Insight to drug delivery aspects for colorectal cancer

Colorectal cancer (CRC) is the third most common cancer diagnosed worldwide in human beings. Surgery, chemotherapy, radiotherapy and targeted therapies are the conventional four approaches which are currently used for the treatment of CRC. The site specific delivery of chemotherapeutics to their site of action would increase effectiveness with reducing side effects. Targeted oral drug delivery systems based on polysaccharides are being investigated to target and deliver chemotherapeutic and chemopreventive agents directly to colon and rectum. Site-specific drug delivery to colon increases its concentration at the target site, and thus requires a lower dose and hence abridged side effects. Some novel therapies are also briefly discussed in article such as receptor (epidermal growth factor receptor, folate receptor, wheat germ agglutinin, VEGF receptor, hyaluronic acid receptor) based targeting therapy; colon targeted proapoptotic anticancer drug delivery system, gene therapy. Even though good treatment options are available for CRC, the ultimate therapeutic approach is to avert the incidence of CRC. It was also found that CRCs could be prevented by diet and nutrition such as calcium, vitamin D, curcumin, quercetin and fish oil supplements. Immunotherapy and vaccination are used nowadays which are showing better results against CRC.

Unpolished Thai Rice Prevents Aberrant Crypt Foci Formation through the Invovement of ?catenin and COX2 Expression in AzoxymethaneTreated Rats

Colorectal cancer (CRC) is a major cause of morbidity and mortality throughout the world, with chronic inflammation and diet as major causes in its development. Chemopreventive effects of natural dietary products have been the focus of studies for prevention over the past decade. This study was conducted to determine the effects of unpolished Thai rice during precancerous stage through the involvement of ?catenin, cyclooxygenase2 (COX2) expression and inflammatory cytokines focusing on azoxymethane (AOM)induced aberrant crypt foci (ACF)related to CRC. Male Sprague Dawley rats received two injections of AOM (15 mg/kg body weight) at weeks 4 and 5 while rats were treated with 20% or 70% unpolished Thai rice. The rats were sacrificed at week 38 and the colons removed for aberrant crypt foci (ACF) identification. Histopathologic changes, immunohistochemical analysis of ?catenin and COX2 expression, and cytokine expression of proinflammatory and antiinflammatory markers were determined. The administration of unpolished Thai rice significantly and dose dependently decreased the total number of ACF and the percentages of ACF with highgrade dysplasia. Interestingly, unpolished Thai rice suppressed the expression of βcatenin and COX2. In addition, it also altered proinflammatory (IL6 and IFNγ) and antiinflammatory (IL 10) markers. The results suggested that unpolished Thai rice may provide a promising dietary intake for prevention during precancerous stage of CRC development, through the involvement of βcatenin and COX2 expression, and also modulate inflammatory cytokinesrelated to CRC.

Phase IIB Randomized Study of Topical Difluoromethylornithine and Topical Diclofenac on Sun-Damaged Skin of the Forearm

Prevention of nonmelanoma skin cancers remains a health priority due to high costs associated with this disease. Diclofenac and difluoromethylornithine (DFMO) have demonstrated chemopreventive efficacy for cutaneous squamous cell carcinomas. We designed a randomized study of the combination of DFMO and diclofenac in the treatment of sun-damaged skin. Individuals with visible cutaneous sun damage were eligible. Subjects were randomized to one of the three groups: topical DFMO applied twice daily, topical diclofenac applied daily, or DFMO plus diclofenac. The treatment was limited to an area on the left forearm, and the duration of use was 90 days. We hypothesized that combination therapy would have increased efficacy compared with single-agent therapy. The primary outcome was change in karyometric average nuclear abnormality (ANA) in the treated skin. Individuals assessing the biomarkers were blinded regarding the treatment for each subject. A total of 156 subjects were randomized; 144 had baseline and end-of-study biopsies, and 136 subjects completed the study. The ANA unexpectedly increased for all groups, with higher values correlating with clinical cutaneous inflammation. Nearly all of the adverse events were local cutaneous effects. One subject had cutaneous toxicity that required treatment discontinuation. Significantly more adverse events were seen in the groups taking diclofenac. Overall, the study indicated that the addition of topical DFMO to topical diclofenac did not enhance its activity. Both agents caused inflammation on a cellular and clinical level, which may have confounded the measurement of chemopreventive effects. More significant effects may be observed in subjects with greater baseline cutaneous damage.

Comparative efficacy of vitamin D status in reducing the risk of bladder cancer: A systematic review and network meta-analysis

OBJECTIVES

The optimal concentration of individual vitamin D intake for preventing bladder cancer has not, to our knowledge, been defined. To evaluate the comparative efficacy of different serum 25-hydroxyvitamin D concentrations in preventing bladder cancer, we conducted a systematic search of the literature published up to April 2015.

METHODS

We applied a pairwise meta-analysis to estimate direct evidence from intervention-control studies and a network meta-analysis within a Bayesian framework to combine direct and indirect evidence. Moreover, a dose-response curve was utilized to predict the optimal median serum 25-hydroxyvitamin D concentration based on the odds ratio (OR) for each quintile concentration.

METHODS

Seven studies of a total of 90757 participants, including 2509 bladder cancer patients, were included. Two prospective cohort studies with 57 591 participants and 494 bladder cancer patients, and five case-control studies with 33 166 participants and 2264 bladder cancer patients. From the network meta-analysis, we observed that sufficient serum 25-hydroxyvitamin D concentrations (>75 nmol/L) were superior to all other 25-hydroxyvitamin D concentrations in decreasing the risk of bladder cancer: OR = 0.68 and 95% credible interval (CrI) 0.52 to 0.87 compared with severely deficient concentrations (<25 nmol/L); OR = 0.65 and 95% CrI 0.49 to 0.86 compared with moderately deficient concentrations (25-37.5 nmol/L); OR = 0.61 and 95% CrI 0.47 to 0.80 compared with slightly deficient concentrations (37.5-50 nmol/L); and OR = 0.65 and 95% CrI 0.48 to 0.85 compared with insufficient concentrations (50-75 nmol/L). In addition, we noted a roughly inverse correlation between bladder cancer risk and 25-hydroxyvitamin D concentrations (R(2) = 0.98, P = 0.007).

CONCLUSIONS

Ensuring sufficient serum 25-hydroxyvitamin D concentrations might play an important role in decreasing the risk of bladder cancer. The serum 25-hydroxyvitamin D concentration ≥74 nmol/L was associated with a 60% lower risk of bladder cancer incidence.

Chemoprevention of Breast Cancer by Dietary Polyphenols

The review will discuss in detail the effects of polyphenols on breast cancer, including both the advantages and disadvantages of the applications of these natural compounds. First, we focus on the characterization of the main classes of polyphenols and then on in vitro and in vivo experiments carried out in breast cancer models. Since the therapeutic effects of the administration of a single type of polyphenol might be limited because of the reduced bioavailability of these drugs, investigations on combination of several polyphenols or polyphenols with conventional therapy will also be discussed. In addition, we present recent data focusing on clinical trials with polyphenols and new approaches with nanoparticles in breast cancer. Besides the clinical and translational findings this review systematically summarizes our current knowledge about the molecular mechanisms of anti-cancer effects of polyphenols, which are related to apoptosis, cell cycle regulation, plasma membrane receptors, signaling pathways and epigenetic mechanisms. At the same time the effects of polyphenols on primary tumor, metastasis and angiogenesis in breast cancer are discussed. The increasing enthusiasm regarding the combination of polyphenols and conventional therapy in breast cancer might lead to additional efforts to motivate further research in this field.

Multistage vector delivery of sulindac and silymarin for prevention of colon cancer

Familial adenomatous polyposis (FAP) is an inherited condition secondary to germline mutations in the APC gene, thus resulting in the formation of hundreds of colonic adenomas that eventually progress into colon cancer. Surgical removal of the colon remains the only treatment option to avoid malignancy, as long-term exposure to chemopreventive agents such as sulindac (a non-steroidal anti-inflammatory drug) and silymarin (phytoestrogen) is not feasible. Here, we have developed a multistage silicon-based drug delivery platform for sulindac and silymarin that preferentially interacts with colon cancer cells as opposed to normal intestinal mucosa. Preferential binding and internalization of these drugs into colon cancer cells was obtained using a targeting strategy against the protein meprin A, which we demonstrate is overexpressed in human colon cancer cells and in the small intestine of Apc(Min/+) mice. We propose that this delivery system could potentially be used to reduce drug-induced side effects in FAP patients, thus enabling long-term prevention of adenoma formation.

Metformin for cancer and aging prevention: is it a time to make the long story short?

During the last decade, the burst of interest is observed to antidiabetic biguanide metformin as candidate drug for cancer chemoprevention. The analysis of the available data have shown that the efficacy of cancer preventive effect of metformin (MF) and another biguanides, buformin (BF) and phenformin (PF), has been studied in relation to total tumor incidence and to 17 target organs, in 21 various strains of mice, 4 strains of rats and 1 strain of hamsters (inbred, outbred, transgenic, mutant), spontaneous (non- exposed to any carcinogenic agent) or induced by 16 chemical carcinogens of different classes (polycycIic aromatic hydrocarbons, nitroso compounds, estrogen, etc.), direct or indirect (need metabolic transformation into proximal carcinogen), by total body X-rays and γ- irradiation, viruses, genetic modifications or special high fat diet, using one stage and two-stage protocols of carcinogenesis, 5 routes of the administration of antidiabetic biguanides (oral gavage, intraperitoneal or subcutaneous injections, with drinking water or with diet) in a wide ranks of doses and treatment regimens. In the majority of cases (86%) the treatment with biguanides leads to inhibition of carcinogenesis. In 14% of the cases inhibitory effect of the drugs was not observed. Very important that there was no any case of stimulation of carcinogenesis by antidiabetic biguanides. It was conclude that there is sufficient experimental evidence of anti-carcinogenic effect of antidiabetic biguanides.

Metformin reduces ovarian cancer risk in Taiwanese women with type 2 diabetes mellitus

BACKGROUND

Whether metformin therapy affects ovarian cancer risk in Asian patients with type 2 diabetes mellitus has not been investigated.

METHODS

Data analysis was performed in 2014. The reimbursement databases of Taiwanese female patients with a new diagnosis of type 2 diabetes mellitus between 1998 and 2002 (n = 479,475) were retrieved from the National Health Insurance for follow-up of ovarian cancer until the end of 2009. Metformin was treated as a time-dependent variable; and of these patients, 286,106 were never-users, and 193,369 were ever-users. A time-dependent approach was used to calculate ovarian cancer incidence and estimate hazard ratios by Cox regression for never-users (as referent group), ever-users and subgroups of metformin exposure (tertiles of cumulative duration and cumulative dose).

RESULTS

During follow-up, 601 metformin ever-users and 2600 never-users developed ovarian cancer, representing an incidence of 49.4 and 146.4 per 100,000 person-years, respectively. The overall fully adjusted hazard ratio (95% confidence intervals) for ever-users versus never-users was 0.658 (0.593-0.730). The fully adjusted hazard ratios for the first, second and third tertiles of cumulative duration of metformin therapy were 1.169 (1.019-1.341), 0.761 (0.644-0.898) and 0.276 (0.225-0.340), respectively (p trend < 0.01) and 1.220 (1.067-1.395), 0.610 (0.513-0.725) and 0.305 (0.248-0.374), respectively (p trend < 0.01), for a cumulative dose of metformin. In additional analyses, sulfonylureas but not the other antidiabetic drugs were associated with a reduced risk of ovarian cancer.

CONCLUSIONS

Metformin use is associated with a decreased risk of ovarian cancer.

Effect of Combined Treatment with Ursolic Acid and Resveratrol on Skin Tumor Promotion by 12-O-Tetradecanoylphorbol-13-Acetate

In this study, the effects of combining ursolic acid + resveratrol, for possible combined inhibitory effects on skin tumor promotion, were evaluated. Ursolic acid, resveratrol, and the combination of ursolic acid + resveratrol were applied topically prior to 12-O-tetracanoylphorbol-13-acetate (TPA) treatment on mouse skin to examine their effect on TPA-induced signaling pathways, epidermal hyperproliferation, skin inflammation, inflammatory gene expression, and skin tumor promotion. The combination of ursolic acid + resveratrol produced a greater inhibition of TPA-induced epidermal hyperproliferation. The combination of ursolic acid + resveratrol inhibited TPA-induced signaling pathways, including EGFR, STAT3, Src, Akt, Cox-2, Fas, NF-κB, p38 MAPK, c-Jun, and JNK1/2 while increasing levels of tumor suppressors, such as p21 and PDCD4, to a greater extent compared with the groups treated with the individual compounds. Ursolic acid + resveratrol also induced a dramatic increase of p-AMPK-α(Thr172). Combined treatment with ursolic acid + resveratrol resulted in a greater inhibition of expression of proinflammatory cytokines, including Il1a, Il1b, and Il22. Furthermore, NF-κB, Egr-1, and AP-1 DNA binding activities after TPA treatment were dramatically decreased by the combination of ursolic acid + resveratrol. Treatment with ursolic acid + resveratrol during skin tumor promotion with TPA produced greater inhibition of tumor multiplicity and tumor size than with either agent alone. Collectively, the greater ability of the combination of ursolic acid + resveratrol to inhibit skin tumor promotion was due to the greater inhibitory effects on growth factor and inflammatory signaling, skin inflammation, and epidermal hyperproliferation induced by TPA treatment.

Medical interventions for high-grade vulval intraepithelial neoplasia

BACKGROUND

This is an updated version of a review first published in theCochrane Database of Systematic Reviews, Issue 4, in 2011. Vulval intraepithelial neoplasia (VIN) is a pre-cancerous condition of the vulval skin and its incidence is increasing in women under 50 years. High-grade VIN (also called usual-type VIN (uVIN) or VIN 2/3 or high-grade vulval intraepithelial lesion) is associated with human papilloma virus (HPV) infection and may progress to vulval cancer, therefore is usually actively managed. There is no consensus on the optimal management of high-grade VIN; and the high morbidity and relapse rates associated with surgical interventions make less invasive interventions highly desirable.

OBJECTIVES

To evaluate the effectiveness and safety of medical (non-surgical) interventions for high-grade VIN.

SEARCH METHODS

We searched the Cochrane Gynaecological Cancer Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015, Issue 3), MEDLINE and EMBASE (up to 30 March 2015). We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that assessed non-surgical interventions in women diagnosed with high-grade VIN.

DATA COLLECTION AND ANALYSIS

We used Cochrane methodology with two review authors independently abstracting data and assessing risk of bias. Where possible, we synthesised data in meta-analyses using random effects methods.

MAIN RESULTS

Five trials involving 297 women with high-grade VIN (defined by trial investigators as VIN 2/3 or VIN 3 or 'high-grade' lesions) met our inclusion criteria: three trials assessed the effectiveness of topical imiquimod versus placebo; one assessed topical cidofovir versus topical imiquimod; and one assessed low- versus high-dose indole-3-carbinol in similar types of participants. Three trials were at a moderate to low risk of bias, two were at a potentially high risk of bias.Meta-analysis of the three trials comparing topical imiquimod 5% cream to placebo found that women in the active treatment group were more likely to show an overall response (complete and partial response) to treatment at five to six months compared with the placebo group (Risk Ratio (RR) 11.95, 95% confidence interval (CI) 3.21 to 44.51; participants = 104; studies = 3; I(2) = 0%; high-quality evidence). A complete response at five to six months occurred in 36/62 (58%) and 0/42 (0%) participants in the active and placebo groups, respectively (RR 14.40, 95% CI 2.97 to 69.80; participants = 104; studies = 3; I(2) = 0%). A single trial reported 12-month follow-up, which revealed a sustained effect in overall response in favour of the active treatment arm at 12 months (RR 9.10, 95% CI 2.38 to 34.77; moderate-quality evidence), with 9/24 (38%) and 0/23 (0%) complete responses recorded in the active and placebo groups respectively. Progression to vulval cancer was also documented in this trial (one versus two participants in the active and placebo groups, respectively) and we assessed this evidence as low-quality. Only one trial reported adverse events, including erythema, erosion, pain and pruritis at the site of the lesion, which were more common in the imiquimod group. Dose reductions occurred more frequently in the active treatment group compared with the placebo group (19/47 versus 1/36 participants; RR 7.77, 95% CI 1.61 to 37.36; participants = 83; studies = 2; I(2) = 0%; high-quality evidence). Only one trial reported quality of life (QoL) and there were no significant differences between the imiquimod and placebo groups.For the imiquimod versus cidofovir trial, 180 women contributed data. The overall response at six months was similar for the imiquimod and cidofovir treatment groups with 52/91 (57%) versus 55/89 (62%) participants responding, respectively (RR 0.92, 95% CI 0.73 to 1.18). A complete response occurred in 41 women in each group (45% and 46%, respectively; RR 1.00, 95% CI 0.73 to 1.37). Although not statistically different, total adverse events were slightly more common in the imiquimod group of this trial with slightly more discontinuations occurring in this group. Longer term response data from this trial are expected.The small trial comparing two doses of indole-3-carbinol contributed limited data. We identified five ongoing randomised trials of various interventions for VIN.

AUTHORS' CONCLUSIONS

Topical imiquimod appears to be a safe and effective treatment for high-grade VIN (uVIN), even though local side-effects may necessitate dose reductions. However, longer term follow-up data are needed to corroborate the limited evidence that response to treatment is sustained, and to assess any effect on progression to vulval cancer. Available evidence suggests that topical cidofovir may be a good alternative to imiquimod; however, more evidence is needed, particularly regarding the relative effectiveness on longer term response and progression. We await the longer-term response data and the results of the five ongoing trials.

Drugs with potential chemopreventive properties in relation to epithelial ovarian cancer--a nationwide case-control study

Ovarian cancer has a poor prognosis because the disease in the majority of patients is diagnosed at an advanced stage as a result of nonspecific symptoms and lack of efficient screening methods. Because of the poor prognosis of ovarian cancer and the challenge of early detection of the disease, identification of protective factors is important. It has been suggested that some commonly used drugs may have a protective effect against cancer, including ovarian cancer; however, the literature on chemopreventive measures for ovarian cancer is sparse and the results are inconclusive. Most previous studies have substantial methodological constraints, including limited study size and self-reporting of drug use, which introduces potential recall bias and misclassification. This PhD thesis includes a nationwide case-control study to evaluate associations between use of drugs with potential chemopreventive properties and risk of epithelial ovarian cancer. The study is nested in the entire Danish female population using data from the following nationwide registries: the Danish Cancer Registry, the Danish Civil Registration System, the Danish Prescription Registry, the Danish National Patient Register, and registries in Statistics Denmark on fertility, education, and income. Information from the included registries is linked by use of the unique personal identification number assigned to all Danish citizens. The cases were all women in Denmark with epithelial ovarian cancer diagnosed during 2000-2009 (Paper 1) and 2000-2011 (Papers 2 and 3), identified in the Cancer Registry. Age-matched female population controls were randomly selected from the Civil Registration System by risk-set sampling. We required that cases and controls have no history of cancer (except non-melanoma skin cancer) and that controls not previously have undergone bilateral oophorectomy or salpingo-oophorectomy. The total study population comprised 3741 epithelial ovarian cancer cases and 50,576 controls in Paper 1, and 4103 epithelial ovarian cancer cases and 58,706 controls in Papers 2 and 3. We used the Danish Prescription Registry to assess use (≥2 prescriptions on separate dates) of paracetamol, non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin, and statins. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for epithelial ovarian cancer associated with use of the study drugs, with adjustment for potential confounding factors selected a priori. We performed detailed analyses according to duration, intensity, and continuity of study drug use, and the analyses were stratified according to specific histologic types of epithelial ovarian cancer. In all studies, non-use (< 2 prescriptions) of the individual study drugs was defined as the reference group. A striking result of the PhD thesis was a strong inverse association between prescription use of paracetamol and risk of epithelial ovarian cancer. The risk estimates decreased with increasing duration and intensity of paracetamol use, reaching a more than 50% reduction for the longest duration (>10 years) and the highest doses (OR: 0.45; 95% CI: 0.24-0.86). In contrast, we did not observe an inverse association between use of non-aspirin NSAIDs and risk of epithelial ovarian cancer. Moreover, this thesis provides further evidence that use of low-dose aspirin is associated with a reduced risk of epithelial ovarian cancer. In particular, long-term (≥5 years) continuous use of low-dose aspirin, defined as overlapping prescription coverage periods, was associated with a large reduction in risk (OR: 0.56; 95% CI: 0.32-0.97). Finally, we found no apparent association between statin use and epithelial ovarian cancer risk, although the analysis by histologic type suggested an inverse association with the risk of mucinous tumors. The results of this PhD thesis add important knowledge to the area of chemoprevention in relation to epithelial ovarian cancer. As for any observational study, we cannot exclude potential con-founding and exposure misclassification; however, methodological limitations appear unlikely to fully explain the observed reductions in epithelial ovarian cancer risk associated with paracetamol and low-dose aspirin use. Additional research, ideally from clinical trials, is needed before our observations may lead to recommendations for chemopreventive measures against ovarian cancer. In case consensus points to a true protective effect of paracetamol or low-dose aspirin, comprehensive risk-benefit evaluations will also have to be performed. We hope that our results will encourage researchers to look more deeply into the potential chemo-preventive effects of the study drugs against epithelial ovarian cancer risk.

Chemopreventive Activity of Ferulago angulate against Breast Tumor in Rats and the Apoptotic Effect of Polycerasoidin in MCF7 Cells: A Bioassay-Guided Approach

Ferulago angulata leaf hexane extract (FALHE) was found to be a potent inducer of MCF7 cell apoptosis. The aims of the present study were to investigate the in vivo chemopreventive effect of FALHE in rats, to identify the contributing anticancer compound in FALHE and to determine its potential mechanism of action against MCF7 cells. Thirty rats harboring LA7-induced breast tumors were divided into five groups: tumor control, low-dose FALHE, high-dose FALHE, treatment control (tamoxifen) and normal control. Breast tissues were then subjected to histopathological and immunohistochemical analyses. A bioassay-guided investigation on FALHE was performed to identify the cytotoxic compound and its mechanism of action through flow cytometry, real-time qPCR and western blotting analyses. An in vivo study showed that FALHE suppressed the expression of the tumor markers PCNA and Ki67. The tumor size was reduced from 2031 ± 281 mm³ to 432 ± 201 mm³ after FALHE treatment. FALHE administration induced apoptosis in breast tumor cells, and this was confirmed by high expression levels of Bax, p53 and caspase 3. Cell cycle arrest was suggested by the expression of p21 and p27. The in vitro experimental results resulted in the isolation of polycerasoidin as a bioactive ingredient of FALHE with an IC₅₀ value of 3.16 ± 0.31 μg/ml against MCF7 cells. Polycerasoidin induced mitochondrial-dependent apoptosis in breast cancer cells via caspase activation and changes in the mRNA and protein expression of Bax and Bcl-2. In addition, flow cytometric analysis demonstrated that the treated MCF7 cells were arrested at the G₁ phase, and this was associated with the up-regulation of p21 and p27 at both the mRNA and protein levels. The results of the present study reinforce further investigations scrutinizing the promising potential of the F. angulata chemical constituents as breast cancer chemopreventive agents.

Flaxseed reduces the pro-carcinogenic micro-environment in the ovaries of normal hens by altering the PG and oestrogen pathways in a dose-dependent manner

The objective of the present study was to find the optimum dose of flaxseed that would decrease PG and alter oestrogen pathway endpoints implicated in ovarian cancer. In the study, four groups of fifty 1.5-year-old chickens were fed different amounts of flaxseed (0, 5, 10 or 15% of their total diet) for 4 months and were then killed to collect blood and tissues. Levels of flaxseed lignan metabolites, Enterolactone (EL) and Enterodiol (ED) were measured in the serum, liver and ovaries by liquid chromatography-MS/MS, and n-3 and n-6 fatty acid (FA) levels were measured by GC. The effects of the varied flaxseed doses were assessed by measuring levels of PGE2 and oestrogen metabolites (16-hydroxyestrone (16-OHE1) and 2-hydroxyestrone (2-OHE1)) as well as by analysing the expression of the oestradiol metabolising enzymes CYP3A4 (cytochrome p450, family 3, subfamily A, polypeptide 4), CYP1B1 (cytochrome p450, family 1, subfamily B, polypeptide 1) and CYP1A1 (cytochrome p450, family 1, subfamily A, polypeptide 1) and that of oestrogen receptor α (ERα) in the ovaries. The ratio of n-3:n-FA increased with an increase in flaxseed supplementation and corresponded to a dose-dependent decrease in cyclo-oxygenase-2 protein and PGE2 levels. EL and ED increased in the serum, liver and ovaries with increased concentrations of flaxseed. Flaxseed decreased the expression of ERα in the ovaries. The ratio of 2-OHE1:16-OHE1 in the serum increased significantly in the 15% flaxseed diet, and there was a corresponding increase in CYP1A1 in the liver and decrease in CYP3A4 in the ovaries. CYP1B1 mRNA also decreased with flaxseed diet in the ovaries. The 15% flaxseed-supplemented diet significantly decreased inflammatory PGE2, ERα, CYP3A4, CYP1B1 and 16-OHE1, but it increased CYP1A1 and 2-OHE1, which thus reduced the inflammatory and pro-carcinogenic micro-environment of the ovaries.

Diffusion Efficiency and Bioavailability of Resveratrol Administered to Rat Brain by Different Routes: Therapeutic Implications

Resveratrol possesses anti-tumor activities against central nervous system (CNS) tumors in vitro but has not yet been used clinically due to its low bioavailability, particularly in the CNS. This study thus aimed to elucidate brain bioavailability of trans-resveratrol by monitoring brain concentrations and dwell times following administration of resveratrol through intragastric, intraperitoneal, external carotid artery/ECA and intrathecal routes. In parallel, we evaluated the biological responses of rat RG2 glioblastoma cells as well as RG2-formed rat intracranial glioblastomas treated with resveratrol via intrathecal administration. The results revealed that resveratrol was detected in rat brains except when administered systemically. Intrathecal administration of reseveratrol led to abundant apoptotic foci and increased staining of the autophagy proteins, LC-3 and Beclin-1 and shrinkage of the intracranial tumors. In conclusion, the BBB penetrability of resveratrol is remarkably increased by intracthecal administration. Regular short-term resveratrol treatments suppress growth and enhance autophagic and apoptotic activities of rat RG2 glioblastoma cells in vitro and in vivo. Therefore, intrathecal administration of resveratrol could be an optimal intervention approach in the adjuvant management of brain malignancies.

Tamoxifen for prevention of breast cancer: extended long-term follow-up of the IBIS-I breast cancer prevention trial

BACKGROUND

Four previously published randomised clinical trials have shown that tamoxifen can reduce the risk of breast cancer in healthy women at increased risk of breast cancer in the first 10 years of follow-up. We report the long-term follow-up of the IBIS-I trial, in which the participants and investigators remain largely masked to treatment allocation.

METHODS

In the IBIS-I randomised controlled trial, premenopausal and postmenopausal women 35-70 years of age deemed to be at an increased risk of developing breast cancer were randomly assigned (1:1) to receive oral tamoxifen 20 mg daily or matching placebo for 5 years. Patients were randomly assigned to the two treatment groups by telephone or fax according to a block randomisation schedule (permuted block sizes of six or ten). Patients and investigators were masked to treatment assignment by use of central randomisation and coded drug supply. The primary endpoint was the occurrence of breast cancer (invasive breast cancer and ductal carcinoma in situ), analysed by intention to treat. Cox proportional hazard models were used to assess breast cancer occurrence and mortality. The trial is closed to recruitment and active treatment is completed, but long-term follow-up is ongoing. This trial is registered with controlledtrials.com, number ISRCTN91879928.

FINDINGS

Between April 14, 1992, and March 30, 2001, 7154 eligible women recruited from genetics clinics and breast care clinics in eight countries were enrolled into the IBIS-I trial and were randomly allocated to the two treatment groups: 3579 to tamoxifen and 3575 to placebo. After a median follow up of 16.0 years (IQR 14.1-17.6), 601 breast cancers have been reported (251 [7.0%] in 3579 patients in the tamoxifen group vs 350 [9.8%] in 3575 women in the placebo group; hazard ratio [HR] 0.71 [95% CI 0.60-0.83], p<0.0001). The risk of developing breast cancer was similar between years 0-10 (226 [6.3%] in 3575 women in the placebo group vs 163 [4.6%] in 3579 women in the tamoxifen group; hazard ratio [HR] 0.72 [95% CI 0.59-0.88], p=0.001) and after 10 years (124 [3.8%] in 3295 women vs 88 [2.6%] in 3343, respectively; HR 0.69 [0.53-0.91], p=0.009). The greatest reduction in risk was seen in invasive oestrogen receptor-positive breast cancer (HR 0.66 [95% CI 0.54-0.81], p<0.0001) and ductal carcinoma in situ (0.65 [0.43-1.00], p=0.05), but no effect was noted for invasive oestrogen receptor-negative breast cancer (HR 1.05 [95% CI 0.71-1.57], p=0.8).

INTERPRETATION

These results show that tamoxifen offers a very long period of protection after treatment cessation, and thus substantially improves the benefit-to-harm ratio of the drug for breast cancer prevention.

FUNDING

Cancer Research UK (UK) and the National Health and Medical Research Council (Australia).

Dietary cocoa protects against colitis-associated cancer by activating the Nrf2/Keap1 pathway

Colorectal cancer (CRC) is the third most common malignancy in males and the second most common cancer worldwide. Chronic colonic inflammation is a known risk factor for CRC. Cocoa contains many polyphenolic compounds that have beneficial effects in humans. The objective of this study is to explore the antioxidant properties of cocoa in the mouse model of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis-associated cancer, focusing on the activation of Nrf2 signaling. Mice were treated with AOM/DSS and randomized to receive either a control diet or a 5 and 10% cocoa diet during the study period. On day 62 of the experiment, the entire colon was processed for biochemical and histopathological examination and further evaluations. Increased levels of malondialdehyde (MDA) were observed in AOM/DSS-induced mice; however, subsequent administration of cocoa decreased the MDA. Enzymatic and nonenzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase, were decreased in the AOM/DSS mice. Cocoa treatment increases the activities/levels of enzymatic and nonenzymatic antioxidants. Inflammatory mediators, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, were elevated during AOM/DSS-induction, and treatment with 5 and 10% cocoa effectively decreases the expression of iNOS and COX-2. The NF-E2-related factor 2 and its downstream targets, such as NQO1 and UDP-GT, were increased by cocoa treatment. The results of our study suggest that cocoa may merit further clinical investigation as a chemopreventive agent that helps prevent CAC.

Chemopreventive effect of apple and berry fruits against colon cancer

Colon cancer arises due to the conversion of precancerous polyps (benign) found in the inner lining of the colon. Prevention is better than cure, and this is very true with respect to colon cancer. Various epidemiologic studies have linked colorectal cancer with food intake. Apple and berry juices are widely consumed among various ethnicities because of their nutritious values. In this review article, chemopreventive effects of these fruit juices against colon cancer are discussed. Studies dealing with bioavailability, in vitro and in vivo effects of apple and berry juices are emphasized in this article. A thorough literature survey indicated that various phenolic phytochemicals present in these fruit juices have the innate potential to inhibit colon cancer cell lines. This review proposes the need for more preclinical evidence for the effects of fruit juices against different colon cancer cells, and also strives to facilitate clinical studies using these juices in humans in large trials. The conclusion of the review is that these apple and berry juices will be possible candidates in the campaign against colon cancer.

Primary prevention of colorectal cancer: Myth or reality?

Colorectal cancer incidence has been rising strongly in parallel with economic development. In the past few decades, much has been learned about the lifestyle, dietary and medication risk factors for this malignancy. With respect to lifestyle, compelling evidence indicates that prevention of weight gain and maintenance of a reasonable level of physical activity can positively influence in lowering the risk. Although there is controversy about the role of specific nutritional factors, consideration of dietary pattern as a whole appears useful for formulating recommendations. Though quite often recommended, the role for many supplements, including omega-3, vitamin D, folate, and vitamin B6, remains unsettled. Only calcium and vitamin D supplementation appear to add a modest benefit, particularly in those with a low daily intake. With regard to chemoprevention, medications such as aspirin and nonsteroidal anti-inflammatory drugs, and postmenopausal hormonal replacement for women might be associated with substantial reductions in colorectal cancer risk, though their utility is affected by their side effect profile. However, the role of agents such as statins, bisphosphonates and antioxidants have yet to be determined. Ultimately, primary prevention strategies focusing on modifying environmental, lifestyle risk factors, and chemopreventive drugs are options that have already been tested, and may impact on colon cancer incidence.

Antiproliferative effect of valproic acid and 5,7-dimethoxycoumarin against A2058 human melanoma cells

Melanoma is one of the most malignant tumors of a dangerous high incidence and high metastatic potential. It grows quickly and in an advanced stage is resistant to radio-, chemo- and immunotherapy, which makes it difficult to cure. Therefore, research efforts are focused on the development of new therapeutics or chemopreventive strategies. The aim of the study was to investigate whether the valproic acid and 5,7-dimethoxycoumarin have an antiproliferative activity against A2058 human melanoma cell line. Investigated compounds inhibited the proliferation of cells, however, no synergistic effect of their co-administration was observed.

EPR studies of free radicals in A-2058 human melanoma cells treated by valproic acid and 5,7-dimethoxycoumarin

Free radicals in A-2058 human melanoma cells were studied by the use of electron paramagnetic resonance (EPR) spectroscopy. The aim of this work was to determine the changes in relative free radical concentrations in tumor A-2058 cells after treatment by valproic acid (VPA) and 5,7-dimethoxycoumarin (DMC). The influences of VPA and DMC on free radicals in A-2058 cells were compared with those for human melanoma malignum A-375 and G-361 cells, which were tested by us earlier. Human malignant melanoma A-2058 cells were exposed to interactions with VPA, DMC, and both VPA and DMC. The tumor cells A-2058 were purchased from LGC Standards (Lomianki, Poland), and they were grown in the standard conditions: at 37°C and in an atmosphere containing 95% air and 5% CO2, in the Minimum Essential Medium Eagle (MEM, Sigma-Aldrich). The A-2058 cells were incubated with VPA (1 mM) and DMC (10 μM) for 4 days. The first-derivative EPR spectra of the control A-2058 cells, and the cells treated with VPA, DMC, and both VPA and DMC, were measured by the electron paramagnetic resonance spectrometer of Radiopan (Poznań, Poland) with microwaves from an X-band (9.3 GHz). The parameters of the EPR lines: amplitudes (A), integral intensities (I), line widths (ΔBpp), and g-factors, were analyzed. The changes of amplitudes and line widths with microwave power increasing from 2.2 to 70 mW were drawn evaluated, o-Semiquinone free radicals of melanin biopolymer are mainly responsible for the EPR lines of A-2058 melanoma malignum cells. The amounts of free radicals in A-2058 cells treated with VPA, and both VPA and DMC, were lower than in the untreated control cells. Application of the tested substances (VPA, and both VPA and DMC) as the antitumor compounds was discussed. DMC without VPA did not decrease free radicals concentration in A-2058 cells. The studies con-firmed that EPR spectroscopy may be used to examine interactions of free radicals with antitumor compounds.

The effects of topical L-selenomethionine on protection against UVB-induced skin cancer when given before, during, and after UVB exposure

Previous studies in mice have shown that topical L-selenomethionine (SeMet) can prevent UVB-induced skin cancer when applied continuously before, during, and after the radiation exposure. With topical application of SeMet, selenium levels were shown to increase in the skin and liver, as well as in tumor tissue. Thus, possibly, the timing of SeMet application could affect the degree of inhibition of UVB-tumorigenesis (or maybe even enhance tumorigenesis at some stage). The goal of this research was to determine whether topical SeMet best inhibits UV-induced skin cancer if (a) begun before and continued during and after UVB exposure, (b) if begun before UVB-exposure and discontinued when tumors are first clinically detected, or (c) if begun only after tumors are first detected and continued thereafter. Groups of ten Skh: 1 hairless, non-pigmented mice were treated topically with vehicle lotion, or with SeMet (0.05%) in that vehicle lotion applied either (a) before, during, and after UV exposure, (b) before UV radiation and continued only until the first tumor was detected, or (c) only after the first tumor was detected. In all cases, UV irradiation was discontinued at the time of detection of the first tumor. Optimal inhibition of skin cancer was achieved by application of topical SeMet before, during, and after exposure; significant protection was also attained with application only after the onset of tumors. Notably, statistically significant protection was not seen with SeMet application only prior to tumor detection. These results suggest that even beginning SeMet supplementation late in the process of tumorigenesis can help protect from UV-induced photodamage and skin cancer.

Protocatechuic acid exerts a cardioprotective effect in type 1 diabetic rats

Oxidative stress has been shown to play an important role in the pathogenesis of diabetes-induced cardiac dysfunction. Protocatechuic acid (PCA) is a phenolic compound, a main metabolite of anthocyanin, which has been reported to display various pharmacological properties. We proposed the hypothesis that PCA exerts cardioprotection in type 1 diabetic (T1DM) rats. T1DM was induced in male Sprague-Dawley rats by a single i.p. injection of 50 mg/kg streptozotocin (STZ) and groups of these animals received the following treatments for 12 weeks: i) oral administration of vehicle, ii) oral administration of PCA at a dose of 50  mg/kg per day, iii) oral administration of PCA at a dose of 100 mg/kg per day, iv) s.c. injection of insulin at a dose of 4 U/kg per day, and v) a combination of PCA, 100 mg/kg per day and insulin, 4 U/kg per day. Metabolic parameters, results from echocardiography, and heart rate variability were monitored every 4 weeks, and the HbA1c, cardiac malondialdehyde (MDA), cardiac mitochondrial function, and cardiac BAX/BCL2 expression were evaluated at the end of treatment. PCA, insulin, and combined drug treatments significantly improved metabolic parameters and cardiac function as shown by increased percentage fractional shortening and percentage left ventricular ejection fraction and decreased low-frequency:high-frequency ratio in T1DM rats. Moreover, all treatments significantly decreased plasma HbA1c and cardiac MDA levels, improved cardiac mitochondrial function, and increased BCL2 expression. Our results demonstrated for the first time, to our knowledge, the efficacy of PCA in improving cardiac function and cardiac autonomic balance, preventing cardiac mitochondrial dysfunction, and increasing anti-apoptotic protein in STZ-induced T1DM rats. Thus, PCA possesses a potential cardioprotective effect and could restore cardiac function when combined with insulin treatment. These findings indicated that supplementation with PCA might be helpful for the prevention and alleviation of cardiovascular complications in T1DM.

Enrichment of maternal diet with conjugated linoleic acids influences desaturases activity and fatty acids profile in livers and hepatic microsomes of the offspring with 7,12-dimethylbenz[a]anthracene-induced mammary tumors

The aim of this study was to assess the influence of diet supplementation of pregnant and breast-feeding female Sprague-Dawley rats with conjugated linoleic acids (CLA) on the Δ6- and Δ5-desaturase activity in hepatic microsomes as well as on fatty acids profile and lipids peroxidation in liver and hepatic microsomes of the progeny with chemically induced mammary tumors. Rats were divided into two groups with different diet supplementation (vegetable oil (which did not contain CLA) or CLA). Their female offspring was divided within these groups into two subgroups: (1)--fed the same diet as mothers (K1 - oil, 01 - CLA), and (2)--fed the standard fodder (K2, O2). At 50th day of life, the progeny obtained carcinogenic agent (7,12-dimethylbenz[a]anthracene). Higher supply of CLA in diet of mothers resulted in lower susceptibility to chemically induced mammary tumors in their offspring (p = 0.0322). It also influenced the fatty acids profile in livers and in hepatic microsomes, especially polyunsaturated n3 and n6 fatty acids. CLA inhibited the activity of the desaturases, which confirmed that CLA can reduce the level of arachidonic acid directly, reducing linoleic acid content in membranes, or indirectly, through the regulation of its metabolism. We were unable to confirm or deny the antioxidative properties of CLA. Our results indicate that the higher supply of CLA in mothers' diet during pregnancy and breastfeeding causes their incorporation into tissues of children, changes the efficiency of fatty acids metabolism and exerts health-promoting effect in their adult life reducing the breast cancer risk.

Role of pomegranate and citrus fruit juices in colon cancer prevention

Colorectal cancer is the second leading cause of cancer-related deaths in the United States. Recent studies prove that though chemotherapeutic agents are being used for the treatment of colon cancer, they become non-effective when the cancer progresses to an invasive stage. Since consumption of certain dietary agents has been linked with various cancers, fruit juices have been investigated for their consistently protective effect against colon cancer. The unique biochemical composition of fruit juices is responsible for their anticancer properties. In this review, the chemo-preventive effect of fruit juices such as pomegranate and citrus juices against colon cancer are discussed. For this purpose, the bioavailability, in vitro and in vivo effects of these fruit juices on colorectal cancer are highlighted. Moreover, there is a scarcity of studies involving human trials to estimate the preventive nature of these juices against colon cancer. This review will support the need for more preclinical tests with these crude juices and their constituents in different colorectal cancer cell lines and also some epidemiological studies in order to have a better understanding and promote pomegranate and citrus juices as crusaders against colon cancer.

Association between folate intake and the risk of lung cancer: a dose-response meta-analysis of prospective studies

Background

Studies have reported inconsistent results regarding the existence of an association between folate intake and the risk of lung cancer. The purpose of this study was to summarize the evidence from prospective cohort studies regarding this relationship by using a dose-response meta-analytic approach.

Methodology and Principal Findings

In September 2013, we performed electronic searches in PubMed, Embase, and the Cochrane Library to identify studies examining the effect of folate intake on the incidence of lung cancer. Only prospective cohort studies that reported the effect estimates about the incidence of lung cancer with 95% confidence intervals (CIs) for more than 2 categories of folate intake were included. Overall, we examined 9 cohort studies reporting the data of 566,921 individuals. High folate intake had little effect on the risk of lung cancer (risk ratio [RR], 0.92; 95% CI, 0.84–1.01; P = 0.076). Dose-response meta-analysis also suggested that a 100 µg/day increase in folate intake had no significant effect on the risk of lung cancer (RR, 0.99; 95% CI, 0.97–1.01; P = 0.318). Subgroup analysis suggested that the potential protective effect of low folate intake (100–299 µg/day) was more evident in women than men, while the opposite was true of high folate intake (>400 µg/day). Finally, subgroup analyses of a 100 µg/day increment in folate intake indicated that its potential protective effect was more evident in men than in women.

Conclusion/Significance

Our study revealed that folate intake had little or no effect on the risk of lung cancer. Subgroup analyses indicated that an increased folate intake was associated with a reduced risk of lung cancer in men. Furthermore, low folate intake may be a protective factor for women, and high folate intake for men.

Fisetin modulates mitochondrial enzymes and apoptotic signals in benzo(a)pyrene-induced lung cancer

The present study was aimed to delineate in vivo mechanisms of orally administered fisetin with special reference to mitochondrial dysfunction in lung tissues employing benzo(a)pyrene (B(a)P) as the model lung carcinogen. The recent revival of interest in the study of mitochondria has been stimulated by the evidence that genetic and/or metabolic alterations in this organelle lead to a variety of human diseases including cancer. These alterations could be either causative or contributing factors. Hence, the activities of mitochondrial-specific enzymes of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase and tumor marker, carcinogenic embryonic antigen were analyzed in control and experimental groups of mice. The induction of apoptotic and anti-apoptotic proteins such as Bcl-2/Bax, cytochrome c, caspase-9 and caspase-3 was confirmed by the immunohistochemistry and Western blot analyses. Furthermore, transmission electron microscopy study of lung sections of B(a)P-induced mice showed the presence of phaemorphic cells with dense granules and increased mitochondria. All the aberrations were alleviated when the mice were treated with fisetin (25 mg/kg body weight). The results proved fisetin to be a very successful drug in combating the mitochondrial dysfunction in an experimental model of lung carcinogenesis induced by B(a)P.

Dose-dependent bioavailability indicators for curcumin and two of its novel derivatives

Novel water-soluble curcumin derivatives have been developed to overcome low in vivo bioavailability of curcumin. The aim of this work is to assess the potential utility of certain downstream targets as bioavailability indicators of systemic activity of pure curcumin and two novel water-soluble curcumin derivatives (NCD) by constructing dose-dependent response curves and to prove whether this novel curcumin derivatives retained, improved, or abolished biological activity of pure curcumin when applied in vivo. Pure curcumin (CUR), curcumin-carboxy derivative (NCD-1), and curcumin protein conjugate (NCD-2) were administered orally to rats at escalating doses: 37, 74, 148, and 296 μM/kg body weight, respectively. Plasma levels of GST activity, cavernous tissue levels of cGMP, and enzymatic activity of both HO-1 and GST were assessed one and half and 24 hours after oral administration of curcumin formulae. This study showed that there was a progressive elevation of cavernous tissue levels of cGMP and enzymatic activity of both HO-1 and GST in a dose-dependent manner that was maintained for 24 h with CUR, NCD-1, and NCD-2. Plasma GST activity was decreased by the lowest doses on the curve. The three dose-dependent bioavailability indicators as surrogates of curcumin and two of its novel derivatives are valid in the studied range of concentration and extended time. The novel curcumin derivatives still conserve with improvement the biological activity of natural curcumin when applied in vivo.

Efficacy of a photolyase-based device in the treatment of cancerization field in patients with actinic keratosis and non-melanoma skin cancer

Eryfotona AK-NMSC (ISDIN Spain) is a film-forming medical device in cream or fluid formulation containing the DNA-repair enzyme photolyase and high-protection UV filters in liposomes (repairsomes) indicated in the treatment of cancerization field in patients with actinic keratosis (AK) or non-melanoma skin cancer (NMSC). Photolyase is an enzyme that recognizes and directly repairs UV-induced DNA damage. The most common UV-induced DNA damage is the formation of cyclobutane pyrimidine dimers (CPD). Clinical studies evaluating the histological and cellular effects of Eryfotona AK-NMSC have shown a potential benefit in the treatment of the cancerization field in AK patients. In particular the use of Eryfotona AK-NMSC improves the confocal microscopic appearance of skin at the cancerization field level. In addition, Eryfotona AK-NMSC improves the p53 gene expression at keratinocyte level. In this study we reported a series of 6 cases of patients with AK or NMSC lesions treated with Eryfotona AK-NMSC fluid, both as coadjuvant and as single treatment, applied twice daily in the affected area with photograph documentation. Clinical photographs of the skin lesions at baseline and after Eryfotona AK-NMSC treatment were taken in all cases using a high-definition digital camera. Six patients with multiple AK lesions of the scalp or face with or without NMSC were treated for a mean of 1-3 months with Eryfotona AK-NMSC fluid formulation. Image documentations before and after treatment of this clinical series show a great improvement in AK lesions count and of cancerization field. This clinical series supports the clinical efficacy of the use of photolyase and high-protection UV filters in the treatment of cancerization field and AK lesions in patients with actinic damage.

Comparison of 3 upper tract anticarcinogenic agent delivery techniques in an ex vivo porcine model

OBJECTIVE

To evaluate the degree of urothelial exposure using 3 upper tract delivery techniques in an ex vivo porcine model, to determine the optimal modality to locally deliver topical anticarcinogenic agents in patients with upper tract urothelial carcinoma.

MATERIALS AND METHODS

An indigo carmine solution was infused into en bloc porcine urinary tracts to test the 3 techniques: antegrade infusion via nephrostomy tube, reflux via indwelling double-pigtail stent, and retrograde administration via a 5F open-ended ureteral catheter. Nine renal units (3 per delivery method) were used. After a 1-hour dwell time, the urinary tracts were bivalved and photographed. Each renal unit was evaluated by 3 blinded reviewers who estimated the total percentage of stained urothelial surface area using a computer-based area approximation system. In addition, as a surrogate for exposure adequacy, a validated equation was used to calculate the staining intensity at 6 predetermined locations in the upper tract, with lower values representing more efficient staining.

RESULTS

Mean percent of surface area stained for the nephrostomy tube, double-pigtail stent, and open-ended ureteral catheter groups was 65.2%, 66.2%, and 83.6%, respectively (P = .002). Mean staining intensities were 40.9, 33.4, and 20.4, respectively (P = .023).

CONCLUSION

Our results suggest that retrograde infusion via open-ended ureteral catheter is the most efficient method of upper tract therapy delivery. Larger studies using in vivo models should be performed to further validate these findings and potentially confirm this method as optimal for delivery of topical anticarcinogenic agents in upper tract urothelial carcinoma.

Anticarcinogenic, cardioprotective, and other health benefits of tomato compounds lycopene, α-tomatine, and tomatidine in pure form and in fresh and processed tomatoes

Tomatoes produce the bioactive compounds lycopene and α-tomatine that are reported to have potential health-promoting effects in animals and humans, but our understanding of the roles of these compounds in the diet is incomplete. Our current knowledge gained from the chemistry and analysis of these compounds in fresh and processed tomatoes and from studies on their bioavailability, bioactivity, and mechanisms of action against cancer cells and other beneficial bioactivities including antibiotic, anti-inflammatory, antioxidative, cardiovascular, and immunostimulating effects in cells, animals, and humans is discussed and interpreted here. Areas for future research are also suggested. The collated information and suggested research might contribute to a better understanding of the agronomical, biochemical, chemical, physiological, molecular, and cellular bases of the health-promoting effects and facilitate and guide further studies needed to optimize the use of lycopene and α-tomatine in pure form and in fresh tomatoes and processed tomato products to help prevent or treat human disease.

Green tea polyphenol, (-)-epigallocatechin-3-gallate, induces toxicity in human skin cancer cells by targeting β-catenin signaling

The green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), has been shown to have anti-carcinogenic effects in several skin tumor models, and efforts are continued to investigate the molecular targets responsible for its cytotoxic effects to cancer cells. Our recent observation that β-catenin is upregulated in skin tumors suggested the possibility that the anti-skin carcinogenic effects of EGCG are mediated, at least in part, through its effects on β-catenin signaling. We have found that treatment of the A431 and SCC13 human skin cancer cell lines with EGCG resulted in reduced cell viability and increased cell death and that these cytotoxic effects were associated with inactivation of β-catenin signaling. Evidence of EGCG-induced inactivation of β-catenin included: (i) reduced accumulation of nuclear β-catenin; (ii) enhanced levels of casein kinase1α, reduced phosphorylation of glycogen synthase kinase-3β, and increased phosphorylation of β-catenin on critical serine(45,33/37) residues; and (iii) reduced levels of matrix metalloproteinase (MMP)-2 and MMP-9, which are down-stream targets of β-catenin. Treatment of cells with prostaglandin E2 (PGE2) enhanced the accumulation of β-catenin and enhanced β-catenin signaling. Treatment with either EGCG or an EP2 antagonist (AH6809) reduced the PGE2-enhanced levels of cAMP, an upstream regulator of β-catenin. Inactivation of β-catenin by EGCG resulted in suppression of cell survival signaling proteins. siRNA knockdown of β-catenin in A431 and SCC13 cells reduced cell viability. Collectively, these data suggest that induction of cytotoxicity in skin cancer cells by EGCG is mediated by targeting of β-catenin signaling and that the β-catenin signaling is upregulated by inflammatory mediators.

Effect of Aegle marmelos leaf extract on N-methyl N-nitrosourea-induced hepatocarcinogensis in Balb/c mice

CONTEXT AND OBJECTIVE

Tobacco smoke and nitrostable foods containing N-methyl N-nitrosourea (MNU) are among the primary causes of liver cancer. To substantiate the beneficial claims ascribed to Aegle marmelos (L.) Corrêa (Rutaceae), the hepatoprotective potential of its leaf extract was studied using an MNU-induced hepatocarcinogenesis model in Balb/c mice.

MATERIALS AND METHODS

After dose selection, 40 mice were randomly assigned to 4 groups: I (control), II (intraperitoneally (i.p.) primed with 50 mg/kg MNU), III (100 mg/kg A. marmelos hydroalcoholic extract (HEAM) i.p.) and IV (MNU + HEAM, i.p.). Inflammatory (IL-1β, IL-6), anti-inflammatory (IL-4) cytokine expression, apoptosis (Bcl-2) and tumor-related (p53, c-jun) genes were assessed at mRNA level. HEAM effects on hematological parameters were examined.

RESULTS AND DISCUSSION

HEAM treatment decreased IL-1β, IL-6, Bcl-2 and c-jun respectively expressions by 90, 25, 53 and 30%, respectively. p53 and IL-4 expression was up-regulated by 1.5- and 2-fold. MNU decreased hemoglobin concentration (25%), lymphocyte count (42%) and increased leukocyte (100%), platelet (4-fold), neutrophil (43%), monocyte (10-fold) and eosinophil (10-fold) counts in Group II mice while HEAM modulated the same parameters by -7%, -21%, +24%, +3-fold, +12%, +3-fold and +4-fold, respectively, in MNU-induced mice compared to control. HEAM protective effect was confirmed by Raman spectroscopy where the MNU-induced peak at 1252 cm(-1) was normalized. DNA fragmentation data suggest apoptosis as one of the protective mechanisms of HEAM.

CONCLUSION

The hepatoprotective, anti-carcinogenic and immunomodulatory effects of A. marmelos extract indicate potential beneficial effects in cancer therapy.

Effect of Celergen, a marine derivative, on in vitro hepatocarcinogenesis

The aim of this study was to test for a potential anticarcinogenic effect of Celergen, a marine derivative devoid of traceable amounts of inorganic arsenic, on cell proliferation, cell cycle progression and apoptosis in the HepG2 human liver cancer cell line. Celergen significantly inhibited the proliferation of cancer cells in a dose-dependent manner while limiting the cell cycle progression at the G1 phase and significantly inducing apoptosis. Further examination showed that Celergen enhanced expression of the p21(CIPl1WAF1), GADD153 genes and downregulated the c-myc gene. These results suggest that Celergen exerts promising chemopreventive properties to be further investigated.

Relationships between pulmonary micro-RNA and proteome profiles, systemic cytogenetic damage and lung tumors in cigarette smoke-exposed mice treated with chemopreventive agents

Assessing the correlation between molecular endpoints and cancer induction or prevention aims at validating the use of intermediate biomarkers. We previously developed murine models that are suitable to detect both the carcinogenicity of mainstream cigarette smoke (MCS) and the induction of molecular alterations. In this study, we used 931 Swiss mice in two parallel experiments and in a preliminary toxicity study. The chemopreventive agents included vorinostat, myo-inositol, bexarotene, pioglitazone and a combination of bexarotene and pioglitazone. Pulmonary micro-RNAs and proteins were evaluated by microarray analyses at 10 weeks of age in male and female mice, either unexposed or exposed to MCS since birth, and either untreated or receiving each one of the five chemopreventive regimens with the diet after weaning. At 4 months of age, the frequency of micronucleated normochromatic erythrocytes was evaluated. At 7 months, the lungs were subjected to standard histopathological analysis. The results showed that exposure to MCS significantly downregulated the expression of 79 of 694 lung micro-RNAs (11.4%) and upregulated 66 of 1164 proteins (5.7%). Administration of chemopreventive agents modulated the baseline micro-RNA and proteome profiles and reversed several MCS-induced alterations, with some intergender differences. The stronger protective effects were produced by the combination of bexarotene and pioglitazone, which also inhibited the MCS-induced clastogenic damage and the yield of malignant tumors. Pioglitazone alone increased the yield of lung adenomas. Thus, micro-RNAs, proteins, cytogenetic damage and lung tumors were closely related. The molecular biomarkers contributed to evaluate both protective and adverse effects of chemopreventive agents and highlighted the mechanisms involved.

Translating colorectal cancer prevention through the guanylyl cyclase C signaling axis

Colorectal cancer (CRC) is a major public health concern, ranking among the leading causes of cancer death in both men and women. Because of this continued burden there is a clear need for improved treatment, and more importantly prevention of this disease. In recent years there is significant evidence to support the hypothesis that guanylyl cyclase C (GCY2C) is a tumor suppressor in the intestine, and that the loss of hormone ligands for this receptor is an important step in the disease process. Thus, ligand replacement therapy has been proposed as a strategy to prevent CRC. Until recently this strategy was not clinically plausible; however, the recent regulatory approval of linaclotide (LINZESS™, Forest Laboratories and Ironwood Pharmaceuticals, Inc.), an oral GUCY2C ligand, has raised the possibility of utilizing this strategy clinically to prevent CRC.

[Pharmacokinetics of genistein in urine of healthy volunteers]

In order to study the excretion of genistein (GEN) capsule, an estrogen drugs, in human, 30 healthy volunteers were selected and orally administered 50, 100, and 300 mg genistein in an parallel study. Genistein were determined in urine by LC-MS/MS and glucuronidated genistein (GENG) were indirectly determined with enzymatic hydrolysis in urine by LC-MS/MS, and the pharmacokinetic parameters were analyzed by DAS software (ver 2.0). The result showed that the concentrations of genistein in human urine were less than 1% of the GENG, and the cumulative excretion of GEN in 48 h were 0.037, 0.134, and 0.142 mg, separately, and the urinary excretion percentage were only 0.07%, 0.13%, and 0.05%, separately. But the cumulative excretion of GENG in 48 h was 5.3, 13.8, and 15.4 mg, separately, and the urinary excretion percentage were 10.6%, 13.8%, and 5.1%, separately, and the max urinary excretive rate was 0.4, 1.0, and 1.4 mg x h(-1), separately (tmax were 6 h). Studies showed that part of drug excreted through kidney in a form of GENG in human, and the cumulative urinary excretion and the maximum excretion rate of GENG showed a proportional increase conditioned with the dose in the range of 50-100 mg, but showed non-linear increase feature in 300 mg.

Wogonin attenuates etoposide-induced oxidative DNA damage and apoptosis via suppression of oxidative DNA stress and modulation of OGG1 expression

Damage to DNA can lead to many different acute and chronic pathophysiological conditions, ranging from cancer to endothelial damage. The current study has been initiated to determine whether the flavonoid wogonin can attenuate etoposide-induced oxidative DNA damage and apoptosis in mouse bone marrow cells. We found that oral administration of wogonin before etoposide injection significantly attenuates etoposide-induced oxidative DNA damage and apoptosis in a dose dependent manner. Etoposide induced a significant down-regulation of mRNA expression of the OGG1 repair gene and marked biochemical alterations characteristic of oxidative DNA stress, including increased 8-OHdG, enhanced lipid peroxidation and reduction in reduced glutathione. Prior administration of wogonin ahead of etoposide challenge restored these altered parameters. Importantly, wogonin had no antagonizing effect on etoposide-induce topoisomerase-II inhibition. Conclusively, our study indicates that wogonin has a protective role in the abatement of etoposide-induced oxidative DNA damage and apoptosis in the bone marrow cells of mice via suppression of oxidative DNA stress and enhancing DNA repair through modulation of OGG1 repair gene expression. Therefore, wogonin can be a promising chemoprotective agent and might be useful to avert secondary leukemia and other drug-related cancers in cured cancer patients and medical personnel exposing to the potent carcinogen etoposide.

Bioavailability of phytochemicals and its enhancement by drug delivery systems

Issues of poor oral bioavailability of cancer chemopreventives have hindered progress in cancer prevention. Novel delivery systems that modulate the pharmacokinetics of existing drugs, such as nanoparticles, cyclodextrins, niosomes, liposomes and implants, could be used to enhance the delivery of chemopreventive agents to target sites. The development of new approaches in prevention and treatment of cancer could encompass new delivery systems for approved and newly investigated compounds. In this review, we discuss some of the delivery approaches that have already made an impact by either delivering a drug to target tissue or increasing its bioavailability by many fold.

Oral chemoprevention of skin cancer in mice by benzophenone sunscreens dioxybenzone and octabenzone in drinking water

BACKGROUND

Sunscreen compounds with added benefit of skin cancer prevention have both public and commercial interests. Our earlier study using the Epstein-Barr virus early antigen in vitro assay reported on skin cancer chemoprevention potential of benzophenone sunscreens. We now report the in vivo antitumor activity of two of the benzophenone sunscreens which tested positively in the in vitro assay, octabenzone (UV-1) and dioxybenzone (UV-2), in the two-stage mouse skin carcinogenesis model using (±)-(E)-4-methyl-2-[-(E)-hydroxyamino]-5-nitro-6-methoxy-3-hexanamide (NOR-1) as inducer and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) as promoter.

MATERIALS AND METHODS

Pathogen-free, female hairless mice of HOS:HR-1 strain, 15 animals per control and test groups, were used. Skin tumors were induced by a single dose of NOR-1 (390 nmol in 100 μl of acetone). One week later, TPA (1.7 nmol in 100 μl of acetone) was applied to skin twice weekly for 20 weeks as tumor a promoter. The test compounds UV-I or UV-2 were administered at 0.0025% to mice through drinking water ad libitum, starting one week prior to and stopping one week after tumor initiation. All animals were examined weekly for the development of skin papillomas.

RESULTS

In both UV-1- and UV-2-treated mice, a two-week delay in tumor appearance, and significant inhibition (p<0.001) of tumor incidence (50% and 60%, respectively) and tumor burden (papilloma inhibition/mouse, 50% and 70%, respectively) were observed when compared to the positive control group. UV-2 (dihydroxy derivative) was a more potent inhibitor of skin tumor than UV-1 (monohydroxy derivative), which followed their antioxidant activity ranking.

CONCLUSION

The results affirm the skin cancer chemoprevention potential of orally-ingested benzophenone sunscreens in mice and warrant studies in humans to validate synergistic protection achievable by complementation of oral and topical sunscreen usage.

Chemopreventive effects of combination of honokiol and magnolol with α-santalol on skin cancer developments

α-Santalol is active component of sandalwood oil and has been shown to have chemopreventive effects against chemically and UVB-induced skin cancer development in mice. α-Santalol is also shown to have skin permeation enhancing effects. Honokiol and magnolol isolated from Magnolia officinalis bark extract have also been shown to have chemopreventive effects against chemically and UVB-induced skin cancer in mice. This study was conducted to investigate the combination effects of α-santalol, honokiol and magnolol to study any additive/synergistic effects to lower the doses required for chemoprevention. Pretreatment of combinations of α-santalol with honokiol and magnolol significantly decreased tumor multiplicity upto 75% than control, α-santalol, honokiol and magnolol alone in SKH-1 mice. Combination of α-santalol with honokiol and magnolol also decreased cell viability, proliferation, and enhanced apotosis in comparison to α-santalol, honokiol and magnolol alone in Human epidrmoid carcinoma A431 cells. Overall, the results of present study indicated combinations of α-santalol with honokiol and magnolol could provide chemoprevention of skin cancer at lower doses than given alone.

Combination of selenium and green tea improves the efficacy of chemoprevention in a rat colorectal cancer model by modulating genetic and epigenetic biomarkers

Dietary supplementation of selenium and green tea holds promise in cancer prevention. In this study, we evaluated the efficacies of selenium and green tea administered individually and in combination against colorectal cancer in an azoxymethane (AOM)-induced rat colonic carcinogenesis model and determined the underlying mechanisms of the protection. Four-week old Sprague-Dawley male rats were fed with diets containing 0.5% green tea extract, 1 ppm selenium as selenium-enriched milk protein, or combination of 1 ppm selenium and 0.5% green tea extract. Animals received 2 AOM (15 mg/kg) treatments to induce colonic oncogenesis. Rats were killed 8 or 30 wk later after the last AOM to examine the effect of dietary intervention on aberrant crypt foci (ACF) formation or tumor development. On sacrifice, colons were examined for ACF and tumors, the mRNA levels of SFRP5 and Cyclin D1, and the proteins levels of ß-catenin, COX-2, Ki-67, DNMT1 and acetyl histone H3. The combination of selenium and green tea resulted in a significant additive inhibition of large ACF formation, this effect was greater than either selenium or green tea alone, P<0.01; the combination also had a significant additive inhibition effect on all tumor endpoints, the effect of the combination diet on tumor incidence, multiplicity and size was greater than selenium or green tea alone, P<0.01. Rats fed the combination diet showed marked reduction of DNMT1 expression and induction of histone H3 acetylation, which were accompanied by restoration of SFRP5 mRNA in normal-appearing colonic crypts. The combination diet also significantly reduced ß-catenin nuclear translocation, Cyclin D1 expression and cell proliferation. These data show, for the first time, that combination of selenium and green tea is more effective in suppressing colorectal oncogenesis than either agent alone. The preventive effect is associated with regulation of genetic and epigenetic biomarkers implicated in colonic carcinogenesis.

Inhibition of bladder tumor growth by chitooligosaccharides in an experimental carcinogenesis model

Urinary bladder cancer is one of the most common cancers worldwide, with the highest incidence in industrialized countries. Patients with cancer commonly use unconventional and complementary therapy including nutraceuticals. In this study we evaluated the efficacy of chitooligosaccharides (in orange juice) in rat bladder cancer chemoprevention and as therapeutic agent, on a rat model of urinary bladder carcinogenesis induced with N-butyl-N-(4-hydroxybutyl) nitrosamine. Results indicate that chitooligosaccharides may have a preventive effect on bladder cancer development and a curative effect upon established bladder tumors, dependent on the concentration ingested 500 mg/kg b.w., every three days, showed capacity to inhibit and prevent the proliferation of bladder cancer; however, this was associated with secondary effects such as hypercholesterolemia and hypertriglyceridemia. The use of lower doses (50 and 250 mg/kg b.w.) showed only therapeutic effects. It is further suggested that this antitumor effect might be due to its expected anti-inflammatory action, as well as by mechanisms not directly dependent of COX-2 inhibition, such as cellular proliferation control and improvement in antioxidant profile.

Dietary polyphenols and colorectal cancer risk: The Fukuoka colorectal cancer study

AIM: To investigate the associations between dietary intake of polyphenols and colorectal cancer.

METHODS: The study subjects were derived from the Fukuoka colorectal cancer study, a community-based case-control study. The study subjects were 816 cases of colorectal cancer and 815 community-based controls. The consumption of 148 food items was assessed by a computer-assisted interview. We used the consumption of 97 food items to estimate dietary intakes of total, tea and coffee polyphenols. The Phenol-Explorer database was used for 92 food items. Of the 5 foods which were not listed in the Phenol-Explorer Database, polyphenol contents of 3 foods (sweet potatoes, satoimo and daikon) were based on a Japanese study and 2 foods (soybeans and fried potatoes) were estimated by ORAC-based polyphenol contents in the United States Department of Agriculture Database. Odds ratios (OR) and 95%CI of colorectal cancer risk according to quintile categories of intake were obtained by using logistic regression models with adjustment for age, sex, residential area, parental history of colorectal cancer, smoking, alcohol consumption, body mass index 10 years before, type of job, leisure-time physical activity and dietary intakes of calcium and n-3 polyunsaturated fatty acids.

RESULTS: There was no measurable difference in total or tea polyphenol intake between cases and controls, but intake of coffee polyphenols was lower in cases than in controls. The multivariate-adjusted OR of colorectal cancer according to quintile categories of coffee polyphenols (from the first to top quintile) were 1.00 (referent), 0.81 (95%CI: 0.60-1.10), 0.65 (95%CI: 0.47-0.89), 0.65 (95%CI: 0.46-0.89) and 0.82 (95%CI: 0.60-1.10), respectively (P_trend = 0.07). Similar, but less pronounced, decreases in the OR were also noted for the third and fourth quintiles of total polyphenol intake. Tea polyphenols and non-coffee polyphenols showed no association with colorectal cancer risk. The site-specific analysis, based on 463 colon cancer cases and 340 rectal cancer cases, showed an inverse association between coffee polyphenols and colon cancer. The multivariate-adjusted OR of colon cancer for the first to top quintiles of coffee polyphenols were 1.00 (referent), 0.92 (95%CI: 0.64-1.31), 0.75 (95%CI: 0.52-1.08), 0.69 (95%CI: 0.47-1.01), and 0.68 (95%CI: 0.46-1.00), respectively (P_trend = 0.02). Distal colon cancer showed a more evident inverse association with coffee polyphenols than proximal colon cancer. The association between coffee polyphenols and rectal cancer risk was U-shaped, with significant decreases in the OR at the second to fourth quintile categories. There was also a tendency that the OR of colon and rectal cancer decreased in the intermediate categories of total polyphenols. The decrease in the OR in the intermediate categories of total polyphenols was most pronounced for distal colon cancer. Intake of tea polyphenols was not associated with either colon or rectal cancer. The associations of coffee consumption with colorectal, colon and rectal cancers were almost the same as observed for coffee polyphenols. The trend of the association between coffee consumption and colorectal cancer was statistically significant.

CONCLUSION: The present findings suggest a decreased risk of colorectal cancer associated with coffee consumption.

Evaluation of 3,3'-diindolylmethane with gardasil quadrivalent HPV vaccine in K14-HPV16-transgenic mice cervical histology

BACKGROUND

The effects of 3,3'-diindolylmethane (DIM) together with the Gardasil vaccine on cervical histology were evaluated using the K14-HPV16-transgenic mouse model. The possibility that DIM could enhance the efficacy of this preventive vaccine in this model was explored.

MATERIALS AND METHODS

Transgenic mice were given 1000 mg/kg of DIM in the diet for 28 weeks. The mice were injected with Gardasil Quadrivalent HPV vaccine. Some mice were sacrificed at 28 weeks. Other groups were removed from the DIM diet after 28 weeks to a diet with no DIM for either 4 or 8 weeks.

RESULTS

Cervical histology indicated that a high percentage of transgenic mice fed DIM and vaccinated with Gardasil manifested normal cervical epitheliums at 4 weeks after DIM discontinuation.

CONCLUSION

Vaccination pre-supplemented with DIM may provide with a window of protection of at least four weeks in this transgenic model. However, extrapolation to the effect in humans is beyond the limited scope of the histological data presented here.

Apoptotic role of natural isothiocyanate from broccoli (Brassica oleracea italica) in experimental chemical lung carcinogenesis

CONTEXT

Sulforaphane (SFN) [1-isothiocyanato-4-(methylsulfinyl)butane] is a naturally occurring isothiocyanate found in cruciferous vegetables such as broccoli [Brassica oleracea L. var. italica Plenck. (Brassicaceae)]. Since it is among the most potent bioactive components with antioxidant and antitumor properties, it has received intense attention in the recent years for its chemopreventive properties.

OBJECTIVE

The present work determined the rehabilitating role in alleviating the oxidative damage caused by benzo(a)pyrene [B(a)P] to biomolecules and the apoptotic cascade mediated by orally administered isothiocyanate-SFN (9 µmol/mouse/day) against B(a)P (100 mg/kg body weight, i.p.) induced pulmonary carcinogenesis in Swiss albino mice.

MATERIALS AND METHODS

Oxidative damage was assessed by measuring lipid peroxidation, 8-hydroxydeoxyguanosine, hydrogen peroxide (H2O2) production, glycoprotein components, protein carbonyl levels and DNA-protein crosslinks. DNA fragmentation by agarose gel electrophoresis and caspase-3 activity by ELISA proved apoptotic induction by SFN along with the protein expression of Bcl-2, Bax and Cyt c.

RESULTS

SFN treatment was found to decrease the H2O2 production (p < 0.001) in cancer induced animals, proving its antioxidant potential. Apoptosis was induced by increasing the release of Cyt c (p < 0.001) from mitochondria, decreasing and increasing the expression of Bcl-2 (p < 0.01) and Bax (p < 0.001), respectively. Caspase-3 activity was also enhanced (p < 0.001) which leads to DNA fragmentation in SFN treated groups.

CONCLUSION

Our results reflect the rehabilitating role of SFN in B(a)P induced lung carcinogenesis.