Baicalin ameliorates lupus autoimmunity by inhibiting differentiation of Tfh cells and inducing expansion of Tfr cells

Twelve-week-old of MRL/lpr mice were treated intraperitoneally with 200？mg/kg Baicalin or PBS vehicle every day for 4 weeks. a The chemical structure of Baicalin. b Baicalin treatment reduced serum anti-ds-DNA antibody levels (n？=？4 for each group). c Baicalin treatment reduced 24？h protein in urine levels (n？=？4 for each group). d Baicalin treatment inhibited spleen enlargement and reduced the spleen index (n？=？4 for each group). e Baicalin treatment relieved kidney inflammation as visualized by H&E staining (left) and reduced the renal scores (right, n？=？4 for each group). Scale bar, 100 μm. f Baicalin treatment inhibited IgG deposition in kidney. Scale bar, 100 μm. g Spleens were enlarged in 12-week-old MRL/lpr mice when compared with age- and sex-matched B6 mice. h CD4+CXCR5+PD-1+ Tfh cells were expanded in 12-week-old MRL/lpr mice when compared with B6 mice (n？=？4 for each group). i Baicalin treatment reduced the percentage of CD4+CXCR5+PD-1+ Tfh cells in the spleens of MRL/lpr mice (n？=？4 for each group). j Baicalin treatment reduced the percentage of CD4+IL-21+ cells in the spleens of MRL/lpr mice (n？=？4 for each group). 12w and 16w indicate the ages of the mice. ANOVA and Student’s t-test were use