Could Selenium Supplementation Prevent COVID-19? A Comprehensive Review of Available Studies.

The purpose of this review is to systematically examine the scientific evidence investigating selenium's relationship with COVID-19, aiming to support, or refute, the growing hypothesis that supplementation could prevent COVID-19 etiopathogenesis. In fact, immediately after the beginning of the COVID-19 pandemic, several speculative reviews suggested that selenium supplementation in the general population could act as a silver bullet to limit or even prevent the disease. Instead, a deep reading of the scientific reports on selenium and COVID-19 that are available to date supports neither the specific role of selenium in COVID-19 severity, nor the role of its supplementation in the prevention disease onset, nor its etiology.

MAPK signalling pathway in cancers: Olive products as cancer preventive and therapeutic agents.

The mitogen-activated protein kinases (MAPKs) are fundamental in inflammation and cancer control, through the crosstalk between the redox regulated nuclear factor E2-related factor 2 (Nrf2) and nuclear factor-kB (NFκB) gene expression. MAPKs regulate various cellular activities involved in cancer progression, including proliferation, apoptosis and immune escape and blockade of upstream kinases is a current therapeutic strategy. However, these therapies are associated with some adverse effects and with the paradoxical activation of the MAPKs pathway. In the context of cancer prevention and treatment, it has been suggested that dietary factors are able to modulate cancer initiation and progression by interacting with the MAPKs. Within these dietary factors, virgin olive oil (VOO) is of particular interest due to its content in squalene, already used as drug delivery system in cancer therapy. The aim of this review is to discuss the studies pointing to the effects of olive-derived foodstuff and nutraceuticals on MAPKs signalling cascades. The reviewed experimental studies suggest that the stress-activated JNK and p38 MAPKs could be targets of olive-derived nutraceuticals. The latter, including phytochemicals from olive cultivation and processing wastes, could be adjuvants in chemotherapies, whereas VOO could be considered a "natural delivery system" of bioactive phytochemicals due to its high content in squalene.

Genetic Polymorphisms and Zinc Status: Implications for Supplementation in Metabolic Diseases.

BACKGROUND: Zinc is an essential component for all living organisms, representing the second most abundant trace element, after iron. This element is widely distributed in the tissues of a human body where it is involved in normal growth, reproduction and several biological functions including immunity, energy metabolism and antioxidant processes. Because of its essential role, zinc levels in the human body must remain constant, independently of dietary intake fluctuations. The homeostasis of zinc is a well-regulated cellular process and has been reported to be chiefly mediated by the expression and activity of zinc-binding proteins such as metallothioneins and zinc transporters. Genes encoding for these proteins are subjected to genetic variants. METHODS: We performed a multi-database electronic search to provide an overview on the relationship between specific polymorphisms (SNP) of genes encoding for metallothioneins and zinc transporters and their relationship with zinc status, immune function and some non-communicable diseases. RESULTS: A number of SNP are implicated in a range of metabolic disease. Some SNP may affect the impact of zinc supplementation on immune function, diabetes, and obesity. CONCLUSION: New studies are needed to clarify the interaction between individual genetic profile and zinc status. Moreover, there is a need for a better interaction between the scientific bodies and health professionals to allow better dietary and behavioural recommendations to promote human health, with particular concern to elderly people.

A simple microsatellite-based method for hazelnut oil DNA analysis.

Molecular food traceability requires continuous updates to identify more robust, efficient and affordable methodologies to guarantee food quality and safety and especially consumers' health. Available commercial kits are often unsatisfactory and require modifications to successfully detect single components on complex and transformed food matrices. Here we report a simple method for molecular traceability of cold-pressed hazelnut oil based on microsatellite DNA markers. Different genomic extraction methodologies were tested and a total genome pre-amplification step was applied on PCR-negative samples. PCR-capillary electrophoresis using nine microsatellites demonstrates the accuracy of the fingerprint analysis even for filtered oil.

Characterization of the hsp70 response in lymphoblasts from aged and centenarian subjects and differential effects of in vitro zinc supplementation.

Human centenarians attract increasing interest as they hold some still undefined molecular mechanisms resulting in the achievement of exceptional old age. Recent data suggest the ability of centenarians to efficiently counter the increased cellular stress normally associated with ageing. The ubiquitous heat shock (HS) protein HSP70, expressed under the control of the heat shock transcription factor 1 (HSF-1), is recognized as one of the main chaperones associated with cell protection against stresses. In fact, HSP70 protein induction by heat, a classic well characterized cellular stress, was recently reported to be reduced in cells of most aged humans but not in centenarians. In order to investigate the molecular basis of this feature, we analyzed in vitro the time course expression of the hsp70 gene and the activation of HSF-1 in heat treated Epstein Barr virus transformed B-lymphocytes of centenarians. Our study demonstrates that lymphoblasts from centenarians maintain the transcriptional response of hsp70 gene to heat stress similar to young subjects. Such normal induction of hsp70 is associated to higher binding activity of HSF-1 that compensates an age-dependent delay in HSF-1 phosphorylation. Moreover, in vitro zinc supplementation had an age-dependent effect on hsp70 expression, indicating a role for this nutritionally important molecule and suggesting its involvement in cellular stress responses.

Tocotrienol-rich fraction from palm oil affects gene expression in tumors resulting from MCF-7 cell inoculation in athymic mice.

It has recently been shown that tocotrienols are the components of vitamin E responsible for inhibiting the growth of human breast cancer cells in vitro, through an estrogen-independent mechanism. Although tocotrienols act on cell proliferation in a dose-dependent manner and can induce programmed cell death, no specific gene regulation has yet been identified. To investigate the molecular basis of the effect of tocotrienols, we injected MCF-7 breast cancer cells into athymic nude mice. Mice were fed orally with 1 mg/d of tocotrienol-rich fraction (TRF) for 20 wk. At end of the 20 wk, there was a significant delay in the onset, incidence, and size of the tumors in nude mice supplemented with TRF compared with the controls. At autopsy, the tumor tissue was excised and analyzed for gene expression by means of a cDNA array technique. Thirty out of 1176 genes were significantly affected. Ten genes were downregulated and 20 genes up-regulated with respect to untreated animals, and some genes in particular were involved in regulating the immune system and its function. The expression of the interferon-inducible transmembrane protein-1 gene was significantly up-regulated in tumors excised from TRF-treated animals compared with control mice. Within the group of genes related to the immune system, we also found that the CD59 glycoprotein precursor gene was up-regulated. Among the functional class of intracellular transducers/effectors/modulators, the c-myc gene was significantly down-regulated in tumors by TRF treatment. Our observations indicate that TRF supplementation significantly and specifically affects MCF-7 cell response after tumor formation in vivo and therefore the host immune function. The observed effect on gene expression is possibly exerted independently from the antioxidant activity typical of this family of molecules.

Tocotrienol-rich fraction from palm oil and gene expression in human breast cancer cells.

Vitamin E is important not only for its cellular antioxidant and lipid-lowering properties, but also as an antiproliferating agent. It has also been shown to contribute to immunoregulation, antibody production, and resistance to implanted tumors. It has recently been shown that tocotrienols are the components of vitamin E responsible for growth inhibition in human breast cancer cells in vitro as well as in vivo through estrogen-independent mechanisms. Although tocotrienols act on cell proliferation in a dose-dependent manner and can induce programmed cell death, no specific gene regulation has yet been identified. In order to investigate the molecular basis of the effect of a tocotrienol-rich fraction (TRF) from palm oil, we performed a cDNA array analysis of cancer-related gene expression in estrogen-dependent (MCF-7) and estrogen-independent (MDA-MB-231) human breast cancer cells. The human breast cancer cells were incubated with or without 8 mug/mL of tocotrienols for 72 h. RNA was subsequently extracted and subjected to reverse transcription before being hybridized onto cancer arrays. Tocotrienol supplementation modulated significantly 46 out of 1200 genes in MDA-MB-231 cells. In MCF-7 cells, tocotrienol administration was associated with a lower number of affected genes. Interestingly, only three were affected in a similar fashion in both cell lines: c-myc binding protein MM-1, 23-kDa highly basic protein, and interferon-inducible protein 9-27 (IFITM-1). These proteins are most likely involved in the cell cycle and can exert inhibitory effects on cell growth and differentiation of the tumor cell lines. These data suggest that tocotrienols are able to affect cell homeostasis, possibly independent of their antioxidant activity.