Inflammation
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The roles of TLR4 in mediation of innate immune response and in regulation of adaptive immune responses triggered by Clonorchis sinensis remain unknown. In the present study, splenocytes derived from C3H/HeN (TLR4 wild ) and C3H/Hej mice (TLR4 mut ) that were infected with 45 metacercariae of C. sinensis were harvested, then stimulated by C. sinensis excretory/secretory products (ESP) or medium (control) for 48 h, respectively. Meanwhile, bone marrow-derived dendritic cells (BMDCs) from normal C3H/HeN and C3H/Hej mice were prepared and stimulated with medium, ESP, LPS, or ESP+LPS for 24 h, respectively. ⋯ For BMDCs, the productions of the cytokines IL-12p70 and IL-10, but not IL-4, in the BMDCs from TLR4 mutation mice were predominantly decreased compared with those from TLR4 wild mice when the BMDCs were co-stimulated by ESP combined with LPS. Flow cytometry analysis showed that ESP could significantly decrease the high levels of CD80, CD86, and MHC II which were elevated by LPS. In conclusion, these data suggest that TLR4 may play a regulatory role in type 1 immune responses during C. sinensis infection.
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The purpose of this study was to investigate the protective effects of Saikosaponin a (SSa), a triterpene saponin derived from Radix bupleuri, on lipopolysaccharide (LPS)-induced acute lung injury (ALI) using a murine model. The mice were given SSa 1 h after intranasal instillation of LPS. Then, lung histopathological examination, the wet/dry (W/D) ratio, myeloperoxidase (MPO), and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were detected in this study. ⋯ Furthermore, LPS-induced lung W/D ratio, MPO activity, and inflammatory cytokines TNF-α and IL-1β in BALF were significantly inhibited by SSa. In addition, SSa suppressed LPS-induced NF-κB activation and NLRP3 inflammasome expression. In conclusion, we found that SSa played a critical anti-inflammatory effect through inhibition of NF-κB and NLRP3 signaling pathways and protected against LPS-induced ALI.