Genistein Is a Natural Inhibitor of Hexose and Dehydroascorbic Acid Transport through the Glucose Transporter, GLUT1

Abstract

Genistein is a dietary-derived plant product that inhibits the activity of protein-tyrosine kinases. We show here that it is a potent inhibitor of the mammalian facilitative hexose transporter GLUT1. In human HL-60 cells, which express GLUT1, genistein inhibited the transport of dehydroascorbic acid, deoxyglucose, and methylglucose in a dose-dependent manner. Transport was not affected by daidzein, an inactive genistein analog that does not inhibit protein-tyrosine kinase activity, or by the general protein kinase inhibitor staurosporine. Genistein inhibited the uptake of deoxyglucose and dehydroascorbic acid in Chinese hamster ovary (CHO) cells overexpressing GLUT1 in a similar dose-dependent manner. Genistein also inhibited the uptake of deoxyglucose in human erythrocytes indicating that its effect on glucose transporter function is cell-independent. The inhibitory action of genistein on transport was instantaneous, with no additional effect observed in cells preincubated with it for various periods of time. Genistein did not alter the uptake of leucine by HL-60 cells, indicating that its inhibitory effect was specific for the glucose transporters. The inhibitory effect of genistein was of the competitive type, with a K i of approximately 12 M for inhibition of the transport of both methylglucose and deoxyglucose. Binding studies showed that genistein inhibited glucose-displaceable binding of cytochalasin B to GLUT1 in erythrocyte ghosts in a competitive manner, with a K i of 7 M. These data indicate that genistein inhibits the transport of dehydroascorbic acid and hexoses by directly interacting with the hexose transporter GLUT1 and interfering with its transport activity, rather than as a consequence of its known ability to inhibit protein-tyrosine kinases. These observations indicate that some of the many effects of genistein on cellular physiology may be related to its ability to disrupt the normal cellular flux of substrates through GLUT1, a hexose transporter universally expressed in cells, and is responsible for the basal uptake of glucose.

Acute regulation of glucose transport in a monocyte–macrophage cell line: Glut-3 affinity for glucose is enhanced during the respiratory burst

“…The cytoplasmic domain of Glut-3, the predominant transporter on RAW cells, exhibits a PKC consensus site but lacks tyrosine phosphorylation sites, indicating an indirect effect of genistein on glucose transport and a potential phosphorylation mechanism for acute regulation of Glut-3 activity. Although genistein has been shown to inhibit basal 2-DOG and 3-OMG uptake by interacting directly with Glut-1 on human erythrocytes, Chinese hamster ovary and leukaemic HL60 cells [41], in the present study preincubation with genistein for at least 40 min was necessary before inhibition was observed. Furthermore, before measuring 2-DOG and 3-OMG uptake, cells were washed to remove genistein, and uptake was determined in genistein-free medium.…”

Effect of mutation of cytoplasmic receptor domain and of genistein on transport of acidic fibroblast growth factor into cells

“…Furthermore, genistein could interfere with this transport or, alternatively, it could inhibit the translocation process as such. In fact, genistein was recently shown to inhibit uptake of glucose and dehydroascorbic acid by the glucose transporter GLUT1 (Vera et al, 1996).…”

Glutathione protects PC12 cells from ascorbate- and dopamine-induced apoptosis

“…There are a few pieces of evidence supporthg our research hypothesiç that AA mduces oxidative stress: (a) AA is e a d y oxidized to DHA by oxygen m solution (Vera et aL, 1995); (b) DHA is rapidly transported mto cells Ma a GLUT transporter (Welch et al, 1995) while AA is slowly taken up through a Na+-dependent mechanism (Welch et al, 1995;Vera, 1995;Ngkeekwong and Ng, 1997); (c) DHA m the cytosol is rapidly reduced to AA by an enzymatic (Hughes, 1964;Bode et al, 1993;Paolicchi et aL, 1996) or non- Since AA is transported mto cells through glucose transporters via the form of DHA (Welch et ai., 1995), we tried to block the glucose transporters with wortmannin and genistein, glucose transporter inhibitors (Clarke et al, 1994;Vera 1996). We found that AA toxicity was prevented by these glucose transporter inhibitors connrming that the oxîdized AA (DHA) was transported mto ceils through glucose transporters (Si and S b , manuscript in preparation).…”