Fruit and vegetable intake and prevalence of colorectal adenoma in a cancer screening trial

Fruit but not vegetable consumption is beneficial for low prevalence of colorectal polyps in a high-risk population: findings from a Chinese Lanxi Pre-colorectal Cancer Cohort study

PURPOSE

The available evidence regarding the role of fruit and vegetable consumption in the development of colorectal polyps remains inconclusive, and there is a lack of data on different histopathologic features of polyps. We aimed to evaluate the associations of fruit and vegetable consumption with the prevalence of colorectal polyps and its subtypes in a high-risk population in China.

METHODS

We included 6783 Chinese participants aged 40-80 years who were at high risk of colorectal cancer (CRC) in the Lanxi Pre-colorectal Cancer Cohort (LP3C). Dietary information was obtained through a validated food-frequency questionnaire (FFQ), and colonoscopy screening was used to detect colorectal polyps. Dose-response associations of fruit and vegetable intake with the prevalence of polyps were calculated using multivariate-adjusted regression models, which was reported as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

2064 cases of colorectal polyps were ascertained in the LP3C during 2018-2019. Upon multivariable adjustments, including the diet quality, fruit consumption was inversely associated with the prevalence of polyps (P trend = 0.02). Participants in the highest tertile of fruit intake had a 25% lower risk (OR: 0.75; 95% CI 0.62‒0.92) compared to non-consumers, while vegetable consumption had no significant association with polyp prevalence (P trend = 0.86). In terms of colorectal histopathology and multiplicity, higher fruit intake was correlated with 24, 23, and 33% lower prevalence of small polyps (OR: 0.76; 95% CI 0.62‒0.94; P trend = 0.05), single polyp (OR: 0.77; 95% CI 0.62‒0.96; P trend = 0.04), and distal colon polyps (OR: 0.67; 95% CI 0.51‒0.87; P trend = 0.003), respectively.

CONCLUSIONS

Fresh fruit is suggested as a protective factor to prevent colorectal polyps in individuals at high risk of CRC, and should be underscored in dietary recommendations, particularly for high-risk populations.

Progress in discovery and development of natural inhibitors of histone deacetylases (HDACs) as anti-cancer agents

The study of epigenetic translational modifications had drawn great interest for the last few decades. These processes play a vital role in many diseases and cancer is one of them. Histone acetyltransferase (HAT) and histone deacetylases (HDACs) are key enzymes involved in the acetylation and deacetylation of histones and ultimately in post-translational modifications. Cancer frequently exhibits epigenetic changes, particularly disruption in the expression and activity of HDACs. It includes the capacity to regulate proliferative signalling, circumvent growth inhibitors, escape cell death, enable replicative immortality, promote angiogenesis, stimulate invasion and metastasis, prevent immunological destruction, and genomic instability. The majority of tumours develop and spread as a result of HDAC dysregulation. As a result, HDAC inhibitors (HDACis) were developed, and they today stand as a very promising therapeutic approach. One of the most well-known and efficient therapies for practically all cancer types is chemotherapy. However, the efficiency and safety of treatment are constrained by higher toxicity. The same has been observed with the synthetic HDACi. Natural products, owing to many advantages over synthetic compounds for cancer treatment have always been a choice for therapy. Hence, naturally available molecules are of particular interest for HDAC inhibition and HDAC has drawn the attention of the research fraternity due to their potential to offer a diverse array of chemical structures and bioactive compounds. This diversity opens up new avenues for exploring less toxic HDAC inhibitors to reduce side effects associated with conventional synthetic inhibitors. The review presents comprehensive details on natural product HDACi, their mechanism of action and their biological effects. Moreover, this review provides a brief discussion on the structure activity relationship of selected natural HDAC inhibitors and their analogues which can guide future research to discover selective, more potent HDACi with minimal toxicity.

Food Intake and Colorectal Cancer

Colorectal cancer (CRC) accounts for considerable mortalities worldwide. Several modifiable risk factors, including a high intake of certain foods and beverages can cause CRC. This review summarized the latest findings on the intake of various foods, nutrients, ingredients, and beverages on CRC development, with the objective of classifying them as a risk or protective factor. High-risk food items include red meat, processed meat, eggs, high alcohol consumption, sugar-sweetened beverages, and chocolate candy. Food items that are protective include milk, cheese and other dairy products, fruits, vegetables (particularly cruciferous), whole grains, legumes (particularly soy beans), fish, tea (particularly green tea), coffee (particularly among Asians), chocolate, and moderate alcohol consumption (particularly wine). High-risk nutrients/ingredients include dietary fat from animal sources and industrial trans-fatty acids (semisolid/solid hydrogenated oils), synthetic food coloring, monosodium glutamate, titanium dioxide, and high-fructose corn sirup. Nutrients/ingredients that are protective include dietary fiber (particularly from cereals), fatty acids (medium-chain and odd-chain saturated fatty acids and highly unsaturated fatty acids, including omega-3 polyunsaturated fatty acids), calcium, polyphenols, curcumin, selenium, zinc, magnesium, and vitamins A, C, D, E, and B (particularly B6, B9, and B2). A combination of micronutrients and multi-vitamins also appears to be beneficial in reducing recurrent adenoma incidence.

Contribution of macro- and micronutrients intake to gastrointestinal cancer mortality in the ONCONUT cohort: Classical vs. modern approaches

The aim of this study was to evaluate the contribution of macro- and micronutrients intake to mortality in patients with gastrointestinal cancer, comparing the classical statistical approaches with a new generation algorithm. In 1992, the ONCONUT project was started with the aim of evaluating the relationship between diet and cancer development in a Southern Italian elderly population. Patients who died of specific death causes (ICD-10 from 150.0 to 159.9) were included in the study (n = 3,505) and survival analysis was applied. This cohort was used to test the performance of different techniques, namely Cox proportional-hazards model, random survival forest (RSF), Survival Support Vector Machine (SSVM), and C-index, applied to quantify the performance. Lastly, the new prediction mode, denominated Shapley Additive Explanation (SHAP), was adopted. RSF had the best performance (0.7653711 and 0.7725246, for macro- and micronutrients, respectively), while SSVM had the worst C-index (0.5667753 and 0.545222). SHAP was helpful to understand the role of single patient features on mortality. Using SHAP together with RSF and classical CPH was most helpful, and shows promise for future clinical applications.

The efficacy of applying some plants and herbs in cancer therapy for humans and animals – a comperhensive review

Cancer is a challenging ailment and represents the main reason for death worldwide for humans and animals. Although great developments have hindered cancer progression, several adverse effects are associated with modern chemotherapy. Natural remedies, such as the usage of medicinal plant or their products in cancer treatment, may decrease prejudicial side properties. Recently, the modern research scheme and innovative screening practices for herbs or plants have enabled phytochemical discovery for the prevention and treatment of cancer. This criticism highlights herbs such as acacia, basil, black seeds, cedar, castus, ficus, garlic, ginger, indigo, onion, pomegranate, quince, and thyme, promising anticancer effects. The present review also revealed the mode of action of each herb as anticancer effects at level in vitro and in vivo studies. The item also totalizes the vital mechanisms and signaling molecules involved in preventing cancer diseases. This will fill the investigate gap in the exploration of using natural molecules and encourage researchers in clinical trials of anticancer agents from herbs for humans and animals.

Combined Effect of Healthy Lifestyle Factors and Risks of Colorectal Adenoma, Colorectal Cancer, and Colorectal Cancer Mortality: Systematic Review and Meta-Analysis

Background

In addition to adiposity, lifestyle factors such as poor diet, low physical activity, alcohol intake and smoking are noted to be associated with the development of colorectal cancer (CRC). This study aims to investigate the association and dose-response relationship between adherence to a healthy lifestyle and CRC risk.

Methods

A systematic literature search was conducted in MEDLINE and EMBASE for studies examining multiple lifestyle factors with risk of CRC, incident colorectal adenoma (CRA), and CRC-specific mortality through June 2021 without restrictions on language or study design. Meta-analysis was performed to pool hazard ratios using random-effects model. Subgroup analyses were performed based upon study and sample characteristics. Random-effects dose-response analysis was also conducted for CRC risk to assess the effect of each additional healthy lifestyle factor.

Results

A total of 28 studies (18 cohort studies, eight case-control studies, and two cross-sectional study) were included. When comparing subjects with the healthiest lifestyle to those with the least healthy lifestyle, the pooled HR was statistically significant for CRC (0.52, 95% CI 0.44-0.63), colon cancer (0.54, 95% CI 0.44-0.67), rectal cancer (0.51, 95% CI 0.37-0.70), CRA (0.39, 95% CI 0.29-0.53), and CRC-specific mortality (0.65, 95% CI 0.52-0.81). The pooled HR for CRC was 0.91 (95% CI: 0.88-0.94) for each increase in the number of healthy lifestyles. The inverse association between healthy lifestyle and CRC risk was consistently observed in all subgroups (HR ranging from 0.26 to 0.86).

Conclusions

Adoption of a higher number of healthy lifestyles is associated with lower risk of CRC, CRA, and CRC-specific mortality. Promoting healthy lifestyle could reduce the burden of CRC.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=231398, identifier CRD42021231398.

Luteolin Synergistically Enhances Antitumor Activity of Oxaliplatin in Colorectal Carcinoma via AMPK Inhibition

Luteolin is a naturally-occurring polyphenolic compound that is known to have antioxidative and antitumor activities in vitro. This study aimed to examine the in vivo anticancer efficacy of luteolin in conjunction with oxaliplatin treatment using a colorectal carcinoma xenograft mouse model. HCT116 human colorectal carcinoma cells were subcutaneously implanted into BALB/c nude mice, followed by the intraperitoneal administration of luteolin at a dose of 50 mg/kg body weight (BW)/day with or without oxaliplatin at a dose of 10 mg/kg BW/day three times per week for a total of 3 weeks. The combined luteolin and oxaliplatin treatment resulted in the synergistic suppression of the growth of HCT116 xenograft tumors when compared to treatment with luteolin or oxaliplatin alone. In addition, the combined treatment significantly increased the expression of cleaved PARP and p53 in the xenograft tumors compared with the vehicle control, but only marginally affected the level of heme oxygenase-1 (HO-1). These results indicated that luteolin treatment retarded oxaliplatin-induced tumor growth by facilitating apoptotic cell death and inhibiting HO-1-mediated cytoprotection. Therefore, these findings suggest the synergistic potential of dietary luteolin in conjunction with conventional chemotherapy for the treatment of colorectal cancer.

Dietary organosulfur compounds: Emerging players in the regulation of bone homeostasis by plant-derived molecules

The progressive decline of bone mass and the deterioration of bone microarchitecture are hallmarks of the bone aging. The resulting increase in bone fragility is the leading cause of bone fractures, a major cause of disability. As the frontline pharmacological treatments for osteoporosis suffer from low patients' adherence and occasional side effects, the importance of diet regimens for the prevention of excessive bone fragility has been increasingly recognized. Indeed, certain diet components have been already associated to a reduced fracture risk. Organosulfur compounds are a broad class of molecules containing sulfur. Among them, several molecules of potential therapeutic interest are found in edible plants belonging to the Allium and Brassica botanical genera. Polysulfides derived from Alliaceae and isothiocyanates derived from Brassicaceae hold remarkable nutraceutical potential as anti-inflammatory, antioxidants, vasorelaxant and hypolipemic. Some of these effects are linked to the ability to release the gasotrasmitter hydrogen sulfide (H₂S). Recent preclinical studies have investigated the effect of organosulfur compounds in bone wasting and metabolic bone diseases, revealing a strong potential to preserve skeletal health by exerting cytoprotection and stimulating the bone forming activity by osteoblasts and attenuating bone resorption by osteoclasts. This review is intended for revising evidence from preclinical and epidemiological studies on the skeletal effects of organosulfur molecules of dietary origin, with emphasis on the direct regulation of bone cells by plant-derived polysulfides, glucosinolates and isothiocyanates. Moreover, we highlight the potential molecular mechanisms underlying the biological role of these compounds and revise the importance of the so-called 'H₂S-system' on the regulation of bone homeostasis.

Inflammation in the CNS - understanding various aspects of the pathogenesis of Alzheimer's disease

Alzheimer's disease is a progressive and deadly neurodegenerative disorder, and one of the most common causes of dementia in the world. Current, insufficiently sensitive and specific methods of early diagnosis and monitoring of this disease prompt a search for new tools. Numerous literature data indicate that the pathogenesis of Alzheimer's disease (AD) is not limited to the neuronal compartment, but involves various immunological mechanisms. Neuroinflammation has been recognized as a very important process in AD pathology. It seems to play pleiotropic roles, both neuroprotective as well as neurodegenerative, in the development of cognitive impairment depending on the stage of the disease. Mounting evidence demonstrates that inflammatory proteins could be considered biomarkers of disease progression. Therefore, the present review summarizes the role of some inflammatory molecules and their potential utility in the detection and monitoring of dementia severity. The paper also provides a valuable insight into new mechanisms leading to the development of dementia, which might be useful in discovering possible anti-inflammatory treatment.

Garlic constituents for cancer prevention and therapy: From phytochemistry to novel formulations

Garlic (Allium sativum L.) is one of the oldest plants cultivated for its dietary and medicinal values. This incredible plant is endowed with various pharmacological attributes, such as antimicrobial, antiarthritic, antithrombotic, antitumor, hypoglycemic, and hypolipidemic activities. Among the various beneficial pharmacological effects of garlic, the anticancer activity is presumably the most studied. The consumption of garlic provides strong protection against cancer risk. Taking into account the multi-targeted actions and absence of considerable toxicity, a few active metabolites of garlic are probably to play crucial roles in the killing of cancerous cells. Garlic contains several bioactive molecules with anticancer actions and these include diallyl trisulfide, allicin, diallyl disulfide, diallyl sulfide, and allyl mercaptan. The effects of various garlic-derived products, their phytoconstituents and nanoformulations have been evaluated against skin, prostate, ovarian, breast, gastric, colorectal, oral, liver, and pancreatic cancers. Garlic extract, its phytocompounds and their nanoformulations have been shown to inhibit the different stages of cancer, including initiation, promotion, and progression. Besides, these bioactive metabolites alter the peroxidation of lipid, activity of nitric oxide synthetase, nuclear factor-κB, epidermal growth factor receptor, and protein kinase C, cell cycle, and survival signaling. The current comprehensive review portrays the functions of garlic, its bioactive constituents and nanoformulations against several types of cancers and explores the possibility of developing these agents as anticancer pharmaceuticals.

Model with the GBDT for Colorectal Adenoma Risk Diagnosis

Background and Objective:

Colorectal cancer (CRC) is a common malignant tumor of the digestive system; it is associated with high morbidity and mortality. However, an early prediction of colorectal adenoma (CRA) that is a precancerous disease of most CRC patients provides an opportunity to make an appropriate strategy for prevention, early diagnosis and treatment. It has been aimed to develop a machine learning model to predict CRA that could assist physicians in classifying high-risk patients, make informed choices and prevent CRC.

Methods:

Patients who had undergone a colonoscopy to fill out a questionnaire at the Sixth People Hospital of Shanghai in China from July 2018 to November 2018 were instructed. A classification model with the gradient boosting decision tree (GBDT) was developed to predict CRA. This model was compared with three other models, namely, random forest (RF), support vector machine (SVM), and logistic regression (LR). The area under the receiver operating characteristic curve (AUC) was used to evaluate performance of the models.

Results:

Among the 245 included patients, 65 patients had CRA. The area under the receiver operating characteristic (AUCs) of GBDT, RF, SVM ,and LR with 10 fold-cross validation was 0.8131, 0.74, 0.769 and 0.763. An online prediction service, CRA Inference System, to substantialize the proposed solution for patients with CRA was also built.

Conclusion:

Four classification models for CRA prediction were developed and compared, and the GBDT model showed the highest performance. Implementing a GBDT model for screening can reduce the cost of time and money and help physicians identify high-risk groups for primary prevention.

Pharmacological Properties of Allium cepa, Preclinical and Clinical Evidences; A Review

Onion or Allium cepa (A. cepa) is one of the most important condiment plants grown and consumed all over the world. This plant has various therapeutic effects attributed to its constituents, such as quercetin, thiosulphinates and phenolic acids. In the present article, various pharmacological and therapeutic effects of A. cepa were reviewed. Different online databases using keywords such as onion, A. cepa, therapeutic effects, and pharmacological effects until the end of December 2019 were searched for this purpose. Onion has been suggested to be effective in treating a broad range of disorders, including asthma, inflammatory disorders, dysentery, wounds, scars, keloids and pain. In addition, different studies have demonstrated that onion possesses numerous pharmacological properties, including anti-cancer, anti-diabetic and anti-platelet properties as well as the effect on bone, cardiovascular, gastrointestinal, nervous, respiratory, and urogenital systems effects such as anti-osteoporosis, anti-hypertensive, antispasmodic, anti-diarrheal, neuro-protective, anti-asthmatic and diuretic effects. The present review provides detailed the various pharmacological properties of onion and its constituents and possible underlying mechanisms. The results of multiple studies suggested the therapeutic effect of onion on a wide range of disorders.

Dietary habits and risk of hepatocellular carcinoma among hepatitis B surface antigen carriers: A prospective cohort study in China

OBJECTIVE

In this prospective cohort study, we aimed to evaluate the association between dietary habits and the risk of developing hepatocellular carcinoma (HCC) in hepatitis B surface antigen (HBsAg)-positive carriers in Qidong, an hepatitis B virus (HBV)-epidemic area in China.

METHODS

A total of 3199 HBsAg carriers aged 30-70 years in a prospective cohort in Qidong, China from 2007 to 2011 were included in the study. At baseline, all participants self-reported their dietary habits in a questionnaire interview. A follow-up check-up was performed every 6 months to identify HCC cases until November 2017. Cox's regression analysis and an interaction analysis were performed to estimate the relative risks of HCC in terms of baseline diet.

RESULTS

Among 3199 HBsAg-positive participants, 270 developed HCC (143.86/100 000 person-years [PYs]). Compared with participants who rarely consume garlic, the risk of HCC in those who consumed it ≥ once per week decreased along with the increase in frequency (HR = 1.00, 0.90 and 0.62 in those who consumed it rarely vs those who consumed it 1-6 times per week and ≥ 7 times per week, respectively). This study found a synergistic effect between garlic and tea consumption on the risk of HCC (P = 0.039 for a multiplicative interaction).

CONCLUSIONS

HBsAg carriers should improve their diet. Regular consumption of garlic and tea drinking may reduce the HCC incidence in HBsAg carriers.

Dietary nutrient patterns and the risk of colorectal cancer and colorectal adenomas: a case-control study

Although the association between food patterns and the risk of colorectal cancer (CRC) and colorectal adenomas (CRA) has been explored previously, a distinct paucity of studies has evaluated the association of nutrient pattern and the risk of CRC and CRA as precursors of CRC. Thus, the purpose of this case-control study was to investigate nutrient patterns and their relationship with CRC and CRA in Iran. Two hundred forty hospital control, 129 newly diagnosed CRC and 130 newly diagnosed CRA patients were asked about their dietary intakes using validated questionnaires. To define the major nutrient patterns, principal component analysis was applied based on preselected nutrients, and four explainable nutrient patterns were obtained: Factor 1 (mixed), factor 2 (the antioxidant), factor 3 (dairy) and factor 4 (the high fat). Logistic regression was used to determine odds ratios (OR) with 95% confidence interval (CI) of CRC and CRA according to categories of nutrient patterns. After adjusting for confounders, factor 2 was significantly associated with lower risk for the CRC and CRA in the second category compared with the first, respectively (OR = 0.20, 95% CI: 0.12-0.34, OR = 0.34, 95% CI: 0.21-0.56). Participants in the highest category of factor 4 showed an increase in the risk of CRC and CRA, respectively, than those in the low category, in both crude and multivariate analysis (OR = 1.77, 95% CI: 1.57-2.95, OR = 1.85, 95% CI: 1.13-3.02). Among derived nutrient patterns, 'the antioxidant pattern' was inversely associated with CRC/CRA, whilst 'high fat pattern' showed a direct association with these diseases.

Sesamin inhibits cervical cancer cell proliferation by promoting p53/PTEN-mediated apoptosis

Background: Sesamin is a major bioactive compound in sesame seeds and has various biological properties, including anti-inflammatory and anticancer activities. Here, we explored whether sesamin activates p53, which is widely inhibited in cervical cancer cells, thereby inducing p53-mediated apoptosis. Methods: Human HeLa and SiHa cervical cancer cells and normal Hs68 dermal cells were used as cell models. Cell proliferation, cell cycle distribution, and apoptosis were evaluated by the CCK-8 assay and flow cytometry using PI/Annexin V staining, respectively. Protein expression and phosphorylation were determined using western blotting. The involvement of p53 in the apoptotic cascade was assessed by a specific inhibitor. Results: Sesamin (75 and 150 μM) clearly inhibited SiHa and HeLa cell proliferation in a dose-dependent fashion, but did not affect the proliferation of Hs68 cells. Meanwhile, sesamin increased the sub-G1 phase ratio and apoptosis, up to approximately 38.5% and 37.8%, respectively. Furthermore, sesamin induced p53 phosphorylation at serine-46 and serine-15 and upregulated the levels of PUMA, Bax, and PTEN, while inhibiting AKT phosphorylation at serine-473. Inhibition of p53 by pifithrin-α significantly reduced the levels of PUMA, Bax, and PTEN but restored AKT phosphorylation in SiHa cells exposed to sesamin. Pifithrin-α also reduced apoptosis and restored the proliferation of HeLa and SiHa cells exposed to sesamin. Conclusions: These findings indicate that sesamin inhibits cervical cancer cell proliferation, and its mechanism may be attributed to the induction of p53/PTEN-mediated apoptosis. This suggests that sesamin might be useful as an adjuvant in promoting anti-cervical cancer treatments.

Progress in primary prevention of colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumors in the digestive tract, with high incidence and mortality. Most of CRC cases are diagnosed at the late stage, and the treatment effect is therefore poor. Thus, the prevention of CRC is particularly important. There have been many studies on the prevention of CRC in recent years. This paper will summarize the latest research on the primary prevention of CRC.

Wnt/β-catenin modulates chronic tobacco smoke exposure-induced acquisition of pulmonary cancer stem cell properties and diallyl trisulfide intervention

Lung cancer is the leading cause of cancer-related death worldwide; tobacco smoke (TS) constitutes the main causes of lung cancer. Acquisition of cancer stem cells (CSCs)-like properties is the essential progression for the initiation of lung cancer. However, the mechanisms for tobacco smoke-induced lung carcinogenesis remain elusive. In the present study, we demonstrated that long-term exposure of human bronchial epithelial (HBE) cells to TS resulted in malignant transformation and acquisition of CSC-like properties. Moreover, Wnt/β-catenin pathway was involved in acquisition of the CSC-like phenotype during neoplastic transformation of HBE cells induced by TS. Downregulation of β-catenin reduced the tumorsphere and decreased the protein expression of lung CSCs markers in TS-transformated HBE sphere-forming cells. Furthermore, Diallyl trisulfide (DATS) inhibited the CSCs activity of TS-transformed HBE cells, as well as Wnt/β-catenin suppression. Activation of Wnt/β-catenin diminished the inhibitory effects of DATS on TS-induced stemness of HBE cells. Together, the present investigation elucidates the modulation of Wnt/β-catenin in chronic TS exposure-triggered pulmonary acquisition of CSCs properties and DATS intervention, which may provide new insights into the interventional strategies against lung CSCs.

Evaluation of the Impact of Cancer Treatment on the Adoption and Consolidation of Pro-Health Attitudes in the Field of Cancer in Treated Patients with Colon Cancer

Colorectal cancer is the second most common cause of cancer deaths worldwide. Although progress in the development of new drugs over the last two decades has expanded treatment options for this disease, many significant problems relating to their optimization remain to be solved. Data on the cancer knowledge and the healthy behavior and lifestyle in patients with colorectal cancer in Poland is missing. We analyzed the course and results of treatment of first-line chemotherapy in 165 patients diagnosed with colorectal cancer treated between May 2010 and December 2013. The respondent's knowledge in the field of cancer and their lifestyle before and after the treatment were rated. The results were compared with a control group. Mean age was 60.89 ± 8.69 years, median 59 years. The general knowledge about cancer and the level of healthy lifestyle before treatment were low. After treatment, both the knowledge about cancer and the level of healthy lifestyle increased compared to the control group. There was a clear relationship between the level of knowledge about cancer and the willingness to adopt attitudes and healthy behavior by patients. In our analysis, the overall quality of life in patients treated with first-line palliative chemotherapy of colorectal cancer did not change during treatment. Our results indicate the need to implement an educational program on cancer prevention in treated patients, and the analysis of quality of life and other factors than treatment effect remains controversial.

Oxidative stress and dietary phytochemicals: Role in cancer chemoprevention and treatment

Several epidemiological observations have shown an inverse relation between consumption of plant-based foods, rich in phytochemicals, and incidence of cancer. Phytochemicals, secondary plant metabolites, via their antioxidant property play a key role in cancer chemoprevention by suppressing oxidative stress-induced DNA damage. In addition, they modulate several oxidative stress-mediated signaling pathways through their anti-oxidant effects, and ultimately protect cells from undergoing molecular changes that trigger carcinogenesis. In several instances, however, the pro-oxidant property of these phytochemicals has been observed with respect to cancer treatment. Further, in vitro and in vivo studies show that several phytochemicals potentiate the efficacy of chemotherapeutic agents by exacerbating oxidative stress in cancer cells. Therefore, we reviewed multiple studies investigating the role of dietary phytochemicals such as, curcumin (turmeric), epigallocatechin gallate (EGCG; green tea), resveratrol (grapes), phenethyl isothiocyanate (PEITC), sulforaphane (cruciferous vegetables), hesperidin, quercetin and 2'-hydroxyflavanone (2HF; citrus fruits) in regulating oxidative stress and associated signaling pathways in the context of cancer chemoprevention and treatment.

Dietary Bioactive Diallyl Trisulfide in Cancer Prevention and Treatment

Bioactive dietary agents have been shown to regulate multiple cancer hallmark pathways. Epidemiologic studies have linked consumption of Allium vegetables, such as garlic and onions, to decreased incidence of cancer. Diallyl trisulfide (DATS), a bioactive compound derived from Allium vegetables, has been investigated as an anti-cancer and chemopreventive agent. Preclinical studies provide ample evidence that DATS regulates multiple cancer hallmark pathways including cell cycle, apoptosis, angiogenesis, invasion, and metastasis. DATS has been shown to arrest cancer cells at multiple stages of the cell cycle with the G2/M arrest being the most widely reported. Additionally, increased pro-apoptotic capacity as a result of regulating intrinsic and extrinsic apoptotic pathway components has been widely reported following DATS treatment. Invasion, migration, and angiogenesis represent emerging targets of DATS and support its anti-cancer properties. This review summarizes DATS mechanisms of action as an anti-cancer and chemopreventive agent. These studies provide rationale for future investigation into its use as a cancer chemopreventive agent.

Chemopreventive effects of a Tamarindus indica fruit extract against colon carcinogenesis depends on the dietary cholesterol levels in hamsters

Tamarind has significant antioxidant potential. We showed that tamarind protects hypercholesterolemic hamsters from atherosclerosis. Hypercholesterolemia might increase the risk of colon cancer. We investigated whether tamarind extract modulates the risk of colon cancer in hypercholesterolemic hamsters. Hamsters (n = 64) were given tamarind and a hypercholesterolemic diet for 8 weeks. The groups were the control, tamarind treatment, hypercholesterolemic, and hypercholesterolemic treated with tamarind groups. Half of each group was exposed to the carcinogen dimethylhydrazine (DMH) at the 8th week. All hamsters were euthanatized at the 10th week. In carcinogen-exposed hypercholesterolemic hamsters, tamarind did not alter the cholesterol or triglyceride serum levels, but it reduced biomarkers of liver damage (alanine transaminase [ALT], and aspartate aminotransferase [AST]). Tamarind decreased DNA damage in hepatocytes, as demonstrated by analysis with an anti-γH2A.X antibody. In liver and serum samples, we found that this fruit extract reduced lipid peroxidation (thiobarbituric acid reactive substances [TBARS]) and increased endogenous antioxidant mechanisms (glutathione peroxidase [GPx] and superoxide dismutase [SOD]). However, tamarind did not alter either lipid peroxidation or antioxidant defenses in the colon, which contrasts with DMH exposure. Moreover, tamarind significantly increased the stool content of cholesterol. Although tamarind reduced the risk of colon cancer in hypercholesterolemic hamsters that were carcinogenically exposed to DMH by 63.8% (Metallothionein), it was still ∼51% higher than for animals fed a regular diet. Staining colon samples with an anti-γH2A.X antibody confirmed these findings. We suggest that tamarind has chemoprotective activity against the development of colon carcinogenesis, although a hypercholesterolemic diet might impair this protection.

Lifestyle and lifestyle-related comorbidities independently associated with colorectal adenoma recurrence in elderly Chinese people

Objective

The purpose of this study was to determine the lifestyle and lifestyle-related comorbidities independently associated with colorectal adenoma (CRA) recurrence in elderly Chinese people.

Methods

During the 5-year follow-up after the initial colonoscopy, participants aged >60 years with the diagnosis and removal of CRA underwent a complete surveillance colonoscopy, and 152 participants with CRA recurrence plus 152 participants free of recurrence were included in this analysis.

Results

Participants with CRA recurrence were more likely to consume less vegetables and fruits, and more red meats compared with the control group (P<0.05 for all). Lifestyle-related comorbidities, including hypertension and nonalcoholic fatty liver disease (NAFLD), were more common in participants with CRA recurrence than in the control group (P<0.05 for all). In the multivariate analysis, pack-years of smoking were independently associated with an increased CRA recurrence (odds ratio [OR]: 1.03; P<0.05). Eating less vegetables (OR: 099; P<0.05) and fruits (OR: 0.98; P<0.05) was identified as a statistically independent factor influencing CRA recurrence, as was eating more red meats (OR: 1.01; P<0.05). Hypertension was also found to be a factor independently associated with an increased CRA recurrence (OR: 2.44; P<0.05). NAFLD had an independent association, with an increased CRA recurrence (OR: 3.43; P<0.05).

Conclusion

Smoking cigarettes, high consumption of red meats, low intake of fruits and vegetables, and the presence of hypertension and NAFLD were independently associated with an increased CRA recurrence in elderly Chinese people. This conclusion helps elderly Chinese people to make effective behavioral changes, such as smoking cessation, substitution of fruits and vegetables for red meats, and timely treatment of hypertension and NAFLD, to reduce CRA recurrence and colorectal cancer risk.

Diallyl Disulfide (DADS), a Constituent of Garlic, Inactivates NF-κB and Prevents Colitis-Induced Colorectal Cancer by Inhibiting GSK-3β

There is a strong belief that garlic has medicinal properties and may even reduce the risk of developing certain cancers including those of the gastrointestinal tract. The chemopreventive effects of garlic may be attributed to the anti-inflammatory properties of the sulfur-containing constituents of garlic, which includes diallyl disulfide (DADS). Here, we demonstrate that DADS prevented colorectal tumorigenesis in a mouse model of colitis-induced colorectal cancer. Supplementation with 85 ppm of DADS (60 mg daily human equivalent dose) in the diet of FVB/N mice treated with chemical carcinogen azoxymethane (AOM) and colonic irritant dextran sodium sulfate (DSS) resulted in the reduction in tumor incidence, tumor number, and tumor burden by 21.54%, 47.3%, and 66.4%, respectively. Further analysis revealed that mice fed the DADS-supplemented diet resolved the initial DSS-induced inflammation faster than those on the control diet, preventing prolonged inflammation and cellular transformation. Subsequent mechanistic studies in vitro suggest that DADS chemopreventive effects are mediated through NF-κB signaling. When SW480 colorectal cancer cells were treated with DADS, NF-κB nuclear localization and activity were diminished. Interestingly, NF-κB suppression was found to be dependent on DADS inhibition of GSK-3β, a positive regulator of NF-κB. Inhibition of GSK-3β and loss of nuclear NF-κB activity were also observed in vivo in AOM/DSS-treated mice fed a diet supplemented with 85 ppm DADS. Our results indicate that DADS can prevent tumorigenesis by suppressing inflammation, a process largely involving GSK-3β inhibition and consequential reduction in NF-κB nuclear localization. Cancer Prev Res; 9(7); 607-15. ©2016 AACR.

Fruit and vegetable intakes and risk of colorectal cancer and incident and recurrent adenomas in the PLCO cancer screening trial

The roles of fruits and vegetables in colorectal cancer development are unclear. Few prospective studies have assessed the association with adenoma, a known precursor to colorectal cancer. Our aim was to evaluate the association between fruit and vegetable intake and colorectal cancer development by evaluating the risk of incident and recurrent colorectal adenoma and colorectal cancer. Study participants were identified from the intervention arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Fruit and vegetable intake was measured using a self-reported dietary questionnaire. Total fruit and vegetable intake was not associated with reduced incident or recurrent adenoma risk overall, but a protective association was observed for multiple adenomas (Odds ratio 3rd tertile vs. 1st tertile = 0.61, 95% confidence interval (CI): 0.38, 1.00). Higher fruit and vegetable intakes were associated with a borderline reduced risk of colorectal cancer (Hazard ratio (HR) 3rd tertile vs. 1st tertile = 0.82, 95% CI: 0.67, 1.01), which reached significance amongst individuals with high processed meat intakes (HR = 0.74, 95% CI: 0.55, 0.99). Our results suggest that increased fruit and vegetable intake may protect against multiple adenoma development and may reduce the detrimental effects of high processed meat intakes on colorectal cancer risk.

Association Between Consumption of Fruits and Vegetables and Risk of Colorectal Adenoma: A PRISMA-Compliant Meta-Analysis of Observational Studies

There have been contradictory results about the association of fruits and vegetables intake with colorectal adenoma (CRA) risk, the precursor lesion of colorectal cancer. Herein, we have conducted a meta-analysis of the published observational studies to have a clear understanding about this association.Eligible studies up to November 30, 2014, were identified and retrieved by searching MEDLINE and EMBASE databases along with the manual review of the reference list of the retrieved studies. The quality of the included studies was evaluated using Newcastle-Ottawa Quality Assessment Scale, and random-effects model was used to calculate summary relative risk (SRR) and corresponding 95% confidence interval (CI).A total of 22 studies involving 11,696 CRA subjects were part of this meta-analysis. The SRR for the highest versus the lowest intake of vegetables alone was 0.91 (95% CI: 0.80-1.02, Pheterogeneity = 0.025), whereas for vegetables and fruits combined, it was 0.82 (95% CI: 0.75-0.91, Pheterogeneity = 0.369), and for fruits alone, it was 0.79 (95% CI: 0.71-0.88, Pheterogeneity = 0.111). In addition, linear dose-response analysis also showed similar results, for example, for per 100 g/d increment of fruits, the SRR was 0.94 (95% CI: 0.92-0.97) and for vegetables it was 0.98 (95% CI: 0.96-1.01). Nonlinear association was only observed for vegetables (Pnonlinearity = 0.024), but not for fruits (Pnonlinearity = 0.583).Thus, this meta-analysis suggested that fruits consumption have a significant protective effect on CRA risk, but not vegetables. Moreover, we recommend additional studies with prospective designs that use validated questionnaires and control for important confounders to further validate the overall results.

Macro- and micronutrients consumption and the risk for colorectal cancer among Jordanians

OBJECTIVE

Diet and lifestyle have been reported to be important risk factors for the development of colorectal cancer (CRC). However, the association between total energy and nutrient intake and the risk of developing CRC has not been clearly explained. The aim of our study is to examine the relationship between total energy intake and other nutrients and the development of CRC in the Jordanian population.

RESEARCH METHODS AND PROCEDURES

Dietary data was collected from 169 subjects who were previously diagnosed with CRC, and 248 control subjects (matched by age, gender, occupation and marital status). These control subjects were healthy and disease free. Data was collected between January 2010 and December 2012, using interview-based questionnaires. Logistic regression was used to evaluate the association between quartiles of total energy, macro- and micronutrient intakes with the risk of developing CRC in our study population.

RESULTS

Total energy intake was associated with a higher risk of developing CRC (OR = 2.60 for the highest versus lowest quartile of intake; 95% CI: 1.21-5.56, p-trend = 0.03). Intakes of protein (OR = 3.62, 95% CI: 1.63-8.05, p-trend = 0.002), carbohydrates (OR = 1.41, 95% CI: 0.67-2.99, p-trend = 0.043), and percentage of energy from fat (OR = 2.10, 95% CI: 0.38-11.70, p-trend = 0.009) significantly increased the risk for the development of CRC. Saturated fat, dietary cholesterol and sodium intake showed a significant association with the risk of developing CRC (OR = 5.23, 95% CI: 2.33-11.76; OR = 2.48, 95% CI: 1.18-5.21; and OR = 3.42, 95% CI: 1.59-7.38, respectively), while vitamin E and caffeine intake were indicative of a protective effect against the development of CRC, OR = 0.002 (95% CI: 0.0003-0.011) and 0.023 (95%CI: 0.008-0.067), respectively.

CONCLUSION

Our results suggest an increased risk for the development of CRC in subjects with high dietary intake of energy, protein, saturated fat, cholesterol, and sodium, and diets high in vitamin E and caffeine were suggestive of a protective effect against the risk of developing CRC.

IMPACT

This is the first study in Jordan to suggest that it may be possible to reduce CRC risk by adjusting the intake of some macro-and micronutrients.

Garlic and onions: their cancer prevention properties

The Allium genus includes garlic, onions, shallots, leeks, and chives. These vegetables are popular in cuisines worldwide and are valued for their potential medicinal properties. Epidemiologic studies, while limited in their abilities to assess Allium consumption, indicate some associations of Allium vegetable consumption with decreased risk of cancer, particularly cancers of the gastrointestinal tract. Limited intervention studies have been conducted to support these associations. The majority of supportive evidence on Allium vegetables cancer-preventive effects comes from mechanistic studies. These studies highlight potential mechanisms of individual sulfur-containing compounds and of various preparations and extracts of these vegetables, including decreased bioactivation of carcinogens, antimicrobial activities, and redox modification. Allium vegetables and their components have effects at each stage of carcinogenesis and affect many biologic processes that modify cancer risk. This review discusses the cancer-preventive effects of Allium vegetables, particularly garlic and onions, and their bioactive sulfur compounds and highlights research gaps.

Effects of canned pineapple consumption on nutritional status, immunomodulation, and physical health of selected school children

This randomized, controlled trial examined the effects of canned pineapple consumption on immunomodulation, nutritional status, and physical health of ninety-eight (98) school children with mean age of 8.44 ± 0.20. The study participants were divided into three groups: Group A (33) includes subjects who were not given canned pineapple, Group B (33) includes those who were given 140 g, and Group C (32) includes those given 280 g of canned pineapple for nine weeks. Each major group was further divided into two groups: normal (N) and underweight (U) based on 2007 WHO Growth Reference Standards. Sociodemographic, anthropometric, physical examination, dietary intake, hemoglobin level, and immunological data were analyzed. Results showed a decrease in incidence of viral and bacterial infections for both Group B and Group C (normal and underweight) after canned pineapple consumption. Granulocyte production increased by 0.77–26.61% for normal weight subjects and 14.95–34.55% for underweight. CD16+56 count augmented by 20.44–22.13% for normal weight and 3.57–15.89% for underweight subjects. Thus, intake of both one can (140 g) and two cans (280 g) of canned pineapple may shorten the duration and incidence of infection and may increase the production of granulocytes and CD16+56, but intake of two cans (280 g) demonstrated higher granulocyte and CD16+56 production. This trial is registered with Philippine Health Research Registry: PHRR140826-000225.

Primary and secondary prevention of colorectal cancer

INTRODUCTION

Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. Colorectal cancer (CRC) is the third most frequent cancer in men, after lung and prostate cancer, and is the second most frequent cancer in women after breast cancer. It is also the third cause of death in men and women separately, and is the second most frequent cause of death by cancer if both genders are considered together. CRC represents approximately 10% of deaths by cancer. Modifiable risk factors of CRC include smoking, physical inactivity, being overweight and obesity, eating processed meat, and drinking alcohol excessively. CRC screening programs are possible only in economically developed countries. However, attention should be paid in the future to geographical areas with ageing populations and a western lifestyle.19,20 Sigmoidoscopy screening done with people aged 55–64 years has been demonstrated to reduce the incidence of CRC by 33% and mortality by CRC by 43%.

OBJECTIVE

To assess the effect on the incidence and mortality of CRC diet and lifestyle and to determine the effect of secondary prevention through early diagnosis of CRC.

METHODOLOGY: A comprehensive search of Medline and Pubmed articles related to primary and secondary prevention of CRC and subsequently, a meta-analysis of the same blocks are performed.

RESULTS

225 articles related to primary or secondary prevention of CRC were retrieved. Of these 145 were considered valid on meta-analysis: 12 on epidemiology, 56 on diet and lifestyle, and over 77 different screenings for early detection of CRC. Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. There is no doubt whatsoever which environmental factors, probably diet, may account for these cancer rates. Excessive alcohol consumption and cholesterol-rich diet are associated with a high risk of colon cancer. A diet poor in folic acid and vitamin B6 is also associated with a higher risk of developing colon cancer with an overexpression of p53. Eating pulses at least three times a week lowers the risk of developing colon cancer by 33%, after eating less meat, while eating brown rice at least once a week cuts the risk of CRC by 40%. These associations suggest a dose–response effect. Frequently eating cooked green vegetables, nuts, dried fruit, pulses, and brown rice has been associated with a lower risk of colorectal polyps. High calcium intake offers a protector effect against distal colon and rectal tumors as compared with the proximal colon. Higher intake of dairy products and calcium reduces the risk of colon cancer. Taking an aspirin (ASA) regularly after being diagnosed with colon cancer is associated with less risk of dying from this cancer, especially among people who have tumors with COX-2 overexpression.16 Nonetheless, these data do not contradict the data obtained on a possible genetic predisposition, even in sporadic or non-hereditary CRC. CRC is susceptible to screening because it is a serious health problem given its high incidence and its associated high morbidity/mortality.

CONCLUSIONS

(1) Cancer is a worldwide problem. (2) A modification of diet and lifestyle could reduce morbidity and mortality. (3) Early detection through screening improves prognosis and reduces mortality.

Colorectal cancer and adenomatous polyps in relation to allium vegetables intake: a meta-analysis of observational studies

SCOPE

To provide updated quantitative estimates of the associations between allium vegetables intake and risk of colorectal cancer and colorectal adenomatous polyps.

METHODS AND RESULTS

We combined all published data on the issue, using a meta-analytic approach. Pooled relative risks (RRs) were calculated using random-effects models. Sixteen studies (13 333 cases) were included in the meta-analyses of colorectal cancer. Seven studies provided information on garlic, six on onion, and four on total allium vegetables. The pooled RRs of colorectal cancer for the highest versus the lowest category of intake were 0.85 (95% confidence interval; CI, 0.72-1.00) for garlic (0.76 for case-control, 0.99 for cohort studies), 0.85 (95% CI, 0.70-1.04) for onion (0.74 for case-control, 1.04 for cohort studies), and 0.78 (95% CI, 0.56-1.08) for total allium vegetables. Significant heterogeneity was found for the three meta-analyses. The pooled RR of colorectal adenomatous polyps for the highest versus the lowest category of total allium vegetables intake was 0.88 (95% CI, 0.80-0.98, three studies), with no heterogeneity.

CONCLUSION

High garlic intake may reduce the risk of colorectal cancer. However, evidence of such protection derived mainly from case-control studies. High intake of total allium vegetables may be associated with a risk reduction of colorectal adenomatous polyps.

Effect of onion flavonoids on colorectal cancer with hyperlipidemia: an in vivo study

Objectives

This study aims to find the effect of onion’s extraction on the colorectal cancer with hyperlipidemia.

Method

We established a hyperlipidemia-subcutaneously heterotopic colorectal cancer orthotopic transplant model and fed mice a high fat diet and performing transplantation. Animal models were treated with capecitabine and/or simvastatin and low-, middle-, high- dose of onion’s extraction and both tumor growth rate and blood lipid levels were monitored.

Results

We found that colorectal cancer in onion’s extraction groups was significantly inhibited, and the effect of high dose of onion’s extraction was equivalent to capecitabine. Onion’s extraction effectively decreased levels of apoB and TC.

Conclusion

Our study established a hyperlipidemia colon tumor model involving subcutaneous colon translocation and orthotopic transplantation, this model was an ideal research model for mutual influence of hyperlipidemia and colorectal cancer. Onion’s extraction could inhibit the proliferation of colorectal cancer; the function of the high-dose of onion’s extraction was fairly to capecitabine, which provided a new direction in protecting and treating colorectal cancer.

Diet and supplements and their impact on colorectal cancer

BACKGROUND

Colorectal cancer is the third commonest cancer and the third leading cause of cancer death among men and women. It has been proposed that dietary factors are responsible for 70-90% of colorectal cancer and diet optimization may prevent most cases.

AIM

To evaluate the role of dietary components and supplements in colorectal cancer.

METHODS

Bibliographical searches were performed in Pubmed for the terms "diet and colorectal cancer", "diet and colon cancer", "diet and rectal cancer", "nutrition and colorectal cancer", "probiotics and colorectal cancer", "prebiotics and colorectal cancer", "alcohol and cancer" and "colorectal cancer epidemiology".

RESULTS

Consumption of processed or red meat, especially when cooked at high temperatures may be associated with increased risk of colorectal cancer. The evidence for dietary fibre is unclear but foods that contain high amounts of fibre are usually rich in polyphenols which have been shown to alter molecular processes that can encourage colorectal carcinogenesis. Meta-analyses provide evidence on the benefits of circulating, diet-derived and supplemented, vitamin D and Calcium. We also found that diets rich in Folate may prevent colorectal carcinoma. The evidence on dietary micronutrients such as Zinc and Selenium in association with colorectal cancer is not conclusive. It has been suggested that there may be a direct association between alcohol intake and colorectal cancer. In vitro and in vivo studies have highlighted a possible protective role of prebiotics and probiotics.

CONCLUSIONS

The lack of randomized trials and the presence of confounding factors including smoking, physical activity, obesity and diabetes may often yield inconclusive results. Carefully designed randomized trials are recommended.

Perceived social-ecological factors associated with fruit and vegetable purchasing, preparation, and consumption among young adults

Most young adults do not consume recommended levels of fruits and vegetables (F/V), and interventions to increase F/V-related behaviors among this understudied population are needed. Therefore, it is important to identify correlates of F/V intake among young adults to guide intervention development. This cross-sectional study used data from an online survey to identify factors related to young adults' F/V purchasing, preparation, and consumption, and to explore between-factor relationships using mediation analysis. In 2010, 1,201 college students in Minnesota completed questionnaires assessing F/V behaviors as well as perceptions of F/V-related individual, social, and environmental factors. Factor analysis identified questionnaire items assessing similar constructs. Seven factors were identified (personal barriers, F/V knowledge, family, friends, neighborhood, access barriers, and campus) and evaluated for relationships with F/V purchasing, preparation, and consumption using linear regression. Results revealed that perceived personal barriers (eg, lacking cooking skills) were inversely related to all F/V outcomes. Perception that family and friends eat healthfully and neighborhood access to F/V were positively related to all outcomes. Individual-, social-, and environment-level perceptions were related to purchasing, preparation, and consumption, and the effects of these factors were similar when accounting for mediated effects. Factors at all three levels and the ways in which these various factors operate together may be important to consider in future efforts to improve F/V behaviors among young adults.

Legume consumption and colorectal adenoma risk: a meta-analysis of observational studies

Background

The anticancer effects of legumes have been explored extensively, but evidence from epidemiologic studies on colorectal adenoma is controversial. We performed a meta-analysis to assess these issues.

Methods

A systemic search of several databases was conducted for relevant studies evaluating the relationship between legume intake and adenoma risk, with no language restriction, from January 1, 1966, to April 1, 2013.

Results

Three cohort and eleven case control studies with 8,380 cases and a total of 101,856 participants were included in the analysis; the pooled odds ratio (95% confidence interval) for the highest vs. lowest consumption categories was 0.83 (0.75–0.93), with moderate level of heterogeneity (I² = 25.9% and P = 0.146) based on a random effects model. A decreased risk of adenoma was also observed in most of our subgroup meta-analyses.

Conclusions

Higher intake of legumes significantly reduced the risk of colorectal adenoma in our meta-analysis. Nevertheless, due to possible confounders and bias, further investigations are warranted to confirm this relationship.

Influence of natural and synthetic histone deacetylase inhibitors on chromatin

SIGNIFICANCE

Histone deacetylase inhibitors (HDACIs) have emerged as a new class of anticancer therapeutics. The hydroxamic acid, suberoylanilide hydroxamic acid (Vorinostat, Zolinza™), and the cyclic peptide, depsipeptide (Romidepsin, Istodax™), were approved by the U.S. Food and Drug Administration (FDA) for the treatment of cutaneous T-cell lymphoma in 2006 and 2009, respectively. At least 15 HDACIs are currently undergoing clinical trials either alone or in combination with other therapeutic modalities for the treatment of numerous hematological and solid malignancies.

RECENT ADVANCES

The potential utility of HDACIs has been extended to nononcologic applications, including autoimmune disorders, inflammation, diseases of the central nervous system, and malaria.

CRITICAL ISSUES

Given the promise of HDACIs, there is growing interest in the potential of dietary compounds that possess HDAC inhibition activity. This review is focused on the identification of and recent findings with HDACIs from dietary, medicinal plant, and microbial sources. We discuss the mechanisms of action and clinical potential of natural HDACIs.

FUTURE DIRECTIONS

Apart from identification of further HDACI compounds from dietary sources, further research will be aimed at understanding the effects on gene regulation on lifetime exposure to these compounds. Another important issue that requires clarification.

Lifestyle Modification

Early detection of cancer through screening is an important step in decreasing both morbidity and mortality. Likewise, specific modifiable lifestyle behaviors are associated with reduced risk of colorectal cancer. Lifestyle practices have also been shown to maximize health after the primary treatment of cancer. Both these roles for lifestyle interventions are discussed.

The "aged garlic extract:" (AGE) and one of its active ingredients S-allyl-L-cysteine (SAC) as potential preventive and therapeutic agents for Alzheimer's disease (AD)

Alzheimer's disease (AD) is the most common form of dementia in the older people and 7(th) leading cause of death in the United States. Deposition of amyloid-beta (Aβ) plaques, hyperphosphorylation of microtubule associated protein tau (MAPT), neuroinflammation and cholinergic neuron loss are the major hallmarks of AD. Deposition of Aβ peptides, which takes place years before the clinical onset of the disease can trigger hyperphophorylation of tau proteins and neuroinflammation, and the latter is thought to be primarily involved in neuronal and synaptic damage seen in AD. To date, four cholinesterase inhibitors or ChEI (tacrine, rivastigmine, donepezil and galantamine) and a partial NMDA receptor antagonist (memantine) are the only approved treatment options for AD. However, these drugs fail to completely cure the disease, which warrants a search for newer class of targets that would eventually lead to effective drugs for the treatment of AD. In addition to selected pharmacological agents, botanical and medicinal plant extracts are also being investigated. Apart from its culinary use, garlic (Allium sativum) is being used to treat several ailments like cancer and diabetes. Herein we have discussed the effects of a specific 'Aged Garlic Extract' (AGE) and one of its active ingredients, S-allyl-L-cysteine (SAC) in restricting several pathological cascades related to the synaptic degeneration and neuroinflammatory pathways associated with AD. Thus, based on the reported positive preliminary results reviewed herein, further research is required to develop the full potential of AGE and/or SAC into an effective preventative strategy for AD.

Integrative oncology in the Middle East: from traditional herbal knowledge to contemporary cancer care

BACKGROUND

Based on traditional, historical, ethnobotanical, laboratory, and clinical findings, we present research framework aiming to identify Middle Eastern herbs that are worthy of further research for their anticancer potential.

METHODS

A comprehensive research project was developed by a multinational team comprising family physicians, medicine specialists, oncologists, an Islamic medicine history specialist, a traditional medicine ethnobotanist, and a basic research scientist. The project followed two consecutive phases: (i) historical and ethnobotanical search for cancer-related keywords and (ii) Medline search for in vitro and in vivo studies.

RESULTS

This search yielded 44 herbs associated with cancer care. The Medline search yielded 34 herbs of which 9 herbs were reported in various clinical studies.

CONCLUSIONS

This multidisciplinary survey was found to be a valuable way to identify herbs with potential clinical significance in cancer care. Based on this pilot study, it is suggested that the Middle East can serve as a valuable region for future multicultural-oriented cancer research.

Foods and food groups associated with the incidence of colorectal polyps: the Adventist Health Study

Colorectal cancer (CRC) is a leading cause of cancer death in the United States. The majority of CRC arise in adenomatous polyps and 25-35% of colon adenoma risk could be avoidable by modifying diet and lifestyle habits. We assessed the association between diet and the risk of self-reported physician-diagnosed colorectal polyps among 2,818 subjects who had undergone colonoscopy. Subjects participated in 2 cohort studies: the AHS-1 in 1976 and the AHS-2 from 2002-2005. Multivariate logistic regression analysis was used to estimate the period risk of incident cases of polyps; 441 cases of colorectal polyps were identified. Multivariate analysis adjusted by age, sex, body mass index, and education showed a protective association with higher frequency of consumption of cooked green vegetables (OR 1 time/d vs. <5/wk = 0.76, 95% CI = 0.59-0.97) and dried fruit (OR 3+ times/wk vs. <1 time/wk = 0.76, 95%CI = 0.58-0.99). Consumption of legumes at least 3 times/wk reduced the risk by 33% after adjusting for meat intake. Consumption of brown rice at least 1 time/wk reduced the risk by 40%. These associations showed a dose-response effect. High frequency of consumption of cooked green vegetables, dried fruit, legumes, and brown rice was associated with a decreased risk of colorectal polyps.

Racial differences in colorectal cancer incidence and mortality in the Women's Health Initiative

BACKGROUND

Colorectal cancer (CRC) incidence and mortality rates are higher in African-Americans as compared with other racial/ethnic groups. The women's health initiative (WHI) study sample was used to determine whether differences in CRC risk factors explain racial/ethnic differences in incidence and mortality.

METHODS

The WHI is a longitudinal study of postmenopausal women recruited from 40 centers. Baseline questionnaires were used to collect sociodemographic and health status information. All CRC diagnoses were centrally adjudicated. Cox regression models were used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) for invasive CRC by race/ethnicity.

RESULTS

The study sample included 131,481 (83.7%) White, 14,323 (9.1%) African-American, 6,362 (4.1%) Hispanic, 694 (0.4%) Native American and 4,148 (2.6%) Asian/Pacific Islanders. After a mean follow-up of 10.8 years (SD 2.9), CRC incidence was the highest in African-Americans (annualized rate = 0.14%), followed by Whites and Native Americans (0.12% each), Asian/Pacific Islanders (0.10%), and Hispanics (0.08%). After adjustment for age and trial assignment, Hispanics had a lower risk compared with Whites, HR 0.73 (95% CI: 0.54-0.97) (P = 0.03), and African-Americans had a marginally greater risk, HR 1.16 (95% CI: 0.99-1.34), P = 0.06. Multivariable adjustment attenuated the difference in incidence between African-Americans and Whites (HR 0.99, 95% CI: 0.82-1.20), while strengthening the lower HR for Hispanics (HR 0.68, 95% CI: 0.48-0.97).

CONCLUSIONS

African-American/White differences in CRC risk are likely due to sociodemographic/cultural factors other than race.

IMPACT

A number of modifiable exposures could be a focus for reducing CRC risk in African-Americans.

The flavonoid quercetin transiently inhibits the activity of taxol and nocodazole through interference with the cell cycle

Quercetin is a flavonoid with anticancer properties. In this study, we examined the effects of quercetin on cell cycle, viability, and proliferation of cancer cells, either singly or in combination with the microtubule-targeting drugs taxol and nocodazole. Although quercetin induced cell death in a dose-dependent manner, 12.5-50 μM quercetin inhibited the activity of both taxol and nocodazole to induce G2/M arrest in various cell lines. Quercetin also partially restored drug-induced loss in viability of treated cells for up to 72 h. This antagonism of microtubule-targeting drugs was accompanied by a delay in cell cycle progression and inhibition of the buildup of cyclin-B1 at the microtubule organizing center of treated cells. However, quercetin did not inhibit the microtubule targeting of taxol or nocodazole. Despite the short-term protection of cells by quercetin, colony formation and clonogenicity of HCT116 cells were still suppressed by quercetin or quercetin-taxol combination. The status of cell adherence to growth matrix was critical in determining the sensitivity of HCT116 cells to quercetin. We conclude that although long-term exposure of cancer cells to quercetin may prevent cell proliferation and survival, the interference of quercetin with cell cycle progression diminishes the efficacy of microtubule-targeting drugs to arrest cells at G2/M.

Colorectal cancer prevention through dietary and lifestyle modifications

Several studies indicate that Western dietary and lifestyle factors are responsible for the high incidence of colorectal cancer in industrialized countries. Diets rich in red and processed meat, refined starches, sugar, and saturated and trans-fatty acids but poor in fruits, vegetables, fiber, omega-3 fatty acids and whole grains are closely associated with an increased risk of colorectal cancer. Other main features of the western lifestyle, such as excess body mass and sedentary behaviours, are also strongly associated with higher risk of developing this cancer. Modifications of the western diet, notably increasing consumption of foods from plant origin and reducing that of red meat intake, and maintenance of physical activity and appropriate body mass could substantially reduce colorectal cancer incidence and mortality.

Silibinin suppresses growth of human colorectal carcinoma SW480 cells in culture and xenograft through down-regulation of beta-catenin-dependent signaling

Mutations in APC/beta-catenin resulting in an aberrant activation of Wnt/beta-catenin pathway are common in colorectal cancer (CRC), suggesting that targeting the beta-catenin pathway with chemopreventive/anticancer agents could be a potential translational approach to control CRC. Using human CRC cell lines harboring mutant (SW480) versus wildtype (HCT116) APC gene and alteration in beta-catenin pathway, herein we performed both in vitro and in vivo studies to examine for the first time whether silibinin targets beta-catenin pathway in its efficacy against CRC. Silibinin treatment inhibited cell growth, induced cell death, and decreased nuclear and cytoplasmic levels of beta-catenin in SW480 but not in HCT116 cells, suggesting its selective effect on the beta-catenin pathway and associated biologic responses. Other studies, therefore, were performed only in SW480 cells where silibinin significantly decreased beta-catenin-dependent T-cell factor-4 (TCF-4) transcriptional activity and protein expression of beta-catenin target genes such as c-Myc and cyclin D1. Silibinin also decreased cyclin-dependent kinase 8 (CDK8), a CRC oncoprotein that positively regulates beta-catenin activity, and cyclin C expression. In a SW480 tumor xenograft study, 100- and 200-mg/kg doses of silibinin feeding for 6 weeks inhibited tumor growth by 26% to 46% (P < .001). Analyses of xenografts showed that similar to cell culture findings, silibinin decreases proliferation and expression of beta-catenin, cyclin D1, c-Myc, and CDK8 but induces apoptosis in vivo. Together, these findings suggest that silibinin inhibits the growth of SW480 tumors carrying the mutant APC gene by down-regulating CDK8 and beta-catenin signaling and, therefore, could be an effective agent against CRC.

Colorectal cancer and adenomas are rare in individuals of Turkish descent living in the Zaanstreek region in the Netherlands

Background

Colorectal cancer is one of the most common malignancies in the Western world. Screening and detection of its precursor lesion, the adenoma could prevent development of colorectal cancer. Many studies have been done to evaluate the prevalence of colorectal cancer in different countries. In daily practice, it was noticed that colorectal cancer was rarely seen in patients of Turkish decent.

Aim

To evaluate the prevalence of colorectal cancer and adenoma in patients living in the Zaanstreek region, the Netherlands, and correlate these findings with ethnicity.

Materials and methods

All patients undergoing endoscopy of the colon and rectum during a period of 16 consecutive years in whom colorectal cancer and/or a polyp were diagnosed, were included in this study. All available histological data were retrieved in order to confirm the endoscopic diagnosis.

Results

In the study period, 907 patients were diagnosed with colorectal cancer. Of these 13 (1.4%) were of Turkish descent (10 men and 3 women). The remaining 894 were authentic Dutch (473 men and 421 women). A total of 2,744 patients had one or more polyp(s) during endoscopy. There were 2,705 authentic Dutch (1,386 men, 1,319 women) and 39 Turkish patients (25 men, 14 women). There was no significant difference in gender in either of the groups.

Conclusion

Colorectal cancer and colonic adenoma are rare in patients of Turkish descent living in the Zaanstreek region, the Netherlands.

Dietary intake of pterostilbene, a constituent of blueberries, inhibits the beta-catenin/p65 downstream signaling pathway and colon carcinogenesis in rats

Stilbenes are phytochemicals present in grapes, berries, peanuts and red wine. A widely studied stilbene, resveratrol (trans-3,5,4'-trihydroxystilbene), has been shown to exert antioxidant, anti-inflammatory, chemopreventive and antiaging effects in a number of biological systems. We reported earlier that pterostilbene (trans-3,5-dimethoxy-4'-hydroxystilbene), a structurally related stilbene found in blueberries, was effective in reducing the incidence and multiplicity of aberrant crypt foci formation in the colon of rats injected with azoxymethane (AOM). Our present study was to identify the chemopreventive potential of pterostilbene with colonic tumor formation as an end point and further to evaluate the mechanistic action of pterostilbene during colon carcinogenesis. F344 rats were given two AOM injections subcutaneously when they were 7 and 8 weeks old and continuously fed the control or 40 p.p.m. pterostilbene diet for 45 weeks. Overall analyses indicated that pterostilbene reduced colon tumor multiplicity of non-invasive adenocarcinomas, lowered proliferating cell nuclear antigen and downregulated the expression of beta-catenin and cyclin D1. Pterostilbene decreased mucosal levels of the proinflammatory cytokines, tumor necrosis factor-alpha, interleukin (IL)-1beta and IL-4. Colon tumors from pterostilbene-fed animals showed reduced expression of inflammatory markers as well as nuclear staining for phospho-p65, a key molecule in the nuclear factor-kappaB pathway. In HT-29 cells, pterostilbene reduced the protein levels of beta-catenin, cyclin D1 and c-MYC, altered the cellular localization of beta-catenin and inhibited the phosphorylation of p65. Our data with pterostilbene in suppressing colon tumorigenesis, cell proliferation as well as key inflammatory markers in vivo and in vitro suggest the potential use of pterostilbene for colon cancer prevention.

Lack of efficacy of blueberry in nutritional prevention of azoxymethane-initiated cancers of rat small intestine and colon

Background

Blueberries may lower relative risk for cancers of the gastrointestinal tract. Previous work indicated an inhibitory effect of consumed blueberry (BB) on formation of aberrant crypt foci (ACF) in colons of male Fisher F344 rats (inbred strain). However, effects of BB on colon tumors and in both genders are unknown.

Methods

We examined efficacy of BB in inhibition of azoxymethane (AOM)-induced colon ACF and intestine tumors in male and female Sprague-Dawley rats (outbred strain). Pregnant rats were fed a diet with or without 10% BB powder; progeny were weaned to the same diet as their dam and received AOM as young adults.

Results

Male and female rats on control diet had similar numbers of ACF at 6 weeks after AOM administration. BB increased (P < 0.05) ACF numbers within the distal colon of female but not male rats. There was a significant (P < 0.05) diet by gender interaction with respect to total colon ACF number. Colon and duodenum tumor incidences were less in females than males at 17 weeks after AOM. BB tended (0.1 > P > 0.05) to reduce overall gastrointestinal tract tumor incidence in males, however, tumor incidence in females was unaffected (P > 0.1) by BB. There was a tendency (0.1 > P > 0.05) for fewer adenocarcinomas (relative to total of adenomatous polyps plus adenocarcinomas) in colons of female than male tumor-bearing rats; in small intestine, this gender difference was significant (P < 0.05). BB favored (P < 0.05) fewer adenocarcinomas and more adenomatous polyps (as a proportion of total tumor number) in female rat small intestine.

Conclusion

Results did not indicate robust cancer-preventive effects of BB. Blueberry influenced ACF occurrence in distal colon and tumor progression in duodenum, in gender-specific fashion. Data indicate the potential for slowing tumor progression (adenomatous polyp to adenocarcinoma) by BB.

Allyl mercaptan, a garlic-derived organosulfur compound, inhibits histone deacetylase and enhances Sp3 binding on the P21WAF1 promoter

Histone deacetylase (HDAC) inhibitors have the potential to derepress epigenetically silenced genes in cancer cells, leading to cell cycle arrest and apoptosis. In the present study, we screened several garlic-derived small organosulfur compounds for their ability to inhibit HDAC activity in vitro. Among the organosulfur compounds examined, allyl mercaptan (AM) was the most potent HDAC inhibitor. Molecular modeling, structure activity and enzyme kinetics studies with purified human HDAC8 provided evidence for a competitive mechanism (K(i) = 24 microM AM). In AM-treated human colon cancer cells, HDAC inhibition was accompanied by a rapid and sustained accumulation of acetylated histones in total cellular chromatin. Chromatin immunoprecipitation assays confirmed the presence of hyperacetylated histone H3 on the P21WAF1 gene promoter within 4 h of AM exposure, and there was increased binding of the transcription factor Sp3. At a later time, 24 h after AM treatment, there was enhanced binding of p53 in the distal enhancer region of the P21WAF1 gene promoter. These findings suggest a primary role for Sp3 in driving P21 gene expression after HDAC inhibition by AM, followed by the subsequent recruitment of p53. Induction of p21Waf1 protein expression was detected at time points between 3 and 72 h after AM treatment and coincided with growth arrest in G(1) of the cell cycle. The results are discussed in the context of other anticarcinogenic mechanisms ascribed to garlic organosulfur compounds and the metabolic conversion of such compounds to potential HDAC inhibitors in situ.