Upland pigmented potatoes as resilient foods with preventive effects: in vitro anti-inflammatory activity based on their distinctive bioactives

Upland potatoes represent a resilient and economical source of health-beneficial bioactives such as polyphenols and carotenoids1-3. In the framework of the JPI FACCE SYSTEMIC project, we aimed at studying the anti-inflammatory effect of three commercial potato varieties cultivated in Starleggia (Valle Spluga, 1560 masl). Biochemical analyses allowed us to consider extracts from Kennebec (white flesh, yellow skin), Desirée (yellow flesh, red skin) and Bleuet (purple flesh and skin) varieties as chlorogenic acid (CGA)-rich, carotenoid-rich and anthocyanin (ACN)-rich, respectively. The anti-inflammatory potential of these compounds was tested on PMA-induced THP-1 macrophages challenged with LPS via qPCR and ELISA. Dose response experiments highlighted that while Kennebec extract reduced LPS-induced inflammation only at supra-physiological doses, Desirèe and Bleuet extracts significantly decreased it at doses near those reachable in plasma after consumption of pigmented potatoes. Surprisingly, the ACN-rich Bleuet raw extract showed a lower anti-inflammatory activity at plasmatic doses compared to the carotenoid-rich Desirée. We speculated that the high level of CGA in Bleuet extract could interfere with ACNs. Consistent with this, the Bleuet isolated ACN fraction showed a stronger anti-inflammatory activity than the raw extract and adding CGA to ACNs significantly reduced the ACN anti-inflammatory effect. We explored their possible interaction with membrane transporters via molecular docking. Overall, upland pigmented potatoes may represent a source of anti-inflammatory phytonutrients, but the possible interference between CGA and ACN anti-inflammatory activity indicates a new starting point to develop/select ACN-rich varieties with a lower content of CGA.