iTRAQ-based quantitative proteomic analysis reveals Bai-Hu-Tang enhances phagocytosis and cross-presentation against LPS fever in rabbit

Ethnopharmacological relevance: Bai-Hu-Tang (BHT), a classical anti-febrile Chinese formula comprising of liquorice, anemarrhena rhizome, gypsum and rice, has been traditionally used to anti-febrile treatment and promote the production of body fluid to relieve thirst. In this paper, we aim to explore anti-febrile mechanism of BHT at protein level through analyzing alteration of differentially expressed proteins (DEPs) both lipopolysaccharide (LPS) fever syndrome and that was treated with BHT in rabbits. Materials and methods: Febrile model was induced by LPS injection (i.v.) in rabbits, and BHT (750 mg dry extract/kg body weight) was gavaged to another group of LPS fever rabbits. After sacrifice of animals, total protein of liver tissue was isolated, and two-dimensional liquid chromatography (LC) - tandem mass spectrometry (MS) coupled with isobaric tags for relative and absolute quantification (iTRAQ) labeling analysis was employed to quantitatively identify differentially expressed proteins in two group animals, which were compared with control group. Then bioinformatic analysis of DEPs was conducted through hierarchical Clustering, Venn analysis, gene ontology (GO) annotation enrichment, and kyoto encyclopedia of genes and genomes (KEGG) pathways enrichment. Result: The results demonstrated there were 63 and 109 DEPs in LPS fever group and BHT-treated group, respectively. Enrichment analysis of GO annotations indicated that BHT mainly regulated expression of some extracellular structural proteins for response to stimulus and stress. KEGG analysis showed that ribosome and phagosome were the most significant pathways. Thereinto, several proteins in phagosome pathway were significantly up-regulated by BHT, including F-actin, coronin, Rac, and major histocompatibility complex class I (MHC I), which work in phagocytosis and cross-presentation Conclusion: BHT may contribute to pyrogen clearance by boosting antigenic phagocytosis, degradation, and cross presentation in the liver.