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Long coronavirus disease (COVID) syndrome leads to chronic inflammatory state onset that can have a multisystem impact and compromise organ function. Moreover, long COVID syndrome is often characterized by the presence of chronic fatigue, which affects subjects' daily activities and worsens their quality of life. The aim of our double-blind, placebo-controlled randomized trial (protocol code RS 150.21, approved on 4 November 2021) was to evaluate the beneficial effects of the consumption of 2 cps/day, for two months, of an oral food supplement (OFS), based on Echinacea angustifolia, rosehip, propolis, royal jelly and zinc, in long COVID patients, compared to a two-month placebo period. The OFS's vitamin C content was equal to 22.17 mg/g (8.87 mg/capsule). The OFS's total polyphenol content was 43.98 mg/g gallic acid equivalents. At the end of the in vivo study, we highlighted a significant decrease in the inflammatory parameters in the OFS period, compared to the placebo period (neutrophil-to-lymphocyte ratio, p = 0.0455; monocyte to-lymphocyte ratio, p = 0.0005; C-reactive protein, p = 0.0145). Our study also highlighted a significant increase in vitamin D serum values (p = 0.0005) and, at the same time, an improvement in patients' life quality and a reduction in fatigue, monitored by the fatigue severity scale. This study showed the OFS's beneficial effects on the inflammatory state, fatigue and quality of life in long COVID patients. [ABSTRACT FROM AUTHOR]

Excess oxidative stress generated in the body causes various types of cellular damage, including DNA damage. Certain trace minerals act as antioxidants by functioning as cofactors for antioxidant enzymes. This study was conducted to evaluate the serum and hair concentrations of major antioxidant trace minerals (zinc, manganese, selenium, and chromium) and to determine the association between the oxidative stress marker urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) and serum or hair antioxidant trace mineral concentrations, according to the general characteristics of healthy adults. Study participants were selected after screening, and 108 participants aged 19–69 years were finally included. Serum and hair trace mineral concentrations were analyzed using inductively coupled plasma mass spectrometry, and urine 8-OHdG levels were quantified using an ELISA kit. Results showed that urinary 8-OHdG levels were significantly higher in exercisers than in those who did not exercise. Correlation analysis revealed that urinary 8-OHdG was negatively correlated with hair zinc in participants over 60 years of age and with poor health status, and positively correlated with hair chromium in participants with irregular dietary habits. In conclusion, these results suggest that urinary 8-OHdG is particularly correlated with hair zinc and chromium levels. Additional large-scale epidemiological studies are needed to generally confirm these findings. [ABSTRACT FROM AUTHOR]

The recent temperature extremes and other associated climatic events pose a detrimental effect to ruminant livestock. To abate this, it is necessary to adopt a functional (biotechnology) approach like the use of nano minerals as feed additives for normal immune function. Nano zinc oxide (nZnO) has demonstrated growth-promoting properties and has been reported to improve antioxidant capacities with high bioavailability recorded in ruminant. This study therefore aimed to research into nano zinc supplementation on growth performance, haematology, serum, oxidative and antioxidant enzymes of West African dwarf (WAD) goats. A total of 18 yearling WAD goats (7.2 ± 0.54 kg) were allocated into 3 treatments of 6 animals per treatment on weight equalization bases. Each group was randomly allotted to three (0, 300 and 600 mg/kg nZnO) experimental diets. Data on haematological parameters, serum minerals and serum biochemical parameters were collected on day 0 and day 84 of the experiment. Data collected were subjected to analysis of variance in a completely randomized design (CRD), and significant means were separated using Tukey's test. It was revealed that West African dwarf goats fed 600 mg/kg nZnO recorded the highest (p < 0.05) PCV and white blood cell values (32.00% and 5.70 × 103/L, respectively) while goats fed 300 mg/kg nZnO recorded the lowest values. At day 84, nZnO supplementation increased serum total protein, globulin and total cholesterol concentration, with higher values (7.57 g/dl, 4.17 g/dl and 95.73 mg/dl) recorded for goats fed 300 mg/kg nZnO. Lower aspartate aminotransferase (66.33 U/L) was observed for goats fed diets containing 300 g/kg nano zinc oxide. Serum minerals (phosphorus, zinc, copper and iron) were elevated in 600 mg/kg nZnO group. Supplementation of nZnO had no significant (p > 0.05) effect on blood superoxide dismutase (SOD) and total bilirubin concentration while reduced (p < 0.05) malondialdehyde (MDA) and urea values were recorded in 300 and 600 mg/kg nZnO supplemented treatments. Goats fed 600 mg/kg nZnO recorded a lower (p < 0.05) glutathione peroxidase value for kidney (24.78 U/mg) and forelimb cut (24.89 U/mg) while kidney, liver and forelimb cut SOD values (4.61, 2.45 and 5.84 U/mg, respectively) were highest at 300 mg/kg nZnO group. The study concluded that supplemented nZnO aided maintenance of and improved the health of the experimental animals through elevated PCV, serum parameters, reduced MDA, urea and other oxidative biomarkers in both serum and organs of West African dwarf goats. [ABSTRACT FROM AUTHOR]

Simple Summary: Optimum trace mineral (TM) status in ruminants is essential for fertility and the survival of the offspring by preventing oxidative stress and improving immunity. The benefits of injectable TM (ITM) supplementation in the lead-up to high-demand periods, such as pregnancy and calving, have been demonstrated in cattle. However, scientific evidence of its benefits for sheep fertility and health is scarce. The objective of this field study was to evaluate the effect of an ITM supplement containing Cu, Se, Zn and Mn pre-joining and pre-lambing to ewes on conception rates, ewe and lamb survival and farm profitability. This study demonstrated that supplementing ewes using ITM before joining and lambing can improve lamb survival, weight at weaning and farm profitability. These results help to understand TM supplementation for animal health, performance and farm profitability beyond the treatment of clinical deficiencies. This study was conducted on five commercial farms across Victoria, Australia, between September 2018 and November 2019, where the TM status of ewes was within normal ranges before joining. Mix breed ewes (n = 1484) were randomly allocated to receive either nil treatment (Control) or two injections of an ITM product containing zinc (40 mg/mL), manganese (10 mg/mL), selenium (3 mg/mL), and copper (10 mg/mL); 0.2 mL per 10 kg BW (Multimin® plus Copper for Sheep, Virbac (Australia) Pty Ltd., Milperra, NSW, Australia) 30 days before the start of joining and 30 days before the start of lambing. Approximately 90 days after joining, pregnancy status and conception rate were determined by ultrasound. The marking rate was determined approximately four weeks after the end of lambing, and lamb weights were determined at weaning (12 weeks after the end of lambing). In all farms, ITM treatment did not affect the conception rate. The average conception rate was 156 ± 11.0% (p > 0.05). The marking rate of ITM ewes was 9% higher than control ewes (95% Confidence Interval 3–21%). Lambs born to ITM ewes were 2.31 kg heavier at weaning than lambs born to control ewes (p < 0.001). Although not significant, ewe mortality across farms was 1.3% lower in the ITM group than in the control group. On average, ewes treated with ITM pre-joining and pre-lambing produced more and heavier lambs that represent an extra AU$ 2338 per 100 ewes net benefit for the producer. These results help to understand strategic TM supplementation for animal health, performance and farm profitability beyond the treatment of clinical deficiencies. [ABSTRACT FROM AUTHOR]

Zinc is one of the essential microelements for the metabolism of animals. Zinc nanoparticles may have higher bioavailability due to their low specific surface area, facilitating absorption by fish. The present study aimed to evaluate the effects of supplementation with different zinc-based products on the growth and health of Nile tilapia Oreochromis niloticus. Zinc, in different sizes (nanoparticles or bulk) and forms (inorganic or organic), were used as a supplement in the tilapia diet at a dose of 15 mg kg feed−1 for 60 days. At the end of the feeding trial, production performance, hemato-immunological parameters, activity of antioxidant system enzymes, exposure to Streptococcus agalactiae and zinc concentration in the muscle were examined. After the bacterial challenge, the mean corpuscular hemoglobin concentration (MCHC) significantly increased in the fish treated with organic zinc, inorganic nano zinc, and organic nano zinc, while in the control group (inorganic zinc), MCHC remained unchanged. Regarding defense cells, dietary inorganic nano zinc increased the number of basophils (1.50 ± 1.10) compared to organic zinc (0.80 ± 0.90). Lymphocyte count increased after the challenge only in the organic zinc treatments (bulk and nanoparticles). Neutrophils decreased in the control (inorganic zinc) (2.20 ± 1.70) and inorganic nano zinc (2.60 ± 2.70) treatments after the challenge. When compared before and after the bacterial challenge, the plasma antimicrobial titer significantly increased after the bacterial challenge in all treatments. No significant differences were observed for total proteins, enzymes (SOD and CAT), cumulative survival and zinc deposition on fillet. In conclusion, organic zinc in nanoparticles or bulk size increased Nile tilapia innate defense during bacterial infection. However, the other parameters evaluated were not affected by zinc particle size or form (organic or inorganic), indicating that further evaluations should be conducted with organic zinc in nanoparticles or bulk size in the tilapia diet. • Lymphocytes increased after challenge only in organic zinc treatments. • Zinc nanoparticles increased basophils compared to organic zinc. • Neutrophils increased in organic zinc treatments and decreased in inorganic treatments after bacterial challenge. • Organic zinc in nanoparticle or bulk size increases lymphocytes and neutrophils during infection. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the protective effects and mechanisms of dietary administration of sodium humate (HNa) and its zinc and selenium chelate (Zn/Se-HNa) in mitigating Salmonella Typhimurium ( S. Typhi ) induced intestinal injury in broiler chickens. Following the gavage of 109 CFU S. Typhi to 240 broilers from 21-d to 23-d aged, various growth performance parameters such as body weight (BW), average daily gain (ADG), average daily feed intake (ADFI), and feed ratio (FCR) were measured before and after infection. Intestinal morphology was assessed to determine the villus height, crypt depth, and chorionic cryptologic ratio. To evaluate intestinal barrier integrity, levels of serum diamine oxidase (DAO), D-lactic acid, tight junction proteins, and the related genes were measured in each group of broilers. An analysis was conducted on inflammatory-related cytokines, oxidase activity, and Nuclear Factor Kappa B (NF-κB) and Nuclear factor erythroid2-related factor 2 (Nrf2) pathway-related proteins and mRNA expression. The results revealed a significant decrease in BW, ADG, and FCR in S. typhi -infected broilers. HNa tended to increase FCR (P = 0.056) while the supplementation of Zn/Se-HNa significantly restored BW and ADG (P < 0.05). HNa and Zn/Se-HNa exhibit favorable and comparable effects in enhancing the levels of serum DAO, D-lactate, and mRNA and protein expression of jejunum and ileal tight junction. In comparison to HNa, Zn/Se-HNa demonstrates a greater reduction in S. Typhi shedding in feces, as well as superior efficacy in enhancing the intestinal morphology, increasing serum catalase (CAT) activity, inhibiting pro-inflammatory cytokines, and suppressing the activation of the NF-κB pathway. Collectively, Zn/Se-HNa was a more effective treatment than HNa to alleviate adverse impact of S. Typhi infection in broiler chickens. [ABSTRACT FROM AUTHOR]

Background: Numerous studies have manifested that sperm deoxyribonucleic acid fragmentation levels can be lowered by use of antioxidants and some studies have shown the consequences of oral antioxidants on sperm chromatin probity. Supplementation of antioxidants in the body is likely to increase the motility and concentration of sperm, and sperm DNA fragmentation. Specific antioxidants such as CoenzymQ10, Vit-E, C, L-Carnitine are supplemented into the body to decrease oxidative stress, reactive oxygen species further sperm DNA disintegration levels. Supplementation of folate helps in improving the sperm concentration. Further, supplementation of zinc and selenium plays essential role in increasing sperm motility. Objectives: To identify the deficiency of the antioxidants and nutrients in infertile male partner. To study the consequences of antioxidants on motility, morphology and count of sperms. To evaluate sperm DNA disintegration levels before and after performing SCD test. Methodology: This non-invasive methodology includes recording of treatment history and the indications. Counselling of the participants for research will be done. Further protocol include supplementation of antioxidants like CoenzymQ10, Vit-C, E to study their effects on Sperm kinetics, concentration of sperm and Sperm DNA disintegration levels. [ABSTRACT FROM AUTHOR]

In this study, effect high-energy diet with supplemented with copper and zinc on oxidative stress, leukocyte function and reproductive performance during the transition period in the crossbred cow under tropical settings. Advanced pregnant crossbred cows of two to four parity and lactation yield of >10 L/day were divided into three equal groups (n = 10 cow/group). Group I cows were fed basal diet to serve as control. Group II cows were supplemented with 20% additional concentrate, copper (15.7/kg DM) and zinc (22 mg/kg DM). Group III cows were provided with only energy in the form of 20% additional concentrate. Copper and zinc were supplemented from −4 before to +8 week of calving, whereas concentrate was given from +2 to +8 week after calving. Blood samples were collected at weekly interval from −4 to +8 week of calving. Group II had a significantly lower MDA, higher TAC and decreased activity of SOD and CAT than that of Group I (P < 0.05). Phagocytic activity and lymphocytic activity increased from 3 to 8 weeks postpartum (P < 0.05) in Group II and III indicating early restoration of leukocyte function. Resumption of postpartum oestrus was shorter in group II (P < 0.05). [ABSTRACT FROM AUTHOR]

Background: Enteromorpha prolifera (E. prolifera) polysaccharide has become a promising feed additive with a variety of physiological activities, such as anti-oxidant, anti-cancer, anti-diabetic, immunomodulatory, hypolipidemic, and cation chelating ability. However, whether Enteromorpha polysaccharide-trace element complex supplementation regulates amino acid and fatty acid metabolism in chicken is largely unknown. This study was conducted to investigate the effects of E. prolifera polysaccharide (EP)-Zn supplementation on growth performance, amino acid, and fatty acid metabolism in chicken. Methods: A total of 184 one-day-old Ross-308 broiler chickens were randomly divided into two treatment groups with 8 replicates, 12 chickens per replicate, and fed either the basal diet (control group) or basal diet plus E. prolifera polysaccharide-Zinc (400 mg EP-Zn/kg diet). Results: Dietary EP-Zn supplementation significantly increased (P < 0.05) the body weight, average daily gain, muscle antioxidant activity, serum HDL level, and reduced serum TG and LDL concentration. In addition, dietary EP-Zn supplementation could modulate ileal amino acid digestibility and upregulate the mRNA expression of amino acid transporter genes in the jejunum, ileum, breast muscle, and liver tissues (P < 0.05). Compared with the control group, breast meat from chickens fed EP-Zn had higher (P < 0.05) Pro and Asp content, and lower (P < 0.05) Val, Phe, Gly, and Cys free amino acid content. Furthermore, EP-Zn supplementation upregulated (P < 0.05) the mRNA expressions of mTOR and anti-oxidant related genes, while down-regulated protein degradation related genes in the breast muscle. Breast meat from EP-Zn supplemented group had significantly lower (P < 0.05) proportions of Σn-3 PUFA, and a higher percentage of Σn-6 PUFA and the ratio of n-6/n-3 PUFA. Besides, EP-Zn supplementation regulated lipid metabolism by inhibiting the gene expression of key enzymes involved in the fatty acid synthesis and activating genes that participated in fatty acid oxidation in the liver tissue. Conclusions: It is concluded that EP-Zn complex supplementation regulates apparent ileal amino acid digestibility, enhances amino acid metabolism, and decreases oxidative stress-associated protein breakdown, thereby improving the growth performance. Furthermore, it promotes fatty acid oxidation and restrains fat synthesis through modulating lipid metabolism-related gene expression. [ABSTRACT FROM AUTHOR]

Purpose: To measure the serum levels of the oxidative stress markers superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPx) and compare them before and after zinc supplementation in patients with early age-related macular degeneration (AMD). Methods: We measured serum zinc levels in 65 patients with early AMD. Of these, 29 patients with macular drusen and a serum zinc level <80 μg/dL received oral zinc acetate dihydrate (50 mg/day). Serum trace metal levels (zinc and copper) and oxidative stress marker levels (SOD, MDA, and GPx) were measured at baseline and 12 weeks after the treatment. The macular drusen areas and best-corrected visual acuity were evaluated in 24 participants who attended the 3-month follow-up. Results: MDA level was significantly decreased from baseline to 12 weeks after zinc administration (170.5 ± 100.9 vs. 148.3 ± 57.9 pmol/mL, P = 0.03), while SOD was significantly increased from baseline to 12 weeks after zinc intake (4.2 ± 0.9 vs. 4.6 ± 0.9 U/mL, P = 0.03). The serum zinc level was significantly correlated with the MDA level (P = 0.03, ρ = -0.26). The area of soft drusen was significantly decreased after zinc treatment (1,936,654.9 ± 1,348,267.6 vs. 966,883.9 ± 719,938.1 μmm2, P = 0.04). Conclusions: The levels of oxidative stress markers MDA and SOD decreased and increased, respectively, after oral zinc administration to 24 patients with AMD. The therapeutic effect of zinc treatment on drusen area might differ depending on the drusen phenotype in early AMD. [ABSTRACT FROM AUTHOR]

Valproic acid (VPA) is widely used antiepileptic agent which is associated with reproductive toxicity via impairment in oxidative redox. Zinc (Zn) and selenium (Se) are trace element with antioxidant effect that known to be essential for spermatogenesis. In the current study, the protective effect of co-administration of Zn and Se on VPA-induced reproductive toxicity in male rats was evaluated. Forty-eight male rats were divided into 8 groups of six (n=6): Control group (treated with normal saline); VPA only (250, 500, 1,000 mg/kg) group; VPA (500 mg/kg) plus Zn (2 mg/kg) group; VPA (500 mg/kg) plus Se (1.5 mg/kg) group; VPA (500 mg/kg) plus a combination of Zn and Se group; and VPA+vitamin E (20 mg/kg) group. The Animals were sacrificed after 28 days of treatment and sperm analysis was taken. Also, evaluation of oxidative stress markers including malondialdehyde (MDA), protein carbonyl (PC), glutathione (GSH) and histopathological changes were done on testis tissue. Morphological changes and a significant decrease in motility and sperm count in rats treated with VPA were observed. Also, an increase in oxidative stress marker, including MDA and PC and a decrease in GSH level was evident in VPA group. Zn and Se administration was able to protect against sperm abnormality, ameliorate the histological change in testis tissue, and suppressed the increase in oxidative stress markers induced by VPA. These results indicated that combination therapy with Zn and Se showed better an ameliorative effect than each one alone. Therefore, it can be suggested as an effective supplement for reproductive impairment in VPA-treated patient. [ABSTRACT FROM AUTHOR]

Recently the complexation-mediated antioxidative and glycaemic control synergism between zinc(II) and caffeic acid was demonstrated in vitro. The present study evaluated the complexation-mediated antidiabetic and antioxidative synergism between zinc(II) and caffeic acid in diabetic rats and the possible underlying mechanisms. Male SD rats were induced with diabetes using 10% fructose and 40 mg/kg bw streptozotocin. The diabetic rats were treated with Zn(II)-caffeic acid complex and its precursors (caffeic acid and zinc acetate) for 4 weeks at predetermined doses. The effect of the treatments on diabetes and oxidative stress was measured. The complex ameliorated diabetic alterations. It reduced polyphagia and polydipsia and recovered weight loss. It increased insulin secretion, insulin sensitivity, hepatic and muscle glycogen, muscle hexokinase activity and Akt phosphorylation, which resulted in improved glucose tolerance and reduced blood glucose in the diabetic rats. The complex concomitantly reduced systemic and tissue lipid peroxidation and increased antioxidant enzymes activity in the diabetic rats. The complex outperformed the antidiabetic and antioxidative action of its precursors and had a broader bioactivity profile. Complexing zinc acetate with caffeic acid improved their ameliorative effect on insulin resistance by ∼24% and 42%, respectively, as well as their anti-hyperglycaemic action by ∼24 – 36% and ∼42 – 47%, respectively, suggesting a complexation-mediated synergism. In some instances, the antidiabetic action of the complex was comparable to metformin, while its antioxidant effect was better than that of metformin. Zinc(II)-caffeic acid complexation may be an alternative approach to improving the efficacy of antidiabetic and antioxidative therapy with minimal adverse or side effects. [Display omitted] [ABSTRACT FROM AUTHOR]

Pre-eclampsia (PE) is a common obstetric disease associated with oxidative stress, systemic inflammation, and angiogenic imbalance, whereas zinc (Zn) presents anti-oxidative and anti-inflammatory effects. This study is to investigate whether zinc gluconate (ZG) supplementation may ameliorate the early signs, adverse pregnancy outcomes, and pathogenic processes of PE in an animal model. Forty pregnant Wistar rats were randomly divided into four groups: blank control (treated with normal saline, NS), Zn control (treated with ZG and followed by NS), PE model (treated with NS and followed by nitro-L-arginine methyl ester, L-NAME), and PE intervention (treated with ZG and followed by L-NAME). ZG (5 mg/kg/day) or NS was administered by gavage from day 0 to 19 of gestation, and L-NAME (80 mg/kg/day) or NS was subcutaneously injected from day 4 to 19 of gestation. The blood pressure, urinary protein, and pregnancy outcomes were recorded. Oxidative stress, inflammation, and angiogenic homeostasis were evaluated. PE rats exhibited oxidative stress (reduced SOD, CAT, and GSH, and increased MDA and 3-NT), inflammation (increased IL-6 and TNF-α), and angiogenic imbalance (reduced VEGF and PlGF, and increased sFlt-1). After intervention with ZG, the blood pressure and urinary protein levels were reverted, and the pregnancy outcomes were improved. The oxidative stress, inflammation, and angiogenic imbalance were effectively restored in accompany by increased Zn and MT levels. ZG can ameliorate the early signs and pathological processes of PE in the animal model, indicating the value of zinc supplementation during pregnancy for PE prevention. • ZG effectively antagonizes oxidative stress and inflammation in the PE rat model. • ZG ameliorates symptoms and adverse pregnancy outcomes of PE in the rat model. • ZG supplementation may prevent PE by induction of antioxidant MT. [ABSTRACT FROM AUTHOR]

Introduction: Current evidence is debatable regarding the feasible effects of zinc supplementation on the inflammation and oxidative stress status of adults. This systematic review and meta-analysis aimed to clarify this inconclusiveness. Methods: Literature search was conducted via online databases such as PubMed, Scopus, ISI Web of Science, Cochrane Library, and Google Scholar until June 2020. The overall effect was presented as the weighted mean difference (WMD) at 95 % confidence interval (CI) in a random-effects meta-analysis model. Publication bias was also assessed using Egger's and Begg's statistics Results: In total, 25 clinical trials (n = 1428) were reviewed, which indicated that zinc supplementation significantly affects the concentration of C-reactive protein (WMD: -0.03 mg/l; 95 % CI: -0.06, 0.0; P = 0.029), interlukin-6 (WMD: -3.81 pg/mL; 95 % CI: -6.87, -0.76; P = 0.014), malondialdehyde (WMD: -0.78 µmol/l; 95 % CI: -1.14, -0.42; P < 0.001), and total antioxidant capacity (WMD: 95.96 mmol/l; 95 % CI: 22.47, 169.44; P = 0.010). In addition, a significant between-study heterogeneity and a non-significant increment was reported in nitric oxide (WMD: 1.47 µmol/l; 95 % CI: -2.45, 5.40; P = 0.461) and glutathione (WMD: 34.84 µmol/l; 95 % CI: -5.12, 74.80; P = 0.087). Conclusions: According to the results, zinc supplementation may have beneficial antiinflammatory and anti-oxidative effects in adults. [ABSTRACT FROM AUTHOR]

Oxidative stress is a contributing factor to many chronic diseases. It has been investigated that zinc (Zn) may enhance the antioxidant defense. The current dose-response and time-response meta-analysis aims to determine the efficacy of Zn supplementation in improving antioxidant defense. Scopus, PubMed/Medline, Web of Science, and Embase databases were searched systematically up to December 30, 2020. Meta-analysis was performed on human controlled clinical trials using random effects method. To find any source of heterogeneity, subgroup analysis and meta-regression were performed. Trim and fill analysis was used for adjusting the publication bias. To find any non-linear relationship between variables and effect size, dose-response and time-response analyses were performed. Cochrane Collaboration's tool was used for evaluating the quality assessment. A total of 23 controlled clinical trials were analyzed. The range of Zn supplementation duration in various studies was within 4–24 weeks. Zn supplementation did not have beneficial effects on glutathione peroxidase (GPx) activity (SMD = −0.34 U/g; 95% CI: -0.93, 0.25; P = 0.258). There were significant increasing effects of Zn supplementation on glutathione (GSH) (SMD = 1.28 μmol/l; 95% CI: 0.42, 2.14; P = 0.003) and total antioxidant capacity (TAC) levels (SMD = 1.39 mmol/l; 95% CI: 0.44, 2.35; P = 0.004). Zn had ameliorative effects on superoxide dismutase (SOD) activity after elimination of publication bias (SMD: 0.84 U/g; 95% CI: 0.12, 1.56, P < 0.05). Zn could also elevate GSH and TAC levels, plus SOD activity after modifying the publication bias. Finally, Zn had no significant effect on GPx activity. [ABSTRACT FROM AUTHOR]