We evaluated the effect of tomato saponin, containing esculeoside A, a major saponin found in Japanese pink-colored tomato, on collagen-induced arthritis DBA/1J mice. Arthritis scores in collagen-injected mice were markedly lower by tomato saponin supplementation than that of the control throughout the 15-days observation period. Notably, there was a significant negative correlation between the arthritis scores and serum concentrations of esculeogenin A, an aglycon of esculeoside A (R² = 0.84, p < 0.05). Additionally, mRNA expression of pro-inflammatory cytokines in the knee joint were significantly decreased by tomato saponin. Moreover, CD38⁺CD45R⁺ splenocytes were significantly increased by tomato saponin, suggesting the shift to the type II helper T cell (Th2) response. In cultured splenocytes from DBA/1J mice, purified esculeogenin A also significantly suppressed the lipopolysaccharide-induced IL-12p40, Th1-driving component, and pro-inflammatory cytokines. Our results suggest that esculeogenin A potentially ameliorates collagen-induced arthritis by inhibiting the pro-inflammatory cytokines involved in the activation of Th1.

我们评估了含有皂苷A（一种在日本粉红番茄中发现的主要皂苷）的番茄皂苷对胶原蛋白诱发的关节炎DBA / 1J小鼠的影响。在整个15天的观察期内，补充番茄皂素的注射胶原蛋白的小鼠的关节炎评分明显低于对照组。值得注意的是，关节炎评分与七叶皂苷A的糖苷皂甙元A的血清浓度之间存在显着的负相关性（R ²  = 0.84，p  <0.05）。此外，番茄皂苷可显着降低膝关节促炎细胞因子的mRNA表达。此外，CD38 ⁺ CD45R ⁺番茄皂素显着增加了脾细胞，提示转移至II型辅助性T细胞（Th2）反应。在培养的DBA / 1J小鼠脾细胞中，纯化的七叶皂甙元A也显着抑制了脂多糖诱导的IL-12p40，Th1驱动成分和促炎性细胞因子。我们的结果表明，七叶皂甙元A通过抑制参与Th1激活的促炎性细胞因子，可以潜在地改善胶原蛋白诱发的关节炎。