Lycopene-rich tomato oleoresin modulates plasma adiponectin concentration and mRNA levels of adiponectin, SIRT1, and FoxO1 in adipose tissue of obese rats

Abstract

Aim: To investigate whether lycopene can modulate adiponectin levels and SIRT1 and FoxO1 gene expression in the adipose tissue of diet-induced obese rats. Methods: Male Wistar rats were first fed with hypercaloric diet (HD, n = 12) for 6 weeks, and afterward, these rats were randomly assigned to receive HD (n = 6) or HD with lycopene-rich tomato oleoresin (equivalent to lycopene 10 mg/kg body weight (BW)/day, HD + L, n = 6) by gavage for additional 6 weeks. Plasma lycopene and adiponectin levels were analyzed by high-performance liquid chromatography and immunoassay, respectively. The messenger RNA (mRNA) expressions of adiponectin, Sirtuin 1 (SIRT1), Forkhead box O 1 (FoxO1), fatty acid translocase/cluster of differentiation 36 (FAT/CD36), and PPARg in adipose tissues were determined by quantitative polymerase chain reaction. Results: Lycopene was detected in the plasma of rats in HD + L group but not in the HD group. Although both BW and adiposity were not different between the two groups, there was a significant increase in both plasma concentration and mRNA expression of adiponectin in the adipose tissue of the HD + L group. In addition, the lycopene supplementation upregulated mRNA expressions of SIRT1, FoxO1, and FAT/CD36 but downregulated PPARg in adipose tissue of obese rats. Conclusion: These data suggest that lycopene, in the concentration used, is not toxic and also its health benefits in adipose tissue may play a role against obesity-related complications.