Biochemical and histological changes in the heart of post-partum rats exposed to Natron

Metronidazole promotes oxidative stress and DNA fragmentation-mediated myocardial injury in albino mice

The purpose of the present study was to investigate the cardiotoxic effects of Metronidazole (Mtz) in albino mice. The mice were divided into four experimental groups: Gp.I (control group): saline, Gp.II:125 mg/kg b.w Mtz, Gp.III:250 mg/kg b.w, Gp.IV:500 mg/kg b.w Mtz. Heart weight ratio, markers of cardiac injury, markers of oxidative stress, histopathological examinations, DNA fragmentation and spectral analysis were used to determine cardiotoxicity. Administration of 125-500 mg/kg Mtz caused an increase in heart weight and a decrease in body weight. Administration of 500 mg/kg Mtz increased heart weight by 35.5% and decreased body weight by 21.9% compared with control. Mtz-treated mice showed a significant increase in cardiac injury biomarkers and serious alterations in cardiac oxidative stress markers. Histopathological changes of cardiac tissues observed in mice treated with Mtz include myocardial hypertrophy, fibrosis, myocarditis, separation of the muscle fibers, congestion-narrowing in vessels, necrosis, myocardium-vacuolation, myocytolysis, myocyte degeneration, nuclear aggregation, cytoplasmic fragmentation and prevalent nuclei. Mtz treatment already resulted in a significant decrease in the percentage of head DNA and an increase in the percentage of tail DNA. The most striking tail formation among the Mtz-treated groups was observed in the group receiving 500 mg/kg Mtz. In the presence of Mtz, there was a hypochromic shift in the absorption spectrum of DNA, and the potential DNA-Mtz interaction was found to occur in the intercalation mode. These results show that Mtz used against anaerobic bacteria and protozoa in gastrointestinal infections can cause severe cardiotoxic findings in albino mice and cause fragmentation in DNA.

Effect of natron administration on the antioxidant status and lipid profile of rats

Natron consumption has been implicated in the pathogenesis of peripartum cardiomyopathy. This work evaluates the effect of natron on the antioxidant status and lipid profile of postpartum rats administered graded doses of natron for four consecutive weeks. After treatment, the rats were assessed for antioxidant status, malondialdehyde level, and lipid profile. The results revealed that natron caused a significant decrease (P ˂ 0.05) in the activity of catalase in rats administered with 300 mg/kg of natron compared to control. The activities of superoxide dismutase and glutathione peroxidase decreased in a dose-dependent manner; however, the difference was not statistically significant when compared with control. Serum levels of antioxidant minerals were also significantly decreased (P ˂ 0.05) at higher doses of natron in comparison to control. There was a significant increase (P < 0.05) in the malondialdehyde level in rats administered with 200 and 300 mg/kg of natron when compared with control. Natron at higher doses caused a significant increase (P ˂ 0.05) in the level of the lipid profile parameters except for high-density lipoprotein-cholesterol that decrease significantly (P ˂ 0.05). This study demonstrated that the administration of natron at high doses induced dyslipidemia and oxidative stress in postpartum rats. PRACTICAL APPLICATION: This research reports the implication of a high intake of natron to health and to establish the relationship between natron intake and peripartum cardiomyopathy (PPCM) using an animal model. Natron has health benefits; however, its consumption at high doses should be discouraged as it can lead to oxidative stress (OS) and dyslipidemia. The results suggest that OS due to natron may contribute to the pathogenesis of PPCM. A high concentration of natron can be used to induce an animal model of PPCM, which would be of practical application in studying the molecular basis and possible discovery of therapeutics for the disease.

Allylmethylsulfide, a Sulfur Compound Derived from Garlic, Attenuates Isoproterenol-Induced Cardiac Hypertrophy in Rats

Allylmethylsulfide (AMS) is a novel sulfur metabolite found in the garlic-fed serum of humans and animals. In the present study, we have observed that AMS is safe on chronic administration and has a potential antihypertrophic effect. Chronic administration of AMS for 30 days did not cause any significant differences in the body weight, electrocardiogram, food intake, serum biochemical parameters, and histopathology of vital organs. Single-dose pharmacokinetics of AMS suggests that AMS is rapidly metabolized into Allylmethylsulfoxide (AMSO) and Allylmethylsulfone (AMSO₂). To evaluate the efficacy of AMS, cardiac hypertrophy was induced by subcutaneous implantation of ALZET® osmotic minipump containing isoproterenol (~5 mg/kg/day), cotreated with AMS (25 and 50 mg/kg/day) and enalapril (10 mg/kg/day) for 2 weeks. AMS and enalapril significantly reduced cardiac hypertrophy as studied by the heart weight to body weight ratio and mRNA expression of fetal genes (ANP and β-MHC). We have observed that TBARS, a parameter of lipid peroxidation, was reduced and the antioxidant enzymes (glutathione, catalase, and superoxide dismutase) were improved in the AMS and enalapril-cotreated hypertrophic hearts. The extracellular matrix (ECM) components such as matrix metalloproteinases (MMP2 and MMP9) were significantly upregulated in the diseased hearts; however, with the AMS and enalapril, it was preserved. Similarly, caspases 3, 7, and 9 were upregulated in hypertrophic hearts, and with the AMS and enalapril treatment, they were reduced. Further to corroborate this finding with in vitro data, we have checked the nuclear expression of caspase 3/7 in the H9c2 cells treated with isoproterenol and observed that AMS cotreatment reduced it significantly. Histopathological investigation of myocardium suggests AMS and enalapril treatment reduced fibrosis in hypertrophied hearts. Based on our experimental results, we conclude that AMS, an active metabolite of garlic, could reduce isoproterenol-induced cardiac hypertrophy by reducing oxidative stress, apoptosis, and stabilizing ECM components.