was evaluated by real time RT-PCR. Luteolin aglycone significantly
inhibited LPS-induced expression of these three cytokines
(Fig. 4b–d). TNF-α and IL-6 expression was reduced by
53.3 ± 10.0% and 73.7 ± 34.7%, respectively, and IL-1β expression
was completely abolished. Concerning the effect of luteolin
glycosylated, only L7OG modulated cytokine expression, reducing
the LPS-induced IL-1β expression by 45.7 ± 30.4%, thus
reinforcing the L7OG anti-inflammatory properties, by
inhibiting NO and also IL-1β production. Interestingly, the
inhibition of NO production and iNOS expression by luteolin
5-O-glucoside was recently reported (Jung, Jin, Min, Kim, & Choi,
2012), thus indicating that the position of O-glycosylation in
the A ring did not affect the anti-inflammatory activity.
All together, the results demonstrated that glycosylation decreased
luteolin activity in vitro and the decrease was higher
for the C-glycosylation than O-glycosylation in the A ring.
Accordingly, previous data evidenced that glycosylation of