Metabolite Composition and Anti-Inflammatory Activity of Ethanol Extract of Camellia oleifera Seed

Abstract

To explore the anti-inflammatory mechanism of Camellia oleifera seed oil, the metabolites in ethanol extracts from 15 batches of C. oleifera seeds were analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and the inhibitory activity of the ethanol extracts on enteritis in Drosophila was evaluated by the “Smurf” test. The correlation between small molecular metabolites in the ethanol extracts and their anti-inflammatory activity was investigated and molecular docking with lipoxidase (LOX) was conducted to identify the key metabolites. Finally, the key metabolites were verified by the “Smurf” test. The results showed that the ethanol extract of C. oleifera seeds had good enteritis inhibitory activity, with percentage inhibition of 15.06%–61.71%, and its metabolites mainly included polyphenols, amino acids, organic acids, nucleotides, sugars and lipids. Seven polyphenolic compounds were identified in C. oleifera seeds for the first time. The monomeric compounds with good anti-enteritis activity were preliminarily identified as bruceine B, miltirone, 8-geranyloxypsoralen, cedrelone, wighteone, kaempferitrin and kaempferol-3-O-rutinoside. The anti-inflammatory activity of wighteone was reported for the first time in this study, and at 0.1 mg/mL, the percentage inhibition of enteritis was 64%, much greater than the positive control sulfasalazine (27.99%). This study lays the foundation for further exploring the anti-enteritis activity and mechanism of C. oleifera seed oil in vitro and in vivo.

Keywords

• camellia oleifera seed; anti-inflammatory activity; ultra-high performance liquid chromatography-tandem mass spectrometry; metabolites; molecular docking