Anti-inflammation Activity Evaluation of Apigenin-O-Glycosides and Apigenin-C-Glycosides

Objective: The anti-inflammatory activities of apigenin-7-O-β-D-glucopyranoside, apigenin 5-O-glucoside, vitexin and isovitexin were evaluated. Methods: Changes of protein in THP-1 cells pretreated with flavonoids were measured by Western blot test. The differences of cytokines were analyzed by enzyme-linked immunosorbent assay and fluorescence quantitative polymerase chain reaction. Results: It showed that all the flavonoids tested could repress the gene expression of IL-10 (P<0.01). Vitexin and isovitexin inhibited the production of cyclooxygenase-2 as well (P<0.01). What’s more, isovitexin significantly suppressed the increases of interleukin-1β (P<0.01) and interleukin-6 (P<0.01). Apigenin-7-O-β-D-glucopyranoside only significantly inhibited TNF-α (P<0.01). Apart from IL-10 mRNA, apigenin 5-O-glucoside displayed no anti-inflammatory effects according to the other results of cytokine analyses. Furthermore, the structure of apigenin-C-glycoside substituted at position 8, namely isovitexin showed the strongest inhibition on nuclear translocation of P65 (P<0.01). However, this suppression effect of isovitexin on P65 was not through inhibiting upstream regulation proteins such as IκBα and IKKβ. Conclusion: In a word, compared with apigenin-O-glycosides, apigenin-C-glycosides especially isovitexin had a better anti-inflammatory activity based on cell line THP-1. But the anti-inflamamtion of isovitexin was not IκBα -dependent NF- κB signal pathway.