Protective Effect of Trace Elements and Their Combination on Isoprenaline-Induced Myocardial Structural Alterations

Nouf AL-Rasheed, Nawal AL-Rasheed, Hala Attia, Iman Hassan, Hanaa AL-Ajmi, Maha AL-Amin, Raessa Ahmed. King Saud University, Riyadh, Saudi Arabia

Background:

Several trace elements are of great importance in a number of biological processes. In this study, we sought to investigate whether selenium, zinc, chromium and their combination offers a protective effect against myocardial infarction induced by isoprenaline in rats.

Methods:

All experiments were carried out with adult male Wistar Albino rats weighing 200-210 g. The animals were grouped as set of ten (housed as 4 rats/cage)-group 1: normal control rats; group 2: isoprenaline (ISO) control rats; group 3: zinc sulfate (30 mg kg-1); group 4: rats pretreated with chromium picolinate (400 µg kg-1); group 5: rats were pretreated with selenium (0.1 mg kg-1); and group 6: rats were pretreated with a combination of three elements. All animal were administered daily by oral gavage for 28 days. At days 27 and 28, myocardial infarction (MI) was induced by subcutaneous injection of ISO (85 mg kg-1) dissolved in 0.9% NaCl in all group except normal control group. The protocol of this study was approved by the Research Ethics Committee of the College of Pharmacy, King Saud University, Riyadh, Saudi Arabia. Cardiac biomarkers (Bodor et al., 1992; Stain, 1985), lipid profile (Lopes-Virella et al., 1977), oxidative stress markers (Aebi, 1984; Moron et al., 1997; Moshage et al., 1995), tumor necrosis factor (TNF-α, inflammatory mediator) (Black et al., 2010) and vascular endothelial growth factor (VEGF, angiogenic marker) (Bates et al., 2002) were measured. A one-way analysis of variance followed by Bonferroni comparisons test was carried out. Data are expressed as mean ± SEM. Differences were considered significant at a P value <0.05.

Results:

ISO-induced MI was indicated by elevation of cardiac biomarkers, oxidative stress, hyperlipidemia, inflammatory response and impaired angiogenesis. Pretreatment with selenium normalized cardiac enzymes, troponin-I (11.5±0.4 Vs 18.66±0.6 pg/ml), TNF-α (25.05±2.3 Vs 45.37±2.3 pg/ml), VEGF (128.2±13.1 Vs 52.8±2.5 pg/ml) as well as reduced oxidative stress (***P<0.001). Selenium failed to correct dyslipidemia. Lipid profile significantly improved by chromium (Triglycerides: 99.5±5.4 Vs 137.3±10.8 mg/dl (*P<0.05), Cholesterol: 80.9±1.8 Vs 94.4±3.8 mg/dl (*P<0.05), HDL: 37.8±1.2 Vs 23.7±1.7 (***P<0.001), LDL: 23.3±0.52 Vs 43±1.6 (***P<0.001). Chromium also improved all other biochemical deviations except for VEGF. Zinc significantly reduced oxidative damage (***P<0.001), triglycerides (*P<0.05), cholesterol (**P<0.01) and TNF-α (***P<0.001) in addition to improved angiogenesis (**P<0.01). Although showed improvement, combination therapy exhibited less prominent protection as compared to individual minerals.

Conclusion:

Daily supplementation with microminerals may be promising for improving myocardial performance via preventing oxidative damage, induction of angiogenesis anti-inflammatory and/or anti-hyperlipidemic mechanisms.

References:

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Black SM et al, Crit Care Med 38:871, 2010.

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Moshage H et al, Clin Chem 41:892, 1995.

Stain W, Med Welt 36:572, 1985.