Hispidulin, a natural flavone with a broad spectrum of biological activities, is a Pim-1 inhibitor (IC50: 2.71 μM).

Hispidulin induces cell death in a dose- and time-dependent manner in HepG2 cells. Hispidulin induces apoptosis through mitochondrial dysfunction, which is characterized by decreased Bcl-2/Bax ratio, disrupted mitochondrial membrane potential and increased release of cytochrome C and activated caspase-3 [2].

Hispidulin treatment effectively mitigates ovariectomy-induced body and bone loss while reducing trabecular spacing in mice [3]. When administered intraperitoneally (10 or 50mg/kg) 30 minutes prior to kainic acid injection (15mg/kg), hispidulin increases seizure latency and lowers seizure scores in rats. Furthermore, it significantly reduces hippocampal neuronal cell death caused by kainic acid, an effect paralleled by diminished microglial activation and decreased production of proinflammatory cytokines, including interleukin-1β, interleukin-6, and tumor necrosis factor-α in the hippocampus [4].

HepG2 cells are treated with different concentrations of hispidulin (50, 100, 200 μM) for 24, 48 and 72 h. Following treatment, cells are further incubated with MTT reagents at 37°C for 4 h before DMSO is added, to dissolve formazan crystals, and absorbance is measured at 570 nm in a microplate reader [2].

The tumor is established in mice. Mice are treated with DMSO or Hispidulin at a dosage of 10, 20 or 40 mg/kg/day for 35 days. The body weight of tumor-bearing mice is recorded every week and tumor volume is calculated [2].