Phenolic compounds and antioxidant activity of Italian extra virgin olive oil Monti Iblei.

The profile of phenolic compounds, antioxidant capacity, oxidative stability, and chemical characteristics (free acidity, peroxide value, specific extinction K232 and K270 values, and DeltaK) of 22 commercial extra virgin olive oil (EVOO) samples coming from the denomination of protected origin (DPO) Monti Iblei and obtained from olives harvested in the period September-December 2005 in the production area of the province of Siracusa (Sicily, Italy) were evaluated. The content of total phenols, expressed as gallic acid equivalents, ranged from 14.80 to 121.20 mg/100 g, with a mean value of 53.72 mg/100 g, mainly attributable to deacetoxyligstroside aglycone, deacetoxyoleuropein aglycone, oleuropein aglycone, and ligstroside aglycone. The mean values of Trolox equivalent antioxidant capacity (TEAC) and of oxidative stability were 54.76 and 11.99 hours, respectively. Both TEAC and oxidative stability were positively correlated to the phenol content and to the percentage of inclusion of the olive cultivar "Tonda Iblea." The high mean content of phenols, besides conferring prolonged oxidative stability, likely confers to the DPO Monti Iblei EVOO marked potential beneficial effects for human health.

Absorption and metabolism of red orange juice anthocyanins in rats.

Anthocyanins are natural pigments that could be involved in various health effects. Red oranges are an important dietary source of anthocyanins, including cyanidin 3-glucoside (Cy 3-glc) and an acylated derivative, cyanidin 3-(6''-malonyl)-glucoside (Cy 3-malglc). The aim of this study was to evaluate the absorption and metabolism of red orange anthocyanins in rats fed an anthocyanin-enriched diet for 12 d (approximately 2.8 micromol anthocyanins/d). Furthermore, the absorption of these anthocyanins was studied in both the stomach and intestine using in situ models in rats. Anthocyanin metabolites were identified and quantified by HPLC-electrospray ionization tandem MS and HPLC-diode array detection, respectively. The red orange anthocyanins, Cy 3-glc and Cy 3-malglc, as well as their respective methylated derivatives, were recovered in urine after red orange juice intake. The 24 h urinary excretion of total anthocyanins was low (0.081 (SEM 0.009) % of the ingested amount). However, a high proportion (about 20 %) of red orange anthocyanins was absorbed from the stomach. More Cy 3-malglc than Cy 3-glc was absorbed in the intestine. This study thus indicated that red orange juice anthocyanins were rapidly absorbed from both stomach and small intestine, and then excreted in the urine as intact and methylated forms. Moreover, the absorption and metabolism of acylated anthocyanins and non-acylated anthocyanins were similar.

Antioxidant activity of pasteurized and sterilized commercial red orange juices.

Blood orange juice is a typical Italian product whose red color is primarily associated with anthocyanin pigments. Two orange-based products are present on the market: pasteurized pure juice with 40 days of shelf life, and sterilized beverage containing minimum 12% of concentrated fruit juice. The aim of the present paper is to verify the relationships between the antioxidant properties and the anthocyanins content in a sampling of pasteurized and sterilized commercial red orange juices. The anthocyanins composition was determined by HPLC-MS/MS, while the antioxidant activity was evaluated by the Briggs-Rauscher reaction, selected in order to acquire information at acid pH values, by three radical scavenging assays (DMPD, 2-2'-azinobis-(3-ethylenbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), DPPH), and by FRAP assay to monitor the ferric reducing power. Results showed that antioxidant activity, particularly when measured by ABTS method, is positively related to the content of anthocyanins and that the reduction of anthocyanins content, typical of commercial long-shelf life juices, leads to a remarkable loss of antioxidant power.

Effects of blood orange juice intake on antioxidant bioavailability and on different markers related to oxidative stress.

Orange juice is a source of antioxidants that might afford in vivo protection from oxidative stress. To test this hypothesis, we carried out a human intervention study with blood orange juice containing high amounts of vitamin C, anthocyanins, and carotenoids. Sixteen healthy female volunteers were enrolled in a crossover study and were given 600 mL/day of blood orange juice or a diet without juice for 21 days. Before and after each intervention period, plasma vitamin C, cyanidin-3-glucoside, and carotenoids were quantified. Furthermore, plasma antioxidant capacity, malondialdehyde concentration in plasma, 11-dehydrotromboxane B(2) urinary excretion, and lymphocyte DNA damage were evaluated as biomarkers of oxidative stress. Blood orange juice consumption determined a significant increase in plasma vitamin C, cyanidin-3-glucoside, beta-cryptoxanthin, and zeaxanthin. Also, lymphocyte DNA resistance to oxidative stress was improved whereas no effect was observed on the other markers that we analyzed. In turn, these results suggest that blood orange juice is a bioavailable source of antioxidants, which might moderately improve the antioxidant defense system; however, the long-term effects of its consumption are to be further investigated.

Ochratoxin A-induced DNA damage in human fibroblast: protective effect of cyanidin 3-O-beta-d-glucoside.

Ochratoxin A (OTA), a mycotoxin produced by Aspergillus ochraceus and other moulds, has recently received growing attention because of its carcinogenic, teratogenic and nephrotoxic properties in both humans and farm animals. Nevertheless, with regard to the mechanism of toxicity, the data in the literature are inconclusive. The aim of our work was to verify in human fibroblasts treated with different OTA dosages the involvement of oxidative pathway in the damage mechanism of this mycotoxin and the possible protective effect exerted by cyanidin 3-O-beta-D-glucoside (C3G), an anthocyanin present in pigmented oranges, red wines, fruits and vegetables. The addition of OTA at 25 and 50 microM concentrations for 48 h determined only a slight but significant (P<.05) increase in radical oxygen species, whereas a substantial increase in their production was observed at longer exposure, in particular, when the fibroblasts were treated with 50 microM OTA for 72 h. Under the same experimental conditions, our data showed a significant (P<.05) increase in the rupture of cellular membrane and high damage to genomic DNA, evaluated by single-cell gel electrophoresis (comet assay), thus confirming the involvement of oxidative stress in the OTA genotoxicity in agreement with other studies. Diversely, mitochondrial functionality does not appear influenced by OTA treatment. C3G (0.125, 0.250 mM) added to the cells treated with 50 microM OTA significantly reduced free radical species production and prevented genomic DNA damage.

Differentiation of human melanoma cells induced by cyanidin-3-O-beta-glucopyranoside.

Great attention has been recently given to a flavonoid of the anthocyanin class, cyanidin-3-O-beta-glucopyranoside (C-3-G), which is widely spread throughout the plant kingdom, and is present in both fruits and vegetables of human diets. In this study, we investigated the effect of C-3-G on proliferation and differentiation of human melanoma cells. Both morphological and functional parameters were evaluated, using electron and confocal microscopy, cytofluorometric analysis, HPLC assay, Western blot analysis, and enzymatic assay, as appropriate. A treatment with a single dose of C-3-G decreased cell proliferation without affecting cell viability and without inducing apoptosis or necrosis. The mitotic index and cell percentage in S phase were significantly lower in C-3-G treated cells compared with untreated control. C-3-G treatment induced, in a dose- and time-dependent manner, melanoma cell differentiation characterized by a strong increase in dendrite outgrowth accompanied with a remodeling of the microtubular network, a dramatic increase of focal adhesion and an increased expression of "brain specific" cytoskeletal components such as NF-160 and NF-200 neurofilament proteins. C-3-G treatment also induced increase of cAMP levels and up-regulation of tyrosinase expression and activity resulting in an enhanced melanin synthesis and melanosome maturation. Up-regulation of the melanoma differentiation antigen Melan-A/MART-1 in treated cells respect to the untreated control was also recorded. Data obtained provide evidence that a single treatment with C-3-G is able to revert the human melanoma cells from the proliferating to the differentiated state. We conclude that C-3-G is a very promising molecule to include in the strategies for treatment of melanoma; also because of its nutritional relevance.

Cyanidins: metabolism and biological properties.

Cyanidin and its glycosides belong to the anthocyanins, a widespread class of water-soluble plant compounds that are responsible for the brilliant color (red, orange, blue) of fruits and flowers. They are widely ingested by humans as it has been estimated a daily intake around 180 mg, mainly deriving from fruits and red wines. This paper reviews the literature on the biological activities, absorption and metabolism of cyanidins, with emphasis to the antioxidant, antimutagenic and other protective activities ascribed to these compounds. Their role in contrasting development of cancer and other pathologies is also reviewed. It is concluded that a great deal of work is still necessary to i) definitively clarify the metabolism of cyanidins in human beings; ii) assess the dietary burden and variations within and between populations; iii) evaluate the relationship between cyanidin glycosides-rich food consumption and incidence of given pathologies. The amount of work to be performed is even more significant when considering a possible therapeutic use of cyanidin glycosides-based drugs. With this aim, information on absorption, distribution, metabolism and excretion of cyanidin-glycosides administered by main possible routes are largely insufficient. However, consisting findings allow looking at cyanidins as dietary compounds with a potential beneficial role for human health.

Cyanidin-3-O-beta-glucopyranoside protects myocardium and erythrocytes from oxygen radical-mediated damages.

The cyanidin-3-O-beta-glucopyranoside (C-3-G) antioxidant capacity towards reactive oxygen species (ROS)-mediated damages was assessed in tissue and cells submitted to increased oxidative stress. In the isolated ischemic and reperfused rat heart, 10 or 30 degreesM C-3-G protected from both lipid peroxidation (66.7 and 94% inhibition of malondialdehyde (MDA) generation in 10 and 30 microM C-3-G-reperfused hearts, respectively, in comparison with control reperfused hearts) and energy metabolism impairment (higher ATP concentration in 10 and 30 microM C-3-G-reperfused hearts than in control reperfused hearts). These effects were associated to C-3-G permeation within myocardial cells, as indicated by results obtained in the isolated rat heart perfused for 30 min in the recirculating Langendorff mode under normoxia with 10 and 30 microM C-3-G. Protective effects were exerted, in a dose-dependent manner, by C-3-G also in 2 mM hydrogen peroxide-treated human erythrocytes. With respect to MDA formation, an apparent IC50 of 5.12 microM was calculated for C-3-G (the polyphenol resveratrol used for comparison showed an apparent IC50 of 38.43 microM). The general indications are that C-3-G (largely diffused in dietary plants and fruits, such as pigmented oranges very common in the Mediterranean diet) represents a powerful natural antioxidant with beneficial effects in case of increased oxidative stress, and at pharmacological concentrations it is able to decrease tissue damages occurring in myocardial ischemia and reperfusion.

Occurrence and Stability of Aflatoxin M1 in Milk and Milk Products: A Worldwide Review.

This paper critically reviews data from the literature since 1980 on the occurrence of aflatoxin M1 (AFM1) in human and animal milk, infant formula, dried milk, cheese, and yogurt. Furthermore the influence of storage and processing of milk and milk products on the occurrence and stability of AFM1 is reviewed. It is concluded that (i) efforts in attempting to harmonize already existing regulatory limits for AF in foods and feed should be made; (ii) further investigations should verify the influence of milk storage and processing on AFM1 occurrence to avoid uncertainty in actual practice; (iii) the occurrence of AFM1 in animal milks and milk products is widespread, although, considering the current scientific fund, contamination levels do not seem to be a serious health hazard; however, further studies should provide accurate scientific information concerning the human health hazard related to long-term exposure to subchronic AF levels; (iv) monitoring programs should be more extensive and frequent; and (v) in tropical and subtropical countries, especially in African countries, a particular attention should be used in monitoring milk and milk products other than those from cows, as well as feed. Furthermore, extensive and periodic surveys on the occurrence of AF and their metabolite in human breast milk should be performed, since a serious health hazard to mother, fetus, or infants could occur.