Effect of bioflavonoids (trihydroxyethylrutin and disodium flavodate) in vitro on neutrophil reactive oxygen production and phagocytic ability assessed by flow cytometry.

Neutrophil granulocytes have been described as agents of defence and destruction. The effect of two flavonoid compounds (trihydroxyethylrutin and disodium flavodate) on the phagocytic ability and generation of reactive oxygen radicals of neutrophils was studied at concentrations of 5 mg/l, 50 mg/l and 100 mg/l. Flow cytometry was used to study phagocytic ability by measuring uptake of fluorescein-labelled bacteria. The generation of reactive oxygen intermediates was estimated by means of a CD16 phycoerythrin-conjugated mouse anti-human monoclonal antibody. In vitro trihydroxyethylrutin (THET) and disodium flavodate (DF) treatment reduced reactive oxygen production (DF at 5 mg/l--40%, at 50 mg/l--71% and at 100 mg/l--82%; THET at 5 mg/l--53%, at 50 mg/l--88%, at 100 mg/l--93%; all p < 0.001). This was rapidly reversible after plasma exchange. Both flavonolds did not affect neutrophil phagocytic ability. We conclude that THET and DF could decrease oxidative tissue damage by neutrophils. A beneficial effect in peripheral vein disease could be anticipated from these results.