Background and aims The purpose of this study is to use in silico molecular docking and in vivo study to identify the potential of Bryophyllum pinnatum as B cell depleting and immune suppression agent in SLE.

Methods In silico was done by docking 32 phytochemical compounds well known immunosuppresive herbs into three B cell activating receptors: B cell activating factor receptors (BAFF-R), trans- membrane activator and calcium modulator and cyclophilin ligand interactor (TACI), and B-cell maturation antigen (BCMA). In vivo study was done in pristane induced mice model treated with different doses of Bryophyllum pinnatum extract (B1 :10.5 mg/kgBW/day, B2 :21 mg/kgBW/day, and B3 :42 mg/kgBW/day). Extracts were given everyday per orally from 3rd to 4th months after pristane injection. spleen mature B cell (CD19⁺ CD22⁺) , Th1,Th2 and Th17 percentages were assessed using flow cytometry assay and serum anti-dsDNA level using ELISA.

Results It was revealed that one compound from Bryophyllum pinnatum had the strongest binding affinity to BAFF-R (−6.3 kcal/mol), to TACI (four compounds,−6.4 kcal/mol) and to BCMA (−7 kcal/mol). In vivo study revealed that Bryophyllum pinnatum treatment significantly lower the percentages of CD19⁺ CD22⁺ cell and anti-dsDNA levels in dose dependent manner which significantly lower compared to control (p=0.002 and p=0.036 respectively). Bryophyllum pinnatum treatment lowered also Th1, Th2, and Th17 percentages dose dependently compared to control.

Conclusions Bryophyllum pinnatum is a potential natural product which may be used for B cell depleting agent in SLE treatment by suppressing Th1, Th2 and Th17 percentages.