Pigmented upland potatoes: different in vitro anti-inflammatory activity based on their distinctive bioactives

BACKGROUND: In a climate change scenario, finding resilient crops able to grow with fewer resources, but still nutritionally relevant and with potential beneficial properties, has become of utmost importance. In this context, pigmented upland potatoes could represent a valid sustainable source of bioactive compounds for the future. Since the pigments that characterize these varieties are naturally occurring anti-inflammatory and antioxidant compounds, such as carotenoids and anthocyanins, these tubers may serve as functional food to prevent non-communicable diseases (NCDs) whose risks factors are, among others, unhealthy diet and consequent chronic inflammation. In fact, carotenoid and anthocyanin consumption inversely correlates with the development of chronic diseases, such as obesity, cancer, neurodegenerative and cardiovascular diseases by counteracting inflammation. OBJECTIVES: We aimed to study the anti-inflammatory activity of different combinations of phytonutrients present in three upland potato varieties proposed as a possible source of bioactive compounds. METHODS: Tubers from three commercial potato varieties differently enriched in phytonutrients, named Kennebec (yellow-skinned and white-fleshed), Desirée (red-skinned and yellow-fleshed) and Bleuet (purple skinned and fleshed) have been cultivated on Italian mountains (Starleggia, Valle Spluga, Lombardy, 1560masl). Extracts from lyophilized whole tubers have been obtained and analyzed through HPLC-DAD and spectrophotometric analysis. THP-1 human monocytes were differentiated in macrophages through PMA-treatment, treated with the three extracts and then challenged with LPS to induce an inflammatory response. The dose-dependent effects of the different combinations of phytonutrients on pro-inflammatory genes and/or proteins were evaluated. RESULTS: The extracts from Kennebec, Desirèe and Bleuet were found to be enriched in clorogenic acid (CGA), carotenoids and anthocyanins, respectively. All three extracts were able to counteract LPS-induced inflammation in THP-1 macrophages when provided at higher doses. Nevertheless, at lower doses, comparable with those detected in human plasma after potato consumption, only the carotenoid- and anthocyanin-rich extracts from Desirèe and Bleuet exerted a significant anti-inflammatory activity. A further analysis of the anti-inflammatory activity of flavonoid fractions suggests a possible interaction among different classes of polyphenols. CONCLUSION: Our results suggest that pigmented upland potatoes, like Desirée and Bleuet, may represent an economical and resilient source of bioactive compounds with the ability to prevent inflammation.