A U-shaped association between selenium intake and cancer risk.

While selenium is a cofactor of several antioxidant enzymes against cancer and is essential for human health, its excess intake may also be harmful. Though a safe intake of selenium has recently been recommended, it is not well understood in the Asian population. We aimed to determine the association between dietary intake of selenium and cancer risk in a case-control study of 3758 incident cancer cases (i.e., stomach, colon, rectum, lung cancers, and other sites) and 2929 control subjects in Vietnam. Daily intake of selenium was derived from a semiquantitative food frequency questionnaire. The unconditional logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the association between selenium intake and cancer risk. We observed a U-shaped association between selenium intake and cancer risk. A safe intake ranged from 110.8 to 124.4 µg/day (mean 117.8 µg/day). Compared to individuals with the safe intake of selenium, individuals with the lowest intake (i.e., 27.8-77.2 µg/day) were associated with an increased risk of cancer (OR = 3.78, 95% CI 2.89-4.95) and those with the highest intake (169.1-331.7 µg/day) also had an increased cancer risk (OR = 1.86, 95% CI 1.45-2.39). A U-shaped pattern of association between selenium intake and cancer risk was stronger among participants with body mass index (BMI) < 23 kg/m2 and never smokers than BMI ≥ 23 kg/m2 and ever smokers (P'sheterogeneity = 0.003 and 0.021, respectively) but found in both never and ever-drinkers of alcohol (Pheterogeneity = 0.001). A U-shaped association between selenium intake and cancer risk was seen in cancer sites of the stomach, colon, rectum, and lung cancers. In summary, we found a U-shaped association between selenium intake and cancer risk and a safe selenium intake (mean: 117.8 µg/day) in the Vietnamese population. Further mechanistic investigation is warranted to understand better a U-shaped association between selenium intake and cancer risk.

State of the art on the separation and purification of proteins by magnetic nanoparticles.

The need for excellent, affordable, rapid, reusable and biocompatible protein purification techniques is justified based on the roles of proteins as key biomacromolecules. Magnetic nanomaterials nowadays have become the subject of discussion in proteomics, drug delivery, and gene sensing due to their various abilities including rapid separation, superparamagnetism, and biocompatibility. These nanomaterials also referred to as magnetic nanoparticles (MNPs) serve as excellent options for traditional protein separation and analytical methods because they have a larger surface area per volume. From ionic metals to carbon-based materials, MNPs are easily functionalized by modifying their surface to precisely recognize and bind proteins. This review excavates state-of-the-art MNPs and their functionalizing agents, as efficient protein separation and purification techniques, including ionic metals, polymers, biomolecules, antibodies, and graphene. The MNPs could be reused and efficaciously manipulated with these nanomaterials leading to highly improved efficiency, adsorption, desorption, and purity rate. We also discuss the binding and selectivity parameters of the MNPs, as well as their future outlook. It is concluded that parameters like charge, size, core-shell, lipophilicity, lipophobicity, and surface energy of the MNPs are crucial when considering protein selectivity, chelation, separation, and purity.

Stability and bioactivity of peptides in food matrices based on processing conditions.

Bioactive peptides (BPs) generated from food proteins can serve therapeutic purposes against degenerative and cardiovascular diseases such as inflammation, diabetes, and cancer. There are numerous reports on the in vitro, animal, and human studies of BPs, but not as much information on the stability and bioactivity of these peptides when incorporated in food matrices. The effects of heat and non-heat processing of the food products, and storage on the bioactivity of the BPs, are also lacking. To this end, we describe the production of BPs in this review, followed by the food processing conditions that affect their storage bioactivity in the food matrices. As this area of research is open for industrial innovation, we conclude that novel analytical methods targeting the interactions of BPs with other components in food matrices would be greatly significant while elucidating their overall bioactivity before, during and after processing.

Hemp bioactive peptides: Nutrition, functional properties and action mechanisms to maximize their nutraceutical applications and future prospects.

The dietary protein requirement for the world population that just clocked 8 billion should ideally come from the environmentally sustainable lithosphere and should be a plant-based and cost-affordable resource. Hemp proteins and peptides come to mind based upon increasing interest by consumers worldwide. We herein describe the composition and nutrition of hemp protein, including the enzymatic production of hemp peptides (HPs), which reportedly have hypoglycemic, hypocholesterolemic, antioxidative, antihypertensive, and immunomodulatory effects. The action mechanisms involved in each of the reported bioactivities are presented, while not undermining the applications or opportunities associated with HPs. The study's major goal is to compile the status of the art of the various therapeutic HPs and their prospect as drugs for multiple diseases while highlighting needed future developments. We present first the composition, nutrition, and functionality of hemp proteins, prior to reports on their hydrolysis for the production of HPs. It is concluded that HPs present excellent functional ingredients as nutraceuticals targeting hypertension and other degenerative diseases, which have yet to be capitalized upon for commercial uses.

Ethanol elicits inhibitory effect on the growth and proliferation of tongue carcinoma cells by inducing cell cycle arrest.

Cellular effects of ethanol in YD-15 tongue carcinoma cells were assessed by MTT assay, caspase activity assay, Western blotting and flow cytometry. Ethanol inhibited the growth and proliferation of YD-15 cells in a dose- and time-dependent manner in an MTT assay. The effects of ethanol on cell cycle control at low percent range of ethanol concentration (0 to 1.5%), the condition not inducing YD-15 cell death, was investigated after exposing cells to alcohol for a certain period of time. Western blotting on the expression of cell cycle inhibitors showed that p21 and p27 was up-regulated as ethanol concentration increases from 0 to 1.5% whilst the cell cycle regulators, cdk1, cdk2, and cdk4 as well as Cyclin A, Cyclin B1 and Cyclin E1, were gradually down-regulated. Flow cytometric analysis of cell cycle distribution revealed that YD-15 cells exposed to 1.5% ethanol for 24 h was mainly arrested at G2/M phase. However, ethanol induced apoptosis in YD-15 cells exposed to 2.5% or higher percent of ethanol. The cleaved PARP, a marker of caspase-3 mediated apoptosis, and the activation of caspase-3 and -7 were detected by caspase activity assay or Western blotting. Our results suggest that ethanol elicits inhibitory effect on the growth and proliferation of YD-15 tongue carcinoma cells by mediating cell cycle arrest at G2/M at low concentration range and ultimately induces apoptosis under the condition of high concentration.

Capsaicin-induced apoptosis of FaDu human pharyngeal squamous carcinoma cells.

PURPOSE: To investigate the anti-tumor effect of capsaicin on human pharyngeal squamous carcinoma cells (FaDu). MATERIALS AND METHODS: The expression of apoptosis/cell cycle-related proteins (or genes) was examined by reverse transcriptase- polymerase chain reaction, western blotting and ELISA methods, while the apoptotic cell population, cell morphology and DNA fragmentation levels were assessed using flow cytometry, fluorescence microscopy and agarose gel electrophoresis. RESULTS: Capsaicin was found to inhibit the growth and proliferation of FaDu cells in a dose- and time-dependent manner. Apoptotic cell death was confirmed by observing increases in nuclear condensation, nuclear DNA fragmentation and sub-G1 DNA content. The observed increase in cytosolic cytochrome c, activation of caspase 3 and PARP (p85) levels following capsaicin treatment indicated that the apoptotic response was mitochondrial pathway-dependent. Gene/protein expression analysis of Bcl-2, Bad and Bax further revealed decreased anti-apoptotic Bcl-2 protein and increased pro-apoptotic Bad/Bax expression. Furthermore, capsaicin suppressed the cell cycle progression at the G1/S phase in FaDu cells by decreasing the expression of the regulators of cyclin B1 and D1, as well as cyclin-dependent protein kinases cdk-1, cdk-2 and cdk-4. CONCLUSION: Our current data show that capsaicin induces apoptosis in FaDu cells and this response is associated with mitochondrial pathways, possibly by mediating cell cycle arrest at G1/S.