Smallanthus sonchifolius (Yacon)‎ Flour Improves Visceral Adiposity and Metabolic Parameters in High-Fat-Diet-Fed Rats

Abstract EN

Smallanthus sonchifolius (yacon), a native plant of South America, was observed to improve lipid profile in rodents and humans.

This study aimed to investigate the antiobesity properties of yacon roots in a high-fat-diet (HFD) model and the underlying mechanisms.

A total of 30 Wistar male rats were divided into five groups (n=6): the standard chow diet (SD) group was fed a SD; the HFD group was fed a HFD; and the HFD Y340 and HFD Y680 groups were fed a HFD plus yacon flour (340 and 680 mg FOS/kg b.

w./day, respectively).

HFD Y340 and HFD Y680 rats exhibited marked attenuation of weight gain, a decrease in visceral fat pad weight, a restoration of the serum lipid profile and atherogenic index in a dose-dependent manner, being the higher dose more effective (p<0.05).

In addition, we found that HFD Y680 rats showed lower glucose and insulin levels, improved glucose tolerance, and insulin sensitivity (p<0.5).

A downregulation of several adipocyte specific-transcription factors, including peroxisome proliferator-activated receptor gamma2 (PPAR-γ2), CCAAT/enhancer binding protein a (C/EBP-a) and activating protein (aP2) mRNA levels, was determined in the visceral adipose tissue of HFD Y680 rats (p<0.05).

An improvement of adipokine profile in HFD Y680 rats and decreased serum proinflammatory cytokine levels (p<0.05) were determined by ELISA.

Decreased macrophage infiltration and F4/80 and MCP-1 expression in the visceral adipose tissue of HFD Y680 rats (p<0.5), together with a higher pAkt/Akt expression (p<0.05) were also observed by immunofluorescence and immunoblotting.

A significant increase in glucagon (Gcg) and PYY mRNA levels in distal ileum of HFD Y680 rats (p<0.05) were also detected.

In the second approach, we determined that yacon supplementation potentiates the effects of the HFD reversion to a standard diet.

In conclusion, yacon showed antiobesity properties by inhibiting adipogenesis and improving the visceral adipose tissue function.