Yacon Flour: A Functional Food Ingredient with an Impact on the Adipose Tissue Remodeling of Obese Rats

Abstract

Background: The increase in the global prevalence of overweight and obesity has prompted a wide range of strategies to reduce its impact on health. Research in the field of nutrition has shown great interest in the potential of functional foods as a non-pharmacological alternative to prevent or counteract obesity. Here we analyzed the effects of Smallanthus sonchifolius (yacon) flour on hypoxia, oxidative stress, inflammation, and differentiation of visceral white adipose (WAT) tissue in HFD-fed rats. We also compared these effects with agave inulin supplementation, to better characterize the prebiotic potential of these oligofructans as functional ingredients. Results: We found that yacon flour mainly exerts comprehensive effects by limiting visceral WAT expansion and downregulating the Hypoxia-inducible transcription factor-1α (HIF-1α) expression, an important regulatory signaling molecule that mediates the inflammatory responses induced by hypoxia. Also, yacon reduces lipid peroxidation, improves the antioxidant system, and attenuates the expression of proinflammatory genes MCP-1, TNF-α, IL-1β and IL-6, and TGF-β1, elevating anti-inflammatory IL-10, in visceral WAT. Further, yacon down-regulates Wnt5a and up-regulates Wnt3a and SLC2A4 expressions in visceral WAT, ameliorating insulin resistance of HFD rats. Otherwise, Agave inulin supplementation can improve visceral WAT pathology, avoiding oxidative stress and inflammation mainly by increasing GSH levels and reducing IL6 expression. No effect on HIF-1α and Wnt5a gene expression was detected in the visceral WAT of inulin-supplemented rats. Conclusion: Collectively, our data indicate that yacon flour, unlike inulin, produces a selective reduction of HIF-1α that improves adipose tissue remodeling. Our results demonstrate the promising efficacy of yacon as a dietary therapeutic strategy to improve the visceral WAT dysfunction and reduce alterations associated with diet- induced obesity.