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Biomedical subjects

F Visioli

Publications and source records attributed to F Visioli.

At least 19 recordsLinked to original sources
PubMed2006

Antioxidant activity of wild plants collected in Valsesia, an alpine region of Northern Italy.

A selection of wild plants collected in Valsesia (Northwest Italy) was screened for their in vitro antioxidant activity. Aerial parts of selected plants were dried at room temperature and powdered. Then, four sequential extractions were performed with increasing polarity solvents, i.e. n-hexane, chloroform, chloroform-methanol (9:1, v/v) and methanol. By employing different assays, it was shown that all the methanol extracts of the samples collected were endowed with antioxidant activity, though, as expected, their potency varied according to the different tests. In particular, plants of the Thymus and Achillea genus displayed the highest activity. Given that a diet rich in wild plants is associated with a reduced incidence of degenerative diseases, such as atherosclerosis and cancer, this study suggests that some Valsesia plants could be pharmaceutically exploited.

Achillea↗
PubMed2005

Lepidium meyenii (Maca) does not exert direct androgenic activities.

Maca is the edible root of the Peruvian plant Lepidum meyenii, traditionally employed for its purported aphrodisiac and fertility-enhancing properties. This study aimed at testing the hypothesis that Maca contains testosterone-like compounds, able to bind the human androgen receptor and promote transcription pathways regulated by steroid hormone signaling. Maca extracts (obtained with different solvents: methanol, ethanol, hexane and chloroform) are not able to regulate GRE (glucocorticoid response element) activation. Further experiments are needed to assess which compound, of the several Maca's components, is responsible of the observed in vivo effects.

Androgens↗
PubMed2005

International conference on the healthy effect of virgin olive oil.

1. Ageing represents a great concern in developed countries because the number of people involved and the pathologies related with it, like atherosclerosis, morbus Parkinson, Alzheimer's disease, vascular dementia, cognitive decline, diabetes and cancer. 2. Epidemiological studies suggest that a Mediterranean diet (which is rich in virgin olive oil) decreases the risk of cardiovascular disease. 3. The Mediterranean diet, rich in virgin olive oil, improves the major risk factors for cardiovascular disease, such as the lipoprotein profile, blood pressure, glucose metabolism and antithrombotic profile. Endothelial function, inflammation and oxidative stress are also positively modulated. Some of these effects are attributed to minor components of virgin olive oil. Therefore, the definition of the Mediterranean diet should include virgin olive oil. 4. Different observational studies conducted in humans have shown that the intake of monounsaturated fat may be protective against age-related cognitive decline and Alzheimer's disease. 5. Microconstituents from virgin olive oil are bioavailable in humans and have shown antioxidant properties and capacity to improve endothelial function. Furthermore they are also able to modify the haemostasis, showing antithrombotic properties. 6. In countries where the populations fulfilled a typical Mediterranean diet, such as Spain, Greece and Italy, where virgin olive oil is the principal source of fat, cancer incidence rates are lower than in northern European countries. 7. The protective effect of virgin olive oil can be most important in the first decades of life, which suggests that the dietetic benefit of virgin olive oil intake should be initiated before puberty, and maintained through life. 8. The more recent studies consistently support that the Mediterranean diet, based in virgin olive oil, is compatible with a healthier ageing and increased longevity. However, despite the significant advances of the recent years, the final proof about the specific mechanisms and contributing role of the different components of virgin olive oil to its beneficial effects requires further investigations.

Aging↗
PubMed2005

Mediterranean food and health: building human evidence.

Adherence to a Mediterranean style diet affords protection from degenerative diseases such as cardiovascular disorders and cancer. Identification of the active constituents of the Mediterranean diet is crucial to the formulation of appropriate dietary guidelines. Also, research on the pharmacological properties of the "minor components" of this diet, eg vitamins and polyphenols, is very active and might lead to the formulation of functional foods and nutraceuticals. Even though in vitro data are plentiful, human studies are difficult to perform due to ethical and practical reasons. Yet, intervention trials represent the best approach to validate claims of healthful activities. This article reviews human evidence of the biological properties of olive oil and tomato constituents and illustrates a research approach by which the bioactive elements of a wild plant (Cynara cardunculus) are first studied in vitro to build biochemical evidence, then in vivo to obtain proof of their vasomodularoty activity.

Antioxidants↗
PubMed2005

The protective ability of the Mediterranean plant extracts against the oxidative DNA damage. The role of the radical oxygen species and the polyphenol content.

The polyphenol plant extracts content seems to be responsible for the scavenging activity of the reactive oxygen species (ROS), resulting in protection against DNA damage induced by the oxidative stress. This assumption was verified analyzing the effect of six Mediterranean plant extracts (Crepis vesicaria L, Origanum heracleoticum, Scandix australis L, Amaranthus sp., Scolymus hispanicus L, Thymus piperella L) on the oxidative DNA damage induced in lymphocytes by H(2)O(2) in relation to the polyphenolic content and the lymphocyte scavenging ability of ROS. The comet assay was used to evaluate oxidative DNA damage and the polyphenol content was analyzed by the Folin-Ciocalteu method. The fluorescence resulting from oxidation of ROS-sensitive dye, dihydrorofluorescein (DHF), was utilized as indicator of the ROS level. Pretreatment with all plant extracts produced the dose-dependent increase in the DNA protection up to the 0.2 microg/ml polyphenol content and the decrease above that dose. Only the Thymus piperella, similarly to quercetin, showed a strong positive correlation between the DNA protection and the polyphenol content, but negative correlation with ROS formation. In conclusion, the DNA protective ability of plant extracts seems to be related to the low polyphenol concentration and only to certain extent depends on the polyphenol ROS scavenging activity.

Comet Assay↗
PubMed2004

Synthesis of long-chain polyunsaturated fatty acids is inhibited in vivo in hypercholesterolemic rabbits and in vitro by oxysterols.

Plasma total lipids, total cholesterol (cholesterol esters and free cholesterol) and oxysterol (mainly 7 beta-hydroxycholesterol (7 beta OH)) concentrations were significantly elevated in New Zealand rabbits fed a 2% cholesterol-containing diet with respect to controls fed the same diet without cholesterol. In addition, linoleic (18:2 n-6) and alpha-linolenic acid (18:3 n-3) plasma concentrations were significantly elevated in hypercholesterolemic rabbits, while concentrations of long-chain n-6 and n-3 derivatives were reduced. Studies in monocytic cell line THP-1 revealed that 7 beta OH markedly inhibited the conversion of 18:2 to 20:4 n-6 and of 18:3 to 22:6 n-3, indicating depression of the desaturation steps; in particular the inhibition was greater for the Delta 5 desaturation step. Furthermore, experiments of Real-Time PCR showed that 5-10 microM 7 beta OH decreased the Delta 5 gene expression. In conclusion, atherogenic oxysterols interfere with the production of long-chain polyunsaturated fatty acids from their precursors both in hypercholesterolemic rabbits and in cultured cells.

Animals↗
PubMed2004

Lycopene and vitamin C concentrations increase in plasma and lymphocytes after tomato intake. Effects on cellular antioxidant protection.

OBJECTIVE: This study seeks to verify whether the regular consumption of small amounts of tomato products can protect lymphocyte DNA and lipids from oxidative damage. DESIGN: Standardized dietary intervention. SUBJECTS: Twelve healthy female subjects (mean age 25.2 y). INTERVENTION: Subjects were instructed to follow a standardized diet for 1 week, followed by 3 weeks consumption of the same diet enriched with small amounts of different tomato products providing as a mean 8 mg lycopene, 0.5 mg beta-carotene and 11 mg vitamin C per day. Plasma and lymphocyte concentrations of carotenoids, vitamin C and vitamin E were analysed. Ex vivo protection of lymphocyte DNA from oxidative injury produced by iron ions was evaluated by means of the Comet assay, and lipid peroxidation by HPLC analysis of malondialdehyde (MDA). RESULTS: Dietary intervention with tomato products increased lycopene concentration both in plasma (P < 0.001) and lymphocytes (P < 0.01). Vitamin C concentrations increased by approximately 35% in plasma (P < 0.05) and by approximately 230% in lymphocytes (P < 0.005). Vitamin E decreased significantly in plasma (P < 0.0001) but not in lymphocytes. Finally, there was an improved protection from DNA oxidative damage (P < 0.05) with no significant effect on MDA levels. CONCLUSIONS: Our results suggest that tomato products are not only good sources of lycopene but also sources of bioavailable vitamin C. A Regular intake of small amounts of tomato products can increase cell protection from DNA damage induced by oxidant species. This effect may originate from the synergism of different antioxidants present in tomatoes.

Administration, Oral↗
PubMed2004

The role of antioxidants in the mediterranean diets: focus on cancer.

The incidence of certain cancers in the Mediterranean area is lower than in other areas of the world (e.g. in northern Europe and the USA). As nutrition and dietary factors comprise one of the three major factors for human carcinogenesis, the hypothesis was formulated that the dietary profile of the Mediterranean diet, rich in antioxidants, might exert preventive actions. Alas, the vast majority of experiments to prove this hypothesis have been obtained in vitro, and most of the necessary information on the absorption, distribution and metabolism of oligonutrients is currently lacking. Yet, even though the exact role of antioxidants in the Mediterranean diet is yet to be fully established, data from observational studies are strong enough to reinforce the notion that a diet low in saturated fat and alcohol and rich in plant food and whole grain, such as the traditional Mediterranean diet, is associated with lower risk of cancer and should be actively promoted.

Antioxidants↗
PubMed2003

In vitro cytotoxicity to human cells in culture of some phenolics from olive oil.

The neutral red in vitro cytotoxicity assay was used to evaluate the comparative responses of human cells isolated from tissues of the oral cavity to olive oil phenolics. The cell lines used included normal gingival fibroblasts, immortalized, nontumorigenic gingival epithelial cells, and carcinoma cells from the salivary gland. No differences in the relative sensitivities to the phenolics amongst the three cell types were noted. In general, for all cell types, the sequence of increasing cytotoxicity was: oleuropein aglycone>oleuropein glycoside, caffeic acid>o-coumaric acid>cinnamic acid>>tyrosol, syringic acid, protocatechuic acid, vanillic acid. Cytotoxicity was noted only at phenolic concentrations far exceeding those attainable after habitual consumption, thus indicating that consumption of phenol-rich olive oil is safe.

Antineoplastic Agents↗
PubMed2001

The role of antioxidants in the Mediterranean diet.

Traditional Mediterranean diets, as opposed to North European and American diets, include a significantly large amount of plant foods; this notable difference between the two eating styles, despite the similarities among other classic risk factors for coronary heart disease (CHD) such as high plasma cholesterol levels, has been associated with a lower risk of developing the CHD and certain cancers. The involvement of excessive free radical production and the great number of epidemiologic studies linking antioxidant intake with a reduced incidence of the above-mentioned diseases indicate that dietary antioxidants likely play a protective role. Because diets in the Mediterranean are (or better yet, were) characterized by abundant plant foods (fruits, vegetables, breads, nuts, seeds; wine and olive oil), this article includes a review of the potential activities of dietary antioxidants, which are plentiful in Mediterranean diets, and wine as related to human disease.

Antioxidants↗
PubMed2001

Antiatherogenic components of olive oil.

Olive oil is the principal source of fat in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Olive oil is characterized by a high proportion of monounsaturated oleic acid, but the main peculiarity of extra-virgin oil is the presence of remarkable quantities of phenolic compounds, notably hydroxytyrosol and oleuropein, that provide high stability and strong taste. Recently, several studies have demonstrated that olive oil phenolics are powerful antioxidants, both in vitro and in vivo, and exert additional potent biologic activities that could partially account for the observed cardioprotective effects of the Mediterranean diet.

Coronary Disease↗
PubMed2001

Direct analysis of total antioxidant activity of olive oil and studies on the influence of heating.

Aim of this study was to evaluate the total antioxidant activity (TAA) of extra virgin olive oil (EVOO) and the effect of heating on the alpha-tocopherol content and TAA in relation to the presence of polyphenols, heating time, and temperature. Experiments included the measurement by ABTS decolorization assay of antioxidant capacity of alpha-tocopherol and 14 simple phenolic compounds present in EVOO, either dissolved in ethanol or added to refined olive oil, and the evaluation of TAA, total phenols, and alpha-tocopherol of six commercial EVOO and three olive oils. Finally, four experimental oils were prepared from refined olive oil containing a fixed amount (300 ppm) of alpha-tocopherol and increasing amounts of polyphenols (25, 125, 225, and 326 ppm) extracted from EVOO. The thermal stability of experimental oils under domestic heating conditions (heating time from 30 to 120 min, heating temperature from 160 to 190 degrees C) was studied by evaluating the loss of alpha-tocopherol and TAA according to a Latin square design. Results indicate that TAA of commercial oils is mainly due to their phenol and alpha-tocopherol content. Heating experiments suggest that polyphenols from EVOO are effective stabilizers of alpha-tocopherol during olive oil heating, thus contributing to the nutritional value of cooked foods.

Antioxidants↗
PubMed2001

Urinary excretion of olive oil phenols and their metabolites in humans.

We have recently demonstrated, in humans, the bioavailability of hydroxytyrosol (3,4-dihydroxyphenylethanol; HT), one of the major antioxidant components of virgin olive oil. In particular, we reported that this compound is present in lipoproteins involved in atherosclerotic processes and is excreted in the urine mainly as glucuronide-conjugate. The aim of the present study was to elucidate, in humans, the metabolic fate of HT after ingestion of virgin olive oil. After administration of virgin olive oil, 24-hour urine collections of healthy volunteers were prepared for gas chromatography-mass spectrometry analyses in order to identify and quantify HT and its metabolites homovanillic alcohol (HVA1c) and homovanillic acid (HVA). The results indicate that this compound undergoes the action of catechol-O-methyl transferase (COMT), enzymes involved in the catecholamine catabolism, resulting in an enhanced excretion of HVA1c. We also found a significant increase of HVA, indicating an oxidation of the ethanolic residue of HT and/or of HVA1c in humans. The excretion of both metabolites significantly correlated with the dose of administered HT.

Biological Availability↗
PubMed2001

Hydroxytyrosol, as a component of olive mill waste water, is dose- dependently absorbed and increases the antioxidant capacity of rat plasma.

Hydroxytyrosol is the most potent phenolic antioxidant of olive oil and olive mill waste water (OMWW) and its biological activities have stimulated research on its potential role in cardiovascular protection. However, evidence of the absorption of OMWW phenolics and on their possible in vivo activity has, until now, never been provided. Three groups male Sprague-Dawley rats were administered 1, 5, or 10 mg/Kg of the OMWW extract, respectively, providing 41.4, 207, and 414 microg/Kg of hydroxytyrosol, respectively. Urine was collected for 24 h and the urinary levels of hydroxytyrosol were quantified by mass spectrometry. Hydroxytyrosol was dose-dependently (R(2) = 0.95) absorbed and excreted in the urines mostly as a glucuronide conjugate. Further, the administration of an hydroxytyrosol-rich OMWW extract (10 mg/kg) to the rats was also associated with an increase of their plasma antioxidant capacity. Future experiments will eventually further clarify its metabolic fate and its in vivo actions.

Animals↗