Dihydrotanshinone I (DHTS) is a natural compound extracted from Salvia miltiorrhiza Bunge used for treating of cardiovascular diseases.

Dihydrotestosterone (DHT, 10 nM) effectively reduces the expression of lectin-like ox-LDL receptor-1 (LOX-1) and NADPH oxidase 4 (NOX4), alongside diminishing reactive oxygen species (ROS) production, nuclear translocation of NF-κB, ox-LDL endocytosis, and monocyte adhesion in lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs)[1]. Additionally, Dihydrotanshinone I prompts caspase-dependent apoptosis in HCT116 cells, with this apoptosis being both concentration and ROS dependent. The presence of Z-VAD-fmk entirely prevents apoptosis, while pre-treatment with Z-LEHD-fmk significantly reduces it, and Z-IETD-fmk only achieves partial inhibition. Intriguingly, knocking down caspase-2 significantly enhances apoptosis induced by Dihydrotanshinone I[3].

In ApoE-/- mice fed with an atherogenic diet, DHT (10 and 25 mg kg-1) significantly attenuated atherosclerotic plaque formation, altered serum lipid profile, decreased oxidative stress and shrunk necrotic core areas. 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].

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°C. 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.