Guggulsterone inhibits adipocyte differentiation and induces apoptosis in 3T3-L1 cells.
OBJECTIVE
To determine the effects of guggulsterone (GS), the active substance in guggulipid, on apoptosis, adipogenesis, and lipolysis using 3T3-L1 cells.


METHODS
For apoptosis and lipolysis experiments, mature adipocytes were treated with GS isomers. Viability, apoptosis, and caspase 3/7 activation were quantified using MTS, enzyme-linked immunosorbent assay (ELISA), caspase-Glo 3/7 activity assay, respectively. The expression of cytochrome c was demonstrated by western blot. Lipolysis was quantified by measuring the release of glycerol. For adipogenesis experiments, postconfluent preadipocytes were incubated with GS isomers for up to 6 days during maturation. Adipogenesis was quantified by measuring lipid content using Nile Red dye. Western blot was also used to demonstrate the adipocyte-specific transcription factors peroxisome proliferator-activated receptor gamma2 (PPARgamma2), CCAAT/enhancer binding protein alpha (C/EBPalpha), and C/EBPbeta.


RESULTS
In mature adipocytes cis-GS decreased viability, whereas the trans-GS isomer had little effect. Both isomers caused dose-dependent increases in apoptosis and cis-GS was more effective than trans-GS in inducing apoptosis. cis- and trans-GS also increased caspase-3 activity and release of cytochrome c from mitochondria. In maturing preadipocytes, both isomers were equally effective in reducing lipid content. The adipocyte-specific transcription factors PPARgamma2, C/EBPalpha, and C/EBPbeta were downregulated after treatment with cis-GS during the maturation period. Furthermore, cis-GS increased basal lipolysis of mature adipocytes, but trans-GS had no effect.


CONCLUSIONS
These results indicate that GS isomers may exert antiobesity effects by inhibiting differentiation of preadipocytes, and by inducing apoptosis and promoting lipolysis of mature adipocytes. The cis-GS isomer was more potent than the trans-GS isomer in inducing apoptosis and lipolysis in mature adipocytes.
Yang
Jeong-Yeh
JY
Department of Animal and Dairy Science, University of Georgia, Athens, Georgia, USA.
Della-Fera
Mary Anne
MA
Baile
Clifton A
CA
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects; D051379:Mice; D047495:PPAR gamma / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011282:Pregnenediones / Q000494:pharmacology*; D014280:Triglycerides / Q000378:metabolism
D047495:PPAR gamma; D011282:Pregnenediones; D014280:Triglycerides; D045304:Cytochromes c; C023617:pregna-4,17-diene-3,16-dione; D048049:Extracellular Signal-Regulated MAP Kinases; D053148:Caspase 3; D053179:Caspase 7