Lycopene and prostate cancer

Revisiting carotenoids as dietary antioxidants for human health and disease prevention

Humans are unique indiscriminate carotenoid accumulators, so the human body accumulates a wide range of dietary carotenoids of different types and to varying concentrations. Carotenoids were once recognized as physiological antioxidants because of their ability to quench singlet molecular oxygen (1O2). In the 1990s, large-scale intervention studies failed to demonstrate that supplementary β-carotene intake reduces the incidence of lung cancer, although its antioxidant activity was supposed to contribute to the prevention of oxidative stress-induced carcinogenesis. Nevertheless, the antioxidant activity of carotenoids has attracted renewed attention as the pathophysiological role of 1O2 has emerged, and as the ability of dietary carotenoids to induce antioxidant enzymes has been revealed. This review focuses on six major carotenoids from fruit and vegetables and revisits their physiological functions as biological antioxidants from the standpoint of health promotion and disease prevention. β-Carotene 9',10'-oxygenase-derived oxidative metabolites trigger increases in the activities of antioxidant enzymes. Lutein and zeaxanthin selectively accumulate in human macular cells to protect against light-induced macular impairment by acting as antioxidants. Lycopene accumulates exclusively and to high concentrations in the testis, where its antioxidant activity may help to eliminate oxidative damage. Dietary carotenoids appear to exert their antioxidant activity in photo-irradiated skin after their persistent deposition in the skin. An acceptable level of dietary carotenoids for disease prevention should be established because they can have deleterious effects as prooxidants if they accumulate to excess levels. Finally, it is expected that the reason why humans are indiscriminate carotenoid accumulators will be understood soon.

Remembering James Barber (1940-2020)

James Barber, known to colleagues and friends as Jim, passed away in January 2020 after a long battle against cancer. During his long and distinguished career in photosynthesis research, Jim made many outstanding contributions with the pinnacle achieving his dream of determining the first detailed structure of the Mn cluster involved in photosynthetic water oxidation. Here, colleagues and friends remember Jim and reflect upon his scientific career and the impact he had on their lives and the scientific community.

Light Spectrum Variably Affects the Acclimatization of Grafted Watermelon Seedlings While Maintaining Fruit Quality

In many countries of Europe and Eastern Asia, watermelon production is mainly based on the use of grafted seedlings. Upon grafting, seedlings undergo a period of healing where artificial lighting is provided by light-emitting diodes in controlled chambers in order to accelerate and improve the healing process. The objective of our study was to test the effect of light quality on the final product (i.e., seedlings ready for transplanting) in the nursery, as well as to evaluate the possible implications on fruit quality after field cultivation. Narrow-band blue (B) and red (R) wavelengths, 64–36% R-B (36B), 76–24% R-B (24B), 88–12% R-B (12B), and 83–12% R-B plus 5% far-red (12B+FR) wavelengths were tested. 12B+FR enhanced the root dry weight, root architecture, and maximum photosynthetic rate, while RB combinations generally showed better root system development with increased blue portion. R light induced inferior root dry weight and quality indices (root/shoot and shoot–dry–weight/length ratios), lower gas exchange parameters, and chlorophyll content, but high shoot length and leaf area. B light led to inferior root architecture, lower stem diameter, leaf area, and maximum photosynthetic rate. Both R and B wavelengths showed decreased concentration of macronutrients and trace elements. After field cultivation, fruit quality (i.e., morphology and color), and valuable nutritive characteristics (i.e., phenolics, carotenoids, lycopene, antioxidants) maintained high quality irrespective of light treatments. Overall, 12B+FR performed well in almost all qualitative parameters including the morphology, the root development, and photosynthesis, while also maintaining high fruit quality.

Lycopene as a Natural Antioxidant Used to Prevent Human Health Disorders

Lycopene, belonging to the carotenoids, is a tetraterpene compound abundantly found in tomato and tomato-based products. It is fundamentally recognized as a potent antioxidant and a non-pro-vitamin A carotenoid. Lycopene has been found to be efficient in ameliorating cancer insurgences, diabetes mellitus, cardiac complications, oxidative stress-mediated malfunctions, inflammatory events, skin and bone diseases, hepatic, neural and reproductive disorders. This review summarizes information regarding its sources and uses amongst different societies, its biochemistry aspects, and the potential utilization of lycopene and possible mechanisms involved in alleviating the abovementioned disorders. Furthermore, future directions with the possible use of this nutraceutical against lifestyle-related disorders are emphasized. Its protective effects against recommended doses of toxic agents and toxicity and safety are also discussed.

Comparative Analysis of Lycopene Content from Different Tomato-Based Food Products on the Cellular Activity of Prostate Cancer Cell Lines

Lycopene is more bioavailable in processed tomato products than in raw tomatoes, since arrangement of cis-isomers of lycopene during food processing and storage may increase its biological activity. The aim of the study is evaluate the influence of lycopene content from different tomato-based food products (extract, paste, ketchup and sauce) on cell proliferation, cell cycle, and rate of apoptosis of human prostate cancer cell lines. DU-145 and PC-3 cell lines were treated with lycopene content from different tomato-based food products (500-5000 μg/mL) for 96 h. The data showed a decrease in cell viability in both DU-145 and PC-3 cells after treatment with all lycopene extracts from tomato-based food products. Analysis of cell cycle revealed a decrease in the percentage of prostate cancer cells in G0/G1 and G2/M phases after 96 h of treatment when using lycopene content from tomato paste and tomato extract. However, lycopene extracted from tomato sauce and ketchup promoted a decrease in the percentage of cells in G0/G1 phase and an increase in S and G2/M phases after 96 h of treatment. Lycopene content from all of those tomato-based food products also increased apoptosis in both prostate cancer cell lines. In this regard, lycopene has proved to be a potent inhibitor of cell viability, arrest cell cycle and increase the apoptosis in human prostate cancer cells, suggesting an effect in the balance of human prostate cancer cell lines growth.

Prebiotic Effect of Lycopene and Dark Chocolate on Gut Microbiome with Systemic Changes in Liver Metabolism, Skeletal Muscles and Skin in Moderately Obese Persons

Lycopene rich food and dark chocolate are among the best-documented products with a broad health benefit. This study explored the systemic effect of lycopene and dark chocolate (DC) on gut microbiota, blood, liver metabolism, skeletal muscle tissue oxygenation and skin. 30 volunteers were recruited for this trial, 15 women and 15 men with a mean age of 55 ± 5.7 years and with moderate obesity, 30 < BMI < 35 kg/m². They were randomized and divided into five equal interventional groups: three received different formulations of lycopene, one of them with a 7 mg daily dose and two with 30 mg; another group was given 10 g of DC with 7 mg lycopene embedded into its matrix, and the last group received 10 g DC. The trial was double-blinded for the three lycopene groups and separately for the 2 DC groups; the trial lasted for 1 month. By the end of the trial there were dose-dependent changes in the gut microbiota profile in all three lycopene groups with an increase of relative abundance of, e.g., Bifidobacterium adolescentis and Bifidobacterium longum. This was also accompanied by dose-dependent changes in the blood, liver metabolism, skeletal muscle and skin parameters. Consumption of DC resulted in increased relative abundance of, e.g., Lactobacillus and a reduction of corneocyte exfoliation. This is the first study which reports the prebiotic potential of lycopene and DC.

Expression of Carotenoid Biosynthetic Genes and Carotenoid Biosynthesis during Seedling Development of Momordica charantia

Carotenoids belong to a large group of secondary metabolites, and have pivotal roles in plants, including photosynthesis and phytohormone synthesis, pigmentation, and membrane stabilization. Additionally, carotenoids are potent antioxidants, and their health benefits are becoming increasingly prominent. In recent years, carotenoids have been studied in many plants. Furthermore, gene expression, as well as carotenoid accumulation in different parts of the bitter melon, has been investigated; however, it has not been studied in bitter melon seedlings. In this study, carotenoid accumulation and transcript levels of McGGPPS1, McGGPPS2, McPSY, McPDS, McZDS, McLCYB, McLCYE1, McLCYE2, McCXHB, and McZEP, involved in carotenoid biosynthesis, were analyzed during seedling development using HPLC and qRT-PCR. The major carotenoids that accumulated in the bitter melon seedlings were lutein and E-β-carotene. The expression of most carotenoid biosynthetic genes increased during seedling development, consistent with the accumulation of violaxanthin, lutein, zeaxanthin, β-cryptoxanthin, 13Z-β-carotene, E-β-carotene, and 9Z-β-carotene in bitter melon seedlings. The results of this study provide a firm basis for comprehending the link between gene expression and carotenoid concentration in bitter melon seedlings.

Protective effect and mechanism of lycopene on endothelial progenitor cells (EPCs) from type 2 diabetes mellitus rats

Endothelial progenitor cells (EPCs), widely existing in bone marrow and peripheral blood, are involved in the repair of injured vascular endothelium and angiogenesis which are important to diabetic mellitus (DM) patients with vascular complications. The number and the function of EPCs are related to the advanced glycation end products (AGEs) generated in DM patients. Lycopene (Lyc) is an identified natural antioxidant that protects EPCs under the microenvironment of AGEs from damage. However, the underlying mechanism remains unclear. To investigate the effect of Lyc on EPCs, we isolated EPCs from DM rat bone marrow and determined cell proliferation, cell cycle,apoptosis and autophagy of EPCs. The present study showed that 10μg/mL Lyc improved cell proliferation and had low cytotoxicity in the presence of AGEs. In addition, Lyc rescued S phase of the cell cycle arrest, reduced apoptosis rate and decreased autophagic reaction including ROS and mitochondrial membrane potential (MMP) of EPCs. Moreover, Lyc combined use of autophagy inhibitors, 3-MA, had better protective effects. Taken together, our data suggests that Lyc promotes EPCs survival and protect EPCs from apoptosis and oxidative autophagy induced by AGEs, further remaining the number and function of EPCs. This study provides new insights into Lyc protective mechanism of AGEs-induced oxidative autophagy in EPCs from DM patients and offers a new therapy for DM vascular complications.

Lycopene Extracts from Different Tomato-Based Food Products Induce Apoptosis in Cultured Human Primary Prostate Cancer Cells and Regulate TP53, Bax and Bcl-2 Transcript Expression

Carotenoids are the main tomato components, especially lycopene. Lycopene is more bioavailable in tomato processed products than in raw tomatos, since formation of lycopene cis-isomers during food processing and storage may increase its biological activity. In the current study, we evaluated the influence of lycopene extracts (5 mg / mL) from different tomato-based food products (paste, sauce, extract and ketchup) on cell viability and apoptosis on primary human prostate cancer cells (PCa cels) for 96h. Using MTT assay, we observed a significant decrease on primary PCa cell viability upon treatment with lycopene extracted from either 4 tomato-based food products. Flow cytometeric analysis revealed that lycopene from tomato extract and tomato sauce promoted up to fifty-fold increase on the proportion of apoptotic cells, when compared to the control group. Using real time PCR assay, we found that lycopene promoted an upregulation of TP53 and Bax transcript expression and also downregulation of Bcl-2 expression in PCa cells. In conclusion, our data demostrate that cis-lycopene promoted a significant inhibition on primary PCa cell viability, as well as an increase on their apoptotic rates, evidencing that cis-lycopene contained in tomato sauce and extract cain mainly modulate of primary human prostate cancer cell survival.

Lycopene acts through inhibition of IκB kinase to suppress NF-κB signaling in human prostate and breast cancer cells

We studied the effect of the potent dietary antioxidant lycopene on multiple points along the nuclear factor kappa B (NF-κB) signaling pathway in prostate and breast cancer cells. Lycopene significantly inhibited prostate and breast cancer cell growth at physiologically relevant concentrations of ≥1.25 μM. Similar concentrations also caused a 30-40 % reduction in inhibitor of kappa B (IκB) phosphorylation in the cells, as determined by western blotting. Furthermore, the same degree of inhibition by lycopene was observed for NF-κB transcriptional activity, as determined by reporter gene assay. Concomitant with this, immunofluorescence staining of lycopene-treated cells showed a significant suppression (≥25 %) of TNF-induced NF-κB p65 subunit nuclear translocation. Further probing of lycopene's effects on upstream elements of the NF-κB pathway showed a 25 % inhibition of both activity of recombinant IκB kinase β (IKKβ) kinase in a cell-free in vitro assay, as well as activity of IKKβ immunoprecipitated from MDA-MB-231 cells treated with lycopene. In conclusion, the anticancer properties of lycopene may occur through inhibition of the NF-κB signaling pathway, beginning at the early stage of cytoplasmic IKK kinase activity, which then leads to reduced NF-κB-responsive gene regulation. Furthermore, these effects in cancer cells were observed at concentrations of lycopene that are relevant and achievable in vivo.

Dietary intake of lycopene by the Belgian adult population

OBJECTIVE

Lycopene is a potent antioxidant, and it has been suggested that intake of tomatoes and tomato products containing lycopene is associated with a decreased risk of various chronic diseases. The aim of the present study was to evaluate the distribution of dietary lycopene intake in the Belgian population and to determine the most important contributors to lycopene intake.

DESIGN

Cross-sectional study.

SETTING

National food consumption data from the Belgian Food Consumption Survey (BFCS) 2004 were used for the intake assessment. Determination of the lycopene content in foods was performed with HPLC-UV. Individual food consumption data were multiplied by the actual mean concentrations of lycopene per food.

SUBJECTS

Individuals (n 3083) aged 15 years and older participated in the study and provided two 24 h recalls.

RESULTS

The mean lycopene intake among Belgian adults was 4·1 (sd 2·3) mg/d or 0·059 (sd 0·033) mg/kg body weight per d. Lycopene intake among men (4·6 (sd 2·6) mg/d) was higher than among women (3·6 (sd 2·1) mg/d), and was higher in the younger compared with the older age groups. Cis-lycopene intake represented about one-third of the total lycopene intake. Tomatoes and tomato products (43%) and sauces and ready-to-eat meals containing tomato sauces (41%) were the main contributors to lycopene intake in Belgium.

CONCLUSIONS

The lycopene intake of the Belgian adult population was comparable to intakes reported in neighbouring countries and was below the acceptable daily intake.

Photoinduced isomerization of lycopene and application to tomato cultivation

The present study aimed to investigate if growth conditions have an impact on the isomeric composition of lycopene in tomatoes. First a model system for photoinduced isomerization was established. Tomato extracts were irradiated with a halogen lamp, whose wavelength spectrum is close to the spectrum of daylight and thus mimics field-grown cultivation. Different optical filters were interposed between lamp and samples to simulate greenhouse conditions. 5-cis-Lycopene was formed preferentially while the concentration of 7-cis-lycopene decreased in field-grown model systems. The change of isomerization in greenhouse model systems led to a significantly different ratio. Consequently 5-cis- and 7-cis-lycopene were identified as potent markers for the differentiation of various lighting conditions during cultivation. This result was verified in biological samples. Authentic field-grown tomatoes (var. Lycopersicon esculentum Mill. var. commune L. H. Bailey "Harzfeuer") showed a significantly higher content of 5-cis-lycopene 5.90 ± 0.45% compared to tomatoes of the same variety grown under electric lighting 4.11 ± 0.10%. Additionally, the ratio of 7-cis-lycopene was significantly lower under field-grown conditions.

Release of antioxidant components from tomatoes determined by an in vitro digestion method

Tomatoes are an important source of antioxidant compounds, such as lycopene, phenolics and ascorbic acid. The main objective of this study was to determine the accessibility (availability for absorption) of the antioxidant compounds (total phenolics, total flavonoids, lycopene, ascorbic acid) and the antioxidant activity in fresh tomatoes of three cultivars (Excell, Tradiro and Flavourine) grown in New Zealand. The tomatoes were subjected to an in vitro digestion method, in which the pH, temperature, enzymes and chemical conditions were maintained according to human gastrointestinal conditions. The results showed that a high amount of the total phenolics and total flavonoids (71-77%) were released from tomatoes during digestion. However, only 3.2-4.5% of the total lycopene was released. No ascorbic acid could be detected after completion of in vitro digestion, probably due to degradation. After completion of digestion, the in vitro digestion extracts were found to have 45-50% antioxidant activity compared with the total antioxidant activity of fresh tomatoes (as measured by the 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid diammonium salt radical decolourization assay). This study shows that the antioxidant components of tomatoes were affected by the in vitro digestion conditions depending on the type of compound. This in vitro digestion method gives an estimate of the release of antioxidant components in tomato, which may predict their in vivo behaviour.

Oxidative stress in prostate cancer: changing research concepts towards a novel paradigm for prevention and therapeutics

A mounting body of evidence suggests that increased production of reactive oxygen species (ROS) is linked to aging processes and to the etiopathogenesis of aging-related diseases, such as cancer, diabetes, atherosclerosis and degenerative diseases like Parkinson's and Alzheimer's. Excess ROS are deleterious to normal cells, while in cancer cells, they can lead to accelerated tumorigenesis. In prostate cancer (PC), oxidative stress, an innate key event characterized by supraphysiological ROS concentrations, has been identified as one of the hallmarks of the aggressive disease phenotype. Specifically, oxidative stress is associated with PC development, progression and the response to therapy. Nevertheless, a thorough understanding of the relationships between oxidative stress, redox homeostasis and the activation of proliferation and survival pathways in healthy and malignant prostate remains elusive. Moreover, the failure of chemoprevention strategies targeting oxidative stress reduced the level of interest in the field after the recent negative results of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) trial. Therefore, a revisit of the concept is warranted and several key issues need to be addressed: The consequences of changes in ROS levels with respect to altered redox homeostasis and redox-regulated processes in PC need to be established. Similarly, the key molecular events that cause changes in the generation of ROS in PC and the role for therapeutic strategies aimed at ameliorating oxidative stress need to be identified. Moreover, the issues whether genetic/epigenetic susceptibility for oxidative stress-induced prostatic carcinogenesis is an individual phenomenon and what measurements adequately quantify prostatic oxidative stress are also crucial. Addressing these matters will provide a more rational basis to improve the design of redox-related clinical trials in PC. This review summarizes accepted concepts and principles in redox research, and explores their implications and limitations in PC.

[A critical assessment of phytotherapy for prostate cancer]

Prostate cancer patients increasingly use complementary and alternative medicines to support the body's immune system in addition to conventional treatment to minimize morbidity associated with conventional treatment, to enhance the quality of life, and ultimately in the hope to cure cancer when conventional treatment fails. As there is a large variety of phytomedicines promoted as potential treatment for prostate cancer, the aim of this review was to differentiate between preventive and therapeutic approaches and evaluate which phytochemicals might be suited for therapy of prostate cancer. Therefore, preclinical in vitro and in vivo data as well as clinical trials with phytosubstances such as genistein, lycopene, epigallocatechin gallate, resveratrol, and mistletoe were assessed. The presented data show that at present there is no clinical evidence that phytochemicals might have a therapeutic use in prostate cancer in relation to reduction of tumor progression or improved survival. The question about an improved immune function or quality of life remains open. Potentially the use of phytochemicals could play a role in a preventive setting.

Systematic investigation of lycopene effects in LNCaP cells by use of novel large-scale proteomic analysis software

Lycopene, the red pigment of tomatoes, is a carotenoid with potent antioxidant properties. Although lycopene might function as a prostate cancer chemoprevention agent, little is known about its effects at the cellular level. To define general changes induced by treatment of cells with lycopene, and to gain insights into the possible chemoprevention properties of lycopene, we investigated changes in protein expression after lycopene treatment in human LNCaP cells. The high throughput proteomics data were then visualized and analyzed by novel biological protein pathway modeling software. Differentially expressed proteins were identified, and the data were analyzed by protein pathway simulation software without need for specialized programming by importing pathway models from a number of sources or creating their own. One notable outcome was the identification of a group of upregulated proteins involved in detoxification of reactive oxygen species. This finding suggests that a possible mechanism of lycopene chemoprevention is the stimulation of detoxification enzymes associated with the antioxidant response element. Novel biological pathway modeling software enhances analysis of large proteomics data. When applied to the analysis of proteins differentially expressed in prostate cancer cells upon treatment with lycopene, the upregulation of detoxification enzymes was identified.

Lycopene inhibits DNA synthesis in primary prostate epithelial cells in vitro and its administration is associated with a reduced prostate-specific antigen velocity in a phase II clinical study

Interest in lycopene has focused primarily on its use in the chemoprevention of prostate cancer (CaP); there are few clinical trials involving men with established disease. In addition, most data examining its mechanism of action have been obtained from experiments using immortal cell lines. We report the inhibitory effect(s) of lycopene in primary prostate epithelial cell (PEC) cultures, and the results of a pilot phase II clinical study investigating whole-tomato lycopene supplementation on the behavior of established CaP, demonstrating a significant and maintained effect on prostate-specific antigen velocity over 1 year. These data reinforce the justification for a large, randomized, placebo-controlled study.

Tissue differential expression of lycopene β-cyclase gene in papaya

Carotene pigments in flowers and fruits are distinct features related to fitness advantages such as attracting insects for pollination and birds for seed dispersal. In papaya, the flesh color of the fruit is considered a quality trait that correlates with nutritional value and is linked to shelf-life of the fruit. To elucidate the carotenoid biosynthesis pathway in papaya, we took a candidate gene approach to clone the lycopene beta-cyclase gene, LCY-B. A papaya LCY-B ortholog, cpLCY-B, was successfully identified from both cDNA and bacterial artificial chromosome (BAC) libraries and complete genomic sequence was obtained from the positive BAC including the promoter region. This cpLCY-B shared 80% amino acid identity with citrus LCY-B. However, full genomic sequences from both yellow- and red-fleshed papaya were identical. Quantitative real-time PCR (qPCR) revealed similar levels of expression at six different maturing stages of fruits for both yellow- and red-fleshed genotypes. Further expression analyses of cpLCY-B showed that its expression levels were seven- and three-fold higher in leaves and, respectively, flowers than in fruits, suggesting that cpLCY-B is down-regulated during the fruit ripening process.

Lycopene and prostate cancer: emerging evidence

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.

Proposed criteria for assessing the efficacy of cancer reduction by plant foods enriched in carotenoids, glucosinolates, polyphenols and selenocompounds

BACKGROUND AND AIMS

The cancer-protective properties of vegetable consumption are most likely mediated through 'bioactive compounds' that induce a variety of physiologic functions including acting as direct or indirect antioxidants, regulating enzymes and controlling apoptosis and the cell cycle. The 'functional food' industry has produced and marketed foods enriched with bioactive compounds, but there are no universally accepted criteria for judging efficacy of the compounds or enriched foods.

SCOPE

Carotenoids, glucosinolates, polyphenols and selenocompounds are families of bioactive compounds common to vegetables. Although numerous studies have investigated the agricultural and human health implications of enriching foods with one or more of these compounds, inadequate chemical identification of compounds, lack of relevant endpoints and inconsistencies in mechanistic hypotheses and experimental methodologies leave many critical gaps in our understanding of the benefits of such compounds. This review proposes a decision-making process for determining whether there is reasonable evidence of efficacy for the both the compound and the enriched food. These criteria have been used to judge the evidence of efficacy for cancer prevention by carotenoids, polyphenols, glucosinolates and selenocompounds.

CONCLUSIONS

The evidence of efficacy is weak for carotenoids and polyphenols; the evidence is stronger for glucosinolates and lycopene, but production of enriched foods still is premature. Additionally there is unacceptable variability in the amount and chemical form of these compounds in plants. The evidence of efficacy for selenocompounds is strong, but the clinical study that is potentially the most convincing is still in progress; also the variability in amount and chemical form of Se in plants is a problem. These gaps in understanding bioactive compounds and their health benefits should not serve to reduce research interest but should, instead, encourage plant and nutritional scientists to work together to develop strategies for improvement of health through food.

Lycopene increases urokinase receptor and fails to inhibit growth or connexin expression in a metastatically passaged prostate cancer cell line: a brief communication

The carotenoid lycopene, found in tomatoes, has been associated with decreasing prostate cancer risk. Potential mechanisms for this risk reduction include lycopene's status as a potent antioxidant, its inhibitory effect on cell proliferation, and its ability to increase intercellular gap junctional communication. Presently, in the United States, almost 200,000 men are diagnosed with prostate cancer and approximately 30,000 succumb to its metastatic effects. Therefore, novel treatment strategies are needed for patients who currently have the disease, especially those in advanced, i.e., metastatic status. In this study, we sought to determine if lycopene's inhibitory properties on premalignancy could be extended to advanced prostate cancer by assessing effects on a cell line derived through metastatic passage, the PC-3MM2. We report that in this cell line, lycopene has a potentially unwanted effect of upregulating expression of the urokinase plasminogen activator receptor and facilitating invasion while failing to significantly inhibit proliferation or to induce detectable levels of the gap junctional protein connexin 43 expression. Our results indicate that some caution should be taken with regard to use of lycopene to treat potentially advanced and metastatic prostate cancers.

Plants and human health in the twenty-first century

The concept of growing crops for health rather than for food or fiber is slowly changing plant biotechnology and medicine. Rediscovery of the connection between plants and health is responsible for launching a new generation of botanical therapeutics that include plant-derived pharmaceuticals, multicomponent botanical drugs, dietary supplements, functional foods and plant-produced recombinant proteins. Many of these products will soon complement conventional pharmaceuticals in the treatment, prevention and diagnosis of diseases, while at the same time adding value to agriculture. Such complementation can be accelerated by developing better tools for the efficient exploration of diverse and mutually interacting arrays of phytochemicals and for the manipulation of the plant's ability to synthesize natural products and complex proteins. This review discusses the history, future, scientific background and regulatory issues related to botanical therapeutics.