Lycium barbarum Polysaccharide Ameliorates Sjogren's Syndrome in a Murine Model

Scope This study aims to evaluate the therapeutic efficacy and mechanisms of Lycium barbarum polysaccharide (LBP) in primary Sjogren's syndrome (pSS). Methods and results Non-obese diabetic mice (the pSS model) are randomly divided into four groups: Low dose LBP (LBP.L, 5 mg kg(-1) d(-1)), high dose LBP (10 mg kg(-1) d(-1)), low dose interleukin (IL)-2 (25 000 IU/d), and control (saline water). Drugs were treated for 12 weeks. LBP.L significantly reduces the salivary gland inflammation compared with the control group (histological score p (LBP.L) vs (Control) = 0.019; foci number: p (LBP.L) vs (Control) = 0.038). LBP.L also remarkably reduces the effector follicular helper T (Tfh) cells and the CD4(+)IL-17A(+) helper T (Th17) cells in both spleen and cervical lymph node (cLN) cells. Additionally, the ratios of regulatory T cell (Treg)/Tfh cells and Treg/Th17 cells are substantially increased in mice treated with LBP.L in both spleen and cLNs. LBP also inhibits Th17 and Tfh cells and markedly increases the Treg/Tfh ratio in human peripheral blood mononuclear cells. Conclusion LBP.L inhibits the progression of pSS in mice, associated with modulation of T cell differentiation.