Glaucocalyxin B is a diterpenoid isolated from Rabdosia japonica with anticancer and antitumor activity. It decreases the growth of HL-60 cells (IC50: 5.86 μM).

HL-60 cell Growth:5.86 μM (IC50)

Glaucocalyxin A (GlnA) and B (GlnB) dose-dependently reduce HL-60 cell growth (IC50s: 6.15 and 5.86 μM at 24 h) and induce apoptosis, G2/M-phase cycle arrest, DNA damage, and the accumulation of reactive oxygen species (ROS) in these cells[1]. GlnB also inhibits the proliferation of human cervical cancer cells in vitro by inducing apoptosis and autophagy, potentially mediated through the phosphatidylinositol 4,5 bisphosphate 3 kinase/Akt signaling pathway, and dose-dependently reduces the proliferation of HeLa and SiHa cervical cancer cell lines, increases the apoptotic cell population, and enhances poly (ADP ribose) polymerase 1 cleavage[2].

The microglia cell viability is assessed by MTT assay. Cells are seeded in 96-well plates at the density of 5 × 10^4 cells/well. The cell culture supernatant is discarded after treatment with various agents, and then 30 μL of MTT (0.5 mg/mL) solution is added into each well. After incubation for 4 h at 37 °C, 100 μL of DMSO is added into each well to dissolve the formazan dye, and then the absorbance of solubilized formazan is measured by microplate reader [3].