Actions of some flavonoids on specific and non-specific immune mechanisms

The immunomodulatory activity of some flavonoids on antigen specific humoral and cell mediated immune responses and complement-mediated hemolysis has been investigated and compared with that of levamisole. Flavanone, 6-methoxyflavanone, 7-methoxyflavanone and bavachinin enhanced the sheep erythrocyte (SRBC), induced primary and secondary humoral immune responses in mice, and 6-hydroxyflavanone, 7-hydroxyflavanone and rutin inhibited primary response. Levamisole slighly stimulated the primary and suppressed the secondary response. All the flavonoids tested decreased the manifestation of SRBC induced delayed type hypersensitivity reaction and showed no effect on classical or alternative pathway dependent hemolysis. The studies revealed the significant immunomodulatory potential of these flavonoids, methoxy derivatives having immunostimulatory activity and hydroxy derivatives immunosuppressive properties.