Effect of Daxx on cholesterol accumulation in hepatic cells

AIM： To study the effect of Daxx on cholesterol accumulation in hepatic cells. METHODS： Sprague Dawley （SD） rats were fed a normal or high fat diet for 6 wk, and serum lipids and Daxx expression of hepatic tissues were measured by immunoblot assays. HepG2 cells were transfected with the pEGFP-C1/Daxx or pEGFP-C1 plasmid. Cells stably transfected with Daxx were identified by RTPCR analysis. Total cholesterol levels were determined by high performance liquid chromatography. Activated- SREBP and caveolin-1 were assayed by western blotting. RESULTS： Hepatic Daxx protein was higher in normal rats than in high fat diet-fed rats. Noticeable negative correlations were seen between Daxx and LDL-C （γ=-7.56, ρ=0.018）, and between Daxx and TC （γ=-9.07, ρ= 0.01）, respectively. The total cholesterol of HepG2/GFP-Daxx cells was lower than that of control cells or HepG2/GFP cells （9.28±0.19 vs 14.36± 4.45 or 13.94±2.62, both P 〈 0.05）. Furthermore, in HepG2/GFP cells, the expression of activated SREBP was lower than that of control cells, whereas caveolin-1 expression was higher. CONCLUSION： Overexpression of Daxx in HepG2 cells decreased intracellular cholesterol accumulation, which might be associated with inhibition of SREBP activity and an increase in caveolin-1 expression.

Optimization of Ultrasound-assisted Enzymatic Polysaccharide Extraction from Turpiniae Folium Based on Response Surface Methodology

Objective To optimize the extraction procedure and obtain the maximum total polysaccharide yield from Turpiniae Folium.Methods Response surface methodology(RSM),combining Plackett–Burman design(PBD),steepest ascent method,and Box–Behnken design(BBD),was employed.The significant factors contributing to polysaccharide production were determined by PBD.The path of steepest ascent method was performed to rapidly reach the neighborhood of the optimum region.BBD and RSM were applied to further investigate the mutual interaction between the variables and to define the optimal values.Results The significant factors contributing to polysaccharide production were enzyme concentration,extraction time,and liquid-to-solid ratio.The optimal conditions for maximal TFP were:enzyme concentration of2.8%,extraction time of41min,and liquid-to-solid ratio of27mL/g.The experimental yield of3.08%was in good agreement with the model-predicted yield of3.1%under the optimized conditions.Conclusion This study was successfully applied to optimize the extraction conditions of Turpiniae Folium polysaccharide,which can contribute to its further production and application.

Effect of Autophagy Over Liver Diseases

In recent years, increasingly evidences show that autophagy plays an important role in the pathogenesis and development of liver diseases, and the relationship between them has increasingly become a focus of concern. Autophagy refers to the process through which the impaired organelles, misfolded protein, and intruding microorganisms is degraded by lysosomes to maintain stability inside cells. This article states the effect of autophagy on liver diseases （hepatic fibrosis, fatty liver, viral hepatitis, and liver cancer）, which aims to provide a new direction for the treatment of liver diseases.

Establishing a Quality Control System of Hedyotis corymbosa

Objective Hedyotis corymbosa(Shui Xian Cao,水线草,HC)is the main antitumor medicine in China and other southeast Asian countries.A comprehensive quality control system of HC was established in this study,as the current system was ineffective.Methods Microscopy was used to observe the characteristics of the powder and cross-sectional tissue.Thin layer chromatography(TLC)was employed to separate HC from Hedyotis diffusa(Bai Hua She She Cao,白花蛇舌草,HD).Simultaneously,high-performance liquid chromatography(HPLC)was used to establish the characteristic spectrum of HC and determine the concentrations of hedyotiscone A.Regarding the issue of systematicness,concentrations of water,total ash,acid-insoluble ash,heavy metals(including lead,arsenic,mercury,cadmium and copper)and pesticide residue were measured by the methods described in the 2015 edition of Chinese Pharmacopoeia.Results Calcium oxalate needle crystal bundles and oil drops were observed in the cross-sectional tissue.Three characteristic blue fluorescent spots were observed in the HC samples by TLC.There were five distinct characteristic peaks in HC but not in HD,and hedyotiscone A was the sharpest characteristic peak.The generated linear equation of hedyotiscone A was Y=3.15×108X+312.04(r2=1.000)between 0.00005270 and 0.002108 mg/mL,and the average recovery was 100.42%.Precision[relative standard deviation(RSD)0.92%],repeatability(RSD 0.14%),and recovery(RSD 0.85%)met the requirements for quantitative analysis.Hedyotiscone A concentrations ranged from 0.00017%~0.00113%across different habitats.Concentrations of water,ash and acid-insoluble ash were 8.80%~11.2%,7.00%~15.3%and 0.440%~7.70%,respectively.Concentrations of Pb,As,Hg,Cd and Cu were 1.60~4.60,0.650~1.60,0.0300~0.100,0.240~0.690 and 10.1~16.6μg/g,respectively.Pesticide residues were less than 0.00100 ppm.Conclusion The quality control system can effectively distinguish HC from HD,so as to comprehensively control the quality of HC,to provide references for the clinical use of HC.