Protein energy-malnutrition: does the in vitro zinc sulfate supplementation improve chromosomal damage repair?

Biological Role of Zinc in Liver Cirrhosis: An Updated Review

Liver cirrhosis is a complication usually due to the consequence of persistent chronic liver disease. It is associated with different mechanisms, including hypoalbuminemia, impaired amino acid turnover, and micronutrient deficiencies. Consequently, cirrhotic patients can develop progressive complications like ascites, hepatic encephalopathy, and hepatocellular carcinoma. The liver is a vital organ that regulates the different metabolic pathways and transportation of trace elements. Zn is an indispensable micronutrient trace element involved in its crucial functions in cellular metabolic activity. Zn mediates its action by binding to a wide range of proteins; therefore, it imparts numerous biological effects, including cellular division, differentiation, and growth. It is also involved in critical processes for the biosynthesis of structural proteins and regulation of transcription factors and acts as a co-factor for the various enzymatic processes. As the liver is a significant regulator of Zn metabolism, its abnormalities lead to Zn deficiency, which has consequences on cellular, endocrine, immune, sensory, and skin dysfunctions. Conversely, Zn deficiency may modify the functions of hepatocytes and immune responses (acute phase protein production) in inflammatory liver diseases. This review has concisely stated the evolving indication of the critical role of Zn in biological processes and complications associated with liver cirrhosis pathogenesis due to Zn deficiency.

Effects of oral supplementation in the management of oral mucositis in cancer patients: A meta-analysis of randomized clinical trials

PURPOSE

To evaluate the effects of oral supplementation on the management of oral mucositis in patients with cancer undergoing chemo and/or radiation therapy.

METHOD

This is a systematic review and meta-analysis. The search was performed at 6 databases, and in the gray literature. Methodology of included studies was evaluated by the Cochrane Collaboration Risk of Bias Tool, and evidence quality was assessed by GRADE instrument.

RESULTS

Twelve randomized clinical trials were included in this review. The oral supplementation used was an oral elemental diet with amino acids and minerals (elental), glutamine, and zinc. The majority of the studies included in this review showed benefits in delaying the occurrence of OM by using glutamine and zinc, and in reducing the severity of OM with glutamine, zinc, and elental in patients receiving chemoradiotherapy. The meta-analysis showed that the risk of oral mucositis in the zinc group was slightly lower than in the control (RR: 0.71, 95% CI: 0.53-0.96, P = 0.02, n = 982) while the glutamine group presented the same risk as the control (RR: 0.91, 95% CI: 0.78-1.05, P = 0.19, n = 314). The evidence quality suggested low confidence for zinc and glutamine studies in the estimated effect from the outcomes assessed.

CONCLUSIONS

Zinc is a promising strategy in the management of oral mucositis since it delayed the occurrence and reduced its severity. Glutamine and Elental, on the other hand, had no strong evidence in the prevention and/or treatment of oral mucositis in patients with cancer.

Epigenetic Regulation of Centromere Chromatin Stability by Dietary and Environmental Factors

The centromere is a genomic locus required for the segregation of the chromosomes during cell division. This chromosomal region together with pericentromeres has been found to be susceptible to damage, and thus the perturbation of the centromere could lead to the development of aneuploidic events. Metabolic abnormalities that underlie the generation of cancer include inflammation, oxidative stress, cell cycle deregulation, and numerous others. The micronucleus assay, an early clinical marker of cancer, has been shown to provide a reliable measure of genotoxic damage that may signal cancer initiation. In the current review, we will discuss the events that lead to micronucleus formation and centromeric and pericentromeric chromatin instability, as well transcripts emanating from these regions, which were previously thought to be inactive. Studies were selected in PubMed if they reported the effects of nutritional status (macro- and micronutrients) or environmental toxicant exposure on micronucleus frequency or any other chromosomal abnormality in humans, animals, or cell models. Mounting evidence from epidemiologic, environmental, and nutritional studies provides a novel perspective on the origination of aneuploidic events. Although substantial evidence exists describing the role that nutritional status and environmental toxicants have on the generation of micronuclei and other nuclear aberrations, limited information is available to describe the importance of macro- and micronutrients on centromeric and pericentromeric chromatin stability. Moving forward, studies that specifically address the direct link between nutritional status, excess, or deficiency and the epigenetic regulation of the centromere will provide much needed insight into the nutritional and environmental regulation of this chromosomal region and the initiation of aneuploidy.

The role of zinc in liver cirrhosis

Zinc is an essential trace element playing fundamental roles in cellular metabolism. It acts mostly by binding a wide range of proteins, thus affecting a broad spectrum of biological processes, which include cell division, growth and differentiation. Zinc is critical to a large number of structural proteins, enzymatic processes, and transcription factors. Zinc deficiency can result in a spectrum of clinical manifestations, such as poor of appetite, loss of body hair, altered taste and smell, testicular atrophy, cerebral and immune dysfunction, and diminished drug elimination capacity. These are common symptoms in patients with chronic liver diseases, especially liver cirrhosis. The liver is the main organ responsible for the zinc metabolism which can be affected by liver diseases. On the other hand, zinc deficiency may alter hepatocyte functions and also immune responses in inflammatory liver diseases. Liver cirrhosis represents the most advanced stage of chronic liver diseases and is the common outcome of chronic liver injury. It is associated with energy malnutrition, with numerous metabolic disorders, such as hypoalbuminemia, with imbalance between branched-chain amino acids and aromatic amino acids, and with reduced zinc serum concentrations. All these processes can influence the clinical outcome of patients, such ascites, hepatic encephalopathy and hepatocellular carcinoma. In the present review, we summarize the emerging evidence on the pitoval role of zinc in the pathogenesis of liver cirrhosis.