Rutin Promotes Browning of 3T3-L1 Preadipocytes and Its Mechanism / 中国实验方剂学杂志

ObjectiveTo investigate the effect of rutin on the browning of 3T3-L1 preadipocytes and the mechanism. MethodCell counting kit-8 （CCK-8） assay was used to detect the effect of different concentration of rutin （3.125， 6.25， 12.5， 25， 50， 100， 200 μmol·L-1） on 3T3-L1 cell activity， and Western blot to examine the effect of rutin （12.5， 25， 50 μmol·L-1） on the expression of thermogenesis-associated proteins uncoupling protein 1 （UCP1）， PR domain containing 16 （PRDM16） and peroxisome proliferator-activated receptor γ coactivator-1α （PGC-1α） in adipocytes. After the optimal concentration of rutin was determined， the effect of rutin on lipid droplet formation in adipocytes was observed based on oil red O staining， and the expression of nuclear respiratory factor 1 （NRF1）， nuclear respiratory factor 2 （NRF2） and mitochondrial transcription factor A （TFAM）， which were the landmark proteins of mitochondrial biosynthesis， was detected by Western blot. ResultCompared with the blank group， 200 μmol·L-1 rutin inhibited 3T3-L1 cell activity （P<0.01）. Compared with the blank group， at the concentration of 12.5， 25， 50 μmol·L-1 rutin significantly promoted the expression of thermogenesis-associated proteins （UCP1， PRDM16， and PGC-1α） （P<0.01）， which was determined as the optimal concentration. Compared with the blank group， 50 μmol·L-1 rutin significantly increased the immunofluorescence intensity of mitochondrial UCP1 protein in 3T3-L1 cells （P<0.01） and the expression of the markers of mitochondrial biosynthesis （NRF1， NRF2， and TFAM） （P<0.01）. In addition， 50 μmol·L-1 rutin significantly inhibited lipid droplet formation of 3T3-L1 adipocytes （P<0.01）. ConclusionRutin inhibited lipid droplet deposition in 3T3-L1 adipocytes and increased the expression of thermogenesis-related proteins （UCP1， PRDM16， and PGC-1α） and markers of mitochondrial biosynthesis （NRF1， NRF2， and TFAM）， thereby inducing the browning of 3T3-L1 adipocytes. This lays a basis for the development of drugs that safely regulate the browning of white cells.

Mechanism of glucagon-like peptide 1 receptor agonist induced weight loss of mice / 天津医药

Objective To investigate the possible mechanisms of glucagon-like peptide 1 receptor agonists (GLP-1Ra) induced weight loss. Methods High fat diet induced obese c57BL/6 mice were divided into normal control group (N, n=8), high fat feeding group (HF, n=32) and GLP-1Ra group treated with GLP-1Ra (liraglutide 200μg/(kg·d) or 400μg/(kg·d) for 8 weeks). Changes of body weight, blood glucose and three acyl glycosides (TG) levels were observed in three groups. HE staining was used to observe the morphological changes. Immunofluorescence staining and real-time PCR were used to mea?sure the expression of UCP-1. Furthermore, the expression of PGC-1αin protein level was observed to explore the possible mechanism of GLP-1Ra induced browning in white fat (WAT). Results After 8-week liraglutide (Lira) administration, the body weights were significantly reduced in obese mice (P<0.05). The levels of blood glucose and TG were significantly high?er in HF group than those in N group, which reduced significantly in Lira (200μg·kg-1) and Lira (400μg·kg-1) administra?tion groups (P<0.05). HE staining showed adipocytes in perirenal and inguinal subcutaneous adipose tissue partly acquired brown-like morphological characteristics. The expression levels of UCP-1 protein and mRNA and PGC-1αprotein were ele?vated in adipse tissues, which increased more in Lira (400) than those in Lira (200, P<0.05). Conclusion GLP-1Ra can induce weight loss through white fat browning by activation of UCP-1.