Plasma Lycopene Concentrations Research Articles

Diet adherence dynamics and physiological responses to a tomato product whole-food intervention in African–American men

Tomatoes may have beneficial effects on prostate health. Efficacy trials would require long-term adherence to high levels of tomato product (TP) consumption. Therefore, factors that affect adherence in men most at risk and whether increased consumption of TP negatively affects diet and health are important concerns. Cancer-free African–American (AA) men (n 36) with mean serum prostate-specific antigen of 7.4 SD 5.6) ng/ml were randomised to consume one serving of TP/d or a control diet for 3 months. Mean intervention group lycopene intake rose to 464%, with negligible control group increase. Plasma lycopene levels rose by 53 and 40% in the intervention group in months 1 and 3, respectively (P < 0.0001), with no control group change. The intervention group’s barriers to adherence score was inversely associated with both dietary (r -0.49, P = 0.02) and plasma lycopene concentration (r -0.37, P = 0.02). Their TP disadvantage score negatively correlated with the 3-month plasma lycopene concentrations (r -0.37, P = 0.008) and their weekly incentives and impediments were remarkably stable, ‘concern for prostate health’ being the most consistent over time. ‘Liking tomatoes’ and ‘study participation’ decreased in citation frequency at weeks 6 and 9, respectively. No major shifts occurred in dietary cholesterol or saturated fat, with no adverse effects on gastrointestinal complaints, serum total cholesterol, body weight or blood pressure. Lower socio-economic status AA men at higher prostate cancer risk can successfully achieve a whole food intervention goal with a corresponding rise in plasma lycopene concentrations, with no adverse effects on self-selected diet quality or health parameters.

Influence of cooking procedure on the bioavailability of lycopene in tomatoes

The aim of this study was to evaluate the influence of raw and processed tomato consumption on plasma lycopene concentration in healthy volunteers. A cross-over dietary intervention study was employed. Fifteen healthy subjects were included in the study. Plasma lycopene concentration was assayed by HPLC. Raw crushed tomato consumption did not significantly influence plasma lycopene concentration. Consumption of raw crushed tomato with olive oil and cooked tomatoes with olive oil, significantly increased blood lycopene levels.

Diets rich in fruits and vegetables suppress blood biomarkers of metabolic stress in overweight women

ObjectiveThis study was performed to evaluate the effects of high vegetable–fruit (high-VF) and low vegetable–fruit (low-VF) diet on surrogate biomarkers of adiposity-related metabolic disturbances. MethodsOverweight women (n=22, 19–29years) participated in the study between July and August, 2007 in Seoul, Korea. The intervention consisted of either high-VF diet (12 servings of VF/day) or low-VF diet (2 servings of VF/day). Plasma concentration of carotenoids and biomarkers of inflammation and oxidative stress were determined before and after each intervention period. ResultsStudy results indicated that body fat content is positively correlated with plasma interleukin (IL)-6, C-reactive protein (CRP), and leptin concentrations at baseline. Oxidative DNA damage and lipopolysaccharide (LPS)-activated production of IL-1β and IL-6 in peripheral blood mononuclear cells (PBMCs) were decreased with high-VF diet while low-VF diet increased those markers. Changes in the concentration of plasma total carotenoid and β-carotene were inversely correlated with change in plasma IL-1β concentration. Differences in IL-β production in LPS-activated PBMCs were inversely correlated with changes in plasma concentration of lutein–zeaxanthin. Also, changes in plasma total carotenoid and lycopene concentration were inversely correlated with the changes in IL-6 production in LPS-activated PBMCs. ConclusionDaily intake of vegetables and fruits can modify adiposity-related metabolic disturbances.

Carotenoid deficiency in chronic pancreatitis: the effect of an increase in tomato consumption

Carotenoids are potentially malabsorbed in patients with chronic pancreatitis (CP). The aims of this study were: (1) to determine the prevalence of low levels of each of the major carotenoids in subjects with CP; (2) to compare carotenoids in CP subjects with or without vascular disease and (3) to test the effect of an increase in dietary lycopene intake in patients with low plasma lycopene concentration. Simultaneous determination of carotenoids was done in 80 patients with CP and 20 healthy subjects, using high-performance liquid chromatography. Of the CP patients who had low lycopene concentration, 22 (<120 μg/l) had to consume daily 40 g tomato paste (approximately 24 mg lycopene). Of these patients, 84.7% had at least one carotenoid deficiency and 27.5% had more than four carotenoid deficiencies. Low plasma concentrations in β-carotene and lycopene were correlated, in CP group, with a low body mass index (BMI), a low low-density lipoprotein (LDL) cholesterol concentration, alcohol consumption and current smoking status, whereas low plasma concentration in β-cryptoxanthine was correlated with a low BMI, a low LDL cholesterol concentration and alcohol consumption. Lycopene concentration was decreased in patients with vascular disease (171±197 vs 99±72 μg/l; P=0.02). After an intervention period of 8±2 months, lycopene concentration increased from 67.5±30 to 121.8±102 μg/l (P=0.025). Carotenoid concentrations are dramatically decreased in CP, especially lycopene in CP patients with vascular disease. Despite malabsorption, it is possible to increase lycopene plasma concentration by increasing heated tomato consumption.

Lycopene absorption in humans after the intake of two different single-dose lycopene formulations

Lycopene is the main carotenoid present in tomato and its derivatives. It can also be obtained from the fungus Blakeslea trispora and its use as novel food ingredient was recently approved. The aim of the present study was to investigate the absorption of lycopene, in humans, after the intake of a single dose providing 15 mg of lycopene from tomato extract (oleoresin 6%) or B. trispora (oil suspension 6%). Twelve female subjects were enrolled and divided into two groups: group 1 was assigned to the sequence tomato lycopene/wash-out/ B. trispora lycopene, whereas group 2 followed the sequence B. trispora lycopene/wash-out/tomato lycopene. The formulations were consumed early in the morning with 5 mL of sunflower oil, 100 g of bread and 150 mL of water. Blood was collected before consumption and after 2, 4, 6, 8, 10, 12 and 24 h. Plasma lycopene concentrations were determined by HPLC analysis. On the whole, statistical analysis of data did not demonstrate a different effect of the type of lycopene source on the carotenoid absorption. The maximum increase in plasma lycopene concentration was about 40 nmol/L for both products at 10–12 h ( p < 0.05) post-consumption and decreased to basal values at 24 h. A transient higher increase in lycopene concentration at 4–6 h ( p < 0.05) after tomato lycopene with respect to B. trispora lycopene intake was observed. In conclusion, the intake of a single dose of the two liposoluble lycopene formulations revealed a comparable, small, but significant increase in plasma lycopene concentrations.

Bioavailability of lycopene in the rat: the role of intestinal lymphatic transport

As a natural antioxidant derived from dietary sources, lycopene has attracted considerable attention as a potent chemopreventative agent. Lycopene is an extremely lipophilic compound and absorption from dietary sources is estimated to be low and highly variable. As a result, plasma lycopene concentrations are poorly correlated with dietary intake of lycopene rich food stuffs. The development of an oral formulation remains a challenge that requires a better understanding of the mechanisms involved in the intestinal absorption of this compound. The solubility of lycopene in simulated physiological fluids and bile salt mixed micelle formulations was determined. The extent of intestinal lymphatic transport and the absolute bioavailability of lycopene from a range of biorelevant media was evaluated in a mesenteric lymph duct cannulated anaesthetised rat model. The absolute bioavailability of lycopene after 8 h was 1.85 +/- 0.39%. The overall extent of the intestinal lymphatic transport was in the range of 0.6-3.4% of the administered dose. A strong positive correlation (r(2) > 0.9) between intestinal lycopene levels and intestinal triglyceride levels was demonstrated. The intestinal lymphatic route is the major uptake mechanism of lycopene from the gastrointestinal tract. Lycopene transport in intestinal lymph was closely associated with triglyceride transport in the lymph. Formulation strategies designed to promote intestinal lymphatic uptake, such as lipid-based formulations containing long-chain fatty acids (LCFA) or lecithin, may serve to enhance oral bioavailability of lycopene.

Lycopene, lutein and β-carotene as determinants of LDL conjugated dienes in serum

Oxidative modification of low-density lipoprotein (LDL) in the vascular endothelium is considered to be important in the development of early atherosclerosis. The aim of this study was to investigate the main determinants of serum LDL conjugated dienes in women ( n = 124) and men ( n = 225). We focused on the influence of fat-soluble vitamins and carotenoids on the concentration of conjugated dienes in LDL. In multivariate linear regression models, including age, body mass index, diastolic blood pressure, symptomatic ischaemic heart disease (IHD) or IHD history, statin medication, leukocytes and serum triglycerides as covariates, plasma lycopene (standardized β = −0.33; P = 0.002) and lutein (standardized β = −0.22; P = 0.027) concentrations were the strongest determinants of serum LDL conjugated dienes in women, whereas plasma β-carotene (standardized β = −0.23; P = 0.002) was the most important factor in men. Furthermore, statin medication, diastolic blood pressure, age and serum triglycerides were significant determinants of LDL conjugated dienes. The regression model with lycopene contributed to 29% in women and 15% in men with β-carotene of the variation of serum LDL conjugated dienes. Results of the present study suggest that plasma lycopene, lutein and β-carotene are the most powerful antioxidants for explaining the content of in vivo oxidatively modified LDL in serum.

Fasting plasma carotenoids concentrations in Crohn’s and pancreatic cancer patients compared to control subjects

Carotenoids are colored molecules that are widespread in the plant kingdom, but animals cannot synthesize them. Carotenes are long, apolar molecules which require fully functioning digestive processes to be absorbed properly. Hence they could be interesting markers of intestinal absorption and digestion. Indeed, only few tests are available to assess these processes and only the D-xylose tolerance test is routinely used. However D-xylose is a sugar that tests only the absorption of water-soluble compounds and it only tests duodenal absorption. In this study, we have evaluated carotenoids as markers of digestion and absorption. We compared fasting plasma carotenoids concentrations in 21 control subjects, 20 patients with Crohn's disease, and 18 patients with pancreatic cancer. Crohn's disease alters intestinal absorption while pancreatic cancer decreases pancreatic enzyme secretion thus impairing digestion. Results show that all carotenoids are significantly lower in Crohn's and cancer patients as compared to control subjects and the multifactorial analysis shows that this decrease is mostly independent of dietary intake. Interestingly, maldigestion as seen in pancreatic cancer more strongly influences plasma lutein and lycopene concentrations while malabsorption in Crohn's disease acts on other carotenoids. Thus carotenoids could be interesting alternatives for testing and following patients that are suspected of having malabsorption or maldigestion syndromes.

Lycopene supplementation (passata sauce) reduces apoptosis but does not affect oxidant-responsive heme oxygenase-1 in human lymphocytes

Objective We tested the hypothesis that lycopene supplementation reduces the expression of oxidant-responsive heme oxygenase-1 (HO-1) in basal conditions and in response to an oxidant challenge and determined whether this is temporally associated with increased cell viability. Methods We determined basal and stimulated ex vivo expression of HO-1 and cell viability in lymphocytes from volunteers after lycopene supplementation. Twenty-four healthy young men on a low lycopene diet consumed 1) 170 g of passata sauce with butter or 2) butter alone for 3 wk in a randomized crossover design. Results Plasma lycopene concentrations at the end of the tomato and control trials were 0.54 ± 0.20 versus 0.20 ± 0.15 μmol/L, respectively ( P < 0.05). There was a significant increase in the proportion of live cells (91 ± 5% versus 87 ± 9%) and a corresponding reduction in apoptosis (6 ± 4% versus 11 ± 9%) in untreated lymphocytes after supplementation ( P < 0.05), with no effect on cell viability in response to hydrogen peroxide treatment. HO-1 protein expression in basal conditions and induction of HO-1 after hydrogen peroxide treatment was not different between trials. Conclusion Lycopene supplementation did not affect basal oxidative stress or susceptibility to oxidant-induced stress as indicated by the expression of the oxidant-responsive protein HO-1 and cell viability in response to hydrogen peroxide treatment. However, lycopene supplementation significantly reduced apoptosis in freshly harvested untreated lymphocytes. We conclude that this was not through an oxidant-mediated mechanism because of the lack of an effect on oxidant-responsive HO-1.

The Effects of Natural Antioxidants from Tomato Extract in Treated but Uncontrolled Hypertensive Patients

To evaluate the effect of adding tomato extract to the treatment regime of moderate hypertensives with uncontrolled blood pressure (BP) levels. Fifty four subjects with moderate HT treated with one or two antihypertensive drugs were recruited and 50 entered two double blind cross-over treatment periods of 6 weeks each, with standardized tomato extract or identical placebo. Plasma concentrations of lycopene, nitrite and nitrate were measured and correlated with BP changes. There was a significant reduction of systolic BP after 6 weeks of tomato extract supplementation, from 145.8 +/- 8.7 to 132.2 +/- 8.6 mmHg (p < 0.001) and 140.4 +/- 13.3 to 128.7 +/- 10.4 mmHg (p < 0.001) in the two groups accordingly. Similarly, there was a decline in diastolic BP from 82.1 +/- 7.2 to 77.9 +/- 6.8 mmHg (p = 0.001) and from 80.1 +/- 7.9 to 74.2 +/- 8.5 mmHg (p = 0.001). There was no significant change in systolic and diastolic BP during the placebo period. Serum lycopene level increased from 0.11 +/- 0.09 at baseline, to 0.30 +/- 01.3 micromol/L after tomato extract therapy (p < 0.001). There was a significant correlation between systolic BP and lycopene levels (r = -0.49, p < 0.001). Tomato extract when added to patients treated with low doses of ACE inhibition, calcium channel blockers or their combination with low dose diuretics, had a clinically significant effect-reduction of BP by more than 10 mmHg systolic and more than 5 mmHg diastolic pressure. No side-effects to treatment were recorded and the compliance with treatment was high. The significant correlation between systolic blood pressure values and level of lycopene suggest the possibility of cause-effect relationships.

Lycopene Absorption in Human Intestinal Cells and in Mice Involves Scavenger Receptor Class B Type I but Not Niemann-Pick C1-Like 1

Cholesterol membrane transporters [scavenger receptor class B type I (SR-BI) and (cluster determinant 36) are involved in intestinal uptake of lutein and β-carotene, 2 of the 3 main carotenoids of the human diet. The aim of this work was therefore to determine whether SR-BI and NPC1L1 (Niemann-Pick C1-like 1), another cholesterol transporter, are implicated in absorption of lycopene, the 3rd main carotenoid of the human diet. Anti-human SR-BI antibody and block lipid transport 1 (BLT1) (a chemical inhibitor of lipid transport by SR-BI) impaired up to 60% (all-E) and (5Z)-lycopene uptake (P < 0.05) by Caco-2 cell monolayers, which were used as a model of human intestinal epithelium. The involvement of SR-BI in lycopene absorption in vivo was then verified by comparing plasma lycopene concentrations in wild-type and SR-BI transgenic mice that were fed a diet enriched with 0.25 g/kg (all-E) -lycopene for 1 mo. Plasma lycopene concentrations were ∼10-fold higher (P < 0.001) in mice overexpressing SR-BI in the intestine than in wild-type mice, confirming the involvement of SR-BI in lycopene absorption. Further experiments showed that (all-E) -lycopene did not affect SR-BI mRNA levels in Caco-2 cells or mouse intestine. In contrast to SR-BI, neither anti-human NPC1L1 antibody nor ezetimibe, used as inhibitors of lycopene uptake via NPC1L1, significantly impaired (all-E) or (5Z)-lycopene uptake by Caco-2 monolayers. Thus, the present data show that lycopene absorption is, at least in part, mediated by SR-BI but not by NPC1L1.

Human fasting plasma concentrations of vitamin E and carotenoids, and their association with genetic variants in apo C-III, cholesteryl ester transfer protein, hepatic lipase, intestinal fatty acid binding protein and microsomal triacylglycerol transfer protein

Plasma concentrations of vitamin E and carotenoids are governed by several factors, including genetic factors. Single nucleotide polymorphisms (SNP) in some genes involved in lipid metabolism have recently been associated with fasting plasma concentrations of these fat-soluble micronutrients. To further investigate the role of genetic factors that modulate the plasma concentrations of these micronutrients, we assessed whether SNP in five candidate genes (apo C-III, CETP, hepatic lipase, I-FABP and MTP) were associated with the plasma concentrations of these micronutrients. Fasting plasma vitamin E and carotenoid concentrations were measured in 129 French Caucasian subjects (forty-eight males and eighty-one females). Candidate SNP were genotyped by PCR amplification followed by restriction fragment length polymorphisms. Plasma gamma-tocopherol, alpha-carotene and beta-carotene concentrations were significantly different (P < 0.05) in subjects who carried different SNP variants in hepatic lipase. Plasma alpha-tocopherol concentrations were significantly different in subjects who had different SNP variants in apo C-III and cholesteryl ester transfer protein (CETP). Plasma lycopene concentrations were significantly different (P < 0.05) in women who had different SNP variants in intestinal fatty acid binding protein (I-FABP). Finally, there was no effect of SNP variants in microsomal TAG transfer protein upon the plasma concentrations of these micronutrients. Most of the observed differences remained significant after the plasma micronutrients were adjusted for plasma TAG and cholesterol. These results suggest that apo C-III, CETP and hepatic lipase play a role in determining the plasma concentrations of tocopherols while hepatic lipase and I-FABP may modulate plasma concentrations of carotenoids.

High Dose Lycopene Supplementation Increases Hepatic Cytochrome P4502E1 Protein and Inflammation in Alcohol-Fed Rats

Recent in vitro evidence suggests that the antioxidant lycopene can prevent alcohol-induced oxidative stress and inflammation. However, knowledge of possible interactions in vivo between escalating doses of lycopene and chronic alcohol ingestion are lacking. In this study, we investigated potential interactions between alcohol ingestion and lycopene supplementation and their effect on hepatic lycopene concentration, cytochrome P4502E1 (CYP2E1) induction, and inflammation. Fischer 344 rats (6 groups, n = 10 per group) were fed either a liquid ethanol Lieber-DeCarli diet or a control diet (isocaloric maltodextrin substituted for ethanol) with or without lycopene supplementation at 2 doses (1.1 or 3.3 mg·kg body weight −1·d −1) for 11 wk. Plasma and hepatic concentrations of lycopene isomers were assessed by HPLC analysis. We examined expressions of hepatic CYP2E1 and tumor necrosis factor-α (TNF α) and the incidence of hepatic inflammatory foci. Both plasma and hepatic lycopene concentrations were greater in alcohol-fed rats than in control rats supplemented with identical doses of lycopene. In contrast, alcohol-fed rats had a lower percentage of lycopene cis isomers in the plasma and the liver compared with control rats fed the same dose of lycopene. Notably, lycopene supplementation at the higher dose significantly induced hepatic CYP2E1 protein, TNF α mRNA, and the incidence of inflammatory foci in the alcohol-fed rats but not in the control rats. These data indicate an interaction between chronic alcohol ingestion and lycopene supplementation and suggest a need for caution among individuals consuming high amounts of both alcohol and lycopene.

Long-term strict raw food diet is associated with favourable plasma β-carotene and low plasma lycopene concentrations in Germans

Dietary carotenoids are associated with a reduced risk of chronic diseases. Raw food diets are predominantly plant-based diets that are practised with the intention of preventing chronic diseases by virtue of their high content of beneficial nutritive substances such as carotenoids. However, the benefit of a long-term adherence to these diets is controversial since little is known about their adequacy. Therefore, we investigated vitamin A and carotenoid status and related food sources in raw food diet adherents in Germany. Dietary vitamin A, carotenoid intake, plasma retinol and plasma carotenoids were determined in 198 (ninety-two male and 106 female) strict raw food diet adherents in a cross-sectional study. Raw food diet adherents consumed on average 95 weight% of their total food intake as raw food (approximately 1800 g/d), mainly fruits. Raw food diet adherents had an intake of 1301 retinol activity equivalents/d and 16.7 mg/d carotenoids. Plasma vitamin A status was normal in 82% of the subjects (> or = 1.05 micromol/l) and 63% had beta-carotene concentrations associated with chronic disease prevention (> or = 0.88 micromol/l). In 77% of subjects the lycopene status was below the reference values for average healthy populations (< 0.45 micromol/l). Fat contained in fruits, vegetables and nuts and oil consumption was a significant dietary determinant of plasma carotenoid concentrations (beta-carotene r 0.284; P < 0.05; lycopene r 0.168; P = 0.024). Long-term raw food diet adherents showed normal vitamin A status and achieve favourable plasma beta-carotene concentrations as recommended for chronic disease prevention, but showed low plasma lycopene levels. Plasma carotenoids in raw food adherents are predicted mainly by fat intake.

Lycopene Inhibits Disease Progression in Patients with Benign Prostate Hyperplasia

Lycopene is a promising nutritional component for chemoprevention of prostate cancer (PCa). A possibly beneficial role of lycopene in patients diagnosed with benign prostate hyperplasia (BPH), who are at increased risk of developing PCa, has been suggested, although clinical data are lacking. Therefore, this pilot study aimed to investigate the effects of lycopene supplementation in elderly men diagnosed with BPH. A total of 40 patients with histologically proven BPH free of PCa were randomized to receive either lycopene at a dose of 15 mg/d or placebo for 6 mo. The effects of the intervention on carotenoid status, clinical diagnostic markers of prostate proliferation, and symptoms of the disease were assessed. The primary endpoint of the study was the inhibition or reduction of increased serum prostate-specific antigen (PSA) levels. The 6-mo lycopene supplementation decreased PSA levels in men (P < 0.05), whereas there was no change in the placebo group. The plasma lycopene concentration increased in the group taking lycopene (P < 0.0001) but other plasma carotenoids were not affected. Whereas progression of prostate enlargement occurred in the placebo group as assessed by trans-rectal ultrasonography (P < 0.05) and digital rectal examination (P < 0.01), the prostate did not enlarge in the lycopene group. Symptoms of the disease, as assessed via the International Prostate Symptom Score questionnaire, were improved in both groups with a significantly greater effect in men taking lycopene supplements. In conclusion, lycopene inhibited progression of BPH.

Effects of Lycopene Supplementation on Plasma and Tissue Lycopene Levels in Various Rodent Strains

Lycopene has been shown to have various biologic effects, and rats and mice are often used for elucidating its in vivo effects and mechanisms. Here, we compared plasma and tissue lycopene levels in F344 rats, BALB/c mice, nude mice, and gerbils by oral supplementation with lycopene (20 mg/kg BW x 2d) every other morning for 10 days. We found that livers accumulated substantially more lycopene than kidneys and that the hepatic lycopene contents varied greatly in these animals, with gerbils being most efficient (1432 +/- 235 nmol/g), followed by nude mice (524 +/- 133 nmol/g), F344 rats (28 +/- 11 nmol/g), and BALB/c mice (5 +/- 2 nmol/g). Plasma lycopene concentrations also varied greatly, of which the highest was found in gerbils (667 +/- 160 nmol/L), followed by nude mice (224 +/- 51 nmol/L), then by BALB/c mice and F344 rats (198 +/- 52 and 139 +/- 41 nmol/L, respectively). Interestingly, plasma and tissue beta-carotene concentrations in these animals were markedly decreased by lycopene supplementation. To determine the steady-state levels of plasma lycopene, we fed 10 gerbils with lycopene (20 mg/kg BW x 2d) for 20 days, and we found a steady-state level of plasma lycopene between 597 to 722 nmol/L. Our results demonstrate that gerbils and nude mice are better accumulators than F344 rats and BALB/c mice, and that the former species may be more useful for studying the in vivo effects of lycopene.

Plasma lycopene concentration is low in subjects with stable asthma

Plasma lycopene concentration is low in subjects with stable asthma

Effect of a Tomato Drink Intervention on Insulin-Like Growth Factor (IGF)-1 Serum Levels in Healthy Subjects

: There is concern that dietary factors can modulate the insulin-like growth factor (IGF) system. The aim of this work was to evaluate the effect of a tomato drink intervention providing small amounts of lycopene and other carotenoids on serum levels of IGF-1. Twenty healthy young subjects participated in a repeated measure double-blind, cross-over design. Subjects consumed 250 ml of a tomato drink or a placebo drink for 26 days separated by 26 days wash-out. The tomato drink intake increased plasma lycopene, phytoene, phytofluene, and β-carotene concentrations by 0.22, 0.12, 0.13, and 0.18 μmol/L, respectively (P < 0.05). No significant effect of the tomato drink intake on IGF-1 levels was observed. However, changes in lycopene before and after each experimental period were inversely and significantly correlated with those of IGF-1 (r = –0.33, P < 0.05, N = 20). No correlation was found with the other carotenoids. A significant reduction of IGF-1 serum level (–5.7%) was observed in subjects (n = 11) with the highest plasma lycopene response but also IGF-1 levels following the tomato drink intake (P < 0.05). No effect was evident after the placebo treatment. The results suggest that further exploration of the role of tomato lycopene on IGF-1 modulation both on healthy and on subjects at risk is necessary.

Effects of ingestion of tomatoes, tomato juice and tomato purée on contents of lycopene isomers, tocopherols and ascorbic acid in human plasma as well as on lycopene isomer pattern

Tomatoes are an important part of the diet. Lycopene, the predominant carotenoid in tomatoes, is hypothesised to mainly mediate the health benefits of tomato products. Anticancer activity of tomato products and lycopene has been suggested by numerous studies. The aim of the present study was to investigate the effect of ingestion of three different tomato-based foodstuffs on plasma contents of lycopene, tocopherols and ascorbic acid. Because isomers of lycopene may have different biological activities, a special interest was to look how the lycopene isomer pattern is changed depending on the matrix of tomato products. Following a 2-week depletion phase volunteers ingested 12.5 mg lycopene/d for 4 weeks comprising tomatoes, tomato juice or tomato purée. The basal levels of lycopene in plasma were comparable for all groups and decreased significantly during the 2 weeks of depletion to approximately half of the basal values. Following intervention, plasma lycopene concentration increased significantly. Conversely, supplementation did not significantly affect levels of tocopherols and ascorbic acid in plasma. Regarding isomers of lycopene, the (Z)-lycopene:(all-E)-lycopene plasma isomer ratio was significantly changed during the study for all groups. A remarkable enrichment of the relative contents of (5Z)-lycopene was observed during the depletion period, which supports the hypothesis that lycopene (Z)-isomers are formed within the human body after ingestion of (all-E)-lycopene. After dietary intervention with lycopene-rich products the isomer ratios returned to those observed at the start of the study. Further investigations will clarify the process of isomerisation in more detail.

&lt;a name="home"&gt;&lt;/a&gt;Lycopene and ß-carotene protect in vivo iron-induced oxidative stress damage in rat prostate

It has been suggested that iron overload may be carcinogenic. In the present study, we evaluated the effect of plasma and prostate carotenoid concentration on oxidative DNA damage in 12-week-old Wistar rats treated with intraperitoneal (ip) ferric nitrilotriacetate (Fe-NTA) (10 mg Fe/kg). Plasma beta-carotene and lycopene concentrations were measured as a function of time after ip injection of carotenoids (10 mg kg(-1) day(-1) beta-carotene or lycopene) in rats. The highest total plasma concentration was reached 3 and 6 h after ip injection of lycopene or beta-carotene, respectively. After 5 days of carotenoid treatment, lycopene and beta-carotene were present in the 0.10-0.51 nmol/g wet tissue range in the prostate. Using a sensitive method to detected 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) by HPLC/EC, the level of 8-oxodGuo in rat prostate DNA was significantly higher (6.3 +/- 0.6 residues/10(6) dGuo) 3 h after Fe-NTA injection compared with control rats (1.7 +/- 0.3 residues/10(6) dGuo). Rats supplemented with lycopene or beta-carotene for 5 days prior to Fe-NTA treatment showed a reduction of about 70% in 8-oxodGuo levels to almost control levels. Compared with control rats, the prostate of Fe-NTA-treated animals showed a 78% increase in malondialdehyde accumulation. Lycopene or beta-carotene pre-treatment almost completely prevented lipid damage. Epidemiological studies have suggested a lower risk of prostate cancer in men reporting a higher consumption of tomato products. However, before associating this effect with tomato sauce constituents, more information is required. The results described here may contribute to the understanding of the protective effects of carotenoids against iron-induced oxidative stress.