(S)-Thalidomide

(S)-Thalidomide ((S)-(-)-Thalidomide) is the S-enantiomer of Thalidomide. (S)-Thalidomide has immunomodulatory, anti-inflammatory, antiangiogenic and pro-apoptotic effects^[1][2][3]. (S)-Thalidomide induces teratogenic effects by binding to cereblon (CRBN) ^[4]. IC50 & Target: Apoptosis^[1] In Vitro: (S)-Thalidomide treatment results in a reduction in cell viability in U266 cells with an IC₅₀ of 362 μM^[1].
(S)-Thalidomide treatment increased apoptosis in a dose-dependent manner in U266 cells^[1].
There are changes in the expression profile of genes involved in angiogenesis and apoptosis, but the changes are most dramatic in the apoptotic genes. In particular, the expression of I-κB kinase is decreased by two-fold, which is associated with a four-fold decrease in NF-κB expression. (S)-Thalidomide increases the Bax:Bcl-2 ratio, also increases I-kB protein levels, and decreases NF-kB activity. A dramatic decrease in Bcl-2 expression with (S)-Thalidomide suggests a possible enhancement of cytotoxic effect if combined with other cytotoxic agents^[1]. In Vivo: Thalidomide does cause limb reduction defects in chick embryos as long as the embryos are directly exposed to the drug. The most useful techniques are implanting Thalidomide-soaked beads into the embryo immediately adjacent to the limb territory or soaking presumptive chick limb territories in Thalidomide and then grafting the explants to a host embryo celom. Thalidomide affects the chick limb grafted to a host embryo in a dose response fashion. Furthermore, (S)-Thalidomide is more teratogenic than (R)-Thalidomide^[1].