Abstract
In the past few years, metabolic disorders, such as type 2 diabetes and metabolic
syndrome, have reached global prevalence. Lycopene is one of the major carotenoids
in tomatoes, watermelons, red grapefruits, and guava. In the current study, using
high fat diet (HFD)-fed mice, we investigated the effect of Lycopene on insulin resistance.
We showed that diet containing Lycopene significantly prevented HFD-induced increase
of fasting blood glucose and insulin level, glucose and insulin intolerance, and decrease
of hepatic glycogen content. We found that Lycopene notably prevented the increase
of IL-1β, TNFα and CRP levels in mice fed HFD. We showed that Lycopene improved the
lipid profiles in HFD-fed mice, as evidenced by decrease of systemic and hepatic TC,
TG and LDL, and increase of HDL. Lycopene suppressed the increase of the expression
of Srebp-1c, FAS and ACC-1 in mice fed HFD. The administration of Lycopene notably
prevented the expression and phosphorylation of STAT3 in livers of mice induced by
HFD. The treatment of adenovirus carrying STAT3 significantly suppressed the decrease
of Srebp-1c expression induced by Lycopene. Furthermore, enhancement of STAT3 signaling
by adenovirus markedly blocked the reduction of fasting blood glucose and insulin
level. In conclusion, in the current study, we found that Lycopene prevented STAT3
signaling and inhibited Srebp-1c and downstream gene expression, resulting in inhibition
of lipid accumulation, inflammation, insulin resistance and metabolic dysfunction.
Overall, the data in the study provide better understanding of the beneficial effects
of Lycopene against insulin resistance and metabolic disorder.
Key words
Lycopene - insulin resistance - metabolic disorder - Srebp-1c - STAT3
