Study on Baicalin Treatment of Mycoplasma pneumoniae Based on D1/ART/LTB4R Pathway
Yin Liqiao1, Sun Yi1,2, Zhang Haifeng1
1Institute of Traditional Chinese Medicine, Heilongjiang Academy of Chinese Medicine Sciences, Harbin, People's Republic of China.
Background:
Baicalin is an ingredient of Qinbai Qingfei concentrated pills that is first new traditional Chinese medicine proved by SFDA for the treatment of Mycoplasma pneumoniae pneumonia in children. We aim to investigate the role of Baicalin in the treatment of Mycoplasma pneumoniae by inhibiting the ADP-ribosyltransferase of the D1 structural domain in the sole toxin CARDS TX of Mycoplasma pneumoniae to down-regulating the expression of G-protein-coupled receptor.
Methods:
The recombinant plasmid pET28α- CARDs TX D1 was transferred into E. coli BL2 (DE3), which was induced to express and purify the target protein by the IPTG. The Biacore T200 SPR technique was utilized to determine specific binding of Baicalin to CARDs TX D1. Differential genes and enrichment analysis using transcriptomic studies. Immunohistochemistry was used to observe the expression of FAS, FADD, and LTB4R and ELISA were used to detect the TNF-α, Caspase-3 expression levels on the lung tissues. The apoptosis of the lung cells was detected by flow cytometry and qRT-PCR was used to detect the mRNA expression of FAS, FASL, LTB4R1, Caspase3.
Results:
The researchers obtained purified CARDs TX D1 protein. Biacore verified a good combination Baicalin and D1 protein. Immunohistochemistry results showed that the expression of FAS, FADD, and LTB4R was reduced in Baicalin compared with the model control group and ELISA results showed that the Baicalin reduced expression of the TNF-α, Caspase-3 compared with the model group. PCR results showed that the mRNA expression of FAS, FASL, LTB4R1, and Caspase-3 was significantly reduced in Baicalin compared with the model control group (P < 0.01).
Conclusion:
Baicalin can improve experimental Mycoplasma pneumoniae pneumonia and reduce the expression of related inflammation and apoptosis markers. Therefore, we propose a hypothesis: Baicalin may regulate G protein coupled receptor through D1 domain, down regulate apoptosis related factors, and treat Mycoplasma pneumoniae pneumonia.
