Evaluation of the Isoflavone Genistein as Reversible Human Monoamine Oxidase-A and -B Inhibitor

Figure 3

Mode of inhibition of recombinant human monoamine oxidases (hMAO-A and hMAO-B) by genistein (GST) compared to control the initial velocity . Lineweaver-Burk plots for hMAO-A (a) and hMAO-B (b) with a gradual increase of luciferin derivative substrate (LDS). Linear regression data are presented as mean ± SEM of . The maximum velocity () (c) and Michaelis constant () of LDS (d) parameters folds of change were measured with a gradual increase of GST concentrations in both isozymes. GST inhibitor constant was determined using the competitive inhibition model for hMAO-A (e) and hMAO-B (f) as the best fit. Regression data are presented as the mean ± SEM of . The significance of difference between the controls and treatments was determined using one-way ANOVA followed by Dunnett’s multiple comparisons test and between two groups of each concentration using -test. ; or .

(a) hMAO-A

(b) hMAO-B

(c) Enzyme

(d) LDS

(e) hMAO-A competitive model

(f) hMAO-B competitive model