TMS

TMS ((E)-2,3',4,5'-tetramethoxystilbene) is a selective and competitive CYP1B1 inhibitor with an IC₅₀ of 6 nM and a K_i value of 3 nM. TMS shows a lesser extent inhibitory effect on CYP1A1 (IC₅₀=300 nM) and CYP1A2 (IC₅₀=3.1 μM). TMS is a methylated derivative of resveratrol and has anti-cancer activity^[1][2][3]. In Vitro:TMS, an analogue of resveratrol, is considered to be a potential cancer preventive agent since it is a potent inhibitor of CYP1B1. To assess survival of MCF-7 cells exposed to 1 μM benzo[a]pyrene (BP), 1 μM BP+1 μM TMS and 1 μM BP+4 μM TMS, cells ae incubated for up to 72 h without a media change. Luminescence units from exposed cells, expressed as a percentage of luminescence units from solvent (DMSO)-treated cells at the same time intervals. In all exposure groups, cell viability remains >90% for the first 24 h, but by 72 h, cell survival drops to 60-70%^[1]. In Vivo:To determine the contribution of CYP1B1 in development of hypertension in spontaneously hypertensive rats (SHR), the effect of TMS is examined on in SHR and WKY rats. Systolic BP steadily increases in SHR from 4 weeks of age. Starting from 8 weeks of age, daily injections of TMS reduce systolic BP in SHR to levels observed at the beginning of the experiment (207±7 vs. 129±2 mmHg). Systolic BP is not altered in WKY injected with TMS or its vehicle (129±7 vs. 127±4 mmHg) ^[1].