Fig. 1.
Entry of sinapine in cardiomyocytes. (A) Chemical structures of sinapic acid and sinapine identifying the potential antioxidant moiety in both compounds and the potential mitochondria-targeting moiety in sinapine. (B) Fluorescence spectrum of sinapine indicates a maximal excitation wavelength at 355 nm and a maximal emission wavelength at 455 nm. (C) Measurement of autofluorescence of sinapine using Metafluor System (Ex 340 nm/Em 450 nm) within cardiomyocytes after subtraction of the background in the red box 1 (Fbkg). (D–F) Example of the stability of fluorescence (Ex 340 nm/Em 450 nm) of two cardiomyocytes in absence of sinapine. (E) When cardiomyocytes are incubated with 2 μM sinapine, the fluorescence within the cell increases suggesting sinapine intracellular accumulation. (F) Fluorescence of individual control cells after 30 min and 60 min (n = 10 control cells, left panel, grey circle) and after incubation with 2 μM sinapine (n = 41 cells, right panel, grey triangle). The average fluorescence of control (black circle) and sinapine (black triangle) incubated cardiomyocytes. Linear mixed model effect: p < 0.0001; Time: p < 0.0001; Group: p < 0.0001. *, p < 0.05, **, p < 0.01. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)