Sensitive biomarker responses of the shrimp Palaemonetes argentinus exposed to chlorpyrifos at environmental concentrations: Roles of alpha-tocopherol and metallothioneins

The aim of this study was to evaluate the toxic effects of chlorpyrifos (CPF) at environmental concentrations on the shrimp Palaemonetes argentinus, a South American native species. Organisms were exposed to environmentally relevant concentrations of CPF (from 3.5 to 94.5ngCPFL(-1)) at laboratory conditions for 96h. A wide battery of biochemical responses including bioaccumulation, damage and defense biomarkers were measured in cephalothorax and abdomen of shrimp. The concentration of CPF was below the detection limit of the method in both body sectors (8ngCPFg(-1)ww), probably indicating fast biotransformation of the parental compound. Our results showed that CPF exposure inhibits acetylcholinesterase activity from 3.5ngCPFL(-1), a concentration below the suggested Argentinean guidelines for the protection of aquatic biota. Moreover, oxidative stress was evidenced by increased H2O2 content and increased levels of TBARs and carbonyl groups in proteins. The induction of antioxidant enzymes like catalase, glutathione S-transferase and glutathione peroxidase seems not be sufficient to prevent oxidative damages. In addition, the mobilization of α-tocopherol from abdomen to cephalothorax was observed and reported for the first time in non-reproductive condition. Likewise, a strong diminution of metallothioneins occurred in cephalothorax from the lowest CPF concentration while induction occurred from the same treatment in abdomen as an oxidative stress response. Finally, significant correlation between Integrated Biomarker Response values and exposure concentrations suggest the usefulness of P. argentinus as bioindicator of CPF exposure at concentrations as low as environmental ones.

Microemulsion co-delivering vitamin A and vitamin E as a new platform for topical treatment of acute skin inflammation

In this study, we developed a water-in-oil microemulsion containing vitamin A (retinol) and vitamin E (α-tocopherol), which serves as a multifunctional nanosystem that co-delivers antioxidants and displayed additive effect against acute skin inflammation. Microemulsion (ME) was prepared by mixing a surfactant blend (Tween 80 and propylene glycol, 5:1) with isopropyl myristate and water (ratio of 50:40:10, respectively). Vitamin A (0.05% w/w concentration) and/or vitamin E (0.1% w/w concentration) were incorporated into the surfactant mixture of ME by stirring with a magnetic stirrer for 30 min. This multifunctional ME displayed physical stability, with low cytotoxicity in 3T3 cell line, as well as cellular internalization into the cytosol. In vivo treatments using ME delivering α-tocopherol reduced dermal expression of TNF-α by 1.3-fold (p < 0.01), when compared to unloaded ME treatment group. When retinol was added into the ME containing α-tocopherol, it further reduced TNF-α expression by 2-fold (p < 0.001), suggesting the additive effect of vitamin E and vitamin A in the treatment against skin inflammation. In conclusion, we successfully developed the use of water-in-oil ME to pack both vitamin E and vitamin A, and demonstrated for the first time its anti-inflammatory potential when applied topically to TPA-induced inflamed skin.

Vitamin E deficiency in South Asian population and the therapeutic use of alpha-tocopherol (Vitamin E) for correction of anemia

Mild to moderate vitamin E deficiency because of inadequate consumption of vitamin E-rich foods and intestinal fat malabsorption is common in growing children, women of reproductive age and elderly South Asian population. Severe vitamin E deficiency may lead to peripheral and motor neurodegenerative diseases (e.g ataxia and motor skeletal myopathy), impaired immune response and free radical-induced hemolytic anemias. Vitamin E insufficiency and/or deficiency status in the general Pakistani population has not been sufficiently investigated. Moreover, there are challenges in determining vitamin E status in apparently healthy humans due to variations in their age, sources of consumed vitamin E and plasma lipid levels. Oxidative stress-induced reactive oxygen species have been shown to cause ineffective erythropoiesis and enhanced lysis of erythrocytes in some of the experimental animals and humans. Several studies on patients with various types of inherited hemolytic anemias, chronic renal disease, premature low birth infants and apparently healthy humans have shown that vitamin E might be therapeutically effective in the prevention and/ or treatment of anemia in these subjects.

Markers of lipid and protein peroxidation among Nigerian university students with dysmenorrhea

INTRODUCTION

Oxidative stress has been associated with primary dysmenorrhea, but studies that have assessed multiple markers of peroxidation are scarce. This study investigated malondialdehyde (MDA), nitrotyrosine (3-NT), and protein carbonyls (PrCarb) as markers of oxidative stress and antioxidant status by serum alpha tocopherol level in young Nigerian women with dysmenorrhea.

MATERIALS AND METHODS

In a case-control design, 45 female undergraduates who had had regular menses for at least six previous cycles were recruited consecutively from a university clinic as cases and 45 apparently healthy age-matched counterparts in their hall of residences as controls. Serum levels of MDA, 3-NT, and PrCarb were determined using standard methods, and the values were compared between cases and controls using Mann-Whitney U-test and graphs.

RESULTS

Study participants' ages range from 16 to 29 years (mean = 22.0 ± 3.1 years). Serum level of 3-NT (45.89 ± 37.11 vs 21.27 ± 13.94 ng/mL) and MDA (0.75 ± 0.19 vs 0.45 ± 0.11 nmol/mL) was significantly higher in cases than controls. Plasma alpha tocopherol was significantly lower in cases (7.51 ± 1.95 μmol/L) than controls (8.98 ± 1.95 μmol/L). Conversely, PrCarb levels were not significantly difference between cases and controls. There were significant correlations between alpha tocopherol and 3-NT (r = -0.285; P = 0.007) and MDA (r = -0.321; P = 0.002), whereas this relationship was not shown with PrCarb (r = -0.073; P = 0.496).

CONCLUSION

Remarkable lipid and protein peroxidation observed in young Nigerian women with dysmenorrhea was accompanied by correspondingly low level of serum alpha tocopherol suggesting potential need for vitamin E supplementation.

Argininic acid alters markers of cellular oxidative damage in vitro: Protective role of antioxidants

We, herein, investigated the in vitro effects of argininic acid on thiobarbituric acid-reactive substances (TBA-RS), total sulfhydryl content and on the activities of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the blood, kidney and liver of 60-day-old rats. We also verified the influence of the antioxidants (each at 1.0mM) trolox and ascorbic acid, as well as of N^G-nitro-l-arginine methyl ester (L-NAME) at 1.0mM, a nitric oxide synthase inhibitor, on the effects elicited by argininic acid on the parameters tested. The liver, renal cortex and renal medulla were homogenized in 10vol (1:10w/v) of 20mM sodium phosphate buffer, pH 7.4, containing 140mM KCl; and erythrocytes and plasma were prepared from whole blood samples obtained from rats. For in vitro experiments, the samples were pre-incubated for 1h at 37°C in the presence of argininic acid at final concentrations of 0.1, 1.0 and 5.0μM. Control experiments were performed without the addition of argininic acid. Results showed that argininic acid (5.0μM) enhanced CAT and SOD activities and decreased GSH-Px activity in the erythrocytes, increased CAT and decreased GSH-Px activities in the renal cortex and decreased CAT and SOD activities in the renal medulla of 60-day-old rats, as compared to the control group. Antioxidants and/or L-NAME prevented most of the alterations caused by argininic acid on the oxidative stress parameters evaluated. Data suggest that argininic acid alters antioxidant defenses in the blood and kidney of rats; however, in the presence of antioxidants and L-NAME, most of these alterations in oxidative stress were prevented. These findings suggest that oxidative stress may be make an important contribution to the damage caused by argininic acid in hyperargininemic patients and that treatment with antioxidants may be beneficial in this pathology.

Experimental therapeutic intervention with alpha tocopherol in ethanol induced testicular injuries in rats

Infertility is well-established harmful effect in chronic alcoholism and so far, there is no effective treatment for this condition. The study was conducted to determine the effects of alpha tocopherol on ethanol induced testicular injuries in male albino rats of Wistar strain. Five groups (n=6) of animals were used. Group I served as control. Group II received daily 1.6g ethanol/kg body weight/day for 4 weeks orally. Group III received 1.6g ethanol+80mg alpha tocopherol/kg body weight/day for four weeks orally. Group IV received 1.6g ethanol/kg body weight for/day 4 weeks and followed by 80mg alpha tocopherol/kg body weight/day for four weeks orally. Group V received 1.6g ethanol/kg body weight/day orally for 4 weeks, followed by 4 weeks abstinence. Twently-four hours after the last treatment the rats were sacrificed using anesthetic ether. Testes were removed and used for the estimation of extent of lipid peroxidation and tissue levels of antioxidants and steroidogenic enzymes. Alpha tocopherol treatment increased the activities of testicularΔ(5), 3β-HSD. Moreover, the treatment was also associated with significant decrease in testicular oxidative stress. Ethanol-induced oxidative stress and decreased steroidogenesis can be reversed by treatment with alpha tocopherol.

Association of measures of body fat with serum alpha-tocopherol and its metabolites in middle-aged individuals

BACKGROUND AND AIMS

The accumulation of fat increases the formation of lipid peroxides, which are partly scavenged by alpha-tocopherol (α-TOH). Here, we aimed to investigate the associations between different measures of (abdominal) fat and levels of urinary α-TOH metabolites in middle-aged individuals.

METHODS AND RESULTS

In this cross-sectional analysis in the Netherlands Epidemiology of Obesity study (N = 511, 53% women; mean [SD] age of 55 [6.1] years), serum α-TOH and α-TOH metabolites from 24-h urine were measured as alpha-tocopheronolactone hydroquinone (α-TLHQ, oxidized) and alpha-carboxymethyl-hydroxychroman (α-CEHC, enzymatically converted) using liquid-chromatography-tandem mass spectrometry. Body mass index and total body fat were measured, and abdominal subcutaneous and visceral adipose tissue (aSAT and VAT) were assessed using magnetic resonance imaging. Using multivariable-adjusted linear regression analyses, we analysed the associations of BMI, TBF, aSAT and VAT with levels of urinary α-TOH metabolites, adjusted for confounders. We observed no evidence for associations between body fat measures and serum α-TOH. Higher BMI and TBF were associated with lower urinary levels of TLHQ (0.95 [95%CI: 0.90, 1.00] and 0.94 [0.88, 1.01] times per SD, respectively) and with lower TLHQ relative to CEHC (0.93 [0.90, 0.98] and 0.93 [0.87, 0.98] times per SD, respectively). We observed similar associations for VAT (TLHQ: 0.94 [0.89, 0.99] times per SD), but not for aSAT.

CONCLUSIONS

Opposite to our research hypothesis, higher abdominal adiposity was moderately associated with lower levels of oxidized α-TOH metabolites, which might reflect lower vitamin E antioxidative activity in individuals with higher abdominal fat instead.

The effect of vitamin E supplementation on serum low-density lipoprotein oxidization: A systematic review and meta-analysis of clinical trials

Oxidation of low-density lipoprotein (LDL) accelerates atherosclerosis. Vitamin E is a powerful fat-soluble antioxidant; some studies have shown its beneficial effects in reducing oxidized LDL levels. Due to the inconsistent reports, we performed a systematic review and meta-analysis to evaluate the impact of vitamin E supplementation on oxidation of LDL levels. PubMed, Scopus, Web of Science, and Google Scholar were systematically searched to find clinical trials published in English. A total of 21 records with 29 intervention arms were included in this review. In the meta-analysis of 6 studies that reported changes in oxidized LDL levels, a significant decrease in LDL oxidation was observed (95% CI: -1.44 [-2.5, -0.38]; I2 = 95.8%, P < 0.001; Tau-squared: 1.6171). Moreover, a meta-analysis of 7 studies that reported lag time as a measure of LDL oxidation showed that vitamin E supplementation significantly increased the lag time of LDL oxidation (95% CI: 20.45 [12.46, 28.43]; I2 = 95.9%, P < 0.001; Tau-squared: 103.3545). Two studies used the thiobarbituric acid-reactive substances (TBARS) assay to evaluate the susceptibility to LDL oxidation. One of them showed a significant decrease in LDL susceptibility to oxidation after supplementation with tocopherol, while the other one did not show a significant effect. Vitamin E significantly reduced the susceptibility of LDL to oxidation and increased the lag time of LDL oxidation.

Vitamin E improves serum markers and histology in adults with metabolic dysfunction-associated steatotic liver disease: Systematic review and meta-analysis

BACKGROUND AND AIM

Multiple clinical trials have been conducted to study the potential benefits of vitamin E for the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). Despite available evidence, vitamin E is not widely used. This study aimed to assess the effect of vitamin E on serum markers of liver inflammation, specifically serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and histology, including resolution of metabolic dysfunction-associated steatohepatitis (MASH), in adult patients with MASLD.

METHODS

A systematic literature search on randomized controlled trials published in English was conducted using electronic databases. Standardized mean difference (SMD) and mean difference (MD) were used for continuous outcomes, while risk ratio (RR) was used for dichotomous outcomes, with corresponding 95% confidence interval (CI).

RESULTS

A total of eight studies were included in the qualitative synthesis while seven studies were included in the meta-analysis. Vitamin E significantly reduced serum ALT and AST levels with SMD of -0.82 (95% CI, -1.13 to -0.51) and -0.68 (95% CI, -0.94 to -0.41), respectively. Vitamin E significantly reduced steatosis, lobular inflammation, and hepatocyte ballooning with a MD of -0.60 (95% CI, -0.83 to -0.37), -0.34 (95% CI, -0.53 to -0.16), -0.32 (95% CI, -0.53 to -0.12), and increased MASH resolution with a RR of 1.9 (95%CI, 1.20 to 3.02). However, vitamin E did not reduce fibrosis, with a MD of -0.23 (95% CI, -0.51 to 0.05).

CONCLUSION

Vitamin E resulted in significant improvement in serum markers of liver inflammation and histology in patients with MASLD.