Salvia miltiorrhiza (SM) Injection Ameliorates Iron Overload-Associated Cardiac Dysfunction by Regulating the Expression of DMT1, TfR1, and FP1 in Rats

Abstract

Previous studies have found that Salvia miltiorrhiza (SM) injection have a protective effect on the iron overloaded (IO) heart. However, the mechanisms are not completely known. In the present study, we investigated the underlying mechanisms based on the iron transport-related proteins. The rats were randomly divided into five groups: control, IO group, low-dose SM group, high-dose SM group, and deferoxamine control group. Iron dextran was injected to establish the IO model. After 14 days of treatment, cardiac histological changes were observed by hematoxylin and eosin (H&E) staining. Iron uptake-related proteins divalent metal transporter-1 (DMT-1), transferrin receptor-1 (TfR-1), and iron export-related proteins ferroportin1 (FP1) in the heart were detected by Western blotting. The results showed that SM injection decreased cardiac iron deposition, ameliorated cardiac function, and inhibited cardiac oxidation. Most important of all, SM injection downregulated the expression of DMT-1 and TfR-1 and upregulated FP1 protein levels compared with the IO group. Our results indicated that reducing cardiac iron uptake and increasing iron excretion may be one of the important mechanisms of SM injection reducing cardiac iron deposition and improving cardiac function under the conditions of IO.

Figure 1

HPLC–UV profiles of Danshen injection (a). The mixed standard solution of Danshen (b). Peaks represent: 1, salvianolic acid A; 2, protocatechuic aldehyde; 3, salvianolic acid B.

Figure 2

Effects of SM injection on morphological changes in heart tissue. Samples were obtained from the control group (saline), iron overload (IO) group (iron dextran 50 mg/kg), high-dose SM group (H-SM, iron dextran 50 mg/kg + SM 6 g/kg), low-dose SM group (L-SM, iron dextran 50 mg/kg + SM 3 g/kg), and DFO group (iron dextran 50 mg/kg + DFO 100 mg/kg). The cell nucleus swelled (black arrow) together with myocardial fibers, which resulted in atrophy and rupture (white arrows) as shown by H&E staining (magnification 200x, scale bar = 100 μm).

Figure 3

Effects of SM injection on iron deposition changes in heart tissue. (a) The blue reactions (black arrow) on the sections represent deposited iron (magnification 200x, scale bar = 100 μm). The percentage of Prussian blue-positive area (Prussian blue area (%) = (positive area/sum area) ∗ 100%) in each group was quantified. Values are mean ± S.E.M. ^##P < 0.01 vs. control group; ^∗∗P < 0.01 vs. IO group. (b) The same sections with figure A from each group were taken as a magnification of 400x, scale bar = 50 μm.

Figure 4

Effects of SM injection on total cardiac iron concentration. Values are mean ± S.E.M. ^##P < 0.01 vs. control group; ^∗∗P < 0.01 vs. IO group.

Figure 5

Effects of SM injection on serum CK and LDH activity. Values are mean ± SEM. ^##P < .01 vs. control group; ^∗∗P < .01 vs. IO group.

Figure 6

Effects of SM injection on SOD activity and MDA concentration in cardiac homogenate. Values are mean ± SEM. ^##P < .01 vs. control group; ^∗∗P < .01 vs. IO group.

Figure 7

Effects of SM injection on expression levels of DMT-1, TfR-1, and FP1 in rat hearts assessed using Western blot analysis. Relative intensities were calculated by normalization to control in each group. Values are mean ± SEM. ^##P < .01 vs. control group; ^∗∗P < .01 vs. IO group.