Effects and mechanisms of curcumin on the hemodynamic variablesof isolated perfused rat hearts

Low Dose Curcumin Administered in Hyaluronic Acid-Based Nanocapsules Induces Hypotensive Effect in Hypertensive Rats

Background

Vascular drug delivery becomes a promising direction in the development of novel therapeutic strategies in the treatment of cardiovascular pathologies, such as hypertension. However, targeted delivery of hydrophobic substances, with poor bioavailability, remains a challenge. Here, we described the hypotensive effects of a low dose of curcumin delivered to the vascular wall using hyaluronic acid-based nanocapsules.

Methods

The group of hypertensive TGR(m-Ren2)27 rats, was administrated respectively with the vehicle, curcumin solution or curcumin delivered using hyaluronic acid-based nanocapsules (HyC12-Cur), for 7 days each, maintaining the wash-out period between treatments. Arterial blood pressure (systolic - SBP, diastolic – DBP) and heart rate (HR) were monitored continuously using a telemetry system (Data Science International), and Mean Arterial Pressure (MAP) was calculated from SBP and DBP.

Results

In hypertensive rats, a low dose of curcumin (4.5 mg/kg) administrated in HyC12-Cur for 7 days resulted in a gradual inhibition of SBP, DBP and MAP increase without an effect on HR. At the end of HyC12-Cur – based treatment changes in SBP, DBP and MAP amounted to −2.0±0.8 mmHg, −3.9±0.7 mmHg and −3.3±0.7 mmHg, respectively. In contrast, the administration of a curcumin solution (4.5 mg/kg) did not result in a significant hypotensive effect and the animals constantly developed hypertension. Vascular delivery of capsules with curcumin was confirmed using newly developed fluorine-rich nanocapsules (HyFC10-PFOB) with a shell based on a HA derivative and similar size as HyC12-Cur. HyFC10-PFOB gave fluorine signals in rat aortas analyzed ex vivo with a ¹⁹F NMR technique after a single intragastric administration.

Conclusion

These results suggest that nanocapsules based on hyaluronic acid, the ubiquitous glycosaminoglycan of the extracellular matrix and an integral part of endothelial glycocalyx, may represent a suitable approach to deliver hydrophobic, poorly bioavailable compounds, to the vascular wall.

Protective effect of curcumin nanoparticles against cardiotoxicity induced by doxorubicin in rat

The present study designed to investigate the protective effect of curcumin nanoparticles (CUR-NPs) on the cardiotoxicity induced by doxorubicin. Rats were divided into four groups; control, rats treated daily with CUR-NPs (50 mg/kg) for 14 days, rats treated with an acute dose of doxorubicin (20 mg/kg) and rats treated daily with CUR-NPs for 14 days injected with doxorubicin on the 10th day. After electrocardiogram (ECG) recording from rats at different groups, rat decapitation was carried out and the heart of each rat was excised out to measure the oxidative stress parameters; lipid peroxidation (MDA), nitric oxide (NO) and reduced glutathione (GSH) and the activities of Na,K,ATPase and acetylcholinesterase (AchE). In addition, the levels of dopamine (DA), norepinephrine (NE) and serotonin (5-HT) were determined in the cardiac tissues. Lactate dehydrogenase (LDH) activity was measured in the serum. The ECG recordings indicated that daily pretreatment with CUR- NPs has prevented the tachycardia (i.e. increase in heart rate) and ameliorated the changes in ST wave and QRS complex induced by doxorubicin. In addition, CUR-NPs prevented doxorubicin induced significant increase in MDA, NO, DA, AchE and LDH and doxorubicin induced significant decrease in GSH, NE, 5-HT and Na,K,ATPase. According to the present findings, it could be concluded that CUR-NPs have a protective effect against cardiotoxicity induced by doxorubicin. This may shed more light on the importance of CUR-NPs pretreatment before the application of doxorubicin therapy.

Curcumin Nanoparticles Protect against Isoproterenol Induced Myocardial Infarction by Alleviating Myocardial Tissue Oxidative Stress, Electrocardiogram, and Biological Changes

Curcumin from Curcuma longa is a nutraceutical compound reported to possess strong antioxidant activity that makes it a candidate for use in counteracting oxidative stress-induced damage. The effect of pre-treatment with curcumin nanoparticles (nC) compared to conventional curcumin (Cs) on blood pressure, electrocardiogram, and biological changes on isoproterenol (ISO)-induced myocardial infarction (MI) in rats had been investigated. The Cs doses of 150 and 200 mg/kg bw and all nC doses (100, 150 and 200 mg/kg bw) significantly reduced heart rate before ISO administration and prevented QRS complex enlargement after MI induction (p < 0.026). All doses of Cs and nC prevented prolongation of the QT and QT corrected (QTc) intervals, with better results for higher doses (p < 0.048). The nC solution had more significant results than Cs in all metabolic parameters assessed (lactate dehydrogenase, glycaemia, aspartate transaminase, and alanine transaminase, p < 0.009). nC was more efficient than Cs in limiting myocardial oxidative stress and enhancing antioxidative capacity (p < 0.004). Compared to Cs, nC better prevented myocardial damage extension, reduced interstitial oedema, and inflammation. Curcumin nanoparticles as compared to conventional curcumin exert better antioxidative effects. Moreover, nC better prevent cardiomyocytes damage, and electrocardiogram alterations, in the case of ISO-induced MI in rats.