Tocotrienols: Vitamin E beyond tocopherols

Effect of surgery on oxidative stress and endogenous tocopherol concentrations in juvenile female dogs

BACKGROUND

Surgery such as ovariectomy causes an inflammatory and oxidative stress. This study was designed to evaluate endogenous tocopherol levels in response to surgical oxidative stress induced by abdominal surgery (ovariectomy) in thirty-two juvenile female dogs. The dogs received meloxicam before surgery (0.2 mg/kg SC) and after surgery (0.1 mg/kg OS every 24 h), 0.03 mg/kg of atropine sulfate (IM), and propofol 4 mg/kg intravenously (IV). General anesthesia was maintained with sevoflurane. Physiological, hematological and biochemical parameters, malondialdehyde (MDA) and α-, δ-, γ-tocopherols were evaluated at baseline, 36 and 48 h after surgery.

RESULTS

The physiological parameters remained within normal ranges. Blood glucose concentration increased, while the albumin levels decreased after surgery. Rescue analgesia was not required. MDA levels increased above the baseline at 36 and 48 h after surgery (P < 0.001). The α-, δ-, and γ-tocopherol concentrations decreased from baseline at 36 and 48 h after surgery (P < 0.001).

CONCLUSIONS

Surgery in juvenile female dogs revealed oxidative, increased MDA concentrations, reduced tocopherol levels, and had a clinically insignificant influence on homeostasis.

Nutrients in rice bran oil and their nutritional functions: a review

Rice is an important food crop throughout the world. Rice bran, the outer layer of rice grain, is a by-product generated during the rice milling process. Rice bran oil (RBO) is extracted from rice bran and has also become increasingly popular. RBO is considered to be one of the healthiest cooking oils due to its balanced proportion of fatty acids, as well as high content of γ-oryzanol together with phytosterols, vitamin E, wax ester, trace and macro elements, carotenoids, and phenolics. The existence of these compounds provides RBO with various functions, including hypotensive and hypolipidemic functions, antioxidant, anticancer, and immunomodulatory functions, antidiabetic function, anti-inflammatory and anti-allergenic functions, hepatoprotective activity function, and in preventing neurological diseases. Recently, research on the nutrients in RBO focused on the detection of nutrients, functions, and processing methods. However, the processing and utilization of rice bran remain sufficiently ineffective, and the processing steps will also affect the nutrients in RBO to different degrees. Therefore, this review focuses on the contents and nutritional functions of different nutrients in RBO and the possible effects of processing methods on nutrients.

Building Synthetic Yeast Factories to Produce Fat-soluble Antioxidants

Fat-soluble antioxidants play a vital role in protecting the body against oxidative stress and damage. The rapid advancements in metabolic engineering and synthetic biology have offered a promising avenue for economically producing fat-soluble antioxidants by engineering microbial chassis. This review provides an overview of the recent progress in engineering yeast microbial factories to produce three main groups of lipophilic antioxidants: carotenoids, vitamin E, and stilbenoids. In addition to discussing the classic strategies employed to improve precursor availability and alleviate carbon flux competition, this review delves deeper into the innovative approaches focusing on enzyme engineering, product sequestration, subcellular compartmentalization, multistage fermentation, and morphology engineering. We conclude the review by highlighting the prospects of microbial engineering for lipophilic antioxidant production.

The Role of Vitamins in Mitigating the Effects of Various Stress Factors in Pigs Breeding

Good practices in farm animal care are crucial for upholding animal well-being, efficiency, and health. Pigs, like other farm animals, are exposed to various stressors, including environmental, nutritional, chemical, psychological, physiological, and metabolic stressors, which can disrupt their internal balance and compromise their well-being. Oxidative stress can adversely affect animal performance, fertility, and immunity, leading to economic losses for farmers. Dietary considerations are hugely important in attaining these objectives. This paper reviews studies investigating the impact of additional vitamin supplementation on stress reduction in pigs. Vitamin A can be beneficial in counteracting viral and parasitic threats. Vitamin B can be a potential solution for reproductive issues, but it might also be beneficial in reducing the effects of inappropriate nutrition. Vitamin C plays a vital role in reducing the effects of heat stress or exposure to toxins in pigs. Vitamin D proves to be beneficial in addressing stress induced mostly by infections and weaning, while vitamin E has been shown to mitigate the effects of toxins, heat stress, or transport stress. This review highlights the potential benefits of these dietary antioxidants in maintaining pig health, enhancing productivity, and counteracting the adverse effects of various stressors. Understanding the role of vitamins in pig nutrition and stress management is vital for optimising farm animal welfare and production efficiency.

Potential Drug-Nutrient Interactions of 45 Vitamins, Minerals, Trace Elements, and Associated Dietary Compounds with Acetylsalicylic Acid and Warfarin-A Review of the Literature

In cardiology, acetylsalicylic acid (ASA) and warfarin are among the most commonly used prophylactic therapies against thromboembolic events. Drug-drug interactions are generally well-known. Less known are the drug-nutrient interactions (DNIs), impeding drug absorption and altering micronutritional status. ASA and warfarin might influence the micronutritional status of patients through different mechanisms such as binding or modification of binding properties of ligands, absorption, transport, cellular use or concentration, or excretion. Our article reviews the drug-nutrient interactions that alter micronutritional status. Some of these mechanisms could be investigated with the aim to potentiate the drug effects. DNIs are seen occasionally in ASA and warfarin and could be managed through simple strategies such as risk stratification of DNIs on an individual patient basis; micronutritional status assessment as part of the medical history; extensive use of the drug-interaction probability scale to reference little-known interactions, and application of a personal, predictive, and preventive medical model using omics.

Carbosilane Dendritic Amphiphiles from Cholesterol or Vitamin E for Micelle Formation

Cationic dendritic amphiphiles were prepared through the linkage of interesting hydrophobic molecules such as cholesterol or vitamin E to the focal point of carbosilane dendrons. These new dendritic systems self-assembled in saline, producing micellar aggregates with hydrodynamic diameters ranging from 6.5 to 9.2 nm, and critical micelle concentrations of approximately 5 and 10 μM for second- and third-generation systems, respectively. The assemblies were able to encapsulate drugs of different charges (anionic, neutral, and cationic). Surprisingly, a 92% encapsulation efficiency for diclofenac was achieved in micelles prepared from second-generation dendrons. Toxicity measurements on peripheral blood mononuclear cells indicated different behavior depending on the generation, corresponding to the micellar regime. In contrast to the third-generation system, the second-generation system was non-toxic up to 20 μM, opening a window for its use in a micellar regimen, thereby operating as a drug delivery system for different biomedical applications.

In Vitro Evaluation of the Antioxidant Capacity of 3,3-Disubstituted-3H-benzofuran-2-one Derivatives in a Cellular Model of Neurodegeneration

Oxidative stress represents a hallmark for many degenerative pathologies of the Central Nervous System. Throughout life, the constant pressure of noxious stimuli and/or episodes of traumatic events may expose the brain to a microenvironment where the non-balanced reactive oxygen species inevitably lead to neuronal loss and cognitive decline. HO-1, a 32 kDa heat-shock protein catalyzing the degradation of heme into carbon monoxide (CO), iron and biliverdin/bilirubin is considered one of the main antioxidant defense mechanisms playing pivotal roles in neuroprotection. Restoring the redox homeostasis is the goal of many natural or synthetic antioxidant molecules pursuing beneficial effects on brain functions. Here, we investigated the antioxidant capacity of four selected benzofuran-2-one derivatives in a cellular model of neurodegeneration represented by differentiated SH-SY5Y cells exposed to catechol-induced oxidative stress. Our main results highlight how all the molecules have antioxidant properties, especially compound 9, showing great abilities in reducing intracellular ROS levels and protecting differentiated SH-SY5Y cells from catechol-induced death. This compound above all seems to boost HO-1 mRNA and perinuclear HO-1 protein isoform expression when cells are exposed to the oxidative insult. Our findings open the way to consider benzofuran-2-ones as a novel and promising adjuvant antioxidant strategy for many neurodegenerative disorders.

Plant-derived natural medicines for the management of osteoporosis: A comprehensive review of clinical trials

Background

Osteoporosis is a chronic and systemic skeletal disease that is defined by low bone mineral density (BMD) along with an increase in bone fragility and susceptibility to fracture. This study aimed to overview clinical evidence on the use of herbal medicine for management of osteoporosis.

Methods

Electronic databases including Pubmed, Medline, Cochrane library, and Scopus were searched until November 2022 for any clinical studies on the efficacy and/or safety of plant-derived medicines in the management of osteoporosis.

Results

The search yielded 57 results: 19 on single herbs, 16 on multi-component herbal preparations, and 22 on plant-derived secondary metabolites. Risk of fracture, bone alkaline phosphatase, BMD, and specific bone biomarkers are investigated outcomes in these studies. Medicinal plants including Acanthopanax senticosus, Actaea racemosa, Allium cepa, Asparagus racemosus, Camellia sinensis, Cissus quadrangularis, Cornus mas, Nigella sativa, Olea europaea, Opuntia ficus-indica, Pinus pinaster, Trifolium pretense and phytochemicals including isoflavones, ginsenoside, Epimedium prenyl flavonoids, tocotrienols are among plant-derived medicines clinically investigated on osteoporosis. It seems that multi-component herbal preparations were more effective than single-component ones; because of the synergistic effects of their constituents. The investigated herbal medicines demonstrated their promising results in osteoporosis via targeting different pathways in bone metabolism, including balancing osteoblasts and osteoclasts, anti-inflammatory, immunomodulatory, antioxidant, and estrogen-like functions.

Conclusion

It seems that plant-derived medicines have beneficial effects on bone and may manage osteoporosis by affecting different targets and pathways involved in osteoporosis; However, Future studies are needed to confirm the effectiveness and safety of these preparations.

Carotenoids and tocols comparison in different Subspecies of Triticum turgidum and aestivum

Carotenoids and Tocols in six genotypes of Triticum turgidum ssp. durum, five of Triticum turgidum ssp. dicoccum, four of Triticum aestivum ssp. aestivum, and six of Triticum aestivum ssp. spelta were investigated. The aim of the present study was to identify, quantify, and compare the content of tocopherols, tocotrienols, and carotenoids in different primitive and modern genotypes of wheat species in order to evaluate the lines with the highest content and possibly use them for selection and breeding programs. The Triticum durum group showed the highest mean content of total carotenoids, with lutein being the most abundant, accounting for 80.12 % (Triticum spelta) to 86.65 % (Triticum turgidum) of total carotenoids. Among the genotypes, Line 6 (Triticum durum) had the highest lutein content (12.17 μg g-1), significantly differing from the lines within its group and the other groups of dicoccum, aestivum, and spelta.Triticum dicoccum exhibited a lower average content of total tocols compared to other Triticum species. The tocols profile showed a prevalence of tocotrienols over tocopherols. β + γ-T3 was the most abundant individual tocol isomer in all Triticum genotypes, contributing for 50.40 % (Triticum ssp. aestivum) and 42.50 % (Triticum spelta) of the total content, respectively. The highest β + γ-T3 content (23.83 μg/g) was found in Line 6 of Triticum durum. Correlation, principal component, and cluster analyses revealed positive correlations between total tocols and β/γ tocotrienols, significant differences between various groups of the same species, formation of six clusters labeled as I to VI, and the identification of genotypes from the same species grouped in different clusters.

Countercurrent chromatography separation of vitamin E isomers in a co-current mode

Vitamin E represents a group of lipophilic phenolic compounds, including α-tocopherol, β-tocopherol, γ-tocopherol, and δ-tocopherol, and α-tocotrienol, β-tocotrienol, γ-tocotrienol, and δ-tocotrienol isomers. Different forms of vitamin E have been proven to exhibit varying biological activities. However, due to their structural similarities, the separation of vitamin E isomers is a challenging task. Therefore, it is crucial to establish an efficient method for isolating individual isomers. In this study, co-current countercurrent chromatography was employed to isolate vitamin E isomers from commercial capsules using a n-heptane-methanol-water (10:9.5:0.5, v/v) solvent system. The partition coefficients of the main constituents in the capsules ranged from 0.94 to 6.23, requiring over 450 min for a complete separation. To improve separation efficiency, a co-current elution mode was implemented and the flow rates of the two liquid phases as well as sample amount were examined. The results suggested that increasing the flow rate of the stationary phase and sample size could result in more effective separation, shorter separation time, and higher yield. It proved that co-current countercurrent chromatography was an effective method for the separation of vitamin E isomers.

Vitamin E Supplementation and Cardiovascular Health: A Comprehensive Review

This article conducts a thorough investigation into the potential role of vitamin E in preventing cardiovascular diseases (CVDs) in the context of shifting mortality patterns from infectious diseases to the continued prominence of CVDs in modern medicine. The primary focus is on vitamin E's antioxidant properties and its specific ability to counter lipid peroxidation, a pivotal process in the early stages of atherosclerosis, a precursor to CVDs. The research spans a wide range of methodologies, including in vitro, in vivo, clinical, and experimental studies, examining how vitamin E affects critical aspects of cardiovascular health, such as signaling pathways, gene expression, inflammation, and cholesterol metabolism. It also explores vitamin E's influence on complex processes like smooth muscle cell development, oxidative stress reduction, foam cell formation, and the stability of atherosclerotic plaques. In the context of clinical studies, the article presents findings that both support and yield inconclusive results regarding the impact of vitamin E supplementation on CVDs. It acknowledges the intricate interplay of factors such as patient selection, pathophysiological conditions, and genetic variations, all of which can significantly influence the efficacy of vitamin E. The article underscores the need for ongoing research, with a specific focus on understanding the regulatory metabolites of vitamin E and their roles in modulating cellular processes relevant to CVDs. It highlights the potential for innovative therapeutic approaches based on a deeper comprehension of vitamin E's multifaceted effects. However, it also candidly addresses the challenges of translating clinical trial findings into practical applications and emphasizes the importance of considering diverse variables to optimize therapeutic outcomes. In summary, this meticulously conducted study provides a comprehensive examination of vitamin E's potential as a preventive agent against CVDs, recognizing the complexity of the subject and the need for continued research to unlock its full potential in cardiovascular health.

Genetic improvement of tocotrienol content enhances the oxidative stability of canola oil

Background

Tocotrienols and tocopherols, which are synthesized in plastids of plant cells with similar functionalities, comprise vitamin E to serve as a potent lipid-soluble antioxidant in plants. The synthesis of tocopherols involves the condensation of homogentisic acid (HGA) and phytyl diphosphate (PDP) under the catalysis of homogentisate phytyltransferase (HPT). Tocotrienol synthesis is initiated by the condensation of HGA and geranylgeranyl diphosphate (GGDP) mediated by homogentisate geranylgeranyl transferase (HGGT). As one of the most important oil crops, canola seed is regarded as an ideal plant to efficiently improve the production of vitamin E tocochromanols through genetic engineering approaches. However, only a modest increase in tocopherol content has been achieved in canola seed to date.

Methods

In this study, we transformed barley HGGT (HvHGGT) into canola to improve total tocochromanol content in canola seeds.

Results and discussion

The results showed that the total tocochromanol content in the transgenic canola seeds could be maximally increased by fourfold relative to that in wild-type canola seeds. Notably, no negative impact on important agronomic traits was observed in transgenic canola plants, indicating great application potential of the HvHGGT gene in enhancing tocochromanol content in canola in the future. Moreover, the oil extracted from the transgenic canola seeds exhibited significantly enhanced oxidative stability under high temperature in addition to the increase in total tocochromanol content, demonstrating multiple desirable properties of HvHGGT.

Vitamin E biofortification: Maximizing oilseed tocotrienol and total vitamin E tocochromanol production by use of metabolic bypass combinations

Vitamin E tocochromanols are generated in plants by prenylation of homogentisate using geranylgeranyl diphosphate (GGDP) for tocotrienol biosynthesis and phytyl diphosphate (PDP) for tocopherol biosynthesis. Homogentisate geranylgeranyl transferase (HGGT), which uses GGDP for prenylation, is a proven target for oilseed tocochromanol biofortification that effectively bypasses the chlorophyll-linked pathway that limits PDP for vitamin E biosynthesis. In this report, we explored the feasibility of maximizing tocochromanol production in the oilseed crop camelina (Camelina sativa) by combining seed-specific HGGT expression with increased biosynthesis and/or reduced homogentisate catabolism. Plastid-targeted Escherichia coli TyrA-encoded chorismate mutase/prephenate dehydrogenase and Arabidopsis hydroxyphenylpyruvate dioxygenase (HPPD) cDNA were co-expressed in seeds to bypass feedback-regulated steps and increase flux into homogentisate biosynthesis. Homogentisate catabolism was also suppressed by seed-specific RNAi of the gene for homogentisate oxygenase (HGO), which initiates homogentisate degradation. In the absence of HGGT expression, tocochromanols were increased by ∼2.5-fold with HPPD/TyrA co-expression, and ∼1.4-fold with HGO suppression compared to levels in non-transformed seeds. No further increase in tocochromanols was observed in HPPD/TyrA lines with the addition of HGO RNAi. HGGT expression alone increased tocochromanol concentrations in seeds by ∼four-fold to ≤1400 μg/g seed weight. When combined with HPPD/TyrA co-expression, we obtained an additional three-fold increase in tocochromanol concentrations indicating that homogentisate concentrations limit HGGT's capacity for maximal tocochromanol production. The addition of HGO RNAi further increased tocochromanol concentrations to 5000 μg/g seed weight, an unprecedented tocochromanol concentration in an engineered oilseed. Metabolomic data obtained from engineered seeds provide insights into phenotypic changes associated with "extreme" tocochromanol production.

How Do Minerals, Vitamins, and Intestinal Microbiota Affect the Development and Progression of Heart Disease in Adult and Pediatric Patients?

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, far ahead of cancer. Epidemiological data emphasize the participation of many risk factors that increase the incidence of CVDs, including genetic factors, age, and sex, but also lifestyle, mainly nutritional irregularities and, connected with them, overweight and obesity, as well as metabolic diseases. Despite the importance of cardiovascular problems in the whole society, the principles of prevention of CVDs are not widely disseminated, especially among the youngest. As a result, nutritional neglect, growing from childhood and adolescence, translates into the occurrence of numerous disease entities, including CVDs, in adult life. This review aimed to draw attention to the role of selected minerals and vitamins in health and the development and progression of CVDs in adults and children. Particular attention was paid to the effects of deficiency and toxicity of the analyzed compounds in the context of the cardiovascular system and to the role of intestinal microorganisms, which by interacting with nutrients, may contribute to the development of cardiovascular disorders. We hope this article will draw the attention of society and the medical community to emphasize promoting healthy eating and proper eating habits in children and adults, translating into increased awareness and a reduced risk of CVD.

Vitamin E (α-Tocopherol) Does Not Ameliorate the Toxic Effect of Bisphenol S on the Metabolic Analytes and Pancreas Histoarchitecture of Diabetic Rats

This study investigated whether the coadministration of vitamin E (VitE) diminishes the harmful effects provoked by plasticizer bisphenol S (BPS) in the serum metabolites related to hepatic and renal metabolism, as well as the endocrine pancreatic function in diabetic male Wistar rats. Rats were divided into five groups (n = 5-6); the first group was healthy rats (Ctrl group). The other four groups were diabetic rats induced with 45 mg/kg bw of streptozotocin: Ctrl-D (diabetic control); VitE-D (100 mg/kg bw/d of VitE); BPS-D (100 mg/kg bw/d of BPS); The animals from the VitE + BPS-D group were administered 100 mg/kg bw/d of VitE + 100 mg/kg bw/d of BPS. All compounds were administered orally for 30 days. Body weight, biochemical assays, urinalysis, glucose tolerance test, pancreas histopathology, proximate chemical analysis in feces, and the activity of antioxidants in rat serum were assessed. The coadministration of VitE + BPS produced weight losses, increases in 14 serum analytes, and degeneration in the pancreas. Therefore, the VitE + BPS coadministration did not have a protective effect versus the harmful impact of BPS or the diabetic metabolic state; on the contrary, it partially aggravated the damage produced by the BPS. VitE is likely to have an additive effect on the toxicity of BPS.

Association between Vitamin A and E Forms and Prostate Cancer Risk in the Singapore Prostate Cancer Study

PURPOSE

This study aimed to assess associations between forms of vitamin A and E (both individually and collectively) and the risk of prostate cancer, as well as identify potential effect modifiers.

METHODS

Utilizing data from the Singapore Prostate Cancer Study, a hospital-based case-control study, we measured the serum concentrations of 15 different forms of vitamins A and E in 156 prostate cancer patients and 118 control subjects, using a high-performance liquid chromatography technique. These forms included retinol, lutein, zeaxanthin, α-cryptoxanthin, β-cryptoxanthin, α-carotene, β-carotene, lycopene, ubiquinone, δ-tocopherol, γ-tocopherol, α-tocopherol, δ-tocotrienol, γ-tocotrienol, and α-tocotrienol. The odds ratio and 95% confidence interval for associations between vitamin A and E and prostate cancer risk were estimated using logistic regression models after adjustment for potential confounders. The analyses were further stratified by smoking and alcohol consumption status. The mixture effect of micronutrient groups was evaluated using weighted quantile sum regression.

RESULTS

Higher concentrations of retinol, lutein, α-carotene, β-carotene, ubiquinone, α-tocopherol, δ-tocotrienol, γ-tocotrienol, and α-tocotrienol were significantly and positively associated with overall prostate cancer risk. Among ever-smokers, associations were stronger for lutein, β-cryptoxanthin and β-carotene compared with never-smokers. Among regular alcohol drinkers, associations were stronger for lutein, β-cryptoxanthin, ubiquinone, γ-tocotrienol and α-tocotrienol compared with non-regular alcohol drinkers. Retinol and α-tocotrienol contributed most to the group indices 'vitamin A and provitamin A carotenoids' and 'vitamin E', respectively.

CONCLUSIONS

Several serum vitamin A and E forms were associated with prostate cancer risk, with significant effect modification by smoking and alcohol consumption status. Our findings shed light on prostate cancer etiology.

Impact of antioxidant supplementation during in vitro culture of ovarian preantral follicles: A review

The in vitro culture systems of ovarian preantral follicles have been developed for studying follicular and oocyte growth, for future use of immature oocytes as sources of fertilizable oocytes and for screening ovarian toxic substances. One of the key limitations of the in vitro culture of preantral follicles is the oxidative stress by accumulation of reactive oxygen species (ROS), which can impair follicular development and oocyte quality. Several factors are associated with oxidative stress in vitro, which implies the need for a rigorous control of the conditions as well as addition of antioxidant agents to the culture medium. Antioxidant supplementation can minimize or eliminate the damage caused by ROS, supporting follicular survival and development and producing mature oocytes competent for fertilization. This review focuses on the use of antioxidants and their role in preventing follicular damage caused by oxidative stress in the in vitro culture of preantral follicles.

α-Tocopherol Protects Lipopolysaccharide-Activated BV2 Microglia

Microglia, the resident macrophage-like population in the central nervous system, play a crucial role in the pathogenesis of many neurodegenerative disorders by triggering an inflammatory response that leads to neuronal death. Neuroprotective compounds to treat or prevent neurodegenerative diseases are a new field of study in modern medicine. Microglia are activated in response to inflammatory stimuli. The pathogenesis of various neurodegenerative diseases is closely related to the constant activation of microglia due to their fundamental role as a mediator of inflammation in the brain environment. α-Tocopherol, also known as vitamin E, is reported to possess potent neuroprotective effects. The goal of this study was to investigate the biological effects of vitamin E on BV2 microglial cells, as a possible neuroprotective and anti-inflammatory agent, following stimulation with lipopolysaccharide (LPS). The results showed that the pre-incubation of microglia with α-tocopherol can guarantee neuroprotective effects during microglial activation induced by LPS. α-Tocopherol preserved the branched morphology typical of microglia in a physiological state. It also reduced the migratory capacity; the production of pro-inflammatory and anti-inflammatory cytokines such as TNF-α and IL-10; and the activation of receptors such as TRL4 and CD40, which modulate the PI3K-Akt signaling pathway. The results of this study require further insights and research, but they present new scenarios for the application of vitamin E as an antioxidant for the purpose of greater neuroprotection in vivo for the prevention of possible neurodegenerative diseases.

Cultivation, nutritional value, bioactive compounds of morels, and their health benefits: A systematic review

Morels are valuable mushrooms being used as foods and medical substances for a long history. The commonly cultivated morel species include M. eximia, M. importuna, and M. sextelata in China, M. conica and M. esculenta in the US. Morels' nutritional profile mainly consists of carbohydrates, proteins, fatty acids, vitamins, minerals, and organic acids, which are also responsible for its complex sensory attributes and health benefits. The bioactive compounds in morels including polysaccharides, phenolics, tocopherols, and ergosterols contribute to the anti-oxidative abilities, anti-inflammation, immunoprotection, gut health preservation, and anti-cancer abilities. This review depicted on the cultivation of morels, major bioactive compounds of different morel species both from fruit bodies and mycelia, and their health benefits to provide a comprehensive understanding of morels and support the future research and applications of morels as high-value functional food sources.

Global metabolic rewiring of the nonconventional yeast Ogataea polymorpha for biosynthesis of the sesquiterpenoid β-elemene

Bioproduction of natural products via microbial cell factories is a promising alternative to traditional plant extraction. Recently, nonconventional microorganisms have emerged as attractive chassis hosts for biomanufacturing. One such microorganism, Ogataea polymorpha is an industrial yeast used for protein expression with numerous advantages, such as thermal-tolerance, a wide substrate spectrum and high-density fermentation. Here, we systematically rewired the cellular metabolism of O. polymorpha to achieve high-level production of the sesquiterpenoid β-elemene by optimizing the mevalonate pathway, enhancing the supply of NADPH and acetyl-CoA, and downregulating competitive pathways. The engineered strain produced 509 mg/L and 4.7 g/L of β-elemene under batch and fed-batch fermentation, respectively. Therefore, this study identified the potential industrial application of O. polymorpha as a good microbial platform for producing sesquiterpenoids.

Antioxidant and anti-inflammatory agents in chronic liver diseases: Molecular mechanisms and therapy

Chronic liver disease (CLD) is a continuous process that causes a reduction of liver function lasting more than six months. CLD includes alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), chronic viral infection, and autoimmune hepatitis, which can lead to liver fibrosis, cirrhosis, and cancer. Liver inflammation and oxidative stress are commonly associated with the development and progression of CLD. Molecular signaling pathways such as AMP-activated protein kinase (AMPK), C-Jun N-terminal kinase, and peroxisome proliferator-activated receptors (PPARs) are implicated in the pathogenesis of CLD. Therefore, antioxidant and anti-inflammatory agents from natural products are new potent therapies for ALD, NAFLD, and hepatocellular carcinoma (HCC). In this review, we summarize some powerful products that can be potential applied in all the stages of CLD, from ALD/NAFLD to HCC. The selected agents such as β-sitosterol, curcumin, genistein, and silymarin can regulate the activation of several important molecules, including AMPK, Farnesoid X receptor, nuclear factor erythroid 2-related factor-2, PPARs, phosphatidylinositol-3-kinase, and lysyl oxidase-like proteins. In addition, clinical trials are undergoing to evaluate their efficacy and safety.

NRF2 modulation in TRAMP mice: an in vivo model of prostate cancer

BACKGROUND

Prostate cancer (PCa) is one of the most common cancers worldwide and oxidative stress is involved in its occurrence, development and progression. In fact, in transgenic adenocarcinoma of mouse prostate (TRAMP) mice, prostate cancer onset is associated with the methylation of the first five CpG in the nuclear factor erythroid 2-related factor 2 (NRF2) promoter, a key regulator of oxidative stress response, leading to its downregulation and accumulation of reactive oxygen species (ROS). It has been demonstrated that both natural and synthetic compounds can reactivate NRF2 expression inhibiting the methylation status of its promoter by downregulation of DNA methyltransferases (DNMTs) and histone deacetylases (HDACs). Interestingly, NRF2 re-expression significantly reduced prostate cancer onset in TRAMP mice highlighting an important role of NRF2 in prostate tumorigenesis.

METHODS AND RESULTS

We analysed the current literature regarding the role of natural and synthetic compounds in modulating NRF2 pathway in TRAMP mice, an in vivo model of prostate cancer, to give an overview on prostate carcinogenesis and its possible prevention.

CONCLUSION

We can conclude that specific natural and synthetic compounds can downregulate DNMTs and/or HDACs inhibiting the methylation status of NRF2 promoter, then reactivating the expression of NRF2 protecting normal prostatic cells from ROS damage and tumorigenesis.

Suppression of Amyloid-β Adsorption on Endoplasmic Reticulum Stress-Mimicking Membranes by α-Tocopherol and α-Tocotrienol

Two forms of hydrophobic vitamin E (VE), α-tocopherol (Toc) and α-tocotrienol (Toc3), have been proposed to be effective against Alzheimer's disease (AD), the etiology of which is thought to involve endoplasmic reticulum (ER) stress. However, previous studies reported conflicting effects of Toc and Toc3 on the risk of AD. We prepared liposomes mimicking the phase separation of the ER membrane (solid-ordered/liquid-disordered phase separation) and studied how VE can influence the interaction between amyloid-β (Aβ) and the ER membrane. We found that Toc could inhibit the formation of the solid-ordered phase more significantly than Toc3. Furthermore, Aβ protofibril adsorption on ER stress-mimicking membranes was more strongly suppressed by Toc compared with Toc3. Therefore, we concluded that VE can relieve ER stress by destabilizing the solid-ordered phase of the ER membrane and subsequently reducing the amount of Aβ adsorbed on the membrane. Moreover, Toc exerted a stronger effect than Toc3.

A meta-analysis of effects of vitamin E supplementation alone and in combination with omega-3 or magnesium on polycystic ovary syndrome

Vitamin E supplementation might have favorable effects on risk factors of polycystic ovary syndrome (PCOS). This systematic review and meta-analysis aimed to summarize the effects of vitamin E supplementation or vitamin E in combination with omega-3 or magnesium on PCOS. PubMed, Scopus, ISI Web of Science, Cochrane, Embase electronic databases, and Google scholar were searched for all available articles up to September 2022. Randomized controlled trials (RCTs) that examined the effect of vitamin E supplementation or vitamin E in combination with omega-3 or magnesium on lipid and glycemic profiles, anthropometric measurements, biomarkers of inflammation and oxidative stress, hormonal profile, and hirsutism score in patients with PCOS were included. Ten RCTs (with 504 participants) fulfilled the eligible criteria. Vitamin E supplementation or vitamin E in combination with omega-3 or magnesium in comparison to placebo could significantly reduce serum levels of TG (weighted mean difference: - 18.27 mg/dL, 95% CI - 34.68 to - 1.87), VLDL (- 5.88 mg/dL, 95% CI - 8.08 to - 3.68), LDL-c (- 12.84 mg/dL, 95% CI - 22.15 to - 3.52), TC (- 16.30 mg/dL, 95% CI - 29.74 to - 2.86), TC/HDL-c ratio (- 0.52, 95% CI - 0.87 to - 0.18), hs-CRP (- 0.60 ng/mL, 95% CI - 0.77 to - 0.44), hirsutism score (- 0.33, 95% CI - 0.65 to - 0.02) and significantly increase nitric oxide levels (2.79 µmol/L, 95% CI 0.79-4.79). No significant effect was found on HDL-c, glycemic indices, hormonal profile, anthropometric measurements, and other biomarkers of inflammation or oxidative stress. This meta-analysis highlights the potential anti-hyperlipidemic, anti-oxidant, and anti-inflammatory properties of vitamin E supplementation alone or in combination with omega-3 or magnesium on PCOS patients.

Tocotrienol in the Treatment of Topical Wounds: Recent Updates

Healing wounds is an important attempt to keep the internal higher organs safe. Complications in topical wound healing may lead to the formation of scars, which can affect the patient's quality of life. Although several approaches are ongoing in parallel in the exploration of natural compounds via advanced delivery, in this article, an attempt has been made to highlight tocotrienol. Tocotrienol is a natural form of vitamin E and has shown its potential in certain pharmacological activities better than tocopherol. Its antioxidant, anti-inflammatory, cell signal-mediating effects, angiogenic properties, management of scar, and promotion of wound environment with essential factors have shown potential in the management of topical wound healing. Therefore, this review has aimed to focus on recent advances in topical wound healing through the application of tocotrienols. Challenges in delivering tocotrienols to the topical wound due to its large molecular weight and higher logP have also been explored using nanotechnological-based carriers, which has made tocotrienol a potential tool to facilitate the closure of wounds. Exploration of tocotrienol has also been made in human volunteers for biopsy wounds; however, the results are yet to be reported. Overall, based on the current findings in the literature, it could be inferred that tocotrienol would be a viable alternative to the existing wound dressing components for the management of topical wounds.

The potential of pumpkin seed oil as a functional food-A comprehensive review of chemical composition, health benefits, and safety

The growing interest in foods that can be beneficial to human health is bringing into focus some products that have been used locally for centuries but have recently gained worldwide attention. One of these foods is pumpkin seed oil, which has been used in culinary and traditional medicine, but recent data also show its use in the pharmaceutical and cosmetic industries. In addition, some sources refer to it as a potential functional food, mainly because it is obtained from pumpkin seeds, which contain many functional components. However, the production process of the oil may affect the content of these components and consequently the biological activity of the oil. In this review, we have focused on summarizing scientific data that explore the potential of pumpkin seed oil as a functional food ingredient. We provide a comprehensive overview of pumpkin seed oil chemical composition, phytochemical content, biological activity, and safety, as well as the overview of production processes and contemporary use. The main phytochemicals in pumpkin seed oil with health-related properties are polyphenols, phytoestrogens, and fatty acids, but carotenoids, squalene, tocopherols, and minerals may also contribute to health benefits. Most studies have been conducted in vitro and support the claim that pumpkin seed oil has antioxidant and antimicrobial activities. Clinical studies have shown that pumpkin seed oil may be beneficial in the treatment of cardiovascular problems of menopausal women and ailments associated with imbalance of sex hormones.

Anti-androgenic potential of the fruit extracts of certain Egyptian Sabal species and their genetic variability studies: a metabolomic-molecular modeling approach

This work aimed to evaluate the anti-androgenic activity of S. blackburniana Glazebrook, S. causiarum (O. F. Cook) Becc, and S. palmetto (Walter) Lodd. Ex Schult fruit extracts in rats using Hershberger assay. Furthermore, to annotate secondary metabolites using LC-HRMS technique, to investigate underlying mechanisms responsible for 5-α-reductase inhibitory activity in silico and to compare cytotoxic effects in vitro against human prostatic stromal myofibroblast (WPMY-1) and human benign prostatic hyperplasia (BPH-1) cell lines using MTT, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (spectrophotometrically). The results showed significant anti-androgenic implications with varying degrees, markedly decreased sex organ weights, reduction in testosterone and increase in LH and FSH serum levels. Genetic diversity study ensured the correct genotype and revealed outperformance of SCoT compared with CBDP markers to interpret polymorphism among selected species. S. blackburniana exhibited selective cytotoxic activity against BPH-1 compared to finasteride. Molecular docking of 59 dereplicated metabolites belonging to various chemical classes revealed that helasaoussazine, pinoresinol and tetra-O-caffeoylquinic acid are the top inhibitors of 5-α-reductase-2. Our study provides an insight into the anti-androgenic activity of selected species of Egyptian Sabal supported by docking study for the first time, demonstrates safety toward liver and kidney and highlights a new potential therapeutic candidate for anti-androgenic related disease such as benign prostatic hyperplasia.

Revisiting the therapeutic potential of tocotrienol

The therapeutic potential of the tocotrienol group stems from its nutraceutical properties as a dietary supplement. It is largely considered to be safe when consumed at low doses for attenuating pathophysiology as shown by animal models, in vitro assays, and ongoing human trials. Medical researchers and the allied sciences have experimented with tocotrienols for many decades, but its therapeutic potential was limited to adjuvant or concurrent treatment regimens. Recent studies have focused on targeted drug delivery by enhancing the bioavailability through carriers, self-sustained emulsions, nanoparticles, and ethosomes. Epigenetic modulation and computer remodeling are other means that will help increase chemosensitivity. This review will focus on the systemic intracellular anti-cancer, antioxidant, and anti-inflammatory mechanisms that are stimulated and/or regulated by tocotrienols while highlighting its potent therapeutic properties in a diverse group of clinical diseases.

Therapeutic effects of intranasal tocotrienol-rich fraction on rhinitis symptoms in platelet-activating factor induced allergic rhinitis

Background

Platelet-activating factor (PAF) has been suggested to be a potent inflammatory mediator in Allergic rhinitis (AR) pathogenesis. Vitamin E, an essential nutrient that comprises tocopherol and tocotrienol, is known as a potential therapeutic agent for airway allergic inflammation. This study aimed to investigate the beneficial effects of intranasal Tocotrienol-rich fraction (TRF) on PAF-induced AR in a rat model.

Methods

Sprague Dawley rats were randomly assigned into 3 groups: Control, PAF-induced AR and PAF-induced AR with TRF treatment. To induce AR, 50 μl of 16 μg/ml PAF was nasally instilled into each nostril. From day 1 to 7 after AR induction, 10 μl of 16 μg/μl TRF was delivered intranasally to the TRF treatment group. Complete upper skulls were collected for histopathological evaluation on day 8.

Results

The average severity scores of AR were significantly higher in the PAF-induced AR rats compared to both control and PAF-induced AR with TRF treatment. The histologic examination of the nasal structures showed moderate degree of inflammation and polymorphonuclear cells infiltration in the lamina propria, mucosa damage and vascular congestion in the PAF-induced AR rats. TRF was able to ameliorate the AR symptoms by restoring the nasal structures back to normal. H&E staining demonstrated a statistically significant benefit upon TRF treatment, where minimal degree of inflammation, and a reduction in the infiltration of polymorphonuclear cells, mucosa damage and vascular congestion were observed.

Conclusion

TRF exhibited symptomatic relief action in AR potentially due to its antioxidant, anti-inflammatory and anti-allergic properties.

Combining GWAS and TWAS to identify candidate causal genes for tocochromanol levels in maize grain

Tocochromanols (tocopherols and tocotrienols, collectively vitamin E) are lipid-soluble antioxidants important for both plant fitness and human health. The main dietary sources of vitamin E are seed oils that often accumulate high levels of tocopherol isoforms with lower vitamin E activity. The tocochromanol biosynthetic pathway is conserved across plant species but an integrated view of the genes and mechanisms underlying natural variation of tocochromanol levels in seed of most cereal crops remains limited. To address this issue, we utilized the high mapping resolution of the maize Ames panel of ∼1,500 inbred lines scored with 12.2 million single-nucleotide polymorphisms to generate metabolomic (mature grain tocochromanols) and transcriptomic (developing grain) data sets for genetic mapping. By combining results from genome- and transcriptome-wide association studies, we identified a total of 13 candidate causal gene loci, including 5 that had not been previously associated with maize grain tocochromanols: 4 biosynthetic genes (arodeH2 paralog, dxs1, vte5, and vte7) and a plastid S-adenosyl methionine transporter (samt1). Expression quantitative trait locus (eQTL) mapping of these 13 gene loci revealed that they are predominantly regulated by cis-eQTL. Through a joint statistical analysis, we implicated cis-acting variants as responsible for colocalized eQTL and GWAS association signals. Our multiomics approach provided increased statistical power and mapping resolution to enable a detailed characterization of the genetic and regulatory architecture underlying tocochromanol accumulation in maize grain and provided insights for ongoing biofortification efforts to breed and/or engineer vitamin E and antioxidant levels in maize and other cereals.

Antibiotics-Free Compounds for Chronic Wound Healing

The rapid rise in the health burden associated with chronic wounds is of great concern to policymakers, academia, and industry. This could be attributed to the devastating implications of this condition, and specifically, chronic wounds which have been linked to invasive microbial infections affecting patients' quality of life. Unfortunately, antibiotics are not always helpful due to their poor penetration of bacterial biofilms and the emergence of antimicrobial resistance. Hence, there is an urgent need to explore antibiotics-free compounds/formulations with proven or potential antimicrobial, anti-inflammatory, antioxidant, and wound healing efficacy. The mechanism of antibiotics-free compounds is thought to include the disruption of the bacteria cell structure, preventing cell division, membrane porins, motility, and the formation of a biofilm. Furthermore, some of these compounds foster tissue regeneration by modulating growth factor expression. In this review article, the focus is placed on a number of non-antibiotic compounds possessing some of the aforementioned pharmacological and physiological activities. Specific interest is given to Aloevera, curcumin, cinnamaldehyde, polyhexanide, retinoids, ascorbate, tocochromanols, and chitosan. These compounds (when alone or in formulation with other biologically active molecules) could be a dependable alternative in the management or prevention of chronic wounds.

Molecular Mechanisms Underlying the Therapeutic Role of Vitamin E in Age-Related Macular Degeneration

The eye is particularly susceptible to oxidative stress and disruption of the delicate balance between oxygen-derived free radicals and antioxidants leading to many degenerative diseases. Attention has been called to all isoforms of vitamin E, with α-tocopherol being the most common form. Though similar in structure, each is diverse in antioxidant activity. Preclinical reports highlight vitamin E’s influence on cell physiology and survival through several signaling pathways by activating kinases and transcription factors relevant for uptake, transport, metabolism, and cellular action to promote neuroprotective effects. In the clinical setting, population-based studies on vitamin E supplementation have been inconsistent at times and follow-up studies are needed. Nonetheless, vitamin E’s health benefits outweigh the controversies. The goal of this review is to recognize the importance of vitamin E’s role in guarding against gradual central vision loss observed in age-related macular degeneration (AMD). The therapeutic role and molecular mechanisms of vitamin E’s function in the retina, clinical implications, and possible toxicity are collectively described in the present review.

Exploring multifunctional antioxidants as potential agents for management of neurological disorders

Free radical or oxidative stress may be a fundamental mechanism underlying several human neurologic diseases. Therapy using free radical scavengers (antioxidants) has the potential to prevent, delay, or ameliorate many neurologic disorders. However, the biochemistry of oxidative pathobiology is complex, and optimum antioxidant therapeutic options may vary and need to be tailored to individual diseases. In vitro and animal model studies support the potential beneficial role of various antioxidant compounds in neurological disease. Antioxidants generally play an important role in reducing or preventing the cell damage and other changes which occur in the cells like mitochondrial dysfunction, DNA mutations, and lipid peroxidation in the cell membrane. Based on their mechanism of action, antioxidants can be used to treat various neurological disorders like Huntington's disease, Alzheimer's disease, and Parkinson's disease. Vitamin E has a scavenging action for reactive oxygen species (ROS) and also prevents the lipid peroxidation. Creatine generally reduces the mitochondrial dysfunction in Parkinson's disease (PD) patients. Various metal chelators are used in PD for the prevention of accumulation of the metals. Superoxidase dismutase (SOD), lipases, and proteases act as repair enzymes in patients with AD. Accordingly, the antioxidant defense system is found to be most useful for treating various neurological disorders.

Comparative Analysis between Synthetic Vitamin E and Natural Antioxidant Sources from Tomato, Carrot and Coriander in Diets for Market-Sized Dicentrarchus labrax

Synthetic vitamin E is commonly used in aquafeeds to prevent oxidative stress in fish and delay feed and flesh oxidation during storage, but consumers’ preferences tend towards natural antioxidant sources. The potential of vegetable antioxidants-rich coproducts, dried tomato (TO), carrot (CA) and coriander (CO) was compared to that of synthetic vitamin E included in diets at either a regular (CTRL; 100 mg kg⁻¹) or reinforced dose (VITE; 500 mg kg⁻¹). Natural antioxidants were added at 2% to the CTRL. Mixes were then extruded and dried, generating five experimental diets that were fed to European sea bass juveniles (114 g) over 12 weeks. Vitamin E and carotenoid content of extruded diets showed signs of degradation. The experimental diets had very limited effects on fish growth or body composition, immunomodulatory response, muscle and liver antioxidant potential, organoleptic properties or consumer acceptance. Altogether, experimental findings suggest that neither a heightened inclusion dose of 500 mg kg⁻¹ of vitamin E, nor a 2% inclusion of natural antioxidants provided additional antioxidant protection, compared to fish fed diets including the regular dose of 100 mg kg⁻¹ of vitamin E.

Toxicity Studies on Essential Oil from Phoenix dactylifera (L.) Seed in Wistar Rats

This study evaluated the toxicological effect of oral administration of Phoenix dactylifera seed essential oil (PDEO) in Wistar rats. PDEO was extracted through a steam-distillation technique. Acute toxicity study evaluated administration of a single dose of the oil in a group (n = 5) of rats followed by 24 h observation, for sub-acute toxicity evaluation, the animals were randomly divided into five groups (n = 3). Group 1 to 4 rats, respectively, received 62.5, 125, 250, and 500 mg/kg bw of PDEO for fourteen days, while the fifth group served as control. At the termination of the study, blood samples were obtained for biochemical and hematological analyses, while vital organs were histopathologically examined. Results from this study revealed no mortality or abnormal behavioral changes in the animals. A dose-related increase in bodyweight and hematological parameters was observed across the treated groups (p < 0.05). At a dosage of 500 mg/kg bw, PDEO caused slight elevation in biochemical marker levels and mild changes in histological architecture of liver and kidney of the test rats. This study revealed that PDEO exhibited significant hematopoietic attributes with no adverse effect on the experimental rats’ vital organs at concentrations below 500 mg/kg bw.

Barley: a potential cereal for producing healthy and functional foods

Barley is the fourth largest cereal crop in the world. It is mainly used for feeding, beer production and food. Barley is receiving more attention from both agricultural and food scientists because of its special chemical composition and health benefits. In comparison with other cereal crops, including wheat, rice and maize, barley grains are rich in dietary fiber (such as β-glucan) and tocols, which are beneficial to human health. It is well proved that diets rich in those chemicals can provide protection against hypertension, cardiovascular disease, and diabetes. Barley has been widely recognized to be great potential as a healthy or functional food. In this review, we present the information about the studies on physical structure of barley grain and the distribution of main chemical components, nutrient and functional composition of barley grain and their health benefits, and the approaches of improving and utilizing the nutrient and functional chemicals in barley grain. With the development of processing technologies, functional components in barley grains, especially β-glucan, can be efficiently extracted and concentrated. Moreover, nutrient and functional components in barley grains can be efficiently improved by precise breeding and agronomic approaches. The review highlights the great potential of barley used as healthy and functional foods, and may be instructive for better utilization of barley in food processing.

Assessment of Biochemical Composition and Antioxidant Properties of Algerian Date Palm (Phoenix dactylifera L.) Seed Oil

Date palm (Phoenix dactylifera L.) trees are largely cultivated across the Algerian oases; they are principal sources of remuneration and the economic basis for residents of these areas. Date palm fruits are rich sources of essential nutrients, vitamins, minerals, and dietary fibers, with many potential health benefits, yet there are few studies on the chemical composition and biological properties of date palm seed oil. In this study, we present an in-depth characterization of the biochemical composition and antioxidant properties of date palm seed oil (DPSO) produced in Algeria. DPSOs of eight Algerian cultivars, Arechti, Degla-Baida, Deglet-Nour, Ghars, Haloua, Itima, Mech-Degla, and Tentbouchet, were investigated to determine their biochemical compositions and antioxidant properties. The results highlight the potential of DPSO as an alternative food and a natural resource, thanks to several important compounds having high antioxidant capacity. In particular, fatty acids and triacylglycerol (TAGs) analyses showed that oleic (42.74–50.19%), lauric (18.40–22.2%), and myristic (8.83–10.17%) were the major fatty acids, while 1-myristoyl 2-oleoyl 3-linoleoyl glycerol, 1-linolenoyl 2-oleoyl 3-linoleoyl glycerol, 1-2-linolenoyl 3-linoleoyl glycerol, and 1-linolenoyl 2-myristoyl 3-linoleoyl glycerol were the major TAGs. Biophenols and tocopherols analyses revealed the presence of important compounds, such as catechin (22.04–24.92 mg/kg), vanillin (10.67–23.98 mg/kg), and α-tocopherol (443.59 mg/kg), at high remarkable levels. Therefore, a comparison with the literature data concerning other seed oils, including olive oil, confirms that DPSO can be considered a high-quality oil, from a biochemical and biological point of view.

Differential Mechanisms of Action and Efficacy of Vitamin E Components in Antioxidant Cytoprotection of Human Retinal Pigment Epithelium

The purpose of this study was to determine if different vitamin E components exhibit similar efficacy and mechanism of action in protecting Retinal pigment epithelium (RPE) cells from oxidative damage. We hypothesized that α-tocopherol (αT) is unique among vitamin E components in its cytoprotective mechanism of action against oxidative stress in RPE cells and that it requires protein synthesis for optimal antioxidant effect. We used cell viability assays, fluorescent chemical labeling of DNA and actin and immuno-labeling of the antioxidant proteins Nrf2 and Sod2 and of the tight junction protein, ZO-1, and confocal microscopy to determine the effects of αT and γT against oxidative stress in immortalized human RPE cells (hTERT-RPE). Using the four main vitamin E components, αT, γT, δ-tocopherol (δT) and α-tocotrienol (αTr), we ascertained that they exhibit similar, but not identical, antioxidant activity as αT when used at equimolar concentrations. In addition, we determined that the exposure time of RPE cells to α-tocopherol is critical for its ability to protect against oxidative damage. Lastly, we determined that αT, but not γT, partially requires the synthesis of new proteins within a 24-h period and prior to exposure to tBHP for optimal cytoprotection. We conclude that, unlike γT and δT, αT appears to be unique in its requirement for transport and/or signaling for it to be an effective antioxidant. As a result, more focus should be paid to which vitamin E components are used for antioxidant interventions.

Associations of Dietary and Circulating Vitamin E Level With Metabolic Syndrome. A Meta-Analysis of Observational Studies

Objective: The associations of dietary and circulating vitamin E level with metabolic syndrome (MetS) remains conflicting. This meta-analysis of observational study was therefore employed to investigate the issue above.

Methods: The PubMed, Web of Science and Embase database were searched up to April 2021. The observational studies on the associations of dietary and circulating vitamin E level with MetS were specified. The pooled relative risk (RR) of MetS for the highest vs. lowest dietary and circulating vitamin E level, and the standard mean difference (SMD) of dietary and circulating vitamin E level for MetS vs. control subjects, were calculated.

Results: A total of 25 observational studies with 51,276 participants, were included in this meta-analysis. The overall multi-variable adjusted RR demonstrated that the dietary vitamin E level was inversely associated with MetS (RR = 0.92, 95%CI: 0.85–1.00; P = 0.044). In addition, the dietary vitamin E level in MetS was also lower than that in control subjects according to the overall combined SMD (SMD = −0.08, 95%CI: −0.14 to −0.02; P = 0.024). On the other hand, the overall multi-variable adjusted RR showed no significant relationship between the circulating vitamin E level and MetS (RR = 1.46, 95%CI: 0.85–2.48; P = 0.17). However, the circulating vitamin E level in MetS was lower than that in control subjects according to the overall combined SMD (SMD = −0.58, 95%CI: −1.04 to −0.13; P = 0.013).

Conclusions: The results of this meta-analysis suggest that the dietary vitamin E level is inversely associated with MetS. On the other hand, current evidence is still insufficient to conclude a relationship between the circulating vitamin E level and MetS. More well-designed prospective cohort studies are needed to address the issues further.

Electrochemical and Mechanistic Study of Reactivities of α-, β-, γ-, and δ-Tocopherol toward Electrogenerated Superoxide in N,N-Dimethylformamide through Proton-Coupled Electron Transfer

Scavenging of superoxide radical anion (O₂^•−) by tocopherols (TOH) and related compounds was investigated on the basis of cyclic voltammetry and in situ electrolytic electron spin resonance spectrum in N,N-dimethylformamide (DMF) with the aid of density functional theory (DFT) calculations. Quasi-reversible dioxygen/O₂^•− redox was modified by the presence of TOH, suggesting that the electrogenerated O₂^•− was scavenged by α-, β-, γ-TOH through proton-coupled electron transfer (PCET), but not by δ-TOH. The reactivities of α-, β-, γ-, and δ-TOH toward O₂^•− characterized by the methyl group on the 6-chromanol ring was experimentally confirmed, where the methyl group promotes the PCET mechanism. Furthermore, comparative analyses using some related compounds suggested that the para-oxygen-atom in the 6-chromanol ring is required for a successful electron transfer (ET) to O₂^•− through the PCET. The electrochemical and DFT results in dehydrated DMF suggested that the PCET mechanism involves the preceding proton transfer (PT) forming a hydroperoxyl radical, followed by a PCET (intermolecular ET–PT). The O₂^•− scavenging by TOH proceeds efficiently along the PCET mechanism involving one ET and two PTs.

Tocopherols as antioxidants in lipid-based systems: The combination of chemical and physicochemical interactions determines their efficiency

Lipid oxidation is a major concern in the food, cosmetic, and pharmaceutical sectors. The degradation of unsaturated lipids affects the nutritional, physicochemical, and organoleptic properties of products and can lead to off-flavors and to the formation of potentially harmful oxidation compounds. To prevent or slow down lipid oxidation, different antioxidant additives are used alone or in combination to achieve the best possible efficiency with the minimum possible quantities. In manufactured products, that is, heterogeneous systems containing lipids as emulsions or bulk phase, the efficiency of an antioxidant is determined not only by its chemical reactivity, but also by its physical properties and its interaction with other compounds present in the products. The antioxidants most widely used on the industrial scale are probably tocopherols, either as natural extracts or pure synthetic molecules. Considerable research has been conducted on their antioxidant activity, but results regarding their efficiency are contradictory. Here, we review the known mechanisms behind the antioxidant activity of tocopherols and discuss the chemical and physical features that determine their efficacy. We first describe their chemical reactivity linked with the main factors that modulate it between efficient antioxidant capacity and potential prooxidant effects. We then describe their chemical interactions with other molecules (phenolic compounds, metals, vitamin C, carotenes, proteins, and phospholipids) that have potential additive, synergistic, or antagonist effects. Finally, we discuss other physical parameters that influence their activity in complex systems including their specific interactions with surfactants in emulsions and their behavior in the presence of association colloids in bulk oils.

Osteoprotective Effects in Postmenopausal Osteoporosis Rat Model: Oral Tocotrienol vs. Intraosseous Injection of Tocotrienol-Poly Lactic-Co-Glycolic Acid Combination

Osteoporosis, the most common bone disease, is associated with compromised bone strength and increased risk of fracture. Previous studies have shown that oxidative stress contributes to the progression of osteoporosis. Specifically, for postmenopausal osteoporosis, the reduction in estrogen levels leads to increased oxidative stress in bone remodeling. Tocotrienol, a member of vitamin E that exhibits antioxidant activities, has shown potential as an agent for the treatment of osteoporosis. Most studies on the osteoprotective effects of tocotrienols had used the oral form of tocotrienols, despite their low bioavailability due the lack of transfer proteins and high metabolism in the liver. Several bone studies have utilized tocotrienol combined with a nanocarrier to produce a controlled release of tocotrienol particles into the system. However, the potential of delivering tocotrienol-nanocarrier combination through the intraosseous route has never been explored. In this study, tocotrienol was combined with a nanocarrier, poly lactic-co-glycolic acid (PLGA), and injected intraosseously into the bones of ovariectomized rats to produce targeted and controlled delivery of tocotrienol into the bone microenvironment. This new form of tocotrienol delivery was compared with the conventional oral delivery in terms of their effects on bone parameters. Forty Sprague-Dawley rats were divided into five groups. The first group was sham operated, while other groups were ovariectomized (OVX). Following 2 months, the right tibiae of all the rats were drilled at the metaphysis region to provide access for intraosseous injection. The estrogen group (OVX + ESTO) and tocotrienol group (OVX + TTO) were given daily oral gavages of Premarin (64.5 mg/kg) and annatto-tocotrienol (60 mg/kg), respectively. The locally administered tocotrienol group (OVX + TTL) was given a single intraosseous injection of tocotrienol-PLGA combination. After 8 weeks of treatment, both OVX + TTO and OVX + TTL groups have significantly lower bone markers and higher bone mineral content than the OVX group. In terms of bone microarchitecture, both groups demonstrated significantly higher trabecular separation and connectivity density than the OVX group (p < 0.05). Both groups also showed improvement in bone strength by the significantly higher stress, strain, stiffness, and Young's modulus parameters. In conclusion, daily oral tocotrienol and one-time intraosseous injection of tocotrienol-PLGA combination were equally effective in offering protection against ovariectomy-induced bone changes.

γ-Tocotrienol Protects against Mitochondrial Dysfunction, Energy Deficits, Morphological Damage, and Decreases in Renal Functions after Renal Ischemia

Ischemia-induced mitochondrial dysfunction and ATP depletion in the kidney result in disruption of primary functions and acute injury of the kidney. This study tested whether γ-tocotrienol (GTT), a member of the vitamin E family, protects mitochondrial function, reduces ATP deficits, and improves renal functions and survival after ischemia/reperfusion injury. Vehicle or GTT (200 mg/kg) were administered to mice 12 h before bilateral kidney ischemia, and endpoints were assessed at different timepoints of reperfusion. GTT treatment reduced decreases in state 3 respiration and accelerated recovery of this function after ischemia. GTT prevented decreases in activities of complexes I and III of the respiratory chain, and blocked ischemia-induced decreases in F₀F₁-ATPase activity and ATP content in renal cortical tissue. GTT improved renal morphology at 72 h after ischemia, reduced numbers of necrotic proximal tubular and inflammatory cells, and enhanced tubular regeneration. GTT treatment ameliorated increases in plasma creatinine levels and accelerated recovery of creatinine levels after ischemia. Lastly, 89% of mice receiving GTT and 70% of those receiving vehicle survived ischemia. Conclusions: Our data show novel observations that GTT administration improves mitochondrial respiration, prevents ATP deficits, promotes tubular regeneration, ameliorates decreases in renal functions, and increases survival after acute kidney injury in mice.

Potential Nutrients from Natural and Synthetic Sources Targeting Inflammaging-A Review of Literature, Clinical Data and Patents

Inflammaging, the steady development of the inflammatory state over age is an attributable characteristic of aging that potentiates the initiation of pathogenesis in many age-related disorders (ARDs) including neurodegenerative diseases, arthritis, cancer, atherosclerosis, type 2 diabetes, and osteoporosis. Inflammaging is characterized by subclinical chronic, low grade, steady inflammatory states and is considered a crucial underlying cause behind the high mortality and morbidity rate associated with ARDs. Although a coherent set of studies detailed the underlying pathomechanisms of inflammaging, the potential benefits from non-toxic nutrients from natural and synthetic sources in modulating or delaying inflammaging processes was not discussed. In this review, the available literature and recent updates of natural and synthetic nutrients that help in controlling inflammaging process was explored. Also, we discussed the clinical trial reports and patent claims on potential nutrients demonstrating therapeutic benefits in controlling inflammaging and inflammation-associated ARDs.

Tocotrienols as an Anti-Breast Cancer Agent

In the past few years, breast cancer has become the most prevalent type of cancer. The majority of patients receive combinatorial chemotherapy treatments, which may result in increased risk of developing drug resistance, a reduced quality of life, and substantial side effects. Treatment modalities that could lessen the physical toll of standard treatments or act in synergy with chemotherapeutic treatments would benefit women worldwide. Research into tocotrienols has thus far demonstrated their potential to be such an agent, with tocotrienols surpassing the pharmacological potential of tocopherols. Further research using in vitro and preclinical breast cancer models to support clinical trials is needed. This review uses bibliometric analysis to highlight this gap in research and summarizes the current and future landscape of tocotrienols as an anti-breast cancer agent.