New fatty dihydropyridines present cardioprotective potential in H9c2 cardioblasts submitted to simulated ischemia and reperfusion

Hydroxysafflor Yellow A Alleviates Acute Myocardial Ischemia/Reperfusion Injury in Mice by Inhibiting Ferroptosis via the Activation of the HIF-1α/SLC7A11/GPX4 Signaling Pathway

Ferroptosis is closely associated with the pathophysiology of myocardial ischemia. Hydroxysafflor yellow A (HSYA), the main active ingredient in the Chinese herbal medicine safflower, exerts significant protective effects against myocardial ischemia/reperfusion injury (MI/RI). The aim of this study was to investigate the protective effects of HSYA against MI/RI and identify the putative underlying mechanisms. An in vivo model of acute MI/RI was established in C57 mice. Subsequently, the effects of HSYA on myocardial tissue injury were evaluated by histology. Lipid peroxidation and myocardial injury marker contents in myocardial tissue and serum and iron contents in myocardial tissue were determined using biochemical assays. Mitochondrial damage was assessed using transmission electron microscopy. H9C2 cardiomyocytes were induced in vitro by oxygen-glucose deprivation/reoxygenation, and ferroptosis inducer erastin was administered to detect ferroptosis-related indicators, oxidative-stress-related indicators, and expressions of ferroptosis-related proteins and HIF-1α. In MI/RI model mice, HSYA reduced myocardial histopathological damage, ameliorated mitochondrial damage in myocardial cells, and decreased total cellular iron and ferrous ion contents in myocardial tissue. HSYA increased the protein levels of SLC7A11, HIF-1α, and GPX4 and mitigated erastin- or HIF-1α siRNA-induced damage in H9C2 cells. In summary, HSYA alleviated MI/RI by activating the HIF-1α/SLC7A11/GPX4 signaling pathway, thereby inhibiting ferroptosis.

Long-chain fatty dihydropyridines: Docking calcium channel studies and antihypertensive activity

AIMS

From the synthesis of 43 lipophilic dihydropyridines, the aim of this study was to verify whether the new dihydropyridines have calcium channel affinity using coupling studies and to determine antihypertensive and antioxidant properties, as well as toxicology and toxicity nifedipine and three new compounds, were chosen from the previous results.

MATERIALS AND METHODS

The animals were treated for 56 days, 28 days with N (ω) -nitro-L-arginine methyl ester to induce hypertension, and then treated for another 28 days with the new di- hydropyridine and the standard drug nifedipine. Throughout the treatment the animals had their blood pressure measured and their heart rate checked by pletysmography. After treatment the animals were euthanised, blood samples were collected for creatine kinase and urea analysis, and the brain, heart and liver were collected for oxidative status analysis (quantification of reactive oxygen species, total antioxidant capacity, and lipid peroxidation).

KEY FINDINGS

Compounds 2c, and 9a, and nifedipine significantly reduced blood pressure to control group levels. The tachycardia caused by the induction of hypertension was reversed by 2c and 9a compounds. Regarding oxidative stress analyzes, the compounds that had the best performances were also 2c and 9a. Overall the results demonstrate that two of the three new dihydropyridines tested demonstrated performance equal to or superior to the standard drug nifedipine.

SIGNIFICANCE

In this study, for the first time, docking was applied to analyse 43 fatty dihydropyridines regarding their calcium channel binding. Afterwards, three fatty dihydropyridines were chosen and their antihypertensive and antioxidant properties.

Evaluation of the antioxidant activities of fatty polyhydroquinolines synthesized by Hantzsch multicomponent reactions

Polyhydroquinolines (PHQs) are the unsymmetrical Hantzsch derivatives of 1,4-dihydropyridines with several biological applications. In this work, new fatty 2- and 3-substituted PHQ derivatives from different fatty acids and fatty alcohol feedstocks were synthesized at good yields via a four-component reaction (4CR). The antioxidant activities of fatty PHQs were investigated using three different antioxidant methods. The experiments showed that the compounds derived from 2-nitrobenzaldehyde and fatty palmitic (C16:0) and oleic (C18:1) chains showed better antioxidant activity. This revealed that combining the ortho NO2 group in the aromatic ring with the insertion of fatty chains in the PHQ core contributed to the antioxidant activity. However, among all the fatty PHQs tested, the fatty 2-substituted compound derived from oleyl alcohol and 2-nitrobenzaldehyde showed the highest antioxidant activity (EC50, 2.11-4.69 μM), which was similar to those of the antioxidant standards butylated hydroxytoluene (EC50, 1.98-6.47 μM) and vitamin E (EC50, 1.19-5.88 μM). In addition, this lipophilic compound showed higher antioxidant activity than the antihypertensive drug nifedipine (EC50, 49.25-126.86 μM). These results indicate that the new fatty PHQs may find novel applications as antioxidant additives.