Biochemical pharmacology of biflavonoids: implications for anti-inflammatory action.

Biflavonoids belong to a subclass of the plant flavonoid family. Distribution of biflavonoids in the plant kingdom is limited to several species. Previously, some pharmacological activities of biflavonoids were described such as inhibition of histamine release from mast cells and inhibition of lymphocyte proliferation, suggesting the anti-inflammatory/antiallergic potential of the biflavonoids. Furthermore, several natural biflavonoids including ochnaflavone and ginkgetin inhibit phospholipase A2. Most importantly, certain biflavonoids exhibit anti-inflammatory activity through the regulation of proinflammatory gene expression in vitro and in vivo. Recently, several synthetic approaches yielded new biflavonoid molecules with anti-inflammatory potential. These molecules also exhibit phospholipase A2 and cyclooxygenase-2 inhibitory activity. Although the bioavailability needs be improved, certain biflavonoids may have potential as new anti-inflammatory agents. This is the first review of biflavonoid pharmacology to date.