Isolation and immunomodulatory properties of a flavonoid, casticin from Vitex agnus-castus.

Casticin (1), a flavonoid isolated from the aerial parts of Vitex agnus-castus, was found to be a potent immunomodulatory and cytotoxic compound. The activity was tested in vitro for chemiluminescence, chemotaxis, T-cell proliferation and cytotoxicity. Casticin (1) exhibited a significant inhibitory effect on monocyte oxidative burst in a dose dependent manner. It was found to have a significant suppressive effect on the chemotaxic action at higher concentrations on fMLP (10(-8) m) stimulated neutrophils. It also showed a potent suppressive effect on PHA stimulated T-cell (PMBC).