Sida rhomboidea. Roxb Leaf Extract Down-Regulates Expression of PPARγ2 and Leptin Genes in High Fat Diet Fed C57BL/6J Mice and Retards in Vitro 3T3L1 Pre-Adipocyte Differentiation

Sida rhomboidea. Roxb leaf extract (SRLE) is being used by the populace of North-East India to alleviate symptoms of diabetes and obesity. We have previously reported its hypolipidemic and anti-diabetic properties. In this study, we report the effect of SRLE on (i) in vivo modulation of genes controlling high fat diet (HFD) induced obesity and (ii) in vitro 3T3L1 pre-adipocyte differentiation and leptin release. Supplementation with SRLE significantly prevented HFD induced increment in bodyweight, plasma lipids and leptin, visceral adiposity and adipocyte hypertrophy. Also, SRLE supplementation reduced food intake, down regulated PPARγ2, SREBP1c, FAS and LEP expressions and up-regulated CPT-1 in epididymal adipose tissue compared to obese mice. In vitro adipogenesis of 3T3L1 pre-adipocytes was significantly retarded in the presence of SRLE extract. Also decreased triglyceride accumulation, leptin release and glyceraldehyde-3-Phosphate dehydrogenase activity along with higher glycerol release without significant alteration of viability of 3T3L1 pre-adipocytes, was recorded. Our findings suggest that prevention of HFD induced visceral adiposity is primarily by down regulation of PPARγ2 and leptin gene expression coupled with attenuation of food intake in C57BL/6J mice. SRLE induced prevention of pre-adipocytes differentiation, and leptin release further substantiated these findings and scientifically validates the potential application of SRLE as a therapeutic agent against obesity.     

低密度支撑剂研究进展

低密度支撑剂是通过化学改性、物理改性等方法制备得到的高性能支撑剂，具有密度低、沉降速度低等特性。本文在调研大量文献基础上，根据改性方法不同将低密度支撑剂分为多孔无包覆陶瓷低密度支撑剂、多孔无机物包覆低密度支撑剂、多孔树脂包覆低密度支撑剂，对比了不同类型低密度支撑剂制备体系组成、密度以及承压性能，总结了制备不同类型低密度支撑剂的机理、主要影响因素及应用情况。根据制备方式不同将超低密度支撑剂（ultra-light weight proppants， ULWP）分为常规方法制备、新技术制备两类。提出未来可通过结合使用多种添加剂、优化烧制工艺等方式探索莫来石相、刚玉相等晶体结构，实现支撑剂超低密度与高强度的有效结合，利用疏水改性、结构改性等方式向多功能、高性能发展，为相关研究提供借鉴和参考。