Upland pigmented potatoes as a climate change-resilient functional food against inflammatory-related diseases

Background: Unhealthy diet and chronic inflammation are involved in the pathogenesis and/or progression of non communicable diseases, such as cardiovascular and neurodegenerative disorders, diabetes and cancer, the leading causes of mortality. Among these, the World Health Organisation cited also climate change as an additional risk factor of these pathologies. In this scenario, finding resilient, sustainable and cost-effective crops able to grow with fewer resources, but still enriched in functional health-promoting bioactives, has become of utmost importance. Thus, pigmented upland potatoes could represent a valuable source of phytonutrients known for their antioxidant, anti-inflammatory and beneficial properties, such as carotenoids and anthocyanins. Methods: Extracts from three commercial upland potato tubers differently enriched in phytonutrients have been characterized through HPLC-DAD and spectrophotometry in terms of content in well-known bioactives, such as chlorogenic acid (Kennebec variety), carotenoids (Desirée variety) and anthocyanins (Bleuet variety). Their potential anti-inflammatory effect was tested on PMA-induced THP-1 derived macrophages insulted with LPS. The dose-dependent activity of the three extracts, fractions or the combination of pure compounds against LPS-induced pro-inflammatory cytokine (TNF-α, IL-1β, IL-6) genes and proteins has been evaluated through qPCR and ELISA. Results: The treatment with Kennebec (chlorogenic acid-rich), Desirée (carotenoid-rich) and Bleuet (anthocyanin-rich) extracts showed that at “supra-physiological” doses, all extracts were able to decrease LPS-induced pro-inflammatory genes, but when provided at “plasmatic doses”, near the ones reachable in vivo after potato consumption, only the carotenoid-rich Desirée and the anthocyanin-rich Bleuet extracts showed anti-inflammatory activity reducing both cytokines gene expression and secretion. Nevertheless, since the anti-inflammatory activity of the Bleuet extract was lower than expected, we speculated that the high concentration of chlorogenic acid in the extract interfered with anthocyanins in counteracting LPS-induced inflammation. In fact, the Bleuet anthocyanin fraction lowered pro-inflammatory gene expression more than the raw extract. Moreover, the addition of pure chlorogenic acid to a mixture of anthocyanins (pure or from Bleuet anthocyanin fraction), significantly reduced the anti-inflammatory activity of these compounds. Conclusions: Our results suggest that pigmented upland potatoes, like Desirée and Bleuet, may represent an economical and resilient source of bioactive compounds with the putative ability to prevent inflammatory-related diseases. Furthermore, the possible interference between chlorogenic acid and the anthocyanin anti-inflammatory activity indicates a new starting point to develop/select anthocyanin-rich potato varieties with a lower content of chlorogenic acid, eventually representing a novel functional food.