Effects of Ginkgo biloba Extract (GbE) on FAS and Perilipin Gene and Protein Expression

Introduction: Taking into consideration the severity and risks associat¬ed with obesity, alternatives treatment strategies are highly necessary and Ginkgo biloba extract (GbE) has been investigated as a non-conventional therapy. Our laboratory has previously demonstrated that GbE treatment reduced body adiposity and fatty depot mass on diet-induced obese rats. However, it is unknown the mechanism of action involved with positive effects of GbE. In view of the above considerations, the aim of this study was to evaluate the effect of GbE on gene and protein expression of pro¬teins involved in lipolysis and de novo synthesis of fatty acids on epididy¬mal adipose fat pad in obese rats.
Methods: Male rats were fed from 2 to 4-mo-old with high fat diet and thereafter treated for 14 days with 500mg/kg of GbE (HFD+GbE) or sa¬line (HFD). NFD group was control group and received normal fat-diet during all the period and saline during treatment. Rats were euthanized and epididymal fat depot was removed. Gene expression of ATGL, HSL, Perilipin, FAS, ap2, SSEBP and PPARγ were evaluated by RT-PCR and Western blotting was used to FAS protein expression levels.
Results: Both HFD and HFD+GbE groups reduced food/energy intake in comparison to NFD group (45.1% and 50.0%, respectively, p = 0.001). HF¬D+GbE also fairly decreased food/energy intake comparing to HFD (8.8%, p = 0.01). Perilipin gene expression was increased by 335%(p = 0.03) in HFD in comparison to NFD, while HFD+GbE was reduced by 95.2% in comparison to HFD (p = 0.01). Gene expression of FAS also decreased 70.7% in HFD+GbE in comparison to NFD (p = 0.02). Besides decreasing gene expression, the protein expression of FAS was reduced by 38% in HFD+GbE group in comparison to NFD group (p = 0.03).
Conclusion: GbE decreased gene and protein expression of important proteins involved in two metabolic process: lipolysis and de novo synthe¬sis of fatty acids. This allows us to suggest GbE might be investigated as an antiobesogenic therapy, since positive results have been observed. It is important to note that the GbE effects were observed in rats kept feeding with high fat diet. The data suggest that GbE might have potential as a therapy to treat obesity and its comorbidities, especially for obese subjects resistant to adhere to a nutritional education program.