Adverse effects of antioxidative vitamins

Glycative stress as a cause of macular degeneration

People are living longer and rates of age-related diseases such as age-related macular degeneration (AMD) are accelerating, placing enormous burdens on patients and health care systems. The quality of carbohydrate foods consumed by an individual impacts health. The glycemic index (GI) is a kinetic measure of the rate at which glucose arrives in the blood stream after consuming various carbohydrates. Consuming diets that favor slowly digested carbohydrates releases sugar into the bloodstream gradually after consuming a meal (low glycemic index). This is associated with reduced risk for major age-related diseases including AMD, cardiovascular disease, and diabetes. In comparison, consuming the same amounts of different carbohydrates in higher GI diets, releases glucose into the blood rapidly, causing glycative stress as well as accumulation of advanced glycation end products (AGEs). Such AGEs are cytotoxic by virtue of their forming abnormal proteins and protein aggregates, as well as inhibiting proteolytic and other protective pathways that might otherwise selectively recognize and remove toxic species. Using in vitro and animal models of glycative stress, we observed that consuming higher GI diets perturbs metabolism and the microbiome, resulting in a shift to more lipid-rich metabolomic profiles. Interactions between aging, diet, eye phenotypes and physiology were observed. A large body of laboratory animal and human clinical epidemiologic data indicates that consuming lower GI diets, or lower glycemia diets, is protective against features of early AMD (AMDf) in mice and AMD prevalence or AMD progression in humans. Drugs may be optimized to diminish the ravages of higher glycemic diets. Human trials are indicated to determine if AMD progression can be retarded using lower GI diets. Here we summarized the current knowledge regarding the pathological role of glycative stress in retinal dysfunction and how dietary strategies might diminish retinal disease.

Effects of Tectona grandis L. Extract in Diabetic Rats on Nitric Oxide and Malondialdehyde Levels

<b>Background and Objective:</b> Diabetes mellitus is characterized by hyperglycemia caused by disturbances in pancreatic β cells resulting in the formation of reactive oxygen species which in this study was characterized by increased levels of nitric oxide and malondialdehyde in male Wistar rats with diabetes mellitus models. <b>Materials and Methods:</b> Animal modeling of diabetes mellitus using 40 mg kg¹ b.wt. streptozotocin intraperitoneally. The antioxidant activity is based on the ferric reducing antioxidant power (FRAP) method. Determination of nitric oxide and MDA levels using the Griess method and Thiobarbituric Acid Reactive Substances (TBARS) Assay, respectively. The animal models were divided into six treatment groups, normal control (KN), positive control (K⁺) (glibenclamide), negative control (K) (Na-CMC 0.5%), teak leaf ethanol extract group at a dose of D₁ (100 mg kg¹ b.wt.), D₂ (200 mg kg¹ b.wt.) and D₃ (300 mg kg¹ b.wt.). <b>Results:</b> The antioxidant activity showed that the IC₅₀ values of vitamin C and the ethanol extract of <i>Tectona grandis</i> leaves were 18.208 and 62.236 μg mL¹, respectively. The NO levels in KN = 83.133 μmol L¹, K⁺ = 118.300 μmol L¹, K = 317.467 μmol L¹, D₁ = 210.133 μmol L¹, D₂ = 184.467 μmol L¹ and D₃ = 129.300 μmol L¹. The MDA levels at KN = 3.767 μmol L¹, K⁺ = 8.854 μmol L¹, K = 31.032 μmol L¹, D₁ = 27.010 μmol L¹, D₂ = 20.166 μmol L¹ and D₃ = 15.512 μmol L¹. <b>Conclusion:</b> The ethanol extract of teak leaves <i>Tectona grandis</i> L. at a dose of 300 mg kg¹ reduces nitric oxide levels and plasma malondialdehyde levels in rats through the activity of antioxidant compounds.

Therapy of women with multiple sclerosis: an analysis of the use of drugs that may have adverse effects on the unborn child in the event of (unplanned) pregnancy

Background:

Although effective contraception is strongly recommended during the therapy of women with multiple sclerosis (MS) with some immunomodulatory drugs, unplanned pregnancies still occur. Adequate medication management is essential to avoid foetal harm in the event of an unplanned pregnancy.

Objective:

The aim was to screen for medications used in women of childbearing age with MS that may pose a risk of side effects on foetal development.

Methods:

Sociodemographic, clinical and medication data were collected from 212 women with MS by structured interviews, clinical examinations and medical records. Using the databases from Embryotox, Reprotox, the Therapeutic Goods Administration and on the German summaries of product characteristics, we assessed whether the taken drugs were potentially harmful regarding the foetal development.

Results:

The majority of patients (93.4%) were taking one or more drugs for which a possible harmful effect on the foetus is indicated in at least one of the four databases used. This proportion was even higher in patients who used hormonal contraceptives (birth control pills or vaginal rings) (PwCo, n = 101), but it was also quite high in patients who did not use such contraceptives (Pw/oCo, n = 111) (98.0% and 89.2%, respectively). PwCo were significantly more likely to take five or more medications with potential foetal risk according to at least one database than Pw/oCo (31.7% versus 6.3%). PwCo were also more severely disabled (average Expanded Disability Status Scale score: 2.8 versus 2.3) and more frequently had comorbidities (68.3% versus 54.1%) than Pw/oCo.

Conclusion:

Data on the most commonly used drugs in MS therapy were gathered to study the risk of possible drug effects on foetal development in female MS patients of childbearing age. We found that the majority of drugs used by patients with MS are rated as having a potential risk of interfering with normal foetal development. More effective contraception and special pregnancy information programmes regarding the therapy management during pregnancy should be implemented to reduce potential risks to mother and child.

Plain Language Summary

Use of drugs not recommended during pregnancy by women with multiple sclerosis Introduction: Patients with multiple sclerosis (MS) often have to take different drugs simultaneously. During the therapy with some immunomodulatory drugs, effective contraception is strongly recommended. Nevertheless, unplanned pregnancies occur regularly in women with MS. Methods: Here, we investigated whether the 212 patients included in this study were taking drugs with known possibility of harm to the development of an unborn child. This was done using four different drug databases. Results: A subset of 111 patients was not taking hormonal contraceptives (birth control pills or vaginal rings). Of those, 99 patients were taking at least one drug that is not recommended during pregnancy according to at least one of the four databases. Most of the medications taken have the potential to affect normal foetal development. Conclusion: To ensure safe use of medications, the patients should be reminded of the importance of effective contraception.

Biological roles of l-carnitine in oocyte and early embryo development

Poor oocyte quality is responsible for female infertility. Multiple studies have been carried out to find supplements to enhance oocyte quality and mitigate infertility problems. l-carnitine and its derivatives have diverse roles in developing oocytes and early embryos. This review focuses on the in vitro and in vivo studies that using l-carnitine alone or in combination with other supplements for oocyte quality enhancement. The key roles of l-carnitine in oocyte quality and embryo growth were summarized, and the underlying mechanism was also elucidated. l-carnitine helps in the lipid metabolism process by controlling the transfer of fatty acids to mitochondria for β-oxidation. l-carnitine modulates glucose metabolism and enhances respiratory chain enzyme activity. Furthermore, it acts as an antioxidant to prevent oxidative damage and inhibit apoptosis, a signal in response to oxidative stress. Results show the potential of l-carnitine as a potential agent in assisted reproductive technology to improve oocyte quality and the subsequent embryonic development.

Therapies with Antioxidant Potential in Psoriasis, Vitiligo, and Lichen Planus

Oxidative stress plays an important pathogenetic role in many chronic inflammatory diseases, including those of dermatological interest. In particular, regarding psoriasis, vitiligo, and lichen planus, excess reactive oxygen species and a decline in endogenous antioxidant systems are observed. In this regard, treatments with antioxidant properties could be appropriate therapeutic options. To date, clinical trials in dermatology on these treatments are limited. We reviewed the available studies on the efficacy of antioxidant therapies in psoriasis, vitiligo, and lichen planus. The role of herbal derivatives, vitamins, and trace elements was analyzed. The antioxidant properties of conventional therapies were also evaluated. Data from the literature suggest that antioxidants might be useful, but available studies on this topic are limited, heterogeneous, not completely standardized, and on small populations. Furthermore, in most cases, antioxidants alone are unable to induce significant clinical changes, except perhaps in mild forms, and must be used in conjunction with standard drug treatments to achieve measurable results. Further studies need to be conducted, considering larger populations and using internationally validated scales, in order to compare the results and clinical efficacy.

Quality Control of Vitamins A and E and Coenzyme Q10 in Commercial Anti-Ageing Cosmetic Products

Vitamins A and E and coenzyme Q10 are common ingredients in anti-ageing cosmetic products. Within this study, we evaluated the quality of commercial cosmetics with vitamin A (35 products), vitamin E (49 products), and coenzyme Q10 (27 products) by using validated HPLC–UV methods. Vitamin A was determined as retinol, retinyl palmitate, retinyl propionate, β carotene, and hydroxypinacolone retinoate in concentrations ranging from 950 ng/g to 19 mg/g. Total vitamin A contents, expressed with retinol equivalents, ranged from 160 ng/g to 19 mg/g, and were above the maximum concentration recommended by the SCCS in six of the 35 tested cosmetics. The content-related quality control of 10 cosmetics with specified vitamin A content revealed significant deviations (between 0% and 400%) of the label claim. Vitamin E was determined as both tocopherol and tocopheryl acetate in concentrations between 8.5 µg/g and 16 mg/g. Coenzyme Q10 was determined as ubiquinone in 24 tested cosmetics, which labelled it, in concentrations between 4.2 µg/g and 100 µg/g. Labelling irregularities were observed in all three active compound groups, resulting in a significant share (42%) of improperly labelled cosmetic products. The results of this study reveal the need for stricter cosmetics regulation and highlight the importance of their quality control, especially by evaluating the contents of the active compounds, in their efficacy and safety assurance.

The potential hepatoprotective effect of metformin in hepatitis C virus-infected adolescent patients with beta thalassemia major: Randomised clinical trial

BACKGROUND

Iron overload-induced oxidative stress and transfusion-acquired hepatitis C virus (HCV) infection are the main reasons of liver damage in beta thalassemia major (β-TM).

OBJECTIVES

Based on metformin's hepatic benefits in nondiabetic populations, the study aims to investigate the safety and the potential hepatoprotective effect of metformin in HCV-infected β-TM adolescent patients.

METHODS

This was a prospective, randomised, parallel, controlled, open-label study in which 60 HCV-infected β-TM adolescent patients aged 11 to 18 years and receiving no antiviral therapy were selected and randomly assigned to treatment or control group in 1:1 allocation. Both groups were receiving β-TM standard-of-care regimen, whereas metformin (500 mg, twice daily) was added to the treatment group's regimen only. Patients were prospectively followed up for 6 months with assessment of liver biochemical profile, oxidative stress markers, liver fibrosis, clinical symptom improvement and metformin's adverse effects.

RESULTS

Aspartate aminotransferase serum level decreased significantly over time in the treatment group only (P = .013). However, improvement was not clinically significant and did not attain normality. Change in total antioxidant capacity and malondialdehyde serum levels indicated significantly improved oxidative stress status in the treatment group versus significant deterioration in the control group (P < .001). Fibrosis grade improvement was observed in 14 patients in the treatment group versus one improved case in the control group.

CONCLUSION

The use of metformin in HCV-infected β-TM adolescent patients as an adjuvant antioxidant hepatoprotective agent is promising and can improve liver damage.

Impaired Vitamin D Signaling in T Cells From a Family With Hereditary Vitamin D Resistant Rickets

The active form of vitamin D, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), mediates its immunomodulatory effects by binding to the vitamin D receptor (VDR). Here, we describe a new point mutation in the DNA-binding domain of the VDR and its consequences for 1,25(OH)₂D₃ signaling in T cells from heterozygous and homozygous carriers of the mutation. The mutation did not affect the overall structure or the ability of the VDR to bind 1,25(OH)₂D₃ and the retinoid X receptor. However, the subcellular localization of the VDR was strongly affected and the transcriptional activity was abolished by the mutation. In heterozygous carriers of the mutation, 1,25(OH)₂D₃-induced gene regulation was reduced by ~ 50% indicating that the expression level of wild-type VDR determines 1,25(OH)₂D₃ responsiveness in T cells. We show that vitamin D-mediated suppression of vitamin A-induced gene regulation depends on an intact ability of the VDR to bind DNA. Furthermore, we demonstrate that vitamin A inhibits 1,25(OH)₂D₃-induced translocation of the VDR to the nucleus and 1,25(OH)₂D₃-induced up-regulation of CYP24A1. Taken together, this study unravels novel aspects of vitamin D signaling and function of the VDR in human T cells.

Biological and Pharmacological Characterization of Ascorbic Acid and Nicotinamide Chitosan Nanoparticles against Insulin-Resistance-Induced Cognitive Defects: A Comparative Study

High consumption of industrialized food with high fat content is generally associated with insulin resistance, which in turn causes memory impairment and cognitive decline. Nicotinamide and ascorbic acid are among the promising neuroprotective molecules; however, an appreciable therapeutic activity necessitates the administration of a large dose of either. Therefore, the study aimed to assess if loading them in chitosan nanoparticles in doses 5-10 times lower than the unencapsulated forms would achieve comparable therapeutic results. Animals were fed a high-fat-high-fructose (HFHF) diet for 75 days. The vitamins in their conventional form (100 mg/kg) and the nanoparticles under investigation (10 and 20 mg/kg) were given orally concomitantly with the diet in the last 15 days. The intake of HFHF diet for 75 days led to an insulin-resistant state, with memory impairment, which was verified behaviorally through the object recognition test. This was accompanied by significant reduction in brain insulin-like growth factor 1 (IGF-1), increased acetylcholine esterase activity, increase in the serotonin and dopamine turnover ratio, and increase in oxidative stress and 8-OHdG, indicating cellular DNA fragmentation. Cellular energy was also decreased, and immunohistochemical examination verified the high immunoreactivity in both the cortex and hippocampus of the brain. The administration of nanoparticulated nicotinamide or ascorbic acid with a 10 times lesser dose than the unencapsulated forms managed to reverse all aforementioned harmful effects, with an even lesser immunoreactivity score than the unencapsulated form. Therefore, it can be concluded that nicotinamide or ascorbic acid chitosan nanoparticles can be recommended as daily supplements for neuroprotection in patients suffering from insulin resistance after conduction of clinical investigations.

Quality control of retinoids in commercial cosmetic products

BACKGROUND

Retinoids are widely used in different cosmetic products because of general improvement of skin appearance. However, retinoid concentration in cosmetics is restricted, and one particular form-retinoic acid, is banned in cosmetics due to safety reasons.

AIMS

Within this study, we aimed to examine the quality of a considerable number of commercial retinoid cosmetic products in terms of their content and labeling, including also screening for the presence of retinoic acid.

METHODS

An appropriate analytical methodology, based on HPLC-UV for the simultaneous determination of common retinoids, along with a screening method for retinoic acid, was developed and validated. Structural identity confirmation of the newer retinoid-hydroxypinacolone retinoate, was performed by LC-MS.

RESULTS

Retinol and retinyl palmitate were most often found, in concentrations mostly below 0.3%, and up to 1.3% retinol equivalents. Determined contents deviated significantly from the quantitatively declared ones in seven products (0%-130%). In more than half of the tested products, inconsistencies between the contained and labeled retinoid were noticed. These products, as well as 14 additional anti-age cosmetics, were screened for retinoic acid, which was detected in two products.

CONCLUSIONS

The obtained results from retinoids assay in commercial cosmetic products confirmed that the proposed method is appropriate for their routine analysis. The presence of retinoic acid in two products and determined retinoid contents above the Scientific Committee on Consumer Safety recommendations in 20% of the tested cosmetics reveal the need for their more strict regulation and quality control to ensure their efficacy and safety.

High-Dose Ascorbic Acid for Burn Shock Resuscitation May Not Improve Outcomes

High dose ascorbic acid (HDAA) has been touted to ameliorate inflammation and reduce fluid requirements during burn shock resuscitation (BSR). Whether this leads to improved outcomes is not known. The authors' aim for this study was to compare ventilator days, ventilator-associated pneumonia, and mortality between patients who did and did not receive HDAA during BSR.The authors performed a retrospective case control study from 2012 to 2015. They identified 38 patients (HDAA) who received HDAA during BSR. Using age and %TBSA, the authors identified and matched 42 control patients (CTL) who did not receive HDAA for BSR during that same time period. The authors collected data for age, %TBSA, hospital days (LOS), ventilator days (VENT), inhalation injury (INH), ventilator-associated pneumonia (VAP), and mortality (MORT).There were no differences in age and %TBSA or %TBSA of third-degree burn injury between groups. There was no significant difference in the incidence of INH (HDAA-52% vs CTL-36%, P = .17) and the groups had similar LOS and VENT. Additionally, there was no significant difference in VAP incidence (HDAA-29% vs CTL-14%, P = .13) or mortality (HDAA-26% vs CTL-23%, P = .8). HDAA patients had a numerically higher incidence of acute renal failure requiring dialysis (23 vs 7%, P = .06) which was confirmed in a multivariate analysis (odds ratio 5.4; 95% confidence interval 1.1-26). HDAA, while potentially reducing inflammation and fluid requirements during BSR, may not improve any meaningful outcomes such as ventilator requirements, ventilator-associated pneumonia, and mortality.

The capability of L-carnitine-mediated antioxidant on cock during aging: evidence for the improved semen quality and enhanced testicular expressions of GnRH1, GnRHR, and melatonin receptors MT 1/2

Precise natural anti-oxidative compounds have facilitated the research of infertile gametes and the development of novel bio-therapeutics, especially the molecules that are based on the reduction of oxidative stress, such as L-carnitine (LC). In addition to, the defect in the functioning of sperm mitochondrial and the decreasing seminal antioxidant ability due to aging, its essential role in permitting the mitochondrial import and oxidation of long chain fatty acids is worthy. Therefore, current study was designed to investigate the effects of dietary LC on semen quality, seminal antioxidant activity, and their implications for the fertility in aged cocks for 12 wk. Supplementation of the feed with two different doses of LC (50 and 150 mg/kg body weight/day) for 12 wk showed significantly increased in the reproductive activity of cock, in comparison to the control group. Seminal analysis showed that supplementation of LC significantly increased (P < 0.05) the sperm motility, concentration, livability, semen quality factor, seminal malondialdehyde concentration, catalase, and glutathione peroxidase activities. In addition, addition of LC significantly increased (P < 0.05) the plasma concentration of testosterone and prostaglandin E2 but posed no significant effect on the concentration of follicle-stimulating hormone. Furthermore, the findings of artificial insemination showed significant increased (P < 0.05) in the percentage of fertility in LC groups, while the percentage hatchability and mortality remained unchanged. Immunohistochemistry analysis revealed that LC significantly increased (P < 0.05) the testicular immunopositivity of MT1 and MT2. Moreover, the administration of LC to the aged cocks enhanced (P < 0.05) GnRH1 and GnRHR mRNA levels when compared with untreated cocks. The results of the present study suggest that LC treatment of aged cocks increases the seminal antioxidant enzymes and sexual hormones levels, which may improve the semen quality by increasing the expression of GnRH1 and melatonin receptors (MT1 and MT2) activities. Collectively, LC could be a suitable feed supplementation to increase reproductive activities through enhancing semen quality in aging cocks.

Effects of different ascorbic acid doses on the mortality of critically ill patients: a meta-analysis

BACKGROUND

Low levels of ascorbic acid (AA) have been detected in critically ill patients in which AA supplementation leads to promising outcomes. However, the ability of AA to reduce mortality in critically ill patients remains controversial. In this study, we have performed a meta-analysis to evaluate the effects of AA dose on the mortality of critically ill adults.

METHODS

Electronic databases were searched for trials in which AA had been intravenously administered to critically ill patients regardless of the dose or the co-administration of antioxidant agents. The predefined primary outcome included all-cause mortality at final follow-up.

RESULTS

The included trials enrolled a total of 1210 patients. Intravenous (IV) AA doses of 3-10 g/d reduced the mortality of critically ill patients (OR 0.25; 95% CI (0.14-0.46); p < 0.001; I2 = 0.0%), while low (< 3 g/d) and high AA doses (≥ 10 g/d) had no effect (OR 1.44; 95% CI (0.79-2.61); p = 0.234; I2 = 0.0% versus OR 1.12; 95% CI (0.62-2.03); p = 0.700; I2 = 0.0%). AA was associated with a decreased duration of vasopressor support and mechanical ventilation, but did not influence fluid requirement or urine output during the first 24 h of admission. The number of patients suffering from acute kidney injury and the length of intensive care unit or hospital stays were also unaffected by the AA.

CONCLUSION

Intravenous AA reduces the duration of vasopressor support and mechanical ventilation; 3-10 g AA results in lower overall mortality rates. Given the limitations of the primary literature, further studies are required to fully clarify the effectiveness of AA during the management of critically ill patients.

Clinical Advances in Immunonutrition and Atherosclerosis: A Review

Atherosclerosis is a chronic low-grade inflammatory disease that affects large and medium-sized arteries and is considered to be a major underlying cause of cardiovascular disease (CVD). The high risk of mortality by atherosclerosis has led to the development of new strategies for disease prevention and management, including immunonutrition. Plant-based dietary patterns, functional foods, dietary supplements, and bioactive compounds such as the Mediterranean Diet, berries, polyunsaturated fatty acids, ω-3 and ω-6, vitamins E, A, C, and D, coenzyme Q10, as well as phytochemicals including isoflavones, stilbenes, and sterols have been associated with improvement in atheroma plaque at an inflammatory level. However, many of these correlations have been obtained in vitro and in experimental animals' models. On one hand, the present review focuses on the evidence obtained from epidemiological, dietary intervention and supplementation studies in humans supporting the role of immunonutrient supplementation and its effect on anti-inflammatory response in atherosclerotic disease. On the other hand, this review also analyzes the possible molecular mechanisms underlying the protective action of these supplements, which may lead a novel therapeutic approach to prevent or attenuate diet-related disease, such as atherosclerosis.

A Review of the Role of Green Tea (Camellia sinensis) in Antiphotoaging, Stress Resistance, Neuroprotection, and Autophagy

Tea is one of the most widely consumed beverages worldwide, and is available in various forms. Green tea is richer in antioxidants compared to other forms of tea. Tea is composed of polyphenols, caffeine, minerals, and trace amounts of vitamins, amino acids, and carbohydrates. The composition of the tea varies depending on the fermentation process employed to produce it. The phytochemicals present in green tea are known to stimulate the central nervous system and maintain overall health in humans. Skin aging is a complex process mediated by intrinsic factors such as senescence, along with extrinsic damage induced by external factors such as chronic exposure to ultraviolet (UV) irradiation—A process known as photoaging—Which can lead to erythema, edema, sunburn, hyperplasia, premature aging, and the development of non-melanoma and melanoma skin cancers. UV can cause skin damage either directly, through absorption of energy by biomolecules, or indirectly, by increased production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Green tea phytochemicals are a potent source of exogenous antioxidant candidates that could nullify excess endogenous ROS and RNS inside the body, and thereby diminish the impact of photoaging. Several in vivo and in vitro studies suggest that green tea supplementation increases the collagen and elastin fiber content, and suppresses collagen degrading enzyme MMP-3 production in the skin, conferring an anti-wrinkle effect. The precise mechanism behind the anti-photoaging effect of green tea has not been explored yet. Studies using the worm model have suggested that green tea mediated lifespan extension depends on the DAF-16 pathway. Apart from this, green tea has been reported to have stress resistance and neuroprotective properties. Its ROS scavenging activity makes it a potent stress mediator, as it can also regulate the stress induced by metal ions. It is known that tea polyphenols can induce the expression of different antioxidant enzymes and hinder the DNA oxidative damage. Growing evidence suggests that green tea can also be used as a potential agent to mediate neurodegenerative diseases, including Alzheimer’s disease. EGCG, an abundant catechin in tea, was found to suppress the neurotoxicity induced by Aβ as it activates glycogen synthase kinase-3β (GSK-3β), along with inhibiting c-Abl/FE65—the cytoplasmic nonreceptor tyrosine kinase which is involved in the development of the nervous system and in nuclear translocation. Additionally, green tea polyphenols induce autophagy, thereby revitalizing the overall health of the organism consuming it. Green tea was able to activate autophagy in HL-60 xenographs by increasing the activity of PI3 kinase and BECLIN-1. This manuscript describes the reported anti-photoaging, stress resistance, and neuroprotective and autophagy properties of one of the most widely known functional foods—green tea.

Nanodispersions of beta-carotene: effects on antioxidant enzymes and cytotoxic properties

Beta-carotene is a carotenoid precursor of vitamin A, known for its biological activities. Due to its high hydrophobicity, nanonization processes, i.e. the transformation into nanoparticles, can improve its water affinity, and therefore the activity in aqueous systems. The objective of this study was to produce beta-carotene nanoparticles by the solid dispersion method and to evaluate their effects on the activity of glutathione-S-transferase and acetylcholinesterase enzymes using Drosophila melanogaster (DM) homogenate, the superoxide dismutase- and catalase-like activities under in vitro conditions, and their cytotoxic properties against tumor and non-tumor cells. The formed nanometric beta-carotene particles resulted in stable colloids, readily dispersed in water, able to modulate acetylcholinesterase (AChE) activity, and presenting high potential to control the cholinergic system. Beta-carotene nanoparticles, at concentrations much lower than the pure pristine beta-carotene, presented in vitro mimetic activity to superoxide dismutase and altered glutathione-S-transferase activity in DM tissue. The content of hydrogen peroxide was neither affected by the nanoparticles (in aqueous solution) nor by pristine beta-carotene (in DMSO). In the cytotoxic assays, beta-carotene nanoparticles dispersed in water showed activity against four different tumor cell lines. Overall, beta-carotene nanoparticles presented significant bioactivity in aqueous medium surpassing their high hydrophobicity constraint.

A review of interventions against fetal alcohol spectrum disorder targeting oxidative stress

INTRODUCTION

Fetal alcohol spectrum disorder is caused by maternal ethanol exposure; it causes physical, behavioral, cognitive, and neural impairments (Murawski et al., 2015). Mechanisms of FASD causing damage are not yet fully elucidated. Oxidative stress might be one of its mechanisms (Henderson et al., 1995). Yet no effective treatment against FASD has been found other than ethanol abstention (Long et al., 2010).

METHODS

This review summarizes relevant literatures regarding interventions targeting oxidative stress that may relieve fetal alcohol spectrum disorder.

RESULTS

Astaxanthin was found to mitigate embryonic growth retardation induced by prenatal ethanol treatment through ameliorating the down regulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA) caused by alcohol in a mice model (Zheng et al., 2014; Vabulas et al., 2002). Vitamin E protected against fatal alchol spectrum disorders by ameliorating oxidative stress in rat models (Mitchell et al., 1999a), and yielded a better outcome when it was combined with Vitamin C (Packer et al., 1979; Peng et al., 2005). Vitamin C mitigated embryonic retardation caused by alcohol and reversed ethanol induced NF-κB activation and ROS (reactive oxygen species) formation in a Xenopus laevis model (Peng et al., 2005). Beta carotene supplement was proved to protect against neurotoxicity in hippocampal cultures of embryos induced by alcohol in a rats model (Mitchell et al., 1999a). Prenatal folic acid supplement reversed the decrease of body weight caused by maternal ethanol treatment and ameliorated the increment of glutathione reductase specific activities as well as the increase of thiobarbituric acid reactive substances (TBARS) induced by alcohol in a rats model (Cano et al., 2001). Omega-3 fatty acids reversed the decrease of reduced glutathione (GSH) levels in brain caused by prenatal ethanol treatment in a rats model (Patten et al., 2013). EUK-134 treatment reduced the incidence of forelimb defects caused by ethanol treatment in a mice model (Chen et al., 2004). Pretreatment of activity-dependent neurotrophic factor-9 (ADNF-9) and NAPVSIPQ (NAP) protected against prenatal ethanol induced fetal death as well as fetal growth abnormalities in a mice model, and such treatment reversed the decrease of the rate of reduced glutathione (GSH)/ oxidative glutathione (GSSG) caused by alcohol (Spong et al., 2001).

CONCLUSION

By now interventions against fetal alcohol spectrum disorder targeting oxidative stress includes astaxanthin, Ascorbic acid (Vitamin C), Vitamin E, beta-carotene, (-)-Epigallocatechin-3-gallate (EGCG), Omega-3 fatty acids, etc (see Fig. 1). However, most interventions are only assayed in animal models, more clinical trials are needed to show whether antioxidants make an effort against FASD damage.

Can Nutrition Lower the Risk of Recurrence in Breast Cancer?

BACKGROUND

The impact of diet on breast cancer prognosis is poorly understood. Therefore, we conducted a literature search summarizing the current evidence on the effect of diet on breast cancer recurrence and mortality.

METHODS

The PubMed database was searched for original studies, reviews, and meta-analyses published between 2010 and 2017. Studies related to diet, dietary patterns, special diets or specific dietary factors, and breast cancer recurrence or mortality were included.

RESULTS

Adherence to high diet quality indices (relative risk (RR) 0.74, 95% confidence interval (CI) 0.60-0.90) and a prudent/healthy dietary pattern (RR 0.76, 95% CI 0.60-0.95) may have a beneficial effect on breast cancer prognosis, whereas a Western/unhealthy diet is associated with poorer overall mortality (RR 1.44, 95% CI 1.17-1.77). For low-fat diets, the findings are inconsistent. A positive effect of the Mediterranean Diet was found for all-cause mortality, but no beneficial effect from other diets such as low-carbohydrate, ketogenic or vegetarian/vegan diets was observed. Alcohol consumption was associated with an increased risk for breast cancer recurrence. No general recommendation for soy exists, but occasional intake seems to be acceptable, whereas the use of other supplements is not justified.

CONCLUSION

Adherence to high-quality diets and a prudent/healthy dietary pattern seem to be beneficial for breast cancer prognosis. No clear evidence for a benefit from special diets, soy products, or other supplements was found.

Antioxidants in dermatology

The skin cells continuously produce, through cellular respiration, metabolic processes or under external aggressions, highly reactive molecules oxidation products, generally called free radicals. These molecules are immediately neutralized by enzymatic and non-enzymatic systems in a physiological and dynamic balance. In situations where this balance is broken, various cellular structures, such as the cell membrane, nuclear or mitochondrial DNA may suffer structural modifications, triggering or worsening skin diseases. several substances with alleged antioxidant effects has been offered for topical or oral use, but little is known about their safety, possible associations and especially their mechanism of action. The management of topical and oral antioxidants can help dermatologist to intervene in the oxidative processes safely and effectively, since they know the mechanisms, limitations and potential risks of using these molecules as well as the potential benefits of available associations.

Role of L-carnitine in female infertility

BACKGROUND

L-carnitine (LC), and its acetylated form, acetyl L-carnitine (ALC), have immense functional capabilities to regulate the oxidative and metabolic status of the female reproductive system. The vulnerability of this system to free radicals demand for advanced strategies to combat them. For this purpose, the 'quasi vitamins' LC and ALC can be used either individually, or in combination with each other or with other antioxidants.

MAIN BODY

This review (a) summarizes the effects of carnitines on female fertility along with the findings from various in vivo and in vitro studies involving human, animal and assisted reproductive technology, and (b) proposes their mechanism of actions in improving female fertility through their integrated actions on reducing cellular stress, maintaining hormonal balance and enhancing energy production. They reportedly aid β-oxidation in oocytes, maintain its cell membrane stability by acetylation of phospholipids and amphiphilic actions, prevent free radical-induced DNA damage and also stabilize acetyl Co-A/Co-A ratio for adequate acetyl storage as energy supply to maintain the robustness of reproductive cells.

CONCLUSION

While both LC and ALC have their applications in improving female fertility, ALC is preferred for its better antioxidant properties and LC for amelioration of energy supply to the cells. These beneficial effects show great promise in its application as a treatment option for women facing infertility disorders.

Vitamin E protects against extraskeletal calcification in uremic rats fed high fat diets

Background

High fat diets are implicated in the pathogenesis of metabolic syndrome, obesity and renal disease. Previous studies have revealed that high fat diets promote vascular calcification in uremic rats. Moreover, vitamin E has been shown to prevent uremic calcifications in genetically obese Zucker rats fed standard diet. The objective of this study was to investigate the influence of vitamin E supplementation on the development of extraskeletal calcifications in non-obese (wild type) uremic rats fed high fat diets.

Methods

Wistar rats (n = 32) were preconditioned by feeding either a normal (NF) or high fat (HF) diet for 45 days and subsequently were subjected to 5/6 nephrectomy (Nx). Just before performing the first Nx step, a blood sample (Pre-Nx) was obtained. After Nx rats were switched to a diet with 0.9% phosphorus and supplemented with calcitriol. Also, after Nx, half of the rats from each group (NF and HF) were treated with vitamin E (VitE) in the diet (30,000 mg/kg) and the other half were maintained on basic VitE requirements (27 mg/kg). Thus, rats were allotted to four experimental groups: Nx-NF (n = 8), Nx-NF-VitE (n = 8), Nx-HF (n = 8) and Nx-HF-VitE (n = 8). At the time of sacrifice (day 66), blood and tissue samples were obtained.

Results

Feeding a HF diet for 45 days did not increase body weight but elicited hyperglycemia, hypertriglyceridemia, an increase in plasma fibroblast growth factor 23 and a reduction in plasma calcitriol concentrations. After Nx, rats fed HF diet showed substantial extraskeletal calcification with aortic calcium content that was higher than in rats fed NF diet. Supplementation with VitE significantly (p < 0.05) reduced aortic (from 38.4 ± 8.8 to 16.5 ± 1.4 mg/g), gastric (from 5.6 ± 2.7 to 1.2 ± 0.4 mg/g) and pulmonary (from 1.8 ± 0.3 to 0.3 ± 0.2 mg/g) calcium content in rats on HF diets.

Conclusions

Uremic rats fed HF diets developed more severe extraosseous calcifications than their normocaloric-fed counterparts and dietary VitE supplementation protected against uremic calcifications in rats fed HF diets. Thus, eating energy-rich foods should be discouraged in patients with renal disease and their deleterious effect may be ameliorated with adequate antioxidant supply.

Neurological Complications of Nutritional Disease

Vitamins and minerals have essential functions in the body, from signal transduction to acting as cofactors for numerous enzymatic processes. Nutritional deficiencies and excess of certain vitamins and minerals can have profound effects on the central and peripheral nervous systems from early development into adulthood. This article summarizes the role of various nutritional factors in the nervous system and the neurological symptoms that can arise from deficiency or excess.

Dietary, circulating beta-carotene and risk of all-cause mortality: a meta-analysis from prospective studies

Observational studies evaluating the relation between dietary or circulating level of beta-carotene and risk of total mortality yielded inconsistent results. We conducted a comprehensive search on publications of PubMed and EMBASE up to 31 March 2016. Random effect models were used to combine the results. Potential publication bias was assessed using Egger’s and Begg’s test. Seven studies that evaluated dietary beta-carotene intake in relation to overall mortality, indicated that a higher intake of beta-carotene was related to a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.83, 95%CI: 0.78–0.88) with no evidence of heterogeneity between studies (I² = 1.0%, P = 0.416). A random-effect analysis comprising seven studies showed high beta-carotene level in serum or plasma was associated with a significant lower risk of all-cause mortality (RR for highest vs. lowest group = 0.69, 95%CI: 0.59–0.80) with low heterogeneity (I² = 37.1%, P = 0.145). No evidence of publication bias was detected by Begg’s and Egger’s regression tests. In conclusion, dietary or circulating beta-carotene was inversely associated with risk of all-cause mortality. More studies should be conducted to clarify the dose-response relationship between beta-carotene and all-cause mortality.

Vitamin A Decreases Cytotoxicity of Oxidized Low-Density Lipoprotein in Patients with Atherosclerosis

BACKGROUND

Oxidized low-density lipoprotein (ox-LDL) is implicated in initiation and progression of atherosclerosis. Previously, we found that ox-LDL increases vulnerability of peripheral blood mononuclear cells (PBMCs) in atherosclerotic patients compared to controls. Vitamin A induces proliferation of PBMCs. The aim of this study was to determine the effect of vitamin A supplementation on PBMC survival against LDL and different doses of ox-LDL.

METHOD

In this double-blind placebo-controlled trial, we recruited 35 atherosclerotic patients and 38 healthy controls and randomly allocated them into placebo and vitamin A groups, which received either placebo or 25,000 IU/day of vitamin A for 3 months. PBMCs were isolated, cultured, and stimulated by 1 µg/mL LDL as well as 1 µg/mL and 50 µg/mL ox-LDL. The stimulation indexes (SIs) of PBMCs were calculated to identify cell viability. Additionally, the circulating ox-LDL levels were measured by ELISA.

RESULTS

Viability of PBMCs stimulated by 50 µg/mL ox-LDL significantly increased following vitamin A supplementation in patients (p < 0.01). The levels of circulating ox-LDL were not changed by vitamin A treatment. Ox-LDL levels were strongly and positively correlated to SI of PBMCs stimulated by 1 µg/mL LDL and1 µg/mL ox-LDL in all groups.

CONCLUSION

Vitamin A decreases cytotoxicity of high-dose ox-LDL and improves PBMC viability. The protective effect of vitamin A is not mediated by an antioxidative mechanism, but may instead have been due to intracellular protection of the apoptotic machinery or induction of proliferation of the cells. Higher levels of ox-LDL increase PBMC irritability in all participants.

Changes in Non-Enzymatic Antioxidants in the Blood Following Anaerobic Exercise in Men and Women

Purpose

The aim of this study was to compare changes in total oxidative status (TOS), total antioxidative capacity (TAC) and the concentration of VitA, VitE, VitC, uric acid (UA), reduced (GSH) and oxidized glutathione (GSSG) in blood within 24 hours following anaerobic exercise (AnEx) among men and women.

Methods

10 women and 10 men performed a 20-second bicycle sprint (AnEx). Concentrations of oxidative stress indicators were measured before AnEx and 3, 15 and 30 minutes and 1 hour afterwards. UA, GSH and GSSH were also measured 24 hours after AnEx. Lactate and H⁺ concentrations were measured before and 3 minutes after AnEx.

Results

The increase in lactate and H⁺ concentrations following AnEx was similar in both sexes. Changes in the concentrations of all oxidative stress indicators were significant and did not differ between men and women. In both sexes, TOS, TAC, TOS/TAC and VitA and VitE concentrations were the highest 3 minutes, VitC concentration was the highest 30 minutes, and UA concentration was the highest 1 hour after AnEx. GSH concentration was significantly lower than the initial concentration from 15 minutes to 24 hour after AnEx. GSSG concentration was significantly higher, while the GSH/GSSG ratio was significantly lower than the initial values 1 hour and 24 hour after AnEx.

Conclusions

With similar changes in lactate and H⁺ concentrations, AnEx induces the same changes in TAC, TOS, TOS/TAC and non-enzymatic antioxidants of low molecular weight in men and women. Oxidative stress lasted at least 24 hours after AnEx.

Beta-carotene reduces oxidative stress, improves glutathione metabolism and modifies antioxidant defense systems in lead-exposed workers

The aim of this study was to determine whether beta-carotene administration reduces oxidative stress and influences antioxidant, mainly glutathione-related, defense systems in workers chronically exposed to lead. The population consisted of two randomly divided groups of healthy male volunteers exposed to lead. Workers in the first group (reference group) were not administered any antioxidants, while workers in the second group (CAR group) were treated orally with 10mg of beta-carotene once a day for 12weeks. Biochemical analysis included measuring markers of lead-exposure and oxidative stress in addition to the levels and activities of selected antioxidants. After treatment, levels of malondialdehyde, lipid hydroperoxides and lipofuscin significantly decreased compared with the reference group. However, the level of glutathione significantly increased compared with the baseline. Treatment with beta-carotene also resulted in significantly decreased glutathione peroxidase activity compared with the reference group, while the activities of other glutathione-related enzymes and of superoxide dismutase were not significantly changed. However, the activities of glucose-6-phosphate dehydrogenase and catalase, as well as the level of alpha-tocopherol, were significantly higher after treatment compared with the baseline. Despite controversy over the antioxidant properties of beta-carotene in vivo, our findings showed reduced oxidative stress after beta-carotene supplementation in chronic lead poisoning.

Plant amino acid-derived vitamins: biosynthesis and function

Vitamins are essential organic compounds for humans, having lost the ability to de novo synthesize them. Hence, they represent dietary requirements, which are covered by plants as the main dietary source of most vitamins (through food or livestock's feed). Most vitamins synthesized by plants present amino acids as precursors (B1, B2, B3, B5, B7, B9 and E) and are therefore linked to plant nitrogen metabolism. Amino acids play different roles in their biosynthesis and metabolism, either incorporated into the backbone of the vitamin or as amino, sulfur or one-carbon group donors. There is a high natural variation in vitamin contents in crops and its exploitation through breeding, metabolic engineering and agronomic practices can enhance their nutritional quality. While the underlying biochemical roles of vitamins as cosubstrates or cofactors are usually common for most eukaryotes, the impact of vitamins B and E in metabolism and physiology can be quite different on plants and animals. Here, we first aim at giving an overview of the biosynthesis of amino acid-derived vitamins in plants, with a particular focus on how this knowledge can be exploited to increase vitamin contents in crops. Second, we will focus on the functions of these vitamins in both plants and animals (and humans in particular), to unravel common and specific roles for vitamins in evolutionary distant organisms, in which these amino acid-derived vitamins play, however, an essential role.

Serum antioxidant nutrients, vitamin A, and mortality in U.S. Adults

BACKGROUND

Observational studies have suggested that antioxidant nutrients may reduce cancer and overall mortality risks. However, most randomized trials have failed to show survival benefits. Examining nonlinear associations between antioxidant levels and health outcomes may help to explain these discrepant findings.

METHODS

We evaluated all-cause, cancer, and cardiovascular mortality risks associated with quintiles (Q1-Q5) of serum antioxidant (vitamins C and E, β-carotene, and selenium) and vitamin A levels, in 16,008 adult participants of The Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994).

RESULTS

Over a median follow-up period of 14.2 years, there were 4,225 deaths, including 891 from cancer and 1,891 from cardiovascular disease. We observed a dose-response decrease in cancer and overall mortality risks with higher vitamin C levels. In contrast, for vitamin A, risk of cancer death decreased from Q1-Q2, with no further decline in risk at higher levels. For vitamin E, having levels in Q4 was associated with the lowest cancer mortality risk. Both vitamin A and E had U-shaped associations with all-cause mortality. Cancer mortality risks decreased from Q1-Q2 for β-carotene and from Q1-Q4 for selenium. However, for β-carotene and selenium, overall mortality risks decreased from Q1-Q2 but then did not change significantly with higher levels.

CONCLUSIONS

Antioxidant supplement use should be studied in the context of overall mortality and other competing mortality risks.

IMPACT

These data suggest the need for novel intervention studies where doses of these agents are individualized based on their serum levels, and possibly, markers of oxidative stress and systemic inflammatory response.