Kinase experiment:

Cells are treated with various concentrations of Dihydrotanshinone I (3.13-20 μM) for 48 h. For the activity assay, Ac-DEVD-AMC (1 μg/μL), Ac-IETD-AMC (1 μg/μL) or Ac-LEDH-AMC (1 μg/μL) and cell lysate are added into Protease Assay Buffer in 96-well plate. Reaction mixtures with lysis buffer are used as negative controls. Cells treated with DMSO (0.1%) are treated as vehicle control. The reaction mixtures are incubated for 1 h at 37℃. The AMC liberated from the substrates is measured using spectrofluorometer of Victor 2 plate reader with an excitation wavelength of 380 nm and an emission wavelength of 430 nm.

Animal experiment:

Male ApoE-/- mice (6-8 weeks old) on C57BL/6J background and age-matched wild-type C57BL/6J controls housed in SPF-grade animal facilities with a 12 h light/dark cycle, at 23℃ (±2℃). Starting from 6 weeks, the mice are fed with a HCD (54.35% raw grain, 20% lard, 0.15% cholesterol, 15% sucrose, 0.5% Sodium Cholate, 10% yolk powder) for 12 weeks. All ApoE-/- mice are dosed daily via intragastric gavage with 10 and 25 mg/kg Dihydrotanshinone I dissolved in 0.5% CMC-Na or administered 0.5% CMC-Na alone (vehicle control) (n=8 per group).

Dihydrotanshinone I is a natural compound extracted from Salvia miltiorrhiza Bunge which has been widely used for treating cardiovascular diseases.

In lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs), DHT (10 nM) decreases lectin-like ox-LDL receptor-1 (LOX-1) and NADPH oxidase 4 (NOX4) expression, reactive oxygen species (ROS) production, NF-κB nuclear translocation, ox-LDL endocytosis and monocytes adhesion[1]. Dihydrotanshinone I induces caspase dependent apoptosis induced in HCT116 cells. Dihydrotanshinone I induces concentration and ROS dependent caspase activation. Apoptosis induced by Dihydrotanshinone I is completely prevented by Z-VAD-fmk. Apoptosis induced by Dihydrotanshinone I is significantly inhibited by pretreatment of Z-LEHD-fmk but only is partially inhibited by Z-IETD-fmk. Apoptosis induced by Dihydrotanshinone I is significantly increased by caspase-2 knockdown[3].

DHT (10 and 25 mg/kg) significantly attenuates atherosclerotic plaque formation, alteres serum lipid profile, decreases oxidative stress and shrinks necrotic core areas in ApoE-/- mice. DHT dramatically inhibits the enhanced expression of LOX-1, NOX4, and NF-κB in aorta[1]. Dihydrotanshinone I (1, 2, 4 mg/kg) treatment can improve cardiac function, reduce infarct size, ameliorate the variations in myocardial zymogram and histopathological disorders, decrease 20-HETE generation, and regulate apoptosis-related protein in myocardial ischemia-reperfusion rats[2].

References:
[1]. Zhao W, et al. Dihydrotanshinone I Attenuates Atherosclerosis in ApoE-Deficient Mice: Role of NOX4/NF-κB Mediated Lectin-Like Oxidized LDL Receptor-1 (LOX-1) of the Endothelium. Front Pharmacol. 2016 Nov 8;7:418. eCollection 2016.
[2]. Wei Y, et al. The cardioprotection of dihydrotanshinone I against myocardial ischemia-reperfusion injury via inhibition of arachidonic acid ω-hydroxylase. Can J Physiol Pharmacol. 2016 Dec;94(12):1267-1275. Epub 2016 Jun 24.
[3]. Wang L, et al. Dihydrotanshinone I induced apoptosis and autophagy through caspase dependent pathway in colon cancer. Phytomedicine. 2015 Nov 15;22(12):1079-87.