Investigation of therapeutic potential and molecular mechanism of vitamin P and digoxin in I/R-induced myocardial infarction in rat

Potential Effects of Digoxin on Renal Functions in Patients With Congestive Heart Failure

INTRODUCTION

Renal dysfunction is a common complication among patients with congestive heart failure (CHF) and can significantly impact their management, especially when medications like digoxin are involved. The clearance of digoxin is closely tied to the glomerular filtration rate (GFR), which suggests that the safety and efficacy of digoxin may vary with renal function. Therefore, this study aimed to assess the potential effects of digoxin on renal function in patients diagnosed with CHF at a tertiary hospital in the Asir region of Saudi Arabia.

METHODS

A retrospective study examined the records of 30 CHF patients treated with digoxin. Renal function markers like estimated GFR (eGFR), creatinine, blood urea nitrogen (BUN), albumin, and urine levels were compared before and after digoxin treatment. Liver enzymes and other relevant parameters were also examined. A statistical analysis using t-tests was conducted to evaluate the changes in renal function indicators before and after digoxin treatment.

RESULTS

The mean eGFR decreased significantly from 65.4 ± 8.9 mL/min/1.73m2 before digoxin to 57.7 ± 7.8 mL/min/1.73m2 after (p = 0.001). Creatinine, BUN, albumin, and urine levels showed no significant changes. Digoxin significantly increased aspartate aminotransferase (AST) from 34.5 ± 11.6 U/L to 53.8 ± 14.6 U/L (p = 0.002), alanine aminotransferase (ALT) from 38.5 ± 12.6 U/L to 55.3 ± 17.6 U/L (p = 0.013), and creatine kinase from 117.7 ± 22.5 U/L to 133.9 ± 15.8 U/L (p = 0.012). Hemoglobin decreased significantly from 12.8 ± 1.4 g/dL to 12.1 ± 1.4 g/dL (p = 0.034). No significant changes occurred in myoglobin, troponin, bilirubin, platelets, potassium, calcium, or chloride levels. Effects on kidney function did not differ significantly by gender or age, except blood urea nitrogen was higher in patients over 50 years (8.3 ± 2.3 vs. 5.6 ± 2.7 mg/dL, p = 0.015).

CONCLUSION

This study suggests digoxin may adversely affect renal function in CHF patients, as evidenced by reduced eGFR. However, the small retrospective design limits definitive conclusions. Further prospective research with larger samples is warranted to elucidate digoxin's renal effects in CHF patients.

The Coadministration of Levosimendan and Exenatide Offers a Significant Cardioprotective Effect to Isolated Rat Hearts against Ischemia/Reperfusion Injury

(1) Background: The present study aims to investigate the effect of administration of Levosimendan and Exenatide in various concentrations, as well as of the coadministration of those agents in an ischemia–reperfusion injury isolated heart model. (2) Methods: After 30 min of perfusion, the hearts underwent a 30 min period of regional ischemia followed by a 120 min period of reperfusion. All animals were randomly divided into 12 experimental groups of nine animals in each group: (1) Control, (2) Sham, (3) Digox (Negative control, Digoxin 1.67 μg/min), (4) Levo 1 (Levosimendan 0.01 μg/min), (5) Levo 2 (Levosimendan 0.03 μg/mL), (6) Levo 3 (Levosimendan 0.1 μg/min), (7) Levo 4 (Levosimendan 0.3 μg/min), (8) Levo 5 (Levosimendan 1 μg/min), (9) Exen 1 (Exenatide 0.001 μg/min), (10) Exen 2 (Exenatide 0.01 μg/min), (11) Exen 3 (Exenatide 0.1 μg/min) and (12) Combi (Levosimendan 0.1 µg/mL + Exenatide 0.001 μg/min). The hemodynamic parameters were recorded throughout the experiment. Arrhythmias and coronary flow were also evaluated. After every experiment the heart was suitably prepared and infarct size was measured. Markers of myocardial injury were also measured. Finally, oxidative stress was evaluated measuring reactive oxygen species. (3) Results: A dose-dependent improvement of the haemodynamic response was observed after the administration of both Levosimendan and Exenatide. The coadministration of both agents presented an even greater effect, improving the haemodynamic parameters further than the two agents separately. Levosimendan offered an increase of the coronary flow and both agents offered a reduction of arrhythmias. A dose-dependent reduction of the size of myocardial infarction and myocardial injury was observed after administration of Levosimendan and Exenatide. The coadministration of both agents offered a further improving the above parameters. Levosimendan also offered a significant reduction of oxidative stress. (4) Conclusions: The administration of Levosimendan and Exenatide offers a significant benefit by improving the haemodynamic response, increasing the coronary flow and reducing the occurrence of arrhythmias, the size of myocardial injury and myocardial oxidative stress in isolated rat hearts.

Molecular Mechanistic Pathways Targeted by Natural Antioxidants in the Prevention and Treatment of Chronic Kidney Disease

Chronic kidney disease (CKD) is the progressive loss of renal function and the leading cause of end-stage renal disease (ESRD). Despite optimal therapy, many patients progress to ESRD and require dialysis or transplantation. The pathogenesis of CKD involves inflammation, kidney fibrosis, and blunted renal cellular antioxidant capacity. In this review, we have focused on in vitro and in vivo experimental and clinical studies undertaken to investigate the mechanistic pathways by which these compounds exert their effects against the progression of CKD, particularly diabetic nephropathy and kidney fibrosis. The accumulated and collected data from preclinical and clinical studies revealed that these plants/bioactive compounds could activate autophagy, increase mitochondrial bioenergetics and prevent mitochondrial dysfunction, act as modulators of signaling pathways involved in inflammation, oxidative stress, and renal fibrosis. The main pathways targeted by these compounds include the canonical nuclear factor kappa B (NF-κB), canonical transforming growth factor-beta (TGF-β), autophagy, and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid factor 2-related factor 2 (Nrf2)/antioxidant response element (ARE). This review presented an updated overview of the potential benefits of these antioxidants and new strategies to treat or reduce CKD progression, although the limitations related to the traditional formulation, lack of standardization, side effects, and safety.

Rutin Modulates MAPK Pathway Differently from Quercetin in Angiotensin II-Induced H9c2 Cardiomyocyte Hypertrophy

Rutin is a flavonoid with antioxidant property. It has been shown to exert cardioprotection against cardiomyocyte hypertrophy. However, studies regarding its antihypertrophic property are still lacking, whether it demonstrates similar antihypertrophic effect to its metabolite, quercetin. Hence, this study aimed to investigate the effects of both flavonoids on oxidative stress and mitogen-activated protein kinase (MAPK) pathway in H9c2 cardiomyocytes that were exposed to angiotensin II (Ang II) to induce hypertrophy. Cardiomyocytes were exposed to Ang II (600 nM) with or without quercetin (331 μM) or rutin (50 μM) for 24 h. A group given vehicle served as the control. The concentration of the flavonoids was chosen based on the reported effective concentration to reduce cell hypertrophy or cardiac injury in H9c2 cells. Exposure to Ang II increased cell surface area, intracellular superoxide anion level, NADPH oxidase and inducible nitric oxide synthase activities, and reduced cellular superoxide dismutase activity and nitrite level, which were similarly reversed by both rutin and quercetin. Rutin had no significant effects on phosphorylated proteins of extracellular signal-related kinases (ERK1/2) and p38 but downregulated phosphorylated c-Jun N-terminal kinases (JNK1/2), which were induced by Ang II. Quercetin, on the other hand, had significantly downregulated the phosphorylated proteins of ERK1/2, p38, and JNK1/2. The quercetin inhibitory effect on JNK1/2 was stronger than the rutin. In conclusion, both flavonoids afford similar protective effects against Ang II-induced cardiomyocyte hypertrophy, but they differently modulate MAPK pathway.

The Physiologic Activity and Mechanism of Quercetin-Like Natural Plant Flavonoids

The term "vitamin P" is an old but interesting concept. Most substances in this category belong to the family of flavonoids. "Vitamin P" has also been used to define the activity of some flavonoids, including quercetin, myricetin, and rutin. According to experimental studies, the "quercetin-like natural plant flavonoids" are beneficial to the body due to their various physiological and pharmacological activities in large doses (5 μM in vitro, 50 mg/kg in mice and 100 mg/kg in rats). The physiologically achievable concentration is 10 to 100 nM, which is quite high and hard to achieve from a normal diet. Thus, the physiologic activity and mechanism of "vitamin P" are still not clear. It should be noted that the quercetin-like natural plant flavonoids are physiological co-factors of cyclooxygenases (COXs), which are the rate-limiting key enzymes of prostaglandins. These quercetin-like natural plant flavonoids can strongly stimulate prostaglandin levels at lower doses (10 nM in vitro and in 0.1 mg/kg in vivo in rats). Although these "vitamin P" substances are not original substances in the body, their physiological functions affect the body. This review is focused on the most compelling evidence regarding the physiologic role and mechanism of quercetin-like natural plant flavonoids, which may be useful in understanding the physiological functions of "vitamin P", with the goal of focusing on the role of flavonoids in human physiological health.

The effect of rutin on ovarian ischemia-reperfusion injury in a rat model

The effect of rutin on ovarian ischemia-reperfusion (I/R) injury was investigated in this experimental study. Eighteen Wistar albino female rats were divided into three groups as follows: I/R group (IRG; n = 6), 50 mg/kg rutin + I/R group (RG; n = 6), and a healthy control group scheduled for a sham operation (SG; n = 6). 2 h of ischemia and following 2 h of reperfusion were created in the IRG and RG by using a torsion model involving atraumatic vascular clips. Rutin, a flavonoid glycoside, was injected intraperitoneally at the dose of 50 mg/kg to RG group 1 h before reperfusion. Then, rats were euthanized and their ovaries were removed for biochemical and histopathological examination and also assessment of the gene expressions. IRG group had a significant increase in malondialdehyde (MDA) levels, in the expressions of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β), and also in the activity of cyclooxygenase 2 (COX-2) unlike the significant decrease in total glutathione (tGSH) levels and the activity of COX-1 when compared to the SG group. However, rutin significantly decreased MDA levels, the expressions of TNF-α and IL-1β, and also the activity of COX-2 while it increased significantly tGSH levels and the activity of COX-1 in the RG group in comparison with the IRG group. Rutin ameliorated the I/R-induced ovarian injury in rats via its possible antioxidative and anti-inflammatory effects.

Rutin attenuates cerebral ischemia-reperfusion injury in ovariectomized rats via estrogen-receptor-mediated BDNF-TrkB and NGF-TrkA signaling

Rutin, a flavonoid glycoside, has been reported to exert neuroprotective effects. Loss of endogenous estrogen and dysregulation of the estrogen receptor (ER) signaling pathway are associated with the increased risk of stroke in women after menopause. This study was performed to investigate whether rutin could protect against cerebral ischemia by modulating the ER pathway. Ovariectomized (OVX) rats were given intraperitoneal injections of vehicle (dimethyl sulfoxide), rutin (100 mg/kg body mass) or 17β-estradiol (100 μg/kg body mass) for 5 consecutive days. Then, the rats were subjected to middle cerebral artery occlusion (MCAO) for 1 h followed by a 24 h reperfusion to establish the cerebral ischemia-reperfusion (I/R) injury. We found that rutin improved the sensorimotor performance and recognition memory of rats subjected to I/R, decreased the infarct size, and attenuated neuron loss. Rutin treatment also increased the levels of ERα, ERβ, brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), tropomyosin receptor kinase A (TrkA), TrkB, and phospho-cAMP-responsive element binding protein (p-CREB) in rat hippocampus and cerebral cortex. The protective effects of rutin were comparable to that of 17β-estradiol, and were partially blocked by ICI182780, an ER antagonist. The above results suggest that rutin preconditioning ameliorates cerebral I/R injury in OVX rats through ER-mediated BDNF-TrkB and NGF-TrkA signaling.