Dietary phytochemicals in colorectal cancer prevention and treatment: A focus on the molecular mechanisms involved.

Worldwide, colorectal cancer (CRC) remains a major cancer type and leading cause of death. Unfortunately, current medical treatments are not sufficient due to lack of effective therapy, adverse side effects, chemoresistance and disease recurrence. In recent decades, epidemiologic observations have highlighted the association between the ingestion of several phytochemical-enriched foods and nutrients and the lower risk of CRC. According to preclinical studies, dietary phytochemicals exert chemopreventive effects on CRC by regulating different markers and signaling pathways; additionally, the gut microbiota plays a role as vital effector in CRC onset and progression, therefore, any dietary alterations in it may affect CRC occurrence. A high number of studies have displayed a key role of growth factors and their signaling pathways in the pathogenesis of CRC. Indeed, the efficiency of dietary phytochemicals to modulate carcinogenic processes through the alteration of different molecular targets, such as Wnt/ß-catenin, PI3K/Akt/mTOR, MAPK (p38, JNK and Erk1/2), EGFR/Kras/Braf, TGF-ß/Smad2/3, STAT1-STAT3, NF-кB, Nrf2 and cyclin-CDK complexes, has been proven, whereby many of these targets also represent the backbone of modern drug discovery programs. Furthermore, epigenetic analysis showed modified or reversed aberrant epigenetic changes exerted by dietary phytochemicals that led to possible CRC prevention or treatment. Therefore, our aim is to discuss the effects of some common dietary phytochemicals that might be useful in CRC as preventive or therapeutic agents. This review will provide new guidance for research, in order to identify the most studied phytochemicals, their occurrence in foods and to evaluate the therapeutic potential of dietary phytochemicals for the prevention or treatment of CRC by targeting several genes and signaling pathways, as well as epigenetic modifications. In addition, the results obtained by recent investigations aimed at improving the production of these phytochemicals in genetically modified plants have been reported. Overall, clinical data on phytochemicals against CRC are still not sufficient and therefore the preventive impacts of dietary phytochemicals on CRC development deserve further research so as to provide additional insights for human prospective studies.

Phenolic Compounds in Honey and Their Associated Health Benefits: A Review.

Honey is a natural substance appreciated for its therapeutic abilities since ancient times. Its content in flavonoids and phenolic acids plays a key role on human health, thanks to the high antioxidant and anti-inflammatory properties that they exert. Honey possesses antimicrobial capacity and anticancer activity against different types of tumors, acting on different molecular pathways that are involved on cellular proliferation. In addition, an antidiabetic activity has also been highlighted, with the reduction of glucose, fructosamine, and glycosylated hemoglobin serum concentration. Honey exerts also a protective effect in the cardiovascular system, where it mainly prevents the oxidation of low-density lipoproteins, in the nervous system, in the respiratory system against asthma and bacterial infections, and in the gastrointestinal system. A beneficial effect of honey can also be demonstrated in athletes. The purpose of this review is to summarize and update the current information regarding the role of honey in health and diseases.

Beeswax by-Products Efficiently Counteract the Oxidative Damage Induced by an Oxidant Agent in Human Dermal Fibroblasts.

The antioxidant capacity and the phytochemical composition of two by-products from beeswax recycling processes were recently investigated. The aim of the present work was to evaluate the efficacy of one of these by-products, MUD1, against the oxidative stress induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) in human dermal fibroblast (HDF) cells. After a preliminary viability assay, the protective effect of MUD1 was investigated through the measurement of apoptosis level, the reactive oxygen species (ROS) and nitrite (NO2-) production, the level of protein and lipid biomarkers (carbonyl groups, total glutathione and thiobarbituric acid-reactive substance) of oxidative damage, and the measurement of antioxidant enzymes activities (glutatione peroxidase, glutathione reductase, glutathione transferase, superoxide dismutase and catalase). The obtained results showed that MUD1 exerted protective effects on HDF, increasing cell viability and counteracted the oxidative stress promoted by AAPH-treatment, and improved mitochondria functionality and wound healing capacities. This work shows the antioxidant effects exerted by beeswax by-products, demonstrating for the first time their potential against oxidative stress in human dermal fibroblast cells; however, further research will be necessary to evaluate their potentiality for human health by more deeply in vitro and in vivo studies.

Protective effects of Manuka honey on LPS-treated RAW 264.7 macrophages. Part 1: Enhancement of cellular viability, regulation of cellular apoptosis and improvement of mitochondrial functionality.

Manuka honey (MH) is a monofloral honey from Australia and New Zealand, well-known for its healthy properties, such as antioxidant, antimicrobial and wound healing capacities. The aim of this work was to assess the phenolic composition and the total antioxidant capacity (TAC) of MH, as well as its effects on cellular viability, proliferation, apoptosis and metabolism in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, highlighting the molecular mechanisms involved. Up to 18 compounds were identified in MH, with gallic acid and quercetin as the major ones; MH showed also remarkable TAC. In addition, MH was able to enhance cellular viability, decrease apoptosis, promote wound healing and attenuate inflammation in a dose-dependent manner, by reducing the expression of caspase 3, p-p38 and p-Erk1/2 proteins, in macrophages stressed with LPS. In addition, it improved mitochondrial respiration and glycolytic activities, stimulating the expression of p-AMPK, SIRT1 and PGC1α, counteracting in this way the deleterious effects of LPS treatment. In conclusion, one of the possible mechanisms by which MH exerts its beneficial effects could be to its capacity to improve cellular viability, promote proliferation and enhance energetic metabolism, by modulating the expression of several proteins involved in apoptosis, inflammation, metabolism and mitochondrial biogenesis.

Phenolic Compounds Isolated from Olive Oil as Nutraceutical Tools for the Prevention and Management of Cancer and Cardiovascular Diseases.

Non-communicable diseases (NCDs) have become the largest contributor to worldwide morbidity and mortality. Among them, cancer and cardiovascular diseases (CVDs) are responsible for a 47% of worldwide mortality. In general, preventive approaches modifying lifestyle are more cost-effective than treatments after disease onset. In this sense, a healthy diet could help a range of NCDs, such as cancer and CVDs. Traditional Mediterranean Diet (MD) is associated by the low-prevalence of certain types of cancers and CVDs, where olive oil plays an important role. In fact, different epidemiological studies suggest that olive oil consumption prevents some cancers, as well as coronary heart diseases and stroke incidence and mortality. Historically, the beneficial health effects of virgin olive oil (VOO) intake were first attributed to the high concentration of monounsaturated fatty acids. Nowadays, many studies indicate that phenolic compounds contained in olive oil have positive effects on different biomarkers related to health. Among them, phenolic compounds would be partially responsible for health benefits. The present work aims to explore, in studies published during the last five years, the effects of the main phenolic compounds isolated from olive oil on different cancer or CVD aspects, in order to clarify which compounds have more potential to be used as nutraceuticals with preventive or even therapeutic properties.

The inhibitory effect of Manuka honey on human colon cancer HCT-116 and LoVo cell growth. Part 2: Induction of oxidative stress, alteration of mitochondrial respiration and glycolysis, and suppression of metastatic ability.

Despite its high content of phenolic compounds, the chemopreventive activity of Manuka honey (MH) is still elusive. The aim of the present work was to evaluate the effects of MH on oxidative stress, antioxidant enzymes, cellular metabolism and the metastatic ability in HCT-116 and LoVo cells, paying particular attention to the molecular mechanisms involved. We observed a strong induction of oxidative stress after MH treatment since it augmented the accumulation of reactive oxygen species and increased the damage to proteins, lipids and DNA. Furthermore, MH suppressed the Nrf2-dependent antioxidant enzyme expression (superoxide dismutase (SOD), catalase and heme oxygenase-1) and the activity of SOD, catalase, glutathione peroxidase and glutathione reductase. Cell metabolisms were markedly disrupted after MH treatment. It decreased maximal oxygen consumption and spare respiratory capacity, which could reduce the mitochondrial function that is correlated with cell survival potential. Simultaneously, MH decreased the extracellular acidification rate (glycolysis) of HCT-116 and LoVo cells. Furthermore, MH suppressed the p-AMPK/AMPK, PGC1α and SIRT1 activation, involved in the survival of HCT-116 and LoVo cells under metabolic stress conditions. Dose-dependently, MH reduced the migration and invasion (MMP-2 and MMP-9) ability, and concurrently regulated EMT-related markers (E cadherin, N cadherin, and ß-catenin) in both cell types. The above findings indicate that MH induces HCT-116 and LoVo cell death partly by enhancing oxidative stress, as well as by regulating the energy metabolism in both aerobic and anaerobic pathways and suppressing the metastatic ability.

Nutritional patterns associated with the maintenance of neurocognitive functions and the risk of dementia and Alzheimer's disease: A focus on human studies.

Ample epidemiological evidence suggests a strong correlation among diet, lifestyle factors and the onset and consolidation of dementia and Alzheimer's disease (AD). It has been demonstrated that AD, diabetes, obesity, insulin resistance, and cardiovascular disease are strongly interconnected pathologies. Preventive strategies and nutritional interventions seem to be promising approaches to delay neurocognitive decline and reduce the risk of AD and other non-psychiatric co-morbidities. In this regard, healthy dietary patterns, characterized by high intake of plant-based foods, probiotics, antioxidants, soy beans, nuts, and omega-3 polyunsaturated fatty acids, and a low intake of saturated fats, animal-derived proteins, and refined sugars, have been shown to decrease the risk of neurocognitive impairments and eventually the onset of AD. Here we review the role of some nutrients and, in particular, of healthy dietary patterns, such as the Mediterranean diet and other emerging healthy diets, DASH (Dietary Approach to Stop Hypertension) and MIND (Mediterranean-DASH dietIntervention for Neurodegenerative Delay), for the maintenance of cognitive performance, focusing specifically on human studies. The beneficial effects associated with overall diet composition, rather than single nutrient supplementations, for the prevention or the delay of AD and dementia are discussed.