ABSTRACT
OBJECTIVE Non-alcoholic fatty liver disease(NAFLD) encompasses a series of patho-logic changes ranging from steatosis to steatohepatitis,which may progress to cirrhosis and hepatocel-lular carcinoma.The purpose of this study was to determine whether Ganoderma lucidum polysaccha-ride peptide (GLPP) has therapeutic effect on NAFLD. METHODS ob/ob mouse model and ApoC3 transgenic mouse model were used for exploring the effect of GLPP on NAFLD. Key metabolic path-ways and enzymes were identified by metabolomics combining with KEGG and PIUmet analyses and key enzymes were detected by Western blotting. Hepatosteatosis models of HepG2 cells and primary hepatocytes were used to further confirm the therapeutic effect of GLPP on NAFLD. RESULTS GLPP administrated for a month alleviated hepatosteatosis, dyslipidemia, liver dysfunction and liver insulin resistance. Pathways of glycerophospholipid metabolism, fatty acid metabolism and primary bile acid biosynthesis were involved in the therapeutic effect of GLPP on NAFLD. Detection of key enzymes revealed that GLPP reversed low expression of CYP7A1,CYP8B1,FXR,SHP and high expression of FGFR4 in ob/ob mice and ApoC3 mice. Besides, GLPP inhibited fatty acid synthesis by reducing the expression of SREBP1c, FAS and ACC via a FXR-SHP dependent mechanism. Additionally, GLPP reduced the accumulation of lipid droplets and the content of TG in HepG2 cells and primary hepato-cytes induced by oleic acid and palmitic acid. CONCLUSION GLPP significantly improves NAFLD via regulating bile acid synthesis dependent on FXR-SHP/FGF pathway, which finally inhibits fatty acid synthesis,indicating that GLPP might be developed as a therapeutic drug for NAFLD.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the protective effects of quercetin on cadmium-induced cytotoxicity in primary cultures of rat proximal tubular (rPT) cells.</p><p><b>METHODS</b>Primary cultures of rPT cells undergoing exponential growth were incubated with 1.0 μg/mL quercetin and/or cadmium (2.5, 5.0 μmol/L), in a serum-free medium at 37 °C at different time intervals. Commercial kits were used and flow cytometric analyses were performed on rPT cell cultures to assay apoptosis and oxidative stress.</p><p><b>RESULTS</b>Exposure of rPT cells to cadmium acetate (2.5, 5.0 µmol/L) induced a decrease in cell viability, caused an increase in apoptotic rate and apoptotic morphological changes. Simultaneously, elevation of intracellular reactive oxygen species, malondialdehyde and calcium levels, depletion of mitochondrial membrane potential and intracellular glutathione, and inhibition of Na+, K+-ATPase, Ca2+-ATPase, glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) activities were revealed during the cadmium exposure of rPT cells. However, simultaneous supplementation with 1 µg/mL quercetin protected rPT cells against cadmium-induced cytotoxicity through inhibiting apoptosis, attenuating lipid peroxidation, renewing mitochondrial function and elevating the intracellular antioxidants (non-enzymatic and enzymic) levels.</p><p><b>CONCLUSION</b>The present study has suggested that quercetin, as a widely distributed dietary antioxidant, contributes potentially to prevent cadmium-induced cytotoxicity in rPT cells.</p>
Subject(s)
Animals , Rats , Antioxidants , Pharmacology , Therapeutic Uses , Apoptosis , Cadmium , Toxicity , Cadmium Poisoning , Calcium , Metabolism , Calcium-Transporting ATPases , Metabolism , Cells, Cultured , Kidney Tubules, Proximal , Metabolism , Malondialdehyde , Metabolism , Membrane Potential, Mitochondrial , Quercetin , Pharmacology , Therapeutic Uses , Reactive Oxygen Species , Metabolism , Sodium-Potassium-Exchanging ATPase , MetabolismABSTRACT
GL-PP-3A, an active polysaccharide peptide, was isolated and purified from Ganoderma lucidum, and then its structure was analyzed. Crude polysaccharide peptides were extracted from Ganoderma lucidum with hot water, precipitated with ethanol and then dialyzed from Ganoderma lucidum. Subsequently GL-PP-3A was isolated and purified from the crude polysaccharide peptides by fractional precipitation and chromatography of Bio-Gel P-10 column. The repetitive unit of GL-PP-3A was analyzed by high performance gel permeation chromatography (HPGPC), monosaccharide composition and methylation analysis, 1H NMR and 13C NMR. GL-PP-3A is a heteropolysaccharide which is composed mainly of glucose (Glc), and also contains saccharide residues such as rhamnose (Rha), xylose (Xyl), mannose (Man) and galactose (Gal) and 17 kinds of amino acids. Its weight-average molecular weight (Mw) and number-average molecular weight (Mn) were 1.7 x 10(4) and 1.1 x 10(4), respectively, with the ratio of Mw/Mn ( molecular weight distribution) being of 1.49. Its backbone chain is composed of 1,6-linked beta-D-Glcp and 1,3-liked beta-D-Glcp at a ratio of 2:1. Some of 1,6-linked glucose residuals of the backbone chain are substituted at 2-0 or 3-0, and there are 1 to 3 1,6-linked beta-D-Galp or 1,3-linked alpha-D-Manp in the branched chains, the nonreducing ends of which consist mainly of beta-D-Glcp and a few Rha.