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Biomedical subjects

F Visioli

Publications and source records attributed to F Visioli.

At least 37 records · Page 2Linked to original sources
PubMed2001

VasoCare. Vasogen.

Vasogen is developing VasoCare, an immune modulation therapy, as a potential treatment for peripheral vascular disease (PVD) and atherosclerosis [308287], [388266]. In December 1998, VasoCare was in late phase II trials in the UK for PVD [308287], and by October 2000, phase I/II trials were underway in the US, Canada and Europe [388254]. By March 2001, Vasogen was planning to launch a US multicenter trial in PVD in support of regulatory approval [402091]. In June 2001, the USPTO issued a patent entitled 'Method for Preventing and Reversing Atherosclerosis', covering the use of VasoCare in the prevention and reduction of atherosclerosis [411783].

Adjuvants, Immunologic↗
PubMed2000

Olive oils rich in natural catecholic phenols decrease isoprostane excretion in humans.

This study was undertaken to evaluate, in humans, the antioxidant activity of olive oil phenolics, namely hydroxytyrosol and oleuropein aglycone that share an orthodiphenolic (catecholic) structure. Human volunteers were administered olive oil samples containing increasing amounts of an olive oil phenolic extract that was characterized by gas-chromatography/mass spectrometry. The administration of phenol-rich oils was dose-dependently associated with a decreased urinary excretion of 8-iso-PGF(2alpha), a biomarker of oxidative stress. Also, a statistically significant negative correlation between homovanillyl alcohol (HValc, hydroxytyrosol's major metabolite, formed through the COMT system) and F(2)-isoprostanes excretion was found. Thus, the administration of oil samples with increasing, albeit low, concentrations of orthodiphenolic compounds, namely hydroxytyrosol and oleuropein aglycone, results in a dose-dependent reduction in the urinary excretion of 8-iso-PGF(2alpha). The statistically significant negative correlation between 8-iso-PGF(2alpha) and HValc urinary concentrations suggests that this metabolite better reflects the in vivo activities of hydroxytyrosol.

Adult↗
PubMed2000

Olive phenol hydroxytyrosol prevents passive smoking-induced oxidative stress.

BACKGROUND: Oxidative stress is involved in the onset of several degenerative disorders, and epidemiological studies indicate that a high intake of dietary antioxidants, as in the case of the Mediterranean basin, is protective. Olive mill waste waters (OMWWs) are a byproduct of olive oil production rich in phenolic antioxidants, such as hydroxytyrosol. We tested the effects of a low dose of an OMWW extract in a model of sidestream smoke-induced oxidative stress in rats by evaluating the urinary excretion of 8-iso-prostaglandin (PG) F(2alpha) (iPF(2alpha)-III). METHODS AND RESULTS: An OMWW extract (5 mg/kg, providing 414 microg/kg of hydroxytyrosol) was administered to rats daily for 4 days, during which time the animals were exposed to sidestream smoke for 20 minutes once a day. Daily urines were collected, and the urinary excretion of 8-iso-PGF(2alpha) was evaluated as an index of oxidative stress-induced in vivo lipid peroxidation. The exposure of rats to passive smoking increased the urinary excretion of 8-iso-PGF(2alpha) by 44+/-4.2% at 48 hours and by 55+/-10% at 96 hours. Treatment with the OMWW extract was able to completely prevent the increase at 48 hours and resulted in lower increments (34+/-18% versus 55+/-10%) of 8-iso-PGF(2alpha) excretion at 96 hours. CONCLUSIONS: A low dose of hydroxytyrosol, administered through OMWW, reduces the consequences of sidestream smoke-induced oxidative stress in rats.

Animals↗
PubMed2000

Diet and prevention of coronary heart disease: the potential role of phytochemicals.

Epidemiological studies, and some clinical trials, demonstrate that a proper diet reduces the rate of occurrence of cardiovascular disorders. Several in vitro studies suggest that some components of plant foods, most of which sharing a phenolic structure, are endowed with interesting 'pharmacological activities'. This article reviews the evidence that links a high dietary intake of phytochemicals from various sources with a reduced incidence of coronary heart disease.

Cacao↗
PubMed2000

In vitro differentiation of human monocytes to macrophages results in depletion of antioxidants and increase in n-3 fatty acids levels.

The lipid composition and alpha-tocopherol content of human monocytes were investigated before and after their differentiation to macrophages. The total lipid and protein content per number of cells increased after the differentiation of monocytes by approximately four-fold; a two-fold increase in docosahexaenoic and docosapentaenoic acids and a two-fold decrease in linoleic acid were also noted. As opposed to an initial monocytic vitamin E content of 4.75 pmol/10(6) cells, macrophagic vitamin E levels were undetectable. Changes in vitamin E and fatty acids contents in macrophages, with respect to monocytes, appear to reflect the lipid composition of fetal calf serum, that is low in vitamin E and has a proportionally higher docosahexaenoic acid content than adult human serum.

Adult↗
PubMed2000

Olive oil phenolics are dose-dependently absorbed in humans.

Olive oil phenolic constituents have been shown, in vitro, to be endowed with potent biological activities including, but not limited to, an antioxidant action. To date, there is no information on the absorption and disposition of such compounds in humans. We report that olive oil phenolics, namely tyrosol and hydroxytyrosol, are dose-dependently absorbed in humans after ingestion and that they are excreted in the urine as glucuronide conjugates. Furthermore, an increase in the dose of phenolics administered increased the proportion of conjugation with glucuronide.

Adult↗
PubMed2000

The kinetics of copper-induced LDL oxidation depend upon its lipid composition and antioxidant content.

Copper promotes oxidation of human low-density lipoprotein (LDL) through molecular mechanisms that are still under investigation. We employed native human LDL, phospholipid-containing delipidated LDL ghosts, or trilinolein-reconstituted, phospholipid-containing LDL to investigate both LDL oxidation and the associated process of copper reduction. Both LDL ghosts and trilinolein-reconstituted LDL were devoid of antioxidants and were extremely susceptible to AAPH-induced oxidation but, paradoxically, were rather resistant to copper-mediated oxidation. The dynamic reduction of Cu(II) to Cu(I) was quantitatively decreased in LDL ghosts and in trilinolein-reconstituted LDL, also lacking the initial rapid reduction and the subsequent inhibition phases, due to the absence of endogenous antioxidants. Conversely, the rate of copper reduction was linear and likely due to lipid peroxides, either already present or formed during copper-induced oxidation. We suggest that copper undergoes redox transitions in LDL by utilizing reducing equivalents originating from endogenous antioxidants and/or from lipid peroxides in the LDL lipid core.

Amidines↗
PubMed2000

Very low intakes of N-3 fatty acids incorporated into bovine milk reduce plasma triacylglycerol and increase HDL-cholesterol concentrations in healthy subjects.

Eight normolipidaemic volunteers, habitual partial skim milk drinkers and non-eaters of fish during the study, were given 500 ml day(-1) of partial skim milk for 1 month; they were then switched to 500 ml day(-1) of a novel commercially available milk preparation, supplying 400 mg of N-3 fatty acids-of which 300 mg were EPA+DHA-and 15 mg vitamin E, for 6 weeks. No changes in plasma lipid parameters were observed after the first run-in month; at 3 and 6 weeks on the N-3-rich milk, marked increments of plasma EPA (44 and 31%, respectively) and DHA (13 and 31%, respectively) were observed. Triacylglycerol (TG) concentrations decreased by 19% and high-density lipoprotein (HDL) concentrations increased by 19% at 6 weeks; plasma vitamin E rose by 21% while the susceptibility of plasma to oxidation was unaffected. Correlations were found between plasma EPA or DHA and TG, cholesterol, and HDL. In conclusion, the intake of a milk preparation providing low amounts of EPA+DHA to healthy individuals led to marked increases of N-3 fatty acids and vitamin E in plasma and in associated favourable changes in HDL and TG.

Adult↗
PubMed2000

Enzymatic assay for the determination of olive oil polyphenol content: assay conditions and validation of the method.

A new spectrophotometric assay for the determination of the polyphenolic content of olive oil is presented. It is a substrate-recycling assay for phenolic compounds that employs tyrosinase in the presence of excess NADH. The reaction of various phenols with the enzyme produces an o-quinone, which is detected by recycling between reactions with the enzyme and NADH. The method offers some advantages over the classical methods employed to determine the polyphenolic content of olive oil, that is, ease and reproducibility of the analysis, highly increased sensitivity, and selectivity toward phenolic compounds. The amount of total polyphenols was determined in virgin olive oils both with the Folin-Ciocalteu reagent and with the proposed enzymatic method. The results suggest a better estimation of the polyphenol content, as compared with the colorimetric method. This has to be attributed to the different reactivities of the two methods toward phenols and catechols. Finally, the enzymatic method demonstrates that there is a linear relationship between the olive oil phenolic content and the antioxidative capacity of oil extracts.

Flavonoids↗
PubMed2000

Role of plant-derived omega-3 fatty acids in human nutrition.

An international workshop on the role of plant-derived omega-3 fatty acids in human nutrition took place in Milan on February 9, 2000. The meeting was sponsored by the Nutrition Foundation of Italy and was organized by its Scientific Director, Dr. Andrea Poli. It was attended by experts in polyunsaturated fatty acids and human lipid nutrition. This is the first meeting devoted to the health aspects of alpha-linolenic acid, the omega-3 fatty acid contained in plant-derived edible products, as distinct from the more widely studied long-chain omega-3 products typically present in fish and fish-derived products. This report, which is based on updated scientific evidence presented and discussed at the workshop, was prepared by the international expert panel.

Animals↗
PubMed1999

The blood perfused isolated heart: characterization of the model.

We have characterized the aerobic blood-perfused isolated heart model evaluating the hemodynamics and metabolism of both the blood donor animal and the isolated organ. Anaesthesia of the blood donor with sodium pentobarbital (30 mg/kg) increases arterial concentration of non esterified fatty acids (NEFA) from 80 +/- 6 to 452 +/- 70 microM; p < 0.01. Injection of 1,000 U/kg heparin causes a second significant increase from 452 +/- 70 to 1012 +/- 104 microM; p < 0.01. Insertion of the perfusion circuit, without the isolated heart, causes a reduction in blood pressure of the blood donor and a significant increase in norepinephrine from 277 +/- 44 to 634 +/- 130 pg/ml; p < 0.05. Two hours of aerobic perfusion of the isolated heart inserted in the perfusion circuit, decreases arterial pressure of the blood donor with a concomitant increase of plasma norepinephrine from 475 +/- 150 to 841 +/- 159 pg/ml; p < 0.05. Developed pressure, oxygen consumption, glucose and NEFA uptake of the isolated heart remain constant during two hours of aerobic perfusion, NEFA being the preferred substrate. Tissue content of high energy phosphates at the end of the perfusion is high and similar to that observed "in vivo". Despite this, there is a release of lactate and CPK from the isolated heart. We conclude that: 1) the model allows accurate measurement of hemodynamics and metabolism of both the isolated heart and the blood donor animal; 2) the perfusion procedure modifies the substrates concentration of the blood donor animal which, in turn, results in the preferential NEFA utilization of the isolated heart. These changes do not affect the functional parameters of the perfused heart.

Animals↗