Inhibition of lipopolysaccharide (LPS)-induced endothelial cytotoxicity by selected flavonoids.

The cytotoxic effect of lipopolysaccharide (LPS) was examined on bovine aortic endothelial cell proliferation in vitro. This LPS-induced cytotoxicity (IC50 = 22 ng/ml) was attenuated by selected flavonoids, such as catechin, myricetin, quercetin, hesperitin, and rutin. No inhibitory effect was induced by flavones, morin, kaempferol, chrysin and naringin. The isoflavone genistein, and the synthetic tyrphostin B46, both known inhibitors of tyrosine kinases, also attenuated the toxic LPS effect. The hypothesis was framed that the inhibition of LPS-induced cytotoxicity in bovine aortic endothelial cell cultures by flavonoids could be mediated via inhibition of specific tyrosine kinases.