The composition and anti-inflammatory properties of pumpkin seeds

Pumpkin seeds (PSs) are common in daily diet, which have diverse biological activities. We characterized the metabolome of PSs and revealed their anti-inflammation mechanism that have not been fully elucidated. The air-dried and powdered PSs were extracted and reconstituted in 600 μl phosphate buffer for NMR analyses, and fatty acid profile was analyzed by GC–MS. The fatty acid esters of hydroxy fatty acids (FAHFAs) were analyzed by HPLC–MS, and anti-inflammatory activity of oleic acid ester of hydroxy oleic acid (OAHOA) was explored in vitro and in vivo. Finally, analysis of variance was performed (statistically significant when P < 0.05). PSs were mainly composed of oleic acid (18:1), linoleic acid (18:2△9,12), amino acids, sugars, trigonelline, and betaine. Further we identified OAHOA in PSs and discovered that OAHOA reduced inflammation in adipose tissue by inhibiting the expression of cytokines IL-12, IL-1β, and TNF-α. The metabolic profile of PSs was established, especially the fatty acids composition. This research revealed that the anti-inflammatory effects of PSs might be exerted through FAHFAs.