Blood cell, liver function, and response changes by PEG-interferon-alpha2b plus ribavirin with polaprezinc therapy in patients with chronic hepatitis C

Antiviral activity of zinc against hepatitis viruses: current status and future prospects

Viral hepatitis is a major public health concern globally. World health organization aims at eliminating viral hepatitis as a public health threat by 2030. Among the hepatitis causing viruses, hepatitis B and C are primarily transmitted via contaminated blood. Hepatitis A and E, which gets transmitted primarily via the feco-oral route, are the leading cause of acute viral hepatitis. Although vaccines are available against some of these viruses, new cases continue to be reported. There is an urgent need to devise a potent yet economical antiviral strategy against the hepatitis-causing viruses (denoted as hepatitis viruses) for achieving global elimination of viral hepatitis. Although zinc was known to mankind for a long time (since before Christ era), it was identified as an element in 1746 and its importance for human health was discovered in 1963 by the pioneering work of Dr. Ananda S. Prasad. A series of follow up studies involving zinc supplementation as a therapy demonstrated zinc as an essential element for humans, leading to establishment of a recommended dietary allowance (RDA) of 15 milligram zinc [United States RDA for zinc]. Being an essential component of many cellular enzymes and transcription factors, zinc is vital for growth and homeostasis of most living organisms, including human. Importantly, several studies indicate potent antiviral activity of zinc. Multiple studies have demonstrated antiviral activity of zinc against viruses that cause hepatitis. This article provides a comprehensive overview of the findings on antiviral activity of zinc against hepatitis viruses, discusses the mechanisms underlying the antiviral properties of zinc and summarizes the prospects of harnessing the therapeutic benefit of zinc supplementation therapy in reducing the disease burden due to viral hepatitis.

Zinc in Human Health and Infectious Diseases

During the last few decades, the micronutrient zinc has proven to be an important metal ion for a well-functioning immune system, and thus also for a suitable immune defense. Nowadays, it is known that the main cause of zinc deficiency is malnutrition. In particular, vulnerable populations, such as the elderly in Western countries and children in developing countries, are often affected. However, sufficient zinc intake and homeostasis is essential for a healthy life, as it is known that zinc deficiency is associated with a multitude of immune disorders such as metabolic and chronic diseases, as well as infectious diseases such as respiratory infections, malaria, HIV, or tuberculosis. Moreover, the modulation of the proinflammatory immune response and oxidative stress is well described. The anti-inflammatory and antioxidant properties of zinc have been known for a long time, but are not comprehensively researched and understood yet. Therefore, this review highlights the current molecular mechanisms underlying the development of a pro-/ and anti-inflammatory immune response as a result of zinc deficiency and zinc supplementation. Additionally, we emphasize the potential of zinc as a preventive and therapeutic agent, alone or in combination with other strategies, that could ameliorate infectious diseases.

The Effects of Zinc Supplementation on C-Reactive Protein and Inflammatory Cytokines: A Meta-Analysis and Systematical Review

Zinc is known for anti-inflammatory and antioxidant roles. In this meta-analysis, we aim to evaluate the impact of zinc supplementation on inflammatory markers, acute-phase reactants, and serum zinc level during inflammatory and infectious diseases. PubMed, Scopus, and Web of Science databases were screened systematically with the terms "zinc supplementation" AND "CRP" OR "IL-1β" OR "IL-2" OR "IL-6" OR "IL-10" OR "IL-12" OR "TNF-α" OR "TGF-β" OR "IFN-γ" OR "WBC (clinical trial)" OR "macrophage (clinical trial)" OR "lymphocyte (clinical trial)" OR "neutrophil (clinical trial)" OR "virus (clinical trial)" OR "antiviral (clinical trial)" for all databases. A total of 2,258 publications were screened, and 73 articles had suitable data for the meta-analysis. Serum zinc level was significantly higher in supplementation group compared with controls [P = 0.0006, mean difference: 11.35 (4.84, 17.87)] (n = 37). Zinc supplementation downregulates acute-phase reactants, especially serum C-reactive protein (CRP) in adults [P < 0.00001, mean difference: -0.75 (-0.98, -0.52)] (n = 22) and pregnant women [FEM P < 0.00001, mean difference: -1.77 (-2.53, -1.00)] (n = 3) but not in children [REM P = 0.10, mean difference: -0.85 (-1.86, 0.17)] (n = 3). In subgroups analysis of chronic inflammatory diseases, serum CRP [REM P < 0.00001, mean difference: -0.57 (-0.76, -0.38)] were significantly lower in zinc-supplemented patients compared with no intervention group. Zinc supplementation (mg/day) correlated with serum interferon-gamma (IFN-γ) level (P = 0.018, r = 1,000). In the nonsupplemented group, serum zinc correlated with serum interleukin-6 (IL-6) level (P = 0.041, r = -0.829) and serum tumor necrosis factor alpha (TNF-α) level (P = 0.063, r = 0.730). Zinc intake correlated with serum zinc (P = 0.0428, r = 0.5115) and TNF-α (P = 0.0043, r = -0.9461). This meta-analysis shows that zinc supplementation improves CRP levels in adults and pregnant women. It might have modulatory effects on cytokine secretions and blood cells in inflammatory and infectious diseases. For the first time, we investigated the effects of zinc supplementation on inflammatory cytokine.

Serum Zinc and Haptoglobin in Noncirrhotic Azeri Patients with Chronic Active Hepatitis C: a Case-Control Study

The aim of present study was to compare levels of serum zinc and haptoglobin between patients with chronic active hepatitis C and controls. Two groups including Azeri patients with chronic active hepatitis C (n = 274) and their healthy family members (n = 100) were studied. Serum zinc and haptoglobin were measured using colorimetric and nephelometric methods, respectively. Patients were 156 males (56.9%) and 118 females (43.1%) with the mean age of 40.15 ± 12.24 years. Controls were 56 males (56%) and 44 females (44%) with the mean age of 39.32 ± 4.40 (p = 0.87 for sex and 0.51 for age). Both the mean levels of serum zinc (72.04 ± 19.08 vs. 106.18 ± 25.52 μg/dL) and haptoglobin (0.72 ± 0.45 vs. 1.08 ± 0.34 g/L) were significantly lower in patients than in controls (p < 0.001 for both comparisons). Serum zinc concentration was significantly higher in males and did not correlate significantly with age, serum glutamic pyruvic transaminase (SGPT), or serum glutamic oxaloacetic transaminase (SGOT). Serum haptoglobin did not differ significantly between males and females, and it correlated significantly with age (r = -0.20), serum SGPT (r = -0.22), and SGOT (r = -0.20). This study showed lower levels of serum zinc and haptoglobin in patients with chronic hepatitis C than in controls. Major confounding factors in previous studies were left out.

Zinc and liver disease

Zinc is an essential trace element required for normal cell growth, development, and differentiation. It is involved in DNA synthesis, RNA transcription, and cell division and activation. It is a critical component in many zinc protein/enzymes, including critical zinc transcription factors. Zinc deficiency/altered metabolism is observed in many types of liver disease, including alcoholic liver disease (ALD) and viral liver disease. Some of the mechanisms for zinc deficiency/altered metabolism include decreased dietary intake, increased urinary excretion, activation of certain zinc transporters, and induction of hepatic metallothionein. Zinc deficiency may manifest itself in many ways in liver disease, including skin lesions, poor wound healing/liver regeneration, altered mental status, or altered immune function. Zinc supplementation has been documented to block/attenuate experimental ALD through multiple processes, including stabilization of gut-barrier function, decreasing endotoxemia, decreasing proinflammatory cytokine production, decreasing oxidative stress, and attenuating apoptotic hepatocyte death. Clinical trials in human liver disease are limited in size and quality, but it is clear that zinc supplementation reverses clinical signs of zinc deficiency in patients with liver disease. Some studies suggest improvement in liver function in both ALD and hepatitis C following zinc supplementation, and 1 study suggested improved fibrosis markers in hepatitis C patients. The dose of zinc used for treatment of liver disease is usually 50 mg of elemental zinc taken with a meal to decrease the potential side effect of nausea.

Interferon-alpha-2a and zinc combination therapy in children with chronic hepatitis B infection

Zinc has been reported to enhance the response to interferon (IFN) or PEG-IFN plus ribavirin therapy, improve liver function, and ameliorate hematologic side effects in patients with chronic hepatitis C. However, the role of zinc supplementation during IFN therapy in chronic hepatitis B infection (CHB) remains unclear. We therefore aimed to report the results of zinc and IFN-alpha-2a therapy in children with CHB. Twenty-two naive, HBeAg-positive children (mean age 10.4 ± 4.4 years) received IFN-α2a (9 MU/m(2) sc) for 6 months plus peroral zinc (7.5 mg/day for <10 years and 10 mg/day for >10 years) for 12 months. Serum zinc, alanine aminotransferase (ALT), complete blood count, hepatitis B virus DNA (HBV DNA), and serological markers were measured. Histological (HR) and sustained response (SR) were evaluated at 6 months after completion of therapy. Normalization of ALT, HBeAg seroconversion, and HBV DNA < 10,000 copies/ml were considered as SR. HR was defined as decrease in Knodell histological activity index (HAI) score by at least 2 points compared to baseline. End of therapy ALT level and log HBV DNA were significantly lower than pretherapy levels (p = 0.001 and p = 0.001, respectively), while zinc level was not different. Portal inflammation score significantly decreased after therapy (p = 0.043), however, total HAI and other HAI components were not different. SR and HR were 25% and 52.9%. In conclusion as a first study investigating the effect of zinc and IFN combination therapy in children with CHB, SR and HR rates were not better than previously reported monotherapy or combination therapies.