[Apigenin regulates lipopolysaccharides-induced activation of inflammasome].
OBJECTIVE
To evaluate whether or not apigenin regulates the activation of inflammasome and elucidate its underlying mechanism.


METHODS
Cultured THP-1 (acute monocytic leukemia cell line) cells were treated with dimethyl sulfoxide (DMSO) alone (control group), lipopolysaccharides (LPS), LPS plus apigenin (25/50 µmol/L) or LPS plus Z-VAD (a caspase inhibitor). The supernatant was harvested and the content of secreted interleukin (IL)-1β was determined by enzyme-linked immunosorbent assay (ELISA). The effects of apigenin on the cleavage of pro-IL-1β and pro-caspase-1 were determined by Western blot. And the effect of apigenin on the nuclear factor (NF)-κB activation was detected by reporter gene assay.


RESULTS
MTT assays showed that the cytotoxicity of apigenin was low. Apigenin could significantly inhibit the LPS-induced secretion of IL-1β in THP-1 cells. The concentration of IL-1β was (362 ± 64) pg/ml in the control group, (1549 ± 320) pg/ml in the LPS group, (397 ± 150) pg/ml in the LPS plus 25 µmol/L apigenin group and (268 ± 142) pg/ml in the LPS plus 50 µmol/L apigenin group (P < 0.05). The results of Western blot indicated that apigenin inhibited the maturation of pro-IL-1β and pro-caspase-1. It could also inhibit the LPS-induced activation of NF-κB. The value of relative light unit was 0.6 ± 0.1 in the control group, 32.7 ± 0.8 in the LPS group, 12.9 ± 1.8 in the LPS plus 25 µmol/L apigenin group and 10.0 ± 3.2 in the LPS plus 50 µmol/L apigenin group respectively (P < 0.05).


CONCLUSIONS
Apigenin may inhibit the LPS-induced activation of inflammasome through an inhibited muturation of caspase-1.
Department of Dermatology, Jishuitan Hospital, Beijing 100035, China. Email: lywang.jst@gmail.com.
Ling-Yan
LY
Wang
Jie
J
Kuang
Jing
J
Li
D047310:Apigenin; D020170:Caspase 1; D002460:Cell Line; D006801:Humans; D058847:Inflammasomes; D053583:Interleukin-1beta / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism
D058847:Inflammasomes; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D016328:NF-kappa B; D047310:Apigenin; D020170:Caspase 1