was effective in preventing stress-induced elevation is adrenal Npy mRNA. These results indicate that EA St36 blocks the chronic stress-induced elevations in the HPA and the sympathetic NPY pathway, which may be a mechanism for its specific stress-allaying effects.

Antioxidative effects of the spice cardamom against non-melanoma skin cancer by modulating nuclear factor erythroid-2-related factor 2 and NF-κB signalling pathways.

The role of dietary factors in inhibiting or delaying the development of non-melanoma skin cancer (NMSC) has been investigated for many years. Cardamom, which is a dietary phytoproduct, has been commonly used in cuisines for flavour and has numerous health benefits, such as improving digestion and stimulating metabolism and having antitumorigenic effects. We have investigated the efficacy of dietary cardamom against 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin papillomatogenesis in Swiss albino mice that closely resembles human NMSC. Mice were grouped into normal wild type (untreated), vehicle-treated (acetone), carcinogen-treated (DMBA), and DMBA and cardamom-treated (DMBA+CARD) to delineate the role of cardamom against DMBA-induced papillomatogenesis. Oral administration of cardamom to DMBA-treated mice up-regulated the phase II detoxification enzymes, such as glutathione-S-transferase and glutathione peroxidase, probably via activation of nuclear factor erythroid-2-related factor 2 transcription factor in 'DMBA+CARD' mice. Furthermore, reduced glutathione, glutathione reductase, superoxide dismutase and catalase were also up-regulated by cardamom in the same 'DMBA+CARD' group of mice compared with DMBA-treated mice. Cardamom ingestion in DMBA-treated mice blocked NF-κB activation and down-regulated cyclo-oxygenase-2 expression. As a consequence, both the size and the number of skin papillomas generated on the skin due to the DMBA treatment were reduced in the 'DMBA+CARD' group. Thus, the results from the present study suggest that cardamom has a potential to become a pivotal chemopreventive agent to prevent papillomagenesis on the skin.