Inhibitory Effect and Mechanism of Arctium lappa Extract on NLRP3 Inflammasome Activation

Figure 1

Inhibitory effects of ALE on NLRP3 inflammasome mediated IL-1β secretion in vitro and in vivo. (a) BMDMs were treated with the indicated concentration of ALE for 6 h. Cell viability was measured by MTT assay. LPS-primed BMDMs were pretreated with ALE or zVAD at an indicated concentration for 1 h and then stimulated with ATP (b, e, and g); nigericin (Nig.) (c, f, and h) for 1 h; and silica crystals (silica) (d and i) for 3 h. IL-1β (b–d) and TNF-α (f) concentrations in the culture supernatant were measured by ELISA. (e) Cytotoxicity of ALE was measured with LDH release in the culture supernatants. (g~i) Culture supernatants (S/N) and cell lysates from BMDMs pretreated with or without sample and primed with LPS and indicated stimulators were analyzed by immunoblotting. LPS-primed BMDMs were treated with ALE or zVAD at an indicated concentration for 1 h, and flagellin (Fla) (j) or poly(dA:dT) (k) was delivered into cytosol through lipofectamine 2000. Culture supernatants were analyzed by immunoblotting. (l and m) C57BL/6 mice were given intraperitoneal injections of ALE or a NLRP3 specific inhibitor, MCC950, 2 h and 12 h prior to LPS injection (20 mg/kg). Blood samples were collected 2 h after the LPS challenge and the concentrations of IL-1β (l) and TNF-α (m) in plasma were measured by ELISA. The data represent the mean ± SEM of three independent experiments performed in triplicate. , , and compared with LPS plus stimuli.

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