1.C.12.1.8
Suilysin (SLY, a hemolysin) of 497 aas is a pore-forming cholesterol-dependent cytolysin of S. suis and a true virulence factor (Tenenbaum et al. 2016). It plays a role during the development of S. suis meningitis in pigs and humans, and is a potential vaccine candidate. Amentoflavone, a natural biflavonoid compound isolated from Chinese herbs is a potent antagonist of suilysin (SLY)-mediated hemolysis without interfering with its expression. Amentoflavone effectively inhibited SLY oligomerization, which is critical for its pore-forming activity. Treatment with amentoflavone reduced S. suis-induced cytotoxicity in macrophages, and S. suis-infected mice that received amentoflavone exhibited lower mortality and bacterial burden (Shen et al. 2018).