Vitamin K3 is a synthetic analog of 1,4-naphthoquinone; it is also a precursor to vitamin K2. Vitamin K3 exhibits anticancer, neuromodulatory, and anti-inflammatory activities. In ovarian carcinoma cells, vitamin K3 induces caspase 8-dependent apoptosis, increases levels of ROS, and decreases levels of glutathione; additionally, vitamin K3 binds tubulin, inhibiting microtubule polymerization. In vitro, vitamin K3 also inhibits monoamine oxidases A and B (MAO-A/B). This compound increases ROS and inhibits leukotriene secretion by altering Ca2+ influx and 5-lipoxygenase signaling in vitro.