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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lycopene is a promising chemopreventive agent for human prostate cancer. To test the hypothesis that the effect of lycopene on prostate cancer is stage specific in the process of carcinogenesis, inhibitory effects of natural lycopene on the proliferation of 3 different human prostate carcinoma cell lines were examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Lycopene more potently inhibited the growth of the androgen-independent DU145 and PC-3 cells than androgen-dependent LNCaP cells. The 50% inhibitory concentration of lycopene for these cell lines was 26.6 micromol/L for DU145, 40.3 micromol/L for PC-3, and 168.5 micromol/L for LNCaP. We also studied the inhibitory effect of lycopene on the growth rate of DU145 tumor xenografts in BALB/c male nude mice. The tumor growth rate was inhibited by 55.6 and 75.8% in mice treated with 100 and 300 mg/kg lycopene, respectively, compared with controls. In addition, no tumors formed in 1 mo in mice treated with DU145 cells that had been pretreated with 20 micromol/L lycopene; however, they did form when DU145 cells were not pretreated. Flow cytometry revealed that lycopene caused DU145 cells to accumulate in the G(0)/G(1) phase and to undergo apoptosis in a dose-dependent manner. The rate of apoptosis was up to 42.4% lower in DU145 cells treated with 32 micromol/L lycopene compared with the untreated control cells. These results suggest that lycopene may specifically inhibit the growth of androgen-independent prostate cancers.
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PMID:Lycopene inhibits the growth of human androgen-independent prostate cancer cells in vitro and in BALB/c nude mice. 1567 Dec 28

Prostate cancer is the second leading cause of cancer deaths among men in the United States. Studies show that people with diets rich in tomato-based foods have reduced risks of cancer, viz., prostate cancer. This is attributed, in part, to lycopene, the most abundant carotenoid in tomatoes. Thus, we studied the effect of lycopene at physiologically attainable concentrations on apoptosis, cellular proliferation, and necrosis in LNCaP human prostate cancer cells. Cells at 37 degrees C and >80% confluency were treated with media alone (0.32% tetrahydrofuran vehicle) or with increasing concentrations (0.3-3.0 microM) of lycopene overnight. After washing monolayers, analyses by high-performance liquid chromatography (HPLC) showed that cellular accumulation of lycopene was 5.5 +/- 0.8, 14.0 +/- 3.2, and 36.7 +/- 12.3 pmole/10(6) cells for 0.3, 1.0, and 3.0 muM, respectively, and not detected in control cells. Lycopene did not alter cellular proliferation because bromodeoxyuridine (BrdU) incorporation and cell numbers were identical among groups. However, results of a 3[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay showed that mitochondrial function decreased 61%-83% with increasing concentrations of lycopene (P < 0.001). Cytotoxicity and necrosis did not contribute to this effect because lactate dehydrogenase (LDH) release (1.5%-1.8%) and trypan blue exclusion (89%-93%) were similar. Subsequently, we demonstrated that increasing concentrations of lycopene significantly (P < 0.05) reduced mitochondrial transmembrane potential, induced the release of mitochondrial cytochrome c, and increased annexin V binding, confirming induction of apoptosis. Thus, lycopene at physiologically relevant concentrations did not affect cellular proliferation or promote necrosis but clearly altered mitochondrial function and induced apoptosis in LNCaP human prostate cancer cells.
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PMID:Physiologically attainable concentrations of lycopene induce mitochondrial apoptosis in LNCaP human prostate cancer cells. 1573 20

Epidemiological studies suggest that environmental factors may mediate the transformation of latent prostate cancer into clinically apparent tumors and that diet appears to influence this progression. Close correlations between average per capita fat intake and prostate cancer mortality internationally generated interest in underlying mechanisms for this link, such as through serum levels of androgens, free radicals, proinflammatory fatty acid metabolites, or insulin-like growth factor. Much interest currently lies in the potential of HMG-CoA reductase inhibitors (statins) to play a chemopreventative role in prostate cancer. Lycopene, a potent antioxidant found in tomatoes, may exert a protective effect in the prostate. Selenium and vitamin E have also been shown to decrease the risk of prostate cancer in some men. Calcium may support vitamin D-related antiproliferative effects in prostate cancer. Certain soy proteins, common in the Asian diet, have been shown to inhibit prostate cancer cell growth. Finally, green tea may also have a chemopreventive effect by inducing apoptosis. Despite confounding factors present in clinical studies assessing the effect of diet on cancer risk, the data remain compelling that a variety of nutrients may prevent the development and progression of prostate cancer.
Prostate Cancer Prostatic Dis 2005
PMID:Impact of diet on prostate cancer: a review. 1613 15

Lycopene (lyc) has emerged as a primary candidate for dietary interventions of prostate cancer; however, research regarding its absorption, tissue distribution, and metabolism is limited. Previously, we evaluated the biodistribution (3-168 h) of a single oral dose of 14C-lyc in rats prefed lyc for 30 d. The liver was the primary depot for lyc, and the 14C and 14C-polar products appeared in tissues as early as 3 h after dosing. In the current study, F344 rats (n = 48) were randomly assigned to 1 of 4 groups prefed either a control or lyc-enriched diet (0.25 g lyc/kg diet) for 30 d and killed at 5 or 24 h after receiving a single oral dose of 14C-lyc. The percentage of the 14C dose absorbed at 24 h was lower (5.5 +/- 0.5%) in lyc-prefed (LP) rats than in control-prefed (CP) rats (6.9 +/- 0.4%, P < 0.04). Hepatic total 14C and 14C-lyc in CP rats was greater than in LP rats at 24 h (P < 0.005). A portion of 14C was delivered to extrahepatic tissues as early as 5 h, irrespective of diet. Of the tissues analyzed, an increase in the percentage in 14C-polar products occurred between 5 and 24 h only in the prostate and seminal vesicles, suggesting increased accumulation of 14C-polar products in these tissues, irrespective of prior dietary treatment. These data suggest that lyc absorption, tissue uptake, and catabolism were affected by prefeeding and that lyc can be partially taken up by extrahepatic tissues from the postprandial triglyceride-rich fraction.
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PMID:The biodistribution of a single oral dose of [14C]-lycopene in rats prefed either a control or lycopene-enriched diet. 1614 Sep

Lycopene is a carotenoid found predominantly in tomatoes and tomato products. In contrast to beta-carotene it is not a precursor of vitamin A in humans. Lycopene is not destroyed during food processing, moreover its bioavailability improves. Lycopene is the most powerful antioxidant amongst carotenoids. Beside the antioxidant effect it influences the expression of various proteins (enzymes of biotransformation, cyclin D1, connexins). According to epidemiologic studies tomato lycopene may reduce the risk of prostate cancer and cardiovascular diseases. Positive effects are also hypothesized in case of other diseases such as osteoporosis, neurodegenerative diseases and hypertension. Neither adverse effects upon lycopene supplementation nor lycopene toxicity have been reported. Therefore, several arguments support the consumption of natural lycopene, whilst there are no contraindications according to the present knowledge.
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PMID:[Lycopene--a natural antioxidant]. 1615 10

Animal and epidemiological studies point to a cancer preventive/therapeutic role for tomato products and its antioxidant, lycopene. It is hypothesized that lycopene will behave as an antioxidant at low concentrations and as a prooxidant at high concentrations in LNCaP human prostate cancer cell culture systems. We characterized the antioxidant, and prooxidant effects of a hexane extract of tomato paste (TP) and water solubilized lycopene at different concentrations using a prostate cancer cell line. Placebo (5% triglyceride, Roche Inc.) was used as a control. After 6, 24 hr and 48 hr incubation, LNCaP cells were harvested and used for each measurement. Cellular proliferation was determined using the MTT colorimetric assay. Lycopene and TP hexane extract inhibited cell growth in a dose-dependent (0.1-50 microM lycopene) manner and growth inhibition was 55% and 35% at 1 microM lycopene and TP hexane extract, respectively after 48 hr incubation. The levels of 8-hydroxydeoxyguanosine/deoxyguanosine (an oxidative DNA damage product) was significantly increased starting at 5 microM lycopene from both TP hexane extract and pure lycopene after 24 and 48 hr incubation with no protection at the lower concentrations. Malondialdehyde formation (a lipid peroxidation product measured by HPLC separation of the MDA-TBA adduct) was significantly reduced at low concentrations (0.1-1 microM) of lycopene in all treatments. Clinically relevant concentrations of lycopene and the tomato fraction containing lycopene significantly reduced LNCaP cancer cell survival which can only be partially explained by increased DNA damage at high lycopene concentrations (> 5 microM). Low concentrations of lycopene acted as a lipid antioxidant but did not protect DNA.
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PMID:Effects of lycopene and tomato paste extracts on DNA and lipid oxidation in LNCaP human prostate cancer cells. 1617 51

Prostate cancer has the third highest incidence of all cancers in men worldwide and is the most common neoplasm diagnosed among men beyond middle age in many developed countries. Mounting evidence surrounding the consumption of tomato products has shown promise for the prevention of prostate cancer. This protective effect has more recently been linked to lycopene, the most abundant carotenoid in tomatoes. Lycopene is a natural pigment that gives the red color to many foods. In Western countries, 85% of dietary lycopene can be attributed to the consumption of tomato-based products. This article reviews emerging evidence from epidemiologic studies for the role of lycopene in prostate cancer prevention. The majority of evidence currently comes from observational studies, but recent human clinical trials and animal studies have provided additional support. Growing evidence on the biologic mechanisms of lycopene in prostate cancer prevention also confirm the epidemiologic findings.
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PMID:Lycopene and prostate cancer: emerging evidence. 1622 Oct 54

Lycopene, the predominant carotenoid in tomatoes and tomato-based foods, is reported to protect against various cancers, especially prostate cancer. We investigated the effect of lycopene on DNA damage and cell growth inhibition in the Hep3B human hepatoma cell line. Lycopene was analyzed by HPLC, and cell proliferation was determined by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay. A final lycopene concentration of 0.1-50 microM was added to cells plated in 96-well plates. After a 24-hr incubation, cell viability was measured as absorbance at 570 nm after the MTT assay. The effects of lycopene on cell cycle progression were investigated with flow cytometry. Lycopene induced G0/G1 arrest and S phase block. Oxidative DNA damage was determined by the Comet (single-cell gel electrophoresis) assay. Lycopene inhibited cell growth in a dose-dependent manner. Cell growth was inhibited 20% at 0.2 microM lycopene and 40% at 50 microM lycopene after a 24-hr incubation. In the Comet assay, lycopene-treated cells showed less DNA damage than did placebo-treated cells. The inhibition of Hep3B cell growth in this study demonstrates the antitumor properties of lycopene.
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PMID:The effect of lycopene on cell growth and oxidative DNA damage of Hep3B human hepatoma cells. 1641 Jun 35

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.
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PMID:Lycopene and beta-carotene protect in vivo iron-induced oxidative stress damage in rat prostate. 1647 Mar 7

Lycopene (C(40) H(56)) is a highly lipophilic antioxidant found in human semen in nanomolar concentrations. It has been shown to be one of the most potent carotenoid antioxidant in various human studies. Prostasomes are organelles secreted by glandular prostatic epithelial cells and are known to play an important role in fertility and prostate cancer. They are also known to possess antioxidant activity and aid the functioning of sperm. We studied the ability of these vesicles to adsorb and retain lycopene into their rich lipid environment in vitro. High-performance liquid chromatography analysis confirmed micrograms of lycopene per milligram of prostasomal protein. In view of the prostasomes' lipid-rich nature it is highly likely that these organelles act as delivery vehicles for this highly lipophilic antioxidant substance into human semen.
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PMID:Can lycopene be delivered into semen via prostasomes? In vitro incorporation and retention studies. 1652 63


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