Patrizia Riso

Absorption of lycopene from single or daily portions of raw and processed tomato

To study the relationship between lycopene intake and plasma concentration, ten healthy female subjects were given one or more portions of tomato purée or fresh raw tomato containing 16.5 mg total lycopene (all-trans + cis forms). In Expt 1 subjects (n 9) were randomly assigned the single portions of the two tomato products and blood samples were collected to follow the change in plasma carotenoid concentrations within the first 12 h and on each of the following 5 d (104 h). In Expt 2 subjects (n 10) were divided into two groups of five each receiving daily dietary portions of tomato purée or fresh raw tomato containing 16.5 mg total lycopene for 7 d. Fasting blood samples were collected daily. In Expt 1 the plasma total lycopene (all-trans + cis forms) concentration, after the single portions of tomato purée and raw tomato, varied significantly over time, with a first peak reached after 6 h, a further increase after 12 h and a slow decrease until 104 h. In Expt 2, when the tomato products were given daily, there was a day-by-day increase in the plasma total lycopene concentration, and through the following week of a diet without tomato there was a gradual decrease. However, values did not return to basal concentrations. Plasma total lycopene concentration was higher after the tomato purée intake than after the raw tomato in both the first (F(1,8) 7.597; P < 0.025) and the second experiments (F(1,8) 12.193; P < 0.01) demonstrating a significant effect of food matrix on absorption.

Effect of different cooking methods on color, phytochemical concentration, and antioxidant capacity of raw and frozen Brassica vegetables.

This study evaluated the effect of common cooking practices (i.e., boiling, microwaving, and basket and oven steaming) on the phytochemical content (carotenoids, chlorophylls, glucosinolates, polyphenols, and ascorbic acid), total antioxidant capacity (TAC), and color changes of three generally consumed Brassica vegetables analyzed fresh and frozen. Among cooking procedures, boiling determined an increase of fresh broccoli carotenoids and fresh Brussels sprout polyphenols, whereas a decrease of almost all other phytochemicals in fresh and frozen samples was observed. Steaming procedures determined a release of polyphenols in both fresh and frozen samples. Microwaving was the best cooking method for maintaining the color of both fresh and frozen vegetables and obtaining a good retention of glucosinolates. During all cooking procedures, ascorbic acid was lost in great amount from all vegetables. Chlorophylls were more stable in frozen samples than in fresh ones, even though steaming methods were able to better preserve these compounds in fresh samples than others cooking methods applied. The overall results of this study demonstrate that fresh Brassica vegetables retain phytochemicals and TAC better than frozen samples.

Weight, Protein, Fat, and Timing of Preloads Affect Food Intake

Two foods, one rich in protein (HP) and one rich in fat (HF), were employed to evaluate the effect of macronutrients on food intake and to underline the differences that occurred when the foods were served as uniform meal, as first course of a varied meal, and as a snack 2 h before a varied meal. Our results showed that HP food always exerted a higher effect on both intrameal satiation and postingestive satiety than HF food. When a uniform meal was consumed, satiation for the specific food was reached before fullness; in this condition, sensory characteristics of foods played an important role in controlling food intake and made the uniform meal more satiating than the varied one. The consumption of a snack far from a meal did not contribute to satiety; consequently, gastric filling seems to be an important factor determining the amount consumed in a varied meal.

Daily intake of a formulated tomato drink affects carotenoid plasma and lymphocyte concentrations and improves cellular antioxidant protection.

The salutary characteristics of the tomato are normally related to its content of carotenoids, especially lycopene, and other antioxidants. Our purpose was to verify whether the daily intake of a beverage prototype called Lyc-o-Mato((R)) containing a natural tomato extract (Lyc-o-Mato((R)) oleoresin 6 %) was able to modify plasma and lymphocyte carotenoid concentrations, particularly those of lycopene, phytoene, phytofluene and beta-carotene, and to evaluate whether this intake was sufficient to improve protection against DNA damage in lymphocytes. In a double-blind, cross-over study, twenty-six healthy subjects consumed 250 ml of the drink daily, providing about 6 mg lycopene, 4 mg phytoene, 3 mg phytofluene, 1 mg beta-carotene and 1.8 mg alpha-tocopherol, or a placebo drink. Treatments were separated by a wash-out period. Plasma and lymphocyte carotenoid and alpha-tocopherol concentrations were determined by HPLC, and DNA damage by the comet assay. After 26 d of consumption of the drink, plasma carotenoid levels increased significantly: concentrations of lycopene were 1.7-fold higher (P<0.0001); of phytofluene were 1.6-fold higher (P<0.0001); of phytoene were doubled (P<0.0005); of beta-carotene were 1.3-fold higher (P<0.05). Lymphocyte carotenoid concentrations also increased significantly: that of lycopene doubled (P<0.001); that of phytofluene was 1.8-fold higher (P<0.005); that of phytoene was 2.6-fold higher (P<0.005); that of beta-carotene was 1.5-fold higher (P<0.01). In contrast, the alpha-tocopherol concentration remained nearly constant. The intake of the tomato drink significantly reduced (by about 42 %) DNA damage (P<0.0001) in lymphocytes subjected to oxidative stress. In conclusion, the present study supports the fact that a low intake of carotenoids from tomato products improves cell antioxidant protection.

Six-Week Consumption of a Wild Blueberry Powder Drink Increases Bifidobacteria in the Human Gut

Wild blueberries are a rich source of polyphenols and other compounds that are highly metabolized by the intestinal microbiota and may, at the same time, affect the intestinal environment itself. A repeated-measure, crossover dietary intervention on human volunteers was designed to study the effect of six week consumption of a wild blueberry ( Vaccinium angustifolium ) drink, versus a placebo drink, in modulating the intestinal microbiota. Relative to total eubacteria, Bifidobacterium spp. significantly increased following blueberry treatment (P ≤ 0.05), while Lactobacillus acidophilus increased after both treatments (P ≤ 0.05). No significant differences were observed for Bacteroides spp., Prevotella spp., Enterococcus spp., and Clostridium coccoides . Bifidobacteria, which have been largely proposed to be of benefit for the host, appeared to be selectively favored suggesting an important role for the polyphenols and fiber present in wild blueberries. Results obtained suggest that regular consumption of a wild blueberry drink can positively modulate the composition of the intestinal microbiota.

Variation in the measurement of DNA damage by comet assay measured by the ECVAG inter-laboratory validation trial

The comet assay has become a popular method for the assessment of DNA damage in biomonitoring studies and genetic toxicology. However, few studies have addressed the issue of the noted inter-laboratory variability of DNA damage measured by the comet assay. In this study, 12 laboratories analysed the level of DNA damage in monocyte-derived THP-1 cells by either visual classification or computer-aided image analysis of pre-made slides, coded cryopreserved samples of cells and reference standard cells (calibration curve samples). The reference standard samples were irradiated with ionizing radiation (0-10 Gy) and used to construct a calibration curve to calculate the number of lesions per 10(6) base pair. All laboratories detected dose-response relationships in the coded samples irradiated with ionizing radiation (1.5-7 Gy), but there were overt differences in the level of DNA damage reported by the different laboratories as evidenced by an inter-laboratory coefficient of variation (CV) of 47%. Adjustment of the primary comet assay end points by a calibration curve prepared in each laboratory reduced the CV to 28%, a statistically significant reduction (P < 0.05, Levenes test). A large fraction of the inter-laboratory variation originated from differences in image analysis, whereas the intra-laboratory variation was considerably smaller than the variation between laboratories. In summary, adjustment of primary comet assay results by reference standards reduces inter-laboratory variation in the level of DNA damage measured by the alkaline version of the comet assay.

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 β-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 ∼35% in plasma (P<0.05) and by ∼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.Sponsorship: Supported by the Ministry of University and Scientific Research (MURST).

Blood orange juice inhibits fat accumulation in mice

Objective:To analyze the effect of the juice obtained from two varieties of sweet orange (Citrus sinensis L. Osbeck), Moro (a blood orange) and Navelina (a blond orange), on fat accumulation in mice fed a standard or a high-fat diet (HFD).Methods:Obesity was induced in male C57/Bl6 mice by feeding a HFD. Moro and Navelina juices were provided instead of water. The effect of an anthocyanin-enriched extract from Moro oranges or purified cyanidin-3-glucoside (C3G) was also analyzed. Body weight and food intake were measured regularly over a 12-week period. The adipose pads were weighted and analyzed histologically; total RNA was also isolated for microarray analysis.Results:Dietary supplementation of Moro juice, but not Navelina juice significantly reduced body weight gain and fat accumulation regardless of the increased energy intake because of sugar content. Furthermore, mice drinking Moro juice were resistant to HFD-induced obesity with no alterations in food intake. Only the anthocyanin extract, but not the purified C3G, slightly affected fat accumulation. High-throughput gene expression analysis of fat tissues confirmed that Moro juice could entirely rescue the high fat-induced transcriptional reprogramming.Conclusion:Moro juice anti-obesity effect on fat accumulation cannot be explained only by its anthocyanin content. Our findings suggest that multiple components present in the Moro orange juice might act synergistically to inhibit fat accumulation.

An ECVAG trial on assessment of oxidative damage to DNA measured by the comet assay

The increasing use of single cell gel electrophoresis (the comet assay) highlights its popularity as a method for detecting DNA damage, including the use of enzymes for assessment of oxidatively damaged DNA. However, comparison of DNA damage levels between laboratories can be difficult due to differences in assay protocols (e.g. lysis conditions, enzyme treatment, the duration of the alkaline treatment and electrophoresis) and in the end points used for reporting results (e.g. %DNA in tail, arbitrary units, tail moment and tail length). One way to facilitate comparisons is to convert primary comet assay end points to number of lesions/106 bp by calibration with ionizing radiation. The aim of this study was to investigate the inter-laboratory variation in assessment of oxidatively damaged DNA by the comet assay in terms of oxidized purines converted to strand breaks with formamidopyrimidine DNA glycosylase (FPG). Coded samples with DNA oxidation damage induced by treatment with different concentrations of photosensitizer (Ro 19-8022) plus light and calibration samples irradiated with ionizing radiation were distributed to the 10 participating laboratories to measure DNA damage using their own comet assay protocols. Nine of 10 laboratories reported the same ranking of the level of damage in the coded samples. The variation in assessment of oxidatively damaged DNA was largely due to differences in protocols. After conversion of the data to lesions/106 bp using laboratory-specific calibration curves, the variation between the laboratories was reduced. The contribution of the concentration of photosensitizer to the variation in net FPG-sensitive sites increased from 49 to 73%, whereas the inter-laboratory variation decreased. The participating laboratories were successful in finding a dose–response of oxidatively damaged DNA in coded samples, but there remains a need to standardize the protocols to enable direct comparisons between laboratories.

Orange juice vs vitamin C : effect on hydrogen peroxide-induced DNA damage in mononuclear blood cells

The intake of fruits rich in vitamin C seems to increase the antioxidant defence of the organism. However, it is still not clear whether vitamin C alone is responsible for this effect. The aim of the present investigation was to study the effect of the intake of a single portion of blood orange juice (BOJ, 300 ml, providing 150 mg vitamin C) on mononuclear blood cell (MNBC) DNA damage, compared with a drink supplemented with the same amount of vitamin C (C-drink) or sugars (S-drink). Seven young healthy subjects were randomised in a repeated-measures design in which they received each drink on different occasions, 2 weeks apart. Blood samples were collected at baseline, every hour for 8 h, and at 24 h after the intake of each drink. Vitamin C was analysed at each time point by HPLC, whereas H2O2-induced MNBC DNA damage was evaluated at 0, 3 and 24 h by means of the comet assay. Plasma vitamin C concentration increased similarly following BOJ or C-drink intake and was not affected by the S-drink. DNA damage significantly decreased 3 h after BOJ intake (about 18 %; P < 0.01) and remained constant at 24 h (about 16 %; P < 0.01). No effect of the C-drink and S-drink was observed. In conclusion, the intake of a single portion of BOJ provided an early protection of MNBC against oxidative DNA damage; however, the protective effect of BOJ was not explained by vitamin C alone, thus other phytochemicals could be involved.