Inhibition of mouse liver sialidase by plant flavonoids.
Flavonoids (103 species) were tested for inhibitory activity against mouse liver sialidase using sodium p-nitrophenyl-N-acetyl-alpha-D-neuraminate (PNP-NeuAc) as substrate. Isoscutellarein-8-O-glucuronide from the leaf of Scutellaria baicalensis showed most potent activity (IC50, 40 microM), and this flavone appeared to be a non-competitive inhibitor of the enzyme. This flavone inhibited the lysosomal solubilized sialidase against PNP-NeuAc and sialyllactose effectively, but not microsomal enzyme against gangliosides and colominic acid, whereas, negligible or weak inhibitory activities were observed for influenza virus sialidase, beta-galactosidase, alpha-mannosidase, and alpha-glucosidase tested. These results indicate that this flavone may be useful to elucidate the function of the lysosomal solubilized sialidase.
Nagai
T
T
Oriental Medicine Research Center, Kitasato Institute, Tokyo, Japan.
Miyaichi
Y
Y
Tomimori
T
T
Yamada
H
H
D000818:Animals; D002599:Chalcone / Q000494:pharmacology*; D044950:Flavanones; D005419:Flavonoids / Q000494:pharmacology*; D008099:Liver / Q000201:enzymology; D008247:Lysosomes / Q000201:enzymology; D051379:Mice; D008861:Microsomes / Q000201:enzymology; D009439:Neuraminidase / Q000037:antagonists & inhibitors*; D010944:Plants; D011427:Propiophenones / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D044950:Flavanones; D005419:Flavonoids; D011427:Propiophenones; D002599:Chalcone; D009439:Neuraminidase; C028610:flavanone