Tomatidine
Tomatidine decreased the expression of inducible NO synthase and COX-2 by inhibiting I-κBα phosphorylation, NF-κB nuclear translocation and JNK activation, thereby suppressing c-jun phosphorylation and Oct-2 expression. Tomatidine, solasodine and diosgenin (40 μM) inhibited nitrite production by 66%, 22% and 41%, respectively. iNOS protein was barely detectable in unstimulated cells but significantly increased after LPS treatment, and tomatidine caused a dose-dependent inhibition of LPS-induced iNOS expression. The effect of tomatidine on p65 DNA-binding activity was determined for p65, the major component of NF-κB in LPS-stimulated macrophages. The binding activity of NF-κB was inhibited in a dose-dependent manner in the presence of 10-40 μM of Tomatidine. Tomatidine inhibited the phosphorylation of I-κB, blocked the production of I-κB, and further inhibited p65 NF-κB translocation to the nucleus and regulated the binding activity.