Antiperoxidative effects of lycopene during N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis

Potential Benefits of Lycopene Consumption: Rationale for Using It as an Adjuvant Treatment for Malaria Patients and in Several Diseases

Malaria is a disease that affects thousands of people around the world every year. Its pathogenesis is associated with the production of reactive oxygen and nitrogen species (RONS) and lower levels of micronutrients and antioxidants. Patients under drug treatment have high levels of oxidative stress biomarkers in the body tissues, which limits the use of these drugs. Therefore, several studies have suggested that RONS inhibition may represent an adjuvant therapeutic strategy in the treatment of these patients by increasing the antioxidant capacity of the host. In this sense, supplementation with antioxidant compounds such as zinc, selenium, and vitamins A, C, and E has been suggested as part of the treatment. Among dietary antioxidants, lycopene is the most powerful antioxidant among the main carotenoids. This review aimed to describe the main mechanisms inducing oxidative stress during malaria, highlighting the production of RONS as a defense mechanism against the infection induced by the ischemia-reperfusion syndrome, the metabolism of the parasite, and the metabolism of antimalarial drugs. Furthermore, the effects of lycopene on several diseases in which oxidative stress is implicated as a cause are outlined, providing information about its mechanism of action, and providing an evidence-based justification for its supplementation in malaria.

Flavonoids' Dual Benefits in Gastrointestinal Cancer and Diabetes: A Potential Treatment on the Horizon?

Diabetes and gastrointestinal cancers (GI) are global health conditions with a massive burden on patients' lives worldwide. The development of both conditions is influenced by several factors, such as diet, genetics, environment, and infection, which shows a potential link between them. Flavonoids are naturally occurring phenolic compounds present in fruits and vegetables. Once ingested, unabsorbed flavonoids reaching the colon undergo enzymatic modification by the gut microbiome to facilitate absorption and produce ring fission products. The metabolized flavonoids exert antidiabetic and anti-GI cancer properties, targeting major impaired pathways such as apoptosis and cellular proliferation in both conditions, suggesting the potentially dual effects of flavonoids on diabetes and GI cancers. This review summarizes the current knowledge on the impact of flavonoids on diabetes and GI cancers in four significant pathways. It also addresses the synergistic effects of selected flavonoids on both conditions. While this is an intriguing approach, more studies are required to better understand the mechanism of how flavonoids can influence the same impaired pathways with different outcomes depending on the disease.

Corilagin induces apoptosis and inhibits HMBG1/PI3K/AKT signaling pathways in a rat model of gastric carcinogenesis induced by methylnitronitrosoguanidine

Gastric cancer, invasive cancer of the gastrointestinal tract, found in developing countries. Chemotherapy to patients with advanced gastric cancer, exhibits greater drug resistance to standard chemotherapy drugs. Therefore, important to establish anti-cancer drugs that are successful for cancer therapy. Corilagin is a natural ellagitannin (ET) with profound pharmacological properties has been used for the study to assess its anticancer effects against N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stimulated gastric cancer rats. Biochemical studies showed Thiobarbituric acid reactive substances (TBARS) and enzymatic and non-enzymatic antioxidants increased in corilagin treated animals compared with controls. Histopathologic evaluation revealed corilagin treated rats showed cell morphology similar that control showing its ameliorating effects. In corillagen treament mRNA protein expression levels of HIF-1α, AKT, PI3K, CT4, CD147 and HMGB1 were drastically lowered transcription factors triggering gastric cancer. In Western blot analysis showed released higher apoptotic marker of caspase-3, -9, Bax while Bcl-2 levels were significantly reduced confirming that corilagin triggers apoptosis in gastric cancer.

Nutrition, Cancer and Personalized Medicine

Cancer is a complex group of diseases where different signaling pathways have been found to be deregulated, mainly related to cell proliferation, angiogenesis, metastasis, evasion of apoptosis and insensitivity to anti-growth sings among others. Diet plays a fundamental role in the treatment of the oncological patients, we must be aware that food can interact with certain types of cancer therapy. On the other hand, cancer therapies sometimes affect the patient's sense of smell, taste, appetite, gastric capacity or nutrient absorption, which often results in malnutrition due to the lack of essential nutriments. In this chapter we will review the effect of different metabolic disorders in cancer and mechanisms of action of some phytochemicals found in different foods like resveratrol, EGCG, curcumin and lycopene.

Effect of Dendrobium officinale Extraction on Gastric Carcinogenesis in Rats

Dendrobium officinale (Tie Pi Shi Hu in Chinese) has been widely used to treat different diseases in China. Anticancer effect is one of the important effects of Dendrobium officinale. However, the molecular mechanism of its anticancer effect remains unclear. In the present study, gastric carcinogenesis in rats was used to evaluate the effect of Dendrobium officinale on cancer, and its pharmacological mechanism was explored. Dendrobium officinale extracts (4.8 and 2.4 g/kg) were orally administered to the rats of the gastric carcinogenesis model. Compared with the cancer model group, the high dose of Dendrobium officinale extracts significantly inhibited the rate of carcinogenesis. Further analysis revealed that Dendrobium officinale extracts could regulate the DNA damage, oxidative stress, and cytokines related with carcinogenesis and induce cell apoptosis in order to prevent gastric cancer.

Lycopene treatment against loss of bone mass, microarchitecture and strength in relation to regulatory mechanisms in a postmenopausal osteoporosis model

Lycopene supplementation decreases oxidative stress and exhibits beneficial effects on bone health, but the mechanisms through which it alters bone metabolism in vivo remain unclear. The present study aims to evaluate the effects of lycopene treatment on postmenopausal osteoporosis. Six-month-old female Wistar rats (n=264) were sham-operated (SHAM) or ovariectomized (OVX). The SHAM group received oral vehicle only and the OVX rats were randomized into five groups receiving oral daily lycopene treatment (mg/kg body weight per day): 0 OVX (control), 15 OVX, 30 OVX, and 45 OVX, and one group receiving alendronate (ALN) (2μg/kg body weight per day), for 12weeks. Bone densitometry measurements, bone turnover markers, biomechanical testing, and histomorphometric analysis were conducted. Micro computed tomography was also used to evaluate changes in microarchitecture. Lycopene treatment suppressed the OVX-induced increase in bone turnover, as indicated by changes in biomarkers of bone metabolism: serum osteocalcin (s-OC), serum N-terminal propeptide of type 1 collagen (s-PINP), serum crosslinked carboxyterminal telopeptides (s-CTX-1), and urinary deoxypyridinoline (u-DPD). Significant improvement in OVX-induced loss of bone mass, bone strength, and microarchitectural deterioration was observed in lycopene-treated OVX animals. These effects were observed mainly at sites rich in trabecular bone, with less effect in cortical bone. Lycopene treatment down-regulated osteoclast differentiation concurrent with up-regulating osteoblast together with glutathione peroxidase (GPx) catalase (CAT) and superoxide dismutase (SOD) activities. These findings demonstrate that lycopene treatment in OVX rats primarily suppressed bone turnover to restore bone strength and microarchitecture.

Lycopene attenuates dichlorvos-induced oxidative damage and hepatotoxicity in rats

Because of the widespread use of dichlorvos (DDVP) for domestic applications, evaluation of their toxic effects is of major concern to public health. Lycopene may lower oxidative stress by a mechanism that is not fully elucidated. The present study was undertaken to evaluate the protective efficacy of lycopene in terms of normalization of altered biochemical parameters following DDVP treatment in rats. Animals were divided into four groups. The first group was used as control, while groups 2, 3, and 4 were orally treated with lycopene (10 mg kg−1 body weight (b.w.)), DDVP (1.6 mg kg−1 b.w.), and DDVP plus lycopene, respectively. Results showed that oral administration of DDVP for 30 days increased the levels of lipid peroxidation markers such as malondialdehyde, 4-hydroxynonanal, and protein carbonyl content in liver. Also, a decrease in levels of vitamin C, vitamin E, and reduced glutathione was detected due to DDVP administration. These were accompanied by a decrease in the activities of antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione- S-transferase in the liver tissue. Moreover, DDVP increased the activities of serum transaminases, alkaline phosphatase, lactate dehydrogenase, and lipoxygenase, and the levels of bilirubin, total cholesterol, low-density lipoprotein cholesterol, triglyceride and DNA–protein crosslinks, and 8-hydroxy-2-deoxyguanosine, while decreased the level of high-density lipoprotein cholesterol. Our results provide new insights into the biochemical studies of relation between DDVP hepatotoxicity and lycopene treatment. Administration of lycopene to DDVP-treated rats reverted the status of hepatic markers to near-normal levels. These data suggest that lycopene can protect against the liver damage induced by DDVP.

Anticancer Effect of Lycopene in Gastric Carcinogenesis

Gastric cancer ranks as the most common cancer and the second leading cause of cancer-related death in the world. Risk factors of gastric carcinogenesis include oxidative stress, DNA damage, Helicobacter pylori infection, bad eating habits, and smoking. Since oxidative stress is related to DNA damage, smoking, and H. pylori infection, scavenging of reactive oxygen species may be beneficial for prevention of gastric carcinogenesis. Lycopene, one of the naturally occurring carotenoids, has unique structural and chemical features that contributes to a potent antioxidant activity. It shows a potential anticancer activity and reduces gastric cancer incidence. This review will summarize anticancer effect and mechanism of lycopene on gastric carcinogenesis based on the recent experimental and clinical studies.

The Effect of Tomato Juice Consumption on Antioxidant Status in Overweight and Obese Females

Tomatoes and their products are the main source of lycopene, a powerful potent antioxidant. Tomato products improve antioxidant defenses and reduce the risk of oxidative stress, at least partly, due to the presence of lycopene. Lycopene, as an antioxidant, induces the upregulation of antioxidant enzymes and reinforces the total enzyme capacity of the human body. Obesity is a chronic condition in which destructive mechanisms increase the reactive oxygen species and attenuation of antioxidant status. We hypothesized that the consumption of a lycopene-rich food would improve the antioxidant defense of women who were overweight or obese. A total of seventy-five overweight or obese female students of the Tehran University of Medical Sciences were enrolled and randomly allocated to one of two groups, intervention (n = 40) or control (n = 35), consuming 330 ml/d of tomato juice or water, respectively, for a 20-day period. At baseline and day 20, total antioxidant capacity and antioxidant enzyme activity (superoxide dismutase, glutathione peroxidase, and catalase) were analyzed using ELISA kits and spectrophotometric methods and then compared between the two groups. Lycopene consumption had no effect on these aforementioned variables. Therefore, it seems that more research with longer duration and more sensitive indicators will be required.

Protective effect of lycopene on oxidative stress and antioxidant status in Cyprinus carpio during cypermethrin exposure

The aim of this study was to investigate the ameliorative properties of lycopene against the toxic effects of cypermethrin (CYP) by examining oxidative damage markers such as lipid peroxidation and the antioxidant defense system components in carp (Cyprinus carpio). The fish were divided into seven groups of 10 fish each and received the following treatments: group 1, no treatment; group 2, orally administered corn oil; group 3, oral lycopene (10 mg/kg body weight); group 4, exposure to 0.202 μg/L CYP; group 5, exposure to 0.202 μg/L CYP plus oral administration of 10 mg/kg lycopene; group 6, exposure to 0.404 μg/L CYP; and group 7, exposure to 0.404 μg/L CYP plus oral administration of 10 mg/kg lycopene. Treatment was continued for 28 days, and at the end of this period, blood and tissue (liver, kidney, and gill) samples were collected. Levels of malondialdehyde (MDA) and reduced glutathione (GSH) as well as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were determined in blood and tissues for measurement of oxidant-antioxidant status. MDA level, as an index of lipid peroxidation, increased in blood and tissues. Antioxidant enzyme activities in blood and tissues were modified in CYP groups compared with controls. Administration of lycopene ameliorated these parameters. The present results suggest that administration of lycopene might alleviate CYP-induced oxidative stress.

Multiple molecular and cellular mechanisms of action of lycopene in cancer inhibition

Epidemiological studies suggest that including fruits, vegetables, and whole grains in regular dietary intake might prevent and reverse cellular carcinogenesis, reducing the incidence of primary tumours. Bioactive components present in food can simultaneously modulate more than one carcinogenic process, including cancer metabolism, hormonal balance, transcriptional activity, cell-cycle control, apoptosis, inflammation, angiogenesis and metastasis. Some studies have shown an inverse correlation between a diet rich in fruits, vegetables, and carotenoids and a low incidence of different types of cancer. Lycopene, the predominant carotenoid found in tomatoes, exhibits a high antioxidant capacity and has been shown to prevent cancer, as evidenced by clinical trials and studies in cell culture and animal models. In vitro studies have shown that lycopene treatment can selectively arrest cell growth and induce apoptosis in cancer cells without affecting normal cells. In vivo studies have revealed that lycopene treatment inhibits tumour growth in the liver, lung, prostate, breast, and colon. Clinical studies have shown that lycopene protects against prostate cancer. One of the main challenges in cancer prevention is the integration of new molecular findings into clinical practice. Thus, the identification of molecular biomarkers associated with lycopene levels is essential for improving our understanding of the mechanisms underlying its antineoplastic activity.

Optimization extraction of Ganoderma lucidum polysaccharides and its immunity and antioxidant activities

Extraction of Ganoderma lucidum polysaccharides (GLP) was optimized by response surface method (RSM). By running the optimization program with design expert within the experimental range investigated, the following optimum values were obtained: extraction time 230 min; extraction temperature 95 °C, and extraction number 5. The predicted polysaccharides production was 1.45%. Results showed that GLP significantly reduced the levels of serum IL-6 and TNF-α levels and increased the levels of serum IL-2, IL-4 and IL-10 in GLP-treated rats compared to gastric cancer model rats. In addition, administration of Ganoderma lucidum polysaccharides to GLP-treated group of rats improved the levels of serum and gastric tissue SOD, CAT and GSH-Px toward the control values in a dose-dependent manner. These findings show that GLP can enhance immunity and antioxidant activities in gastric cancer rats.

Protective role of lycopene against Aroclor 1254-induced changes on GLUT4 in the skeletal muscles of adult male rat

Aroclor 1254 is the commercial mixture of highly toxic environmental pollutant, polychlorinated biphenyls (PCBs). Being immensely durable, it is extensively used and widely distributed. Studies show that Aroclor 1254 causes a variety of adverse health effects through free radical generation. The present investigation was designed to check the effect of Aroclor 1254 on the glucose transporter protein, GLUT4, which plays a key role in glucose homeostasis. The protective role of lycopene against the adverse effect of Aroclor 1254 was also tested. Group 1 rats received corn oil as vehicle and served as control. Groups 2, 3, and 4 were administered with Aroclor 1254 [2 mg kg(-1) body weight (b.w.) day(-1)] intraperitoneally for 30 days. Groups 3 and 4 received lycopene (2 and 4 mg kg(-1) b.w. day(-1), respectively) orally in addition to Aroclor 1254. After 30 days, animals were euthanized and the skeletal muscles were dissected to determine the following parameters: GLUT4 messenger RNA (mRNA), GLUT4 protein (both plasma membrane and cytosolic fractions), and (14)C-2-deoxyglucose uptake. Though there was no change in GLUT4 mRNA and fasting plasma glucose levels, Aroclor 1254 significantly decreased the GLUT4 protein level in both the subcellular fractions of the gracilis and triceps muscles. Most important, (14)C-2-deoxyglucose uptake showed a significant decrease in Aroclor 1254 alone treated rats, and Aroclor 1254 plus 4 mg lycopene supplementation treatment maintained the same at par with control. Thus, Aroclor 1254 has adverse effects on GLUT4 translocation and (14)C-2-deoxyglucose uptake, and lycopene administered along with Aroclor 1254 has a protective role over it.

Protective effect of lycopene on deltamethrin-induced histological and ultrastructural changes in kidney tissue of rats

Deltamethrin is globally used in crop protection and control of malaria and other vector-borne diseases. It has a potent insecticidal activity with an appreciable safety margin. However, a number of studies have demonstrated nephrotoxicity of deltamethrin in mammalian and nonmammalian species. Lycopene, a carotenoid occurring naturally in tomatoes, has attracted considerable attention as an antioxidant. This study was focused on investigating the possible protective effect of coadministration of lycopene on deltamethrin toxicity. In this study, male albino rats were divided into four groups of 10 animals each: group I served as control, which received standard diet; group II received oral administration of deltamethrin (1.28 mg/kg per day) for 30 days; group III received both deltamethrin and lycopene (1 mg/kg per day); group IV received lycopene (1 mg/kg per day). After the experiment, the animals were anesthetized and the cytokine, tumor necrosis factor-α (TNF-α), in the serum was measured; the kidney was taken for histological and ultrastructural studies. Deltamethrin significantly increased the TNF-α. The histopathological examination of kidney showed mild necrotic changes. Ultrastructural changes in renal proximal tubules of deltamethrin-treated group included an increased number and irregular shape of mitochondria with sparse fragmented cristae, serious ultrastructural lesions in renal proximal tubular lining cells, vacuolar degeneration in the epithelial cells, increased number of lysosomes and loss of apical microvilli. In addition, focal segmental thickening and the duplication of glomerular basement membrane and podocyte changes were observed. Histopathological and ultrastructural study showed some protective effect of lycopene on kidney tissues.

The effect of lycopene on oxytetracycline-induced oxidative stress and immunosuppression in rainbow trout (Oncorhynchus mykiss, W.)

The aim of this study was to determine the effects of lycopene on oxytetracycline (OTC)-induced oxidative stress and immunosuppression in rainbow trout. The experimental fish analysed in this study were divided into 6 different experimental groups. Group 1 was the control group, and groups 2, 3 and 4 received corn oil, lycopene and OTC, respectively, for 14 days. Group 5 received OTC for 14 days after lycopene pre-treatment for 14 days, while group 6 received OTC for 14 days before lycopene post-treatment for 14 days. Blood and tissue samples were collected at the end of the experiment and analysed for the oxidant-antioxidant status and changes in the immune response. There was a significant increase in the malondialdehyde level, which is an index of lipid peroxidation, and a decrease in superoxide dismutase, catalase, and glutathione peroxidase activity as well as a decrease in the glutathione level in the blood, liver, kidney and spleen of OTC-treated fish. Glutathione-S-transferase activity was significantly increased in the blood, liver, kidney and spleen samples of the group that received OTC alone. OTC also appeared to suppress specific and nonspecific immune system parameters, such as the haematocrit, leucocyte count, oxidative radical production (nitroblue tetrazolium activity), total plasma protein and immunoglobulin levels and phagocytic activity. Pre- and post-treatment with lycopene attenuated the OTC-induced oxidative stress by significantly decreasing the tissue malondialdehyde level. The superoxide dismutase, catalase and glutathione peroxidase activities as well as the glutathione levels were significantly increased with lycopene administration, while glutathione-S-transferase activity was significantly decreased. Lycopene administration was also associated with a significant increase in the OTC-suppressed immune system parameters in fish. Thus, the present results suggest that pre- and post-treatment with lycopene (10 mg per kg fish weight, delivered orally) may alleviate OTC-induced oxidative stress and immunosuppression.

Lycopene enhances antioxidant enzyme activities and immunity function in N-methyl-N'-nitro-N-nitrosoguanidine-enduced gastric cancer rats

To investigate anticancer effect of lycopene, we examined the effects of lycopene on the oxidative injury and immunity activities of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric cancer rats. The animals were divided into five groups. Group I served as the normal control and was given corn oil orally for 20 weeks. Group II were induced with MNNG 200 mg/kg body weight by oral gavage at days 0 and 14, and saturated NaCl (1 mL per rats) was given once every three days for four weeks until the end of the experimental period. Group III, IV and V were posttreated with lycopene (50, 100 and 150 mg/kg body weight, dissolved in corn oil) from the sixth week of MNNG (as in group II) induction up to the end of the experimental period. In the presence of MNNG, MDA and immunity levels were significantly increased, whereas enzymatic (SOD, CAT, and GPx) antioxidant activities were decreased in the treated rats compared with normal control rats. Administration of lycopene to gastric carcinoma-induced rats largely up-regulated the redox status and immunity activities to decrease the risk of cancer compared to group II. We conclude that up-regulation of antioxidants and immunity by lycopene treatment might be responsible for the anticancer effect in gastric carcinoma.

Effects of cadmium on some haematological and biochemical characteristics of Oreochromis niloticus (Linnaeus, 1758) dietary supplemented with tomato paste and vitamin E

The present study investigates the potential protective effects of tomato paste (9 mg/kg-lycopene) in comparison with vitamin E (50 mg/kg) against the impacts of cadmium (Cd) toxicity (4.64 mg/l: ¼ of 96 h LC50) on fishes Cd exposed for 15 and 30 days. Cd impacts were evaluated in terms of biological, haematological and biochemical characteristics. Cd significantly induced free radicals in serum and liver. The activities of aspartate aminotransferase and alanine aminotransferase in serum were significantly increased due to Cd. Treatment with Cd caused a significant increase in Lipid peroxidation and DNA fragmentation in liver tissue and serum glucose and total lipid. On the other hand, Cd significantly led to decline in serum total protein, blood haemoglobin, red blood cell count, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. Dietary supplementation with vitamin E and/or tomato paste to Cd-exposed fish declined significantly the increased lipid peroxidation and DNA fragmentation in liver tissue and the increased aspartate aminotransferase, alanine aminotransferase, glucose and total lipid in serum to the normal condition. This supplementation also significantly increased the declined serum total protein, blood haemoglobin, red blood cell count, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration to the normal state. Cd impacts and tomato paste/or vitamin E supplementations did not reflected on the condition factor of the fish. These findings demonstrated the beneficial diet supplementation of tomato paste phytonutrients and vitamin E in counteracting the harmful effects of Cd on the characters investigated.

Oral supplementation of silibinin prevents colon carcinogenesis in a long term preclinical model

Chemoprevention through dietary intervention is an emerging option to reduce colon cancer mortality. beta-catenin plays an important role in the Wnt signaling cascade that is most commonly dysregulated in colorectal cancer. Our aim was to explore the modulatory effect of silibinin on beta-catenin expression employing 1,2-dimethylhydrazine (DMH) induced colon cancer in male Wistar rats as an experimental model during the different stages of carcinogenesis. Colon tissues were analyzed for the expression of beta-catenin, proliferating cell nuclear antigen (PCNA) and argyrophilic nucleolar organizer regions by using immunohistochemistry and silver staining. Immunoblotting was employed to study cyclin D1 expression. Glutathione (GSH) and glutathione related enzymes were assayed by spectrophotometric analysis. Silibinin inhibited DMH-induced colon cancer by decreasing tumor incidence and multiplicity. Silibinin supplementation to DMH-treated rats restored the levels of GSH-dependent enzymes and decreased the levels of beta-catenin, PCNA, argyrophilic nucleolar organizer regions and cyclin D1. Mechanistically silibinin inhibits DMH-induced colon carcinogenesis by modulating the Wnt/beta-catenin pathway and glutathione redox system. Since colon cancer is highly sensitive to dietary intervention adults who may have preneoplastic lesions in their colon may be benefited by silibinin.

Naringenin reduces tumor size and weight lost in N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis in rats

Carcinoma of the stomach is reportedly the second most common cancerous condition affecting the general population. Administration of antioxidants is reported to effectively alleviate the risk of gastric carcinoma. Therefore, we assessed the protective role of naringenin, an antioxidant and naturally occurring citrus flavanone, on gastric carcinogenesis induced by MNNG (200 mg/kg body weight) and S-NaCl (1 mL per rat) in Wistar rats (obtained from the Central Animal House Facility, University of Madras, Taramani Campus, Chennai, India). The animals were divided into 5 groups, and the effects of naringenin on simultaneous and posttreated stages of MNNG were tested. Cancer risk was analyzed along with their antioxidant status. The LPO levels in the experimental groups were assessed as an index of oxidative milieu. Altered redox status was subsequently investigated by assaying the superoxide and hydroxyl radicals, the enzymatic antioxidants (SOD, CAT, GPx), and the nonenzymatic antioxidants viz reduced GSH, vitamin C, and vitamin E. In the presence of MNNG, cancer incidence and LPO levels were significantly increased, whereas enzymatic (SOD, CAT, and GPx) and nonenzymatic antioxidant activities (GSH, Vitamins C, and E) were decreased in the treated rats compared with control rats. Administration of naringenin to gastric carcinoma-induced rats largely up-regulated the redox status to decrease the risk of cancer. We conclude that up-regulation of antioxidants by naringenin treatment might be responsible for the anticancer effect in gastric carcinoma.

Lycopene in cancer prevention and treatment

Dietary intake of lycopene is inversely associated with the risk of many cancers. Preclinical studies show that lycopene has potent in vitro and in vivo antitumor effects, suggesting potential preventive and therapeutic roles for the compound. However, clinical trials with lycopene have only recently been started, and available clinical data preclude firm conclusions with regard to its use in cancer prevention and treatment. Further mechanistic studies and randomized controlled clinical intervention trials with lycopene involving cancer patients are warranted.

Enhancement of erythrocyte antioxidants by green and black tea polyphenols during 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis

We evaluated the comparative chemopreventive efficacy of green tea polyphenols (polyphenon-E) and black tea polyphenols (polyphenon-B) on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Lipid peroxidation, reduced and oxidized glutathione (GSH and GSSG, respectively), and the GSH-dependent enzymes glutathione peroxidase and glutathione S-transferase in the erythrocytes were used as biomarkers of chemoprevention. Enhanced lipid peroxidation in erythrocytes of DMBA-treated animals was accompanied by a significant decrease in the antioxidant status. Dietary administration of polyphenon-E and -B to DMBA-treated animals significantly decreased the extent of lipid peroxidation and enhanced the levels of GSH, GSH/GSSG ratio, and activities of GSH-dependent enzymes. Our study provides evidence that polyphenon-B is more effective in inhibiting HBP carcinogenesis than polyphenon-E by enhancing the antioxidant status, suggesting that polyphenon-B may have a major impact in the chemoprevention of oral cancer.

Lycopene supplementation prevents smoke-induced changes in p53, p53 phosphorylation, cell proliferation, and apoptosis in the gastric mucosa of ferrets

Cigarette smoking increases the risk for gastric cancer. Higher intakes or blood levels of lycopene are associated with a decreased risk of gastric cancer. However, the biological mechanisms by which lycopene may protect against gastric carcinogenesis are poorly understood. We evaluated the effects of lycopene supplementation on smoke-induced changes in protein levels of p53, p53 target genes (p21(Waf1/Cip1) and Bax-1), cell proliferation, and apoptosis in the gastric mucosa of ferrets. Ferrets were assigned to cigarette smoke exposure or to no exposure and to no, low-dose, or high-dose lycopene supplementation (2 x 3 factorial design) for 9 wk. Lycopene concentrations were significantly elevated in a dose-dependent manner in the gastric mucosa of ferrets supplemented with lycopene alone, but were markedly reduced in ferrets supplemented with lycopene and exposed to smoke. Although ferrets were given lycopene containing 95% all-trans isomers, cis isomers were the predominant forms in the gastric mucosa. Total p53 and phosphorylated p53 levels were greater in ferrets exposed to smoke alone than in all other groups. Levels were approximately 300 and 500% of the controls, respectively. However, smoke-elevated total p53 and phosphorylated p53 were markedly attenuated by both doses of lycopene. p21(Waf1/Cip1), Bax-1, and cleaved caspase 3 were substantially decreased, whereas cyclin D1 and proliferating cellular nuclear antigen (PCNA) were increased in ferrets exposed to smoke alone. Lycopene prevented smoke-induced changes in p21(Waf1/Cip1), Bax-1, cleaved caspase 3, cyclin D1, and PCNA in a dose-dependent fashion. These data indicate that lycopene may prevent smoke exposure-induced changes in p53, p53 phosphorylation, p53 target genes, cell proliferation, and apoptosis in the gastric mucosa of ferrets.

Protective effect of lycopene on gentamicin-induced oxidative stress and nephrotoxicity in rats

A potential therapeutic approach to protect or reverse gentamicin-induced oxidative stress and nephrotoxicity would have more importance for clinical consequences. Therefore, the present study was designed to investigate the possible protective effects of lycopene against gentamicin-induced renal damage in rats. Male Sprague-Dawley rats were divided into four groups of six rats in each one; first group served as control. The other groups were treated intraperitoneally with gentamicin alone (100 mg kg(-1) per day) for six successive days, gentamicin for 6 days following 10 days of orally lycopene (4 mg kg(-1) per day) pre-treatment and 6-days of simultaneous lycopene and gentamicin. Biochemical and histopathological examinations were utilized for evaluation of the oxidative stress and renal nephrotoxicity. Creatinine, urea, Na(+) and K(+) levels in plasma and malondialdehyde (MDA), reduced glutathione (GSH) levels and glutathione peroxidase (GSH-Px) and catalase (CAT) activities were determined in kidney tissue. Administration of gentamicin to rats induced a marked renal failure, characterized by a significant increase in plasma creatinine and urea concentrations. The animals treated with gentamicin alone showed a significantly higher kidney MDA and lower GSH-Px and CAT activities but unaffected GSH concentrations when compared with the control group. Pre-treatment with lycopene produced amelioration in biochemical indices of nephrotoxicity in plasma. However, little changes were observed in the kidney MDA and GSH levels and GSH-Px and CAT activities when compared with the gentamicin treated group. The histological structures of the renal proximal tubules showed similar patterns. On the other hand, administration of simultaneous lycopene to rats produced amelioration in MDA and GSH levels and GSH-Px and CAT activities when compared with gentamicin group. In addition, simultaneous lycopene was found to reduce the degree of kidney tissue damage in histopathological findings. These results indicate that specially simultaneous treatment of lycopene might have produced amelioration in biochemical indices and oxidative stress parameters against gentamicin-induced nephrotoxicity, but pre-treatments with lycopene had no beneficial effects on these parameters. It was concluded that lycopene as a novel natural antioxidant might have protective effects against gentamicin-induced nephrotoxicity and oxidative stress in rats.

The effect of lycopene on cell growth and oxidative DNA damage of Hep3B human hepatoma cells

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.

Prediagnostic Levels of Serum Micronutrients in Relation to Risk of Gastric Cancer in Shanghai, China

Data on blood levels of specific carotenoids and vitamins in relation to gastric cancer are scarce. Little is known about the relationship between prediagnostic serum levels of carotenoids other than β-carotene and risk of gastric cancer especially in non-Western populations. Prediagnostic serum concentrations of α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin, retinol, α-tocopherol, γ-tocopherol, and vitamin C were determined on 191 cases and 570 matched controls within a cohort of 18,244 middle-aged or older men in Shanghai, China, with a follow-up of 12 years. High serum levels of α-carotene, β-carotene, and lycopene were significantly associated with reduced risk of developing gastric cancer (all Ps for trend ≤ 0.05); the odds ratios (95% confidence intervals) for the highest versus the lowest quartile of α-carotene, β-carotene, and lycopene were 0.38 (0.13-1.11), 0.54 (0.32-0.89), and 0.55 (0.30-1.00), respectively. Increased serum level of vitamin C was significantly associated with reduced risk of gastric cancer among men who neither smoked cigarettes over lifetime nor consumed ≥3 drinks of alcohol per day; the odds ratios (95% confidence intervals) for the second, third, and fourth quartile categories were 0.69 (0.28-1.70), 0.36 (0.14-0.94), and 0.39 (0.15-0.98), respectively, compared with the lowest quartile of vitamin C (P for trend = 0.02). There were no statistically significant relationships of serum levels of β-cryptoxanthin, lutein/zeaxanthin, retinol, α-tocopherol, and γ-tocopherol with gastric cancer risk. The present study implicates that dietary carotenes, lycopene, and vitamin C are potential chemopreventive agents for gastric cancer in humans.

Review article: How useful are the rodent animal models of gastric adenocarcinoma?

Gastric cancer is the second most common cause of cancer-related mortality world-wide. In most cases, it develops via the pre-malignant stages of atrophic gastritis, intestinal metaplasia and dysplasia, following Helicobacter pylori infection of susceptible individuals. A number of rodent models have recently provided valuable insights into the host, bacterial and environmental factors involved in gastric carcinogenesis. Wild-type rodents do not develop gastric adenocarcinoma, but early studies showed that the disease could be induced in several rodent species by chemical carcinogens. More recently, it has been demonstrated that gastric adenocarcinoma can be induced in Mongolian gerbils by H. pylori infection and in C57BL/6 mice by long-term H. felis infection. These models have allowed the importance of Helicobacter virulence genes, host factors, such as gender, strain and immune response, and environmental factors, such as dietary salt, to be explored. A number of transgenic mice with alterations in various pathways, including the immune response, gastrin biosynthesis, parietal cell development, growth factors and tumour suppressors, have also provided models of various stages of gastric carcinogenesis. One model that has proved to be particularly valuable is the hypergastrinaemic INS-GAS mouse, in which gastric carcinoma develops spontaneously in old animals, but the process is greatly accelerated by Helicobacter infection.