Role of acid phosphatase and enzymatic and non-enzymatic antioxidant systems in tolerance of alfalfa (Medicago sativa L.) populations to low phosphorus availability

Received: April 27th, 2022 ; Accepted: July 25th, 2022 ; Published: October, 12th, 2022 ; Correspondence: [email protected] study aims at evaluating the tolerance of four alfalfa (Medicgao sativa L.) populations to low phosphorus (P) in rooting medium. The experiment was carried out under controlled conditions. The seedlings of 15 old days were subjected to P deficiency using Ca3HPO4, insoluble form and P sufficiency using KH2PO4, as soluble form, at a final concentration of 250 μmol P plant−1. week−1. After 60 days P deficit, several agro–physiological and biochemical traits were measured and determined in both conditions. The obtained results indicated that the P–starvation significantly (P < 0.001) reduced the agroeconomic traits evaluated such as plant dry weight and leaf area. The root and shoot P contents were found (P < 0.001) decreased by low–P availability in the rooting medium. This constraint induced significant (P < 0.001) increase in phosphatase acid activity and caused lipid peroxidation and oxidative damage to cells, evaluated through malondialdehyde and hydrogen peroxide contents. Our results showed also, that low P availability significantly (P < 0.001) increased the enzymatic antioxidant responses reflected by the activities of superoxide dismutase (SOD), guaiacol peroxidase and catalase. The non-enzymatic antioxidant molecule such as proline and total polyphenols were found significantly increased in alfalfa stressed plants. The behavior of alfalfa populations tested was significantly different (P >0.05). The OL population was found to be the least affected and the DEM was most sensitive one, whereas the populations TATA and RICH showed a moderate tolerance. Our study advises that the tolerance of Moroccan alfalfa populations to low P–availability was associated with increased acid phosphate activity and ability to induce enzymatic and non-enzymatic antioxidant responses leading to cell detoxification from reactive oxygen species (ROS)

Beneficial Effects of Pomegranate Fruit Consumption in Cardiovascular Diseases Prevention

Oxidative stress, dyslipidemia, hypercoagulability, endothelial dysfunction and inflammation are key elements in the development of atherosclerosis. Oxidative stress has been implicated as well in most of the key steps in the pathophysiology of atherosclerosis and the consequential clinical manifestations of cardiovascular diseases. In addition to the formation of atherosclerosis, oxidative stress acute thrombotic events, including dyslipidemia, the oxidation of low-density lipoproteins (LDLs) and plaque rupture leading to atherothrombosis and myocardial infarction. In the last decades, multiple experimental studies and clinical trials have demonstrated that diet plays a central role in the prevention of atherosclerosis. Pomegranate (Punica granatum L.) is one of nature's most concentrated sources of antioxidants. It contains some very potent antioxidants (i.e. tannins, anthocyanins and flavonoids), which provide a wide spectrum of action against free radicals and are considered to be potent anti-atherogenic products. These properties make pomegranate a healthy fruit with a high potential in preventing cardiovascular diseases. In this review, we give an overview on the newest insights in the role of pomegranate in therapy of vascular diseases

Vasorelaxant activity of indole alkaloids from Tabernaemontana dichotoma.

The aim of this study was to search for bioactive natural products from medicinal plants targeting vasorelaxant activity and we found the methanol extract from bark of Tabernaemontana dichotoma showed vasorelaxant activity on rat aorta. We isolated eight indole alkaloids including 10-methoxyalstonerine (1), a new macroline type indole alkaloid, from bark of T. dichotoma. These were respectively identified as 10-methoxyaffinisine (2), lochnerine (3), cathafoline (4), (−)-alstonerine (5), 19,20-dehydro-10-methoxytalcarpine (6), alstonisine (7), and alstonal (8) based on spectroscopic analysis. Among them, sarpagine type (2 and 3), akuammiline type (4), and macroline oxindole type (7 and 8) showed potent vasorelaxant activity. Mechanism of action on vasorelaxant activity of 10-methoxyaffinisine (2), cathafoline (4), and alstonisine (7) was clarified. Effects of 10-methoxyaffinisine (2), cathafoline (4), and alstonisine (7) were partially mediated the NO release from endothelial cells. Furthermore, 10-methoxyaffinisine (2) and alstonisine (7) attribute to the inhibitory effect of VDC and ROC, and cathafoline (4) have inhibitory effect on Ca2+ influx via ROC. In addition, 10-methoxyaffinisine (2) as a major compound from bark of T. dichotoma showed hypotensive effect on normotensive rats in vivo

Mitochondrial function is involved in regulation of cholesterol efflux to apolipoprotein (apo)A-I from murine RAW 264.7 macrophages

<p>Abstract</p> <p>Background</p> <p>Mitochondrial DNA damage, increased production of reactive oxygen species and progressive respiratory chain dysfunction, together with increased deposition of cholesterol and cholesteryl esters, are hallmarks of atherosclerosis. This study investigated the role of mitochondrial function in regulation of macrophage cholesterol efflux to apolipoprotein A-I, by the addition of established pharmacological modulators of mitochondrial function.</p> <p>Methods</p> <p>Murine RAW 264.7 macrophages were treated with a range of concentrations of resveratrol, antimycin, dinitrophenol, nigericin and oligomycin, and changes in viability, cytotoxicity, membrane potential and ATP, compared with efflux of [³H]cholesterol to apolipoprotein (apo) A-I. The effect of oligomycin treatment on expression of genes implicated in macrophage cholesterol homeostasis were determined by quantitative polymerase chain reaction, and immunoblotting, relative to the housekeeping enzyme, <it>Gapdh</it>, and combined with studies of this molecule on cholesterol esterification, <it>de novo</it> lipid biosynthesis, and induction of apoptosis. Significant differences were determined using analysis of variance, and Dunnett’s or Bonferroni post <it>t</it>-tests, as appropriate.</p> <p>Results</p> <p>The positive control, resveratrol (24 h), significantly enhanced cholesterol efflux to apoA-I at concentrations ≥30 μM. By contrast, cholesterol efflux to apoA-I was significantly inhibited by nigericin (45%; <it>p</it><0.01) and oligomycin (55%; <it>p</it><0.01), under conditions (10 μM, 3 h) which did not induce cellular toxicity or deplete total cellular ATP content. Levels of ATP binding cassette transporter A1 (ABCA1) protein were repressed by oligomycin under optimal efflux conditions, despite paradoxical increases in <it>Abca1</it> mRNA. Oligomycin treatment did not affect cholesterol biosynthesis, but significantly inhibited cholesterol esterification following exposure to acetylated LDL, and induced apoptosis at ≥30 μM. Finally, oligomycin induced the expression of genes implicated in both cholesterol efflux (<it>Abca1</it>, <it>Abcg4</it>, <it>Stard1</it>) and cholesterol biosynthesis (<it>Hmgr</it>, <it>Mvk</it>, <it>Scap</it>, <it>Srebf2</it>), indicating profound dysregulation of cholesterol homeostasis.</p> <p>Conclusions</p> <p>Acute loss of mitochondrial function, and in particular Δψ_m, reduces cholesterol efflux to apoA-I and dysregulates macrophage cholesterol homeostasis mechanisms. Bioavailable antioxidants, targeted to mitochondria and capable of sustaining effective mitochondrial function, may therefore prove effective in maintenance of arterial health.</p