IN-VITRO evidence for the protective properties of the main components of the Mediterranean diet against colorectal cancer: A systematic review

Phytochemicals and Glioma: Results from Dietary Mixed Exposure

The information about phytochemicals' potential to prevent cancer is encouraging, including for glioma. However, most studies on phytochemicals and glioma mainly focused on preclinical studies. Their epidemiological studies were not sufficient, and the evidence on the dose-response relationship is usually limited. Therefore, this investigation examined the association between dietary phytochemical intake and glioma in Chinese adults. This case-control study was carried out in a hospital in China. Based on the dietary information obtained from the food frequency questionnaire, the researchers estimated the phytochemical intake of 506 patients with glioma and 506 controls. Compared with participants in the lowest tertile, the highest intakes of carotene, flavonoids, soy isoflavones, anthocyanin, and resveratrol were associated with a reduced risk of glioma. The WQS and BKMR models suggested that anthocyanin and carotene have a greater influence on glioma. The significant nonlinear dose-response associations between dietary phytochemicals and glioma were suggested using the restricted cubic spline function. According to this study on phytochemicals and glioma, higher intakes of carotene, flavonoids, soy isoflavones, anthocyanins, and resveratrol are linked to a lower risk of glioma. So, we might not be able to ignore how phytochemicals affect gliomas.

Mediterranean-Like Dietary Pattern Associations With Gut Microbiome Composition and Subclinical Gastrointestinal Inflammation

BACKGROUND & AIMS

Case-control studies have shown that patients with Crohn's disease (CD) have a microbial composition different from healthy individuals. Although the causes of CD are unknown, epidemiologic studies suggest that diet is an important contributor to CD risk, potentially via modulation of bacterial composition and gut inflammation. We hypothesized that long-term dietary clusters (DCs) are associated with gut microbiome compositions and gut inflammation. Our objectives were to identify dietary patterns and assess whether they are associated with alterations in specific gut microbial compositions and subclinical levels of gut inflammation in a cohort of healthy first-degree relatives (FDRs) of patients with CD.

METHODS

As part of the Genetic, Environmental, Microbial (GEM) Project, we recruited a cohort of 2289 healthy FDRs of patients with CD. Individuals provided stool samples and answered a validated food frequency questionnaire reflecting their habitual diet during the year before sample collection. Unsupervised analysis identified 3 dietary and 3 microbial composition clusters.

RESULTS

DC3, resembling the Mediterranean diet, was strongly associated with a defined microbial composition, with an increased abundance of fiber-degrading bacteria, such as Ruminococcus, as well as taxa such as Faecalibacterium. The DC3 diet was also significantly associated with lower levels of subclinical gut inflammation, defined by fecal calprotectin, compared with other dietary patterns. No significant associations were found between individual food items and fecal calprotectin, suggesting that long-term dietary patterns rather than individual food items contribute to subclinical gut inflammation. Additionally, mediation analysis demonstrated that DC3 had a direct effect on subclinical inflammation that was partially mediated by the microbiota.

CONCLUSIONS

Overall, these results indicated that Mediterranean-like dietary patterns are associated with microbiome and lower intestinal inflammation. This study will help guide future dietary strategies that affect microbial composition and host gut inflammation to prevent diseases.

Health benefits of polyphenols: A concise review

Plants produce polyphenols, which are considered highly essential functional foods in our diet. They are classified into several groups according to their diverse chemical structures. Flavanoids, lignans, stilbenes, and phenolic acids are the four main families of polyphenols. Several in vivo and in vitro research have been conducted so far to evaluate their health consequences. Polyphenols serve a vital function in the protection of the organism from external stimuli and in eliminating reactive oxygen species (ROS), which are instigators of several illnesses. Polyphenols are present in tea, chocolate, fruits, and vegetables with the potential to positively influence human health. For instance, cocoa flavan-3-ols have been associated with a decreased risk of myocardial infarction, stroke, and diabetes. Polyphenols in the diet also help to improve lipid profiles, blood pressure, insulin resistance, and systemic inflammation. Quercetin, a flavonoid, and resveratrol, a stilbene, have been linked to improved cardiovascular health. Dietary polyphenols potential to elicit therapeutic effects might be attributed, at least in part, to a bidirectional association with the gut microbiome. This is because polyphenols are known to affect the gut microbiome composition in ways that lead to better human health. Specifically, the gut microbiome converts polyphenols into bioactive compounds that have therapeutic effects. In this review, the antioxidant, cytotoxicity, anti-inflammatory, antihypertensive, and anti-diabetic actions of polyphenols are described based on findings from in vivo and in vitro experimental trials. PRACTICAL APPLICATIONS: The non-communicable diseases (NCDs) burden has been increasing worldwide due to the sedentary lifestyle and several other factors such as smoking, junk food, etc. Scientific literature evidence supports the use of plant-based food polyphenols as therapeutic agents that could help to alleviate NCD's burden. Thus, consuming polyphenolic compounds from natural sources could be an effective solution to mitigate NCDs concerns. It is also discussed how natural antioxidants from medicinal plants might help prevent or repair damage caused by free radicals, such as oxidative stress.

Phenolic Compounds and Triterpenes in Different Olive Tissues and Olive Oil By-Products, and Cytotoxicity on Human Colorectal Cancer Cells: The Case of Frantoio, Moraiolo and Leccino Cultivars (Olea europaea L.)

Phenolic and triterpenoid compounds of the olive tree are recognized as having a key role in health promotion, thanks to their multiple protective actions in humans. To expand the source of these bioactive compounds, the phenolic and triterpenoid profiles of leaf, branch, destoned fruit, destoned pomace, shell, seed, and extra virgin olive oil from the Frantoio, Leccino, and Moraiolo olive cultivars were simultaneously characterized by HPLC-DAD-MS. Overall, 43 molecules were quantitated and expressed on the obtained dry extracts. Oleuropein was mainly concentrated in branches (82.72 g/kg), fruits (55.79 g/kg), leaves (36.71 g/kg), and shells (1.26 g/kg), verbascoside (4.88 g/kg) in pomace, and nüzhenide 11-methyl oleoside (90.91 g/kg) in seeds. Among triterpenoids, which were absent in shells, the highest amount of oleanolic acid was found in olive leaves (11.88 g/kg). HCT-116 colorectal cells were chosen to assess the cytotoxicity of the dry extract, using the phytocomplex from Frantoio, which was the richest in phenols and triterpenoids. The IC₅₀ was also determined for 13 pure molecules (phenols and terpenoids) detected in the extracts. The greatest inhibition on the cell’s proliferation was induced by the branch dry extract (IC₅₀ 88.25 μg/mL) and by ursolic acid (IC₅₀ 24 μM). A dose-dependent relationship was observed for the tested extracts.

In vitro evidence of the antitumor capacity of Solanaceae and Cucurbitaceae in colon cancer: A systematic review

Colon cancer is the fourth leading cause of cancer deaths around the world. Despite advances in understanding its etiology and in diagnosis and treatment, new therapeutic strategies are still required. In this sense, the Solanaceae and Cucurbitaceae families have been widely used to treat various pathologies, including cancer, for their bioactive components. The objective of this systematic review was to analyze the antitumor activity of the bioactive components present in extracts from Solanaceae and Cucurbitaceae families using different in in vitro models of colon cancer. 241 publications have been identified (published from January 2008 to January 2020) from different electronic data base. 44 articles were included, 26 of which examined the Solanaceae family. The antitumor activity exhibited by this family was due to the withanolide-type steroid compounds they harbor. 18 articles were related to the Cucurbitaceae family. This family is characterized by their production of cucurbitacin-type triterpenoid compounds and their derivatives, which confer antitumor activity. In conclusion, the different genera belonging to both families are an important source of bioactive compounds with relevant activity against colon cancer. More experimental and in vivo studies will be required to corroborate their antitumor activity and to leverage them in future clinical practice.

Plant-sourced cooking oil consumption is associated with lower total mortality in a longitudinal nationwide cohort study

BACKGROUND & AIMS

Evidence linking individual cooking oil consumption with total mortality is limited in China. The aim of this study was to examine the associations of intakes of plant-sourced and animal-sourced cooking oils with total mortality in a Chinese nationwide cohort.

METHODS

We analyzed data from 14,305 adults aged ≥20 y at entry in the China Health and Nutrition Survey (CHNS). The 3-day 24-h dietary records were used to collect dietary information. Cox proportional hazards regression models were established to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause death.

RESULTS

Overall 1006 deaths were documented during a median of 14 years (199,091 person-years) of follow-up. Multivariate-adjusted HRs (95% CIs) of total mortality via comparing the highest tertile of cooking oil consumption with no consumption were 0.86 (0.70-1.06) for lard, 0.59 (0.47-0.74) for peanut oil, 0.71 (0.54-0.93) for soybean oil, 0.76 (0.61-0.94) for canola oil, 0.71 (0.50-0.99) for salad oil, and 0.59 (0.44-0.79) for other plant cooking oils. Replacing animal cooking oils with 1 tablespoon/d of total plant cooking oils or other plant cooking oils was related to 4% or 17% lower total mortality, respectively, while consumption of peanut oil or salad oil in replacement of animal cooking oils had a marginal inverse association with total mortality.

CONCLUSIONS

Intakes of plant-sourced cooking oils, including peanut oil, soybean oil, canola oil, salad oil, and other plant cooking oils and substituting plant cooking oils for animal cooking oils were associated with lower total mortality among general Chinese population (NCT03259321).

Targeting PI3K/Akt/mTOR signaling pathway by polyphenols: Implication for cancer therapy

Cancer is one of the biggest challenges facing medicine and its cure is regarded to be the Holy Grail of medicine. Therapy in cancer is consisted as various artificial cytotoxic agents and radiotherapy, and recently immunotherapy. Recently much attention has been directed to the use of natural occurring agents in cancer therapy. One of the main group of agents utilized in this regard is polyphenols which are found abundantly in berries, fruits and vegetables. Polyphenols show to exert direct and indirect effects in progression of cancer, angiogenesis, proliferation and enhancing resistance to treatment. One of the cellular pathways commonly affected by polyphenols is PI3K/Akt/mTOR pathway, which has far ranging effects on multiple key aspects of cellular growth, metabolism and death. In this review article, evidence regarding the biology of polyphenols in cancer via PI3K/Akt/mTOR pathway is discussed and their application on cancer pathophysiology in various types of human malignancies is shown.

Reporting quality in systematic reviews of in vitro studies: a systematic review

Background: Systematic reviews (SRs) and/or meta-analyses of in vitro research have an important role in establishing the foundation for clinical studies. In this study, we aimed to evaluate the reporting quality of SRs of in vitro studies using the PRISMA checklist.Method: Four databases were searched including PubMed, Virtual Health Library (VHL), Web of Science (ISI) and Scopus. The search was limited from 2006 to 2016 to include all SRs and/or meta-analyses (MAs) of pure in vitro studies. The evaluation of reporting quality was done using the PRISMA checklist.Results: Out of 7702 search results, 65 SRs were included and evaluated with the PRISMA checklist. Overall, the mean overall quality score of reported items of the PRISMA checklist was 68%. We have noticed an increasing pattern in the numbers of published SRs of in vitro studies over the last 10 years. In contrast, the reporting quality was not significantly improved over the same period (p = .363). There was a positive but not significant correlation between the overall quality score and the journal impact factor of the included studies.Conclusions: The adherence of SRs of in vitro studies to the PRISMA guidelines was poor. Therefore, we believe that using reporting guidelines and journals paying attention to this fact will improve the quality of SRs of in vitro studies.

The Mediterranean Diet, a Rich Source of Angiopreventive Compounds in Cancer

Diet-based chemoprevention of cancer has emerged as an interesting approach to evade the disease or even target its early phases, reducing its incidence or slowing down tumor progression. In its basis in the essential role of angiogenesis for tumor growth and metastasis, angioprevention proposes the use of inhibitors of angiogenesis in cancer prevention. The anti-angiogenic potential exhibited by many natural compounds contained in many Mediterranean diet constituents makes this dietary pattern especially interesting as a source of chemopreventive agents, defined within the angioprevention strategy. In this review, we focus on natural bioactive compounds derived from the main foods included in the Mediterranean diet that display anti-angiogenic activity, as well as their possible use as angiopreventive agents.

Resveratrol is a promising agent for colorectal cancer prevention and treatment: focus on molecular mechanisms

Colorectal cancer (CRC) is the third most common cancer and one of the main causes of cancer death entire the world. Environmental, dietary, and lifestyle factors including red meat consumption, cigarette smoking, alcohol intake and family history are the most important risk factors of CRC. Multiple pathways including inflammation, oxidative stress, and apoptosis are involved in its incidence and progression. Resveratrol, a polyphenolic compound, has different pharmacologic functions including anti-inflammation, cancer prevention, lipid-lowering effect, and hypoglycemic effect. Many studies have proved that resveratrol might also represent a chemo preventive effect on CRC. Thus, the aim of the current review is to depict the role of resveratrol in treatment of CRC in a molecular manner.

A whole-food approach to the in vitro assessment of the antitumor activity of gazpacho

Gazpacho is a traditional cold soup of the Mediterranean diet consisting of a main base of fresh pureed tomato and other vegetables. Tomato and tomato products have demonstrated chemopreventive activity against several types of cancer through in vitro studies, and in animal and clinical research. Here we have applied a whole-food approach for the preclinical assessment of the antitumor potential of gazpacho. Colon cancer cells (HT-29) were exposed to growing concentrations of gazpacho previously digested in vitro to simulate the delivery of bioactive molecules to colon cells after food consumption. The cytotoxicity of gazpacho ingredients was also tested in independent experiments. Programmed cell death by apoptosis was detected by using a multiparametric analysis that combines image-based bright-field and fluorescence cytometry, intracellular ATP level determination and enzymatic activity of caspase-3/7. Modulation of gene expression of key regulatory genes (p53, Bcl-2, BAX, and cyclin D1) was also investigated. Our cytotoxicity data showed that in vitro digestion of samples allowed the delivery of bioactive levels of antitumor phytochemicals to cultured cells. Controlled experiments showed significant repetitive dose and time-response cytotoxicity of gazpacho. Gazpacho digestates caused net cell death of cultures suggesting synergic activity among phytochemicals from its vegetable ingredients. Multiparametric and genetic analyses showed that gazpacho digestates can trigger colon cancer cells death by apoptosis through the activation of caspase cascade. Our results show that coupled in vitro methodology employed can be applied to investigate the antitumor potential of complex food matrixes or combinations of foods in the diet.

Feasibility and Safety of Laparoscopic Right Colectomy in Oldest-Old Patients with Colon Cancer: Results of the CLIMHET Study Group

BACKGROUND

Laparoscopy for colorectal cancer treatment is widely accepted. However, there is no consensus as to whether or not laparoscopy can be considered the preferred treatment strategy in octogenarian and nonagenarian patients with colon cancer. The aim of this study was to compare operative and postoperative outcomes of laparoscopic right colectomy between oldest-old (≥80 years) and younger (<80 years) patients with colon cancer.

METHODS

The study population was sampled from the CLIMHET Study Group cohort. Between January 2005 and December 2015, data were retrieved for all patients who had undergone elective laparoscopic right colectomy for colon cancer in five University Hospital centers in France (CHU of Clermont-Ferrand, Hôpital Civil of Strasbourg-IRCAD, Hôpital Henri-Mondor of Créteil, Hôpital Européen Georges Pompidou of Paris, and CHRU of Tours).

RESULTS

Overall, 473 cancer patients were selected and analyzed. There were 156 oldest-old patients (median age: 84.1 years, range: 80-96) and 317 younger patients (median age: 67 years, range: 25-79). After adjusting based on propensity score on gender, obesity, American Society of Anesthesiologists score, smoking, arteriopathy, coronaropathy, comorbidity, and American Joint Committee on Cancer staging, no significant difference was found in operative and postoperative outcomes, except for time to resume a regular diet (3.6 days versus 3.0 days, P = .008) and length of hospital stay (12.1 days versus 9.1 days, P = .03), which were longer for oldest-old patients. Overall and disease-free survival rates were also equivalent between groups.

CONCLUSION

These findings support that laparoscopic right colectomy can be safely performed in cancer patients aged 80 and older, and its outcomes are similar in oldest-old and younger patients.

Effect of phenolic extracts from different extra-virgin olive oil varieties on osteoblast-like cells

The reported incidence of osteoporosis is lower in countries in which the Mediterranean diet predominates, and this apparent relationship may be mediated by the phenolic compounds present in olive oil. The objective of this study was to determine the effect of phenolic extracts from different varieties of extra-virgin olive oil (Picual, Arbequina, Picudo, and Hojiblanca) on the differentiation, antigenic expression, and phagocytic capacity of osteoblast-like MG-63 cells. At 24 h of treatment a significant increase in phosphatase alkaline activity and significant reductions in CD54, CD80, and HLA-DR expression and in phagocytic activity were observed in comparison to untreated controls. The in vitro study performed has demonstrated that phenolic compounds from different extra virgin olive oil varieties can modulate different parameters related to osteoblast differentiation and function.

The RS4939827 polymorphism in the SMAD7 GENE and its association with Mediterranean diet in colorectal carcinogenesis

Background

The objective of our investigation is to study the relationship between the rs4939827 SNP in the SMAD7 gene, Mediterranean diet pattern and the risk of colorectal cancer.

Methods

We examined 1087 cases of colorectal cancer and 2409 population controls with available DNA samples from the MCC-Spain study, 2008–2012. Descriptive statistical analyses, and multivariate logistic mixed models were performed. The potential synergistic effect of rs4939827 and the Mediterranean diet pattern was evaluated with logistic regression in different strata of of adherence to the Mediterranean diet and the genotype.

Results

High adherence to Mediterrenean diet was statistically significantly associated with colorectal cancer risk. A decreased risk for CRC cancer was observed for the CC compared to the TT genotype (OR = 0.65 and 95% CI = 0.51–0.81) of the rs4939827 SNP Also, we could show an association between the Mediterranean diet pattern (protective factor) and rs4939827. Although the decreased risk for the CC genotype was slightly more pronounced in subjects with high adherence to Mediterrenean diet, there was no statistically significant synergistic effect between genotype CC and adherence to the Mediterranean dietary pattern factors.

Conclusion

The SMAD7 gene and specifically the allele C could be protective for colorectal cancer. An independent protective association was also observed between high adherence Mediterranean diet pattern and CRC risk. Findings form this study indicate that high adherence to Mediterranean diet pattern has a protective role for CRC cancer probably involving the Tumor Growth Factor- β pathway in this cancer.

Electronic supplementary material

The online version of this article (10.1186/s12881-017-0485-5) contains supplementary material, which is available to authorized users.

Nutrient-Gene Interaction in Colon Cancer, from the Membrane to Cellular Physiology

The International Agency for Research on Cancer recently released an assessment classifying red and processed meat as "carcinogenic to humans" on the basis of the positive association between increased consumption and risk for colorectal cancer. Diet, however, can also decrease the risk for colorectal cancer and be used as a chemopreventive strategy. Bioactive dietary molecules, such as n-3 polyunsaturated fatty acids, curcumin, and fermentable fiber, have been proposed to exert chemoprotective effects, and their molecular mechanisms have been the focus of research in the dietary/chemoprevention field. Using these bioactives as examples, this review surveys the proposed mechanisms by which they exert their effects, from the nucleus to the cellular membrane. In addition, we discuss emerging technologies involving the culturing of colonic organoids to study the physiological effects of dietary bioactives. Finally, we address future challenges to the field regarding the identification of additional molecular mechanisms and other bioactive dietary molecules that can be utilized in our fight to reduce the incidence of colorectal cancer.

Research progress on chemopreventive effects of phytochemicals on colorectal cancer and their mechanisms

Colorectal cancer (CRC) is a type of cancer with high morbidity and mortality rates worldwide and has become a global health problem. The conventional radiotherapy and chemotherapy regimen for CRC not only has a low cure rate but also causes side effects. Many studies have shown that adequate intake of fruits and vegetables in the diet may have a protective effect on CRC occurrence, possibly due to the special biological protective effect of the phytochemicals in these foods. Numerous in vitro and in vivo studies have demonstrated that phytochemicals play strong antioxidant, anti-inflammatory and anti-cancer roles by regulating specific signaling pathways and molecular markers to inhibit the occurrence and development of CRC. This review summarizes the progress on CRC prevention using the phytochemicals sulforaphane, curcumin and resveratrol, and elaborates on the specific underlying mechanisms. Thus, we believe that phytochemicals might provide a novel therapeutic approach for CRC prevention, but future clinical studies are needed to confirm the specific preventive effect of phytochemicals on cancer.

Mediterranean diet and colorectal cancer risk: a pooled analysis of three Italian case-control studies

BACKGROUND

Adherence to the Mediterranean diet (MD) is associated with a reduced risk of several cancers. However, studies conducted in Mediterranean regions are scanty.

METHODS

To investigate the relation between MD and colorectal cancer risk in Italy, we pooled data from three case-control studies, including a total of 3745 colorectal cancer cases and 6804 hospital controls. Adherence to the MD was assessed using an a priori Mediterranean Diet Score (MDS), based on nine components.

RESULTS

Compared with the lowest adherence to the MD (0-2 MDS), the odds ratio (OR) was 0.52 (95% confidence interval (CI) 0.43-0.62) for the highest adherence (7-9 MDS), with a significant inverse trend in risk (P<0.0001). The OR for a 1-point increment in the MDS was 0.89 (95% CI 0.86-0.91). The inverse association was consistent across studies, cancer anatomical subsites and strata of selected covariates.

CONCLUSIONS

This Italian study confirms a favourable role of MD on colorectal cancer risk.

Oxidative Stress: A Promising Target for Chemoprevention

Cancer is a leading cause of death worldwide, and treating advanced stages of cancer remains clinically challenging. Epidemiological studies have shown that oxidants and free radicals induced DNA damage is one of the predominant causative factors for cancer pathogenesis. Hence, oxidants are attractive targets for chemoprevention as well as therapy. Dietary agents are known to exert an anti-oxidant property which is one of the most efficient preventive strategy in cancer progression. In this article, we highlight dietary agents can potentially target oxidative stress, in turn delaying, preventing, or treating cancer development. Some of these agents are currently in use in basic research, while some have been launched successfully into clinical trials.