A Review on the Relationship between Tocotrienol and Alzheimer Disease

Vitamin E and conflicting understandings in noncommunicable diseases: Is it worth supplementing?

Vitamin E is a lipid-soluble nutrient found mainly in vegetable oils and oilseeds. It is divided into eight homologous compounds; however, only α-tocopherol exhibits vitamin activity. Many advantages are related to these compounds, including cellular protection through antioxidant and anti-inflammatory activity, and improving lipid metabolism. Physiopathology of many diseases incepts with reduced antioxidant defense, characterized by an increased reactive oxygen species production and activation of transcription factors involved in inflammation, such as nuclear factor-kappa B (NF-κB), that can be linked to oxidative stress. Moreover, disorders of lipid metabolism can increase the risk of cardiovascular diseases. In addition, intestinal dysbiosis plays a vital role in developing chronic non-communicable diseases. In this regard, vitamin E can be considered to mitigate those disorders, but data still needs to be more conclusive. This narrative review aims to elucidate the mechanisms of action of vitamin E and if supplementation can be beneficial in a disease scenario regarding non-communicable diseases.

Unraveling the Peculiar Features of Mitochondrial Metabolism and Dynamics in Prostate Cancer

Prostate cancer (PCa) is the second leading cause of cancer deaths among men in Western countries. Mitochondria, the "powerhouse" of cells, undergo distinctive metabolic and structural dynamics in different types of cancer. PCa cells experience peculiar metabolic changes during their progression from normal epithelial cells to early-stage and, progressively, to late-stage cancer cells. Specifically, healthy cells display a truncated tricarboxylic acid (TCA) cycle and inefficient oxidative phosphorylation (OXPHOS) due to the high accumulation of zinc that impairs the activity of m-aconitase, the enzyme of the TCA cycle responsible for the oxidation of citrate. During the early phase of cancer development, intracellular zinc levels decrease leading to the reactivation of m-aconitase, TCA cycle and OXPHOS. PCa cells change their metabolic features again when progressing to the late stage of cancer. In particular, the Warburg effect was consistently shown to be the main metabolic feature of late-stage PCa cells. However, accumulating evidence sustains that both the TCA cycle and the OXPHOS pathway are still present and active in these cells. The androgen receptor axis as well as mutations in mitochondrial genes involved in metabolic rewiring were shown to play a key role in PCa cell metabolic reprogramming. Mitochondrial structural dynamics, such as biogenesis, fusion/fission and mitophagy, were also observed in PCa cells. In this review, we focus on the mitochondrial metabolic and structural dynamics occurring in PCa during tumor development and progression; their role as effective molecular targets for novel therapeutic strategies in PCa patients is also discussed.

Non-Enzymatic Antioxidants against Alzheimer's Disease: Prevention, Diagnosis and Therapy

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although substantial research has been conducted to elucidate the complex pathophysiology of AD, the therapeutic approach still has limited efficacy in clinical practice. Oxidative stress (OS) has been established as an early driver of several age-related diseases, including neurodegeneration. In AD, increased levels of reactive oxygen species mediate neuronal lipid, protein, and nucleic acid peroxidation, mitochondrial dysfunction, synaptic damage, and inflammation. Thus, the identification of novel antioxidant molecules capable of detecting, preventing, and counteracting AD onset and progression is of the utmost importance. However, although several studies have been published, comprehensive and up-to-date overviews of the principal anti-AD agents harboring antioxidant properties remain scarce. In this narrative review, we summarize the role of vitamins, minerals, flavonoids, non-flavonoids, mitochondria-targeting molecules, organosulfur compounds, and carotenoids as non-enzymatic antioxidants with AD diagnostic, preventative, and therapeutic potential, thereby offering insights into the relationship between OS and neurodegeneration.

Ferroptosis: a potential therapeutic target for Alzheimer's disease

The most prevalent dementia-causing neurodegenerative condition is Alzheimer's disease (AD). The aberrant buildup of amyloid β and tau hyperphosphorylation are the two most well-known theories about the mechanisms underlying AD development. However, a significant number of pharmacological clinical studies conducted around the world based on the two aforementioned theories have not shown promising outcomes, and AD is still not effectively treated. Ferroptosis, a non-apoptotic programmed cell death defined by the buildup of deadly amounts of iron-dependent lipid peroxides, has received more attention in recent years. A wealth of data is emerging to support the role of iron in the pathophysiology of AD. Cell line and animal studies applying ferroptosis modulators to the treatment of AD have shown encouraging results. Based on these studies, we describe in this review the underlying mechanisms of ferroptosis; the role that ferroptosis plays in AD pathology; and summarise some of the research advances in the treatment of AD with ferroptosis modulators. We hope to contribute to the clinical management of AD.

Nutrients and amyloid β status in the brain: A narrative review

Amyloid beta (Aβ) is a peptide and a hallmark of Alzheimer's disease (AD). Emerging evidence suggests that Aβ levels could be influenced by diet. However, the evidence is sparse and for some nutrients, controversial. The aim of this narrative review is to gather the findings of observational and clinical trials involving human participants on the relationships between nutrients and brain Aβ status. Some dietary patterns are associated to reduced levels of Aβ in the brain, such as the Mediterranean diet, ketogenic diet as well as low intake of saturated fat, high-glycemic-index food, sodium, and junk/fast food. Low Aβ status in the brain was also associated with higher density lipoproteins (HDL) cholesterol and polyunsaturated fatty acids consumption. Data on alcohol intake is not conclusive. On the contrary, high Aβ levels in the brain were related to a higher intake of total cholesterol, triglycerides, low-density lipoproteins (LDL) cholesterol, saturated fat, sucrose, and fructose. Folic acid, cobalamin, vitamin E, and vitamin D were not associated to Aβ status, while high blood concentrations of Calcium, Aluminum, Zinc, Copper, and Manganese were associated with decreased Aβ blood levels but were not associated with Aβ cerebral spinal fluid (CSF) concentrations. In conclusion, certain dietary patterns and nutrients are associated to brain Aβ status. Further research on the association between nutrients and brain Aβ status is needed in order to pave the way to use nutritional interventions as efficacious strategies to prevent Aβ disturbance and potentially AD.

Associations of 24 h urinary excretions of α- and γ-carboxyethyl hydroxychroman with plasma α- and γ-tocopherol and dietary vitamin E intake in older adults: the Lifelines-MINUTHE Study

BACKGROUND

Urinary metabolites of vitamin E, i.e., α- and γ-carboxyethyl hydroxychroman (α- and γ-CEHC), have gained increasing attention and have been proposed as novel biomarkers of vitamin E intake and status. However, there are insufficient data on the relationship of plasma α-tocopherol and γ-tocopherol and dietary vitamin E intake with 24 h urinary excretions of α- and γ-CEHC.

OBJECTIVES

We aimed to (1) investigate the associations of urinary α- and γ-CEHC/creatinine ratios and 24 h urinary excretions of α- and γ-CEHC with plasma α- and γ-tocopherol, respectively; (2) investigate the associations of urinary α- and γ-CEHC/creatinine ratios and 24 h urinary excretions of α- and γ-CEHC with dietary vitamin E intake, and we hypothesize that 24 h urinary excretions of α- and γ-CEHC will better correlate with vitamin E intake than urinary α- and γ-CEHC/creatinine ratios.

DESIGN

24 h Urine and plasma samples were collected from 1519 participants (60-75 years, male: 50%) included in the Lifelines-MINUTHE Study for the assessments of urinary α- and γ-CEHC/creatinine ratios and 24 h urinary excretions of α- and γ-CEHC, and plasma α- and γ-tocopherol. Among those participants, dietary vitamin E intake data from 387 participants were available from an externally validated Flower-Food Frequency Questionnaire (FFQ). The associations of plasma α- and γ-tocopherol, dietary vitamin E intake, with urinary α- and γ-CEHC were assessed using multivariate linear regressions.

RESULTS

24 h Urinary excretion of α-CEHC (median (IQR): 0.9 (0.3-2.4) µmol) was less than that of γ-CEHC (median (IQR): 1.5 (0.5-3.5) µmol). After adjustment for covariates, we found that 24 h urinary α-CEHC excretion and urinary α-CEHC/creatinine ratio were both positively associated with plasma α-tocopherol (std.beta: 0.06, p = 0.02; std.beta: 0.06, p = 0.01, respectively). Furthermore, the sum of 24 h urinary α- and γ-CEHC excretions was positively associated with dietary vitamin E intake (std.beta: 0.08; p = 0.03), whereas there was no relation between urinary α- and γ-CEHC/creatinine ratios and vitamin E intake. No association was observed neither between plasma α- and γ-tocopherol and dietary vitamin E intake, nor between urinary γ-CEHC and plasma γ-tocopherol.

CONCLUSION

Our study confirmed our hypothesis that 24 h urinary α- and γ-CEHC excretions would be a better marker for dietary vitamin E intake than urinary α- and γ-CEHC/creatinine ratios. Considering that both 24 h urinary α- and γ-CEHC excretions and α- and γ-CEHC/creatinine ratios were also associated with plasma α-tocopherol status, we suggest that 24 h urinary α- and γ-CEHC excretions could be used to assess overall vitamin E status.

Evaluation of chromane derivatives: Promising privileged scaffolds for lead discovery within Alzheimer's disease

The chromane ring system is widely distributed in nature and has proven to be a highly potent pharmacophore in medicinal chemistry, which includes the area of Alzheimer's and Parkinson's diseases. We report on the development of a gem-dimethylchroman-4-ol family that was shown to give good inhibition of equine serum butyrylcholinesterase (eqBuChE) (in the range 2.9 - 7.3 μM) and in the same range of currently used drugs. We also synthesized a small library of gem-dimethylchroman-4-amine compounds, via a simple reductive amination of the corresponding chromanone precursor, that were also selective for eqBuChE presenting inhibitions in the range 7.6 - 67 μM. Kinetic studies revealed that they were mixed inhibitors. Insights into their mechanism of action were obtained through molecular docking and STD-NMR experiments, and the most active examples showed excellent drug-likeness and pharmacological properties predicted using Swiss-ADME. We also prepared a set of propargyl gem-dimethylchromanamines, for monoamine oxidase (MAO) inhibition but they were only moderately active (the best being 28% inhibition at 1 µM on MAO-B). Overall, our compounds were found to be best suited as inhibitors for BuChE.

Mutation Burden Analysis of Six Common Mental Disorders in African Americans by Whole Genome Sequencing

Mental disorders present a global health concern, with limited treatment options. In today's medical practice, medications such as antidepressants are prescribed not only for depression, but also for conditions such as anxiety and attention deficit hyperactivity disorder (ADHD). Therefore, identifying gene targets for specific disorders is important and offers improved precision. In this study, we performed a genetic analysis of six common mental disorders, ADHD, anxiety, depression, delays in mental developments, intellectual disabilities (ID), and speech/language disorder in the ethnic minority of African Americans (AA) using whole genome sequencing (WGS). WGS data was generated from blood-derived DNA from 4178 AA individuals, including 1384 patients with the diagnosis of at least one mental disorder. Mutation burden analysis was applied based on rare and deleterious mutations in the AA population between cases and controls, and further analyzed in the context of patients with single mental disorder diagnosis. Certain genes uncovered demonstrated significant p values in mutation burden analysis. In addition, exclusive recurrences in specific type of disorder were scanned through gene-drug interaction databases to assess for availability of potential medications. We uncovered 15 genes harboring deleterious mutations, including HMGCR and UST for ADHD; FNTB for anxiety, XIRP2, NPPC, , STK33, PANX1 and NTS for depression; RUNX3, TACR1, and NDUFS7 for delays in mental developments; HPN for ID; COL6A3, DDB1, and NDUFA11 for speech/language disorder. Taken together, we have established critical insight into the development of new precision medicine approaches for mental disorders in African Americans.

An Interactive Review on the Role of Tocotrienols in the Neurodegenerative Disorders

Neurodegenerative disorders, such as Parkinson's and Alzheimer's disease, are claimed to be of major concern causing a significant disease burden worldwide. Oxidative stress, mitochondrial dysfunction and nerve damage are the main reasons for the emergence of these diseases. The formation of reactive oxygen species (ROS) is the common chemical molecule that is formed from all these three interdependent mechanisms which is highly reactive toward the neuronal cells. For these reasons, the administration of tocotrienols (T3s), which is a potent antioxidant, is proven to cater to this problem, through in vitro and in vivo investigations. Interestingly, their therapeutic potentials are not only limited to antioxidant property but also to being able to reverse the neuronal damage and act as a shield for mitochondria dysfunction. Thereby, T3s prevents the damage to the neurons. In regards to this statement, in this review, we focused on summarizing and discussing the potential therapeutic role of T3s on Alzheimer's and Parkinson's diseases, and their protective mechanisms based on evidence from the in vitro and in vivo studies. However, there is no clinical trial conducted to prove the efficacy of T3s for Alzheimer's and Parkinson's subjects. As such, the therapeutic role of T3s for these neurodegenerative disorders is still under debate.

Possible role of rice bran extract in microglial modulation through PPAR-gamma receptors in alzheimer's disease mice model

Alzheimer's Disease (AD), the most prevalent neurodegenerative disorder among elderly people, is ordinarily associated with progressive cognitive decline. Peroxisome proliferator-activated receptors-gamma (PPAR-γ) agonists can be targeted as a beneficial therapeutic strategy against AD. In the present study, we aimed to investigate the preventive and therapeutic effects of rice bran extract (RBE) as a possible PPAR-γ agonist on the microglial phenotype modulation in AD in mice compared to the effects of pioglitazone. This study included 64 adult male Swiss Albino mice divided into 8 groups, each group comprised 8 mice; control group, RBE group, lipopolysaccharide-induced neurodegeneration (a) (LPSa) group, (LPSb) group, RBE-preventive group (RBE + LPSa), pioglitazone-preventive group (PG + LPSa), RBE-treated group (RBE + LPSb), and pioglitazone-treated group (PG + LPSb). Cognitive functions were assessed by Y-maze and Morris water maze tests. The expression of PPAR-γ, CD45, arginase1, CD36, and CD163 genes was assessed by real time qPCR and the estimation of NF-kβ protein level was done by Western blot technique. Moreover, the assessment of Aβ42 and P-tau levels was performed by ELISA. Histopathological examination of brain tissues was performed for all the studied groups. Our results showed that RBE and pioglitazone could modulate microglial phenotype from M1 to M2 where they significantly decreased the expression of NF-κβ and the pro-inflammatory microglial marker (CD45) in parallel with increasing the expression of the anti-inflammatory microglial and phagocytic markers (arginase1, CD163, and CD36). In addition, RBE and pioglitazone significantly increased PPAR-γ expression and reduced Aβ42 deposition as well as p-tau protein levels. In conclusion, our study identified the possible role of PPAR-γ agonistic activity of RBE as a preventive and therapeutic agent in the treatment of the neuro-inflammation associated with AD.

Alzheimer's disease in elderly COVID-19 patients: potential mechanisms and preventive measures

Advanced age correlates with higher morbidity and mortality among patients affected with the novel coronavirus disease 2019 (COVID-19). Because systemic inflammation and neurological symptoms are also common in severe COVID-19 cases, there is concern that COVID-19 may lead to neurodegenerative conditions such as Alzheimer’s disease (AD). In this review, we summarize possible mechanisms by which infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, may cause AD in elderly COVID-19 patients and describe preventive measures to mitigate risk. Potential mechanisms include NLRP3 inflammasome activation and IL-1β release, renin-angiotensin system hyperactivation, innate immune activation, oxidative stress, direct viral infection, and direct cytolytic β-cell damage. Anti-inflammatory therapies, including TNF-α inhibitors and nonsteroidal anti-inflammatory drugs, antioxidants such as the vitamin E family, nutritional intervention, physical activity, blood glucose control, and vaccination are proposed as preventive measures to minimize AD risk in COVID-19 patients. Since several risk factors for AD may converge during severe SARS-CoV-2 infection, neurologists should be alert for potential symptoms of AD and actively implement preventive measures in patients presenting with neuropsychiatric symptoms and in high-risk patients such as the elderly.

Enjoy Carefully: The Multifaceted Role of Vitamin E in Neuro-Nutrition

Vitamin E is often associated with health benefits, such as antioxidant, anti-inflammatory and cholesterol-lowering effects. These properties make its supplementation a suitable therapeutic approach in neurodegenerative disorders, for example, Alzheimer’s or Parkinson’s disease. However, trials evaluating the effects of vitamin E supplementation are inconsistent. In randomized controlled trials, the observed associations often cannot be substantiated. This could be due to the wide variety of study designs regarding the dosage and duration of vitamin E supplementation. Furthermore, genetic variants can influence vitamin E uptake and/or metabolism, thereby distorting its overall effect. Recent studies also show adverse effects of vitamin E supplementation regarding Alzheimer’s disease due to the increased synthesis of amyloid β. These diverse effects may underline the inhomogeneous outcomes associated with its supplementation and argue for a more thoughtful usage of vitamin E. Specifically, the genetic and nutritional profile should be taken into consideration to identify suitable candidates who will benefit from supplementation. In this review, we will provide an overview of the current knowledge of vitamin E supplementation in neurodegenerative disease and give an outlook on individualized, sustainable neuro-nutrition, with a focus on vitamin E supplementation.

The Beneficial Effect of Rice Bran Extract Against Rotenone-Induced Experimental Parkinson's Disease in Rats

BACKGROUND

Neurodegenerative diseases have become an increasing cause of various disabilities worldwide, followed by aging, including Parkinson's disease (PD). Parkinson's disease is a degenerative brain disorder distinguished by growing motor & non-motor failure due to the degeneration of medium-sized spiked neurons in the striatum region. Rotenone is often employed to originate the animal model of PD. It is a powerful blocker of mitochondrial complex-I, mitochondrial electron transport chain that reliably produces Parkinsonism-like symptoms in rats. Rice bran (RB) is very rich in polyunsaturated fatty acids (PUFA) and nutritionally beneficial compounds, such as γ-oryzanol, tocopherols, and tocotrienols and sterols are believed to have favorable outcomes on oxidative stress & mitochondrial function.

OBJECTIVE

The present study has been designed to explore RB extract's effect against rotenone-induced neurotoxicity in rats.

METHODS

In the present study, Rotenone (2 mg/kg, s.c) was administered systemically for 28 days. The hexane extract of RB was prepared using Soxhlation. Hexane extract (250 & 500 mg/kg) was administered per oral for 28 days in rotenone-treated groups. Behavioral parameters (grip strength, motor coordination, locomotion, and catalepsy) were conducted on the 7th, 14th, 21st, and 28th day. Animals were sacrificed on the 29th day for biochemical estimation in the striatum and cortex.

RESULTS

This study demonstrates significant alteration in behavioral parameters, oxidative burden (increased lipid peroxidation, nitrite concentration, and decreased glutathione, catalase, SOD) in rotenone-treated animals. Administration of hexane extract of RB prevented the behavioral, biochemical alterations induced by rotenone. The current research has been sketched to inspect RB extract's effect against rotenone-developed neurotoxicity in rats.

CONCLUSION

The findings support that PD is associated with impairments in motor activity. The results also suggest that the nutraceutical rice bran that contains γ-oryzanol, Vitamin-E, ferulic acid etc., may underlie the adjuvant susceptibility towards rotenone-induced PD in experimental rats.

Rice bran, an off-shoot to newer therapeutics in neurological disorders

Normal brain functioning involves the interaction of interconnected molecular and cellular activities, which appear to alter normal to abnormal brain functioning when worsened, contributing to the emergence of neurological disorders. There are currently millions of people who are living with brain disorders globally and this will rise if suitable prevention strategies are not explored. Nutraceutical intended to treat numerous health goals with little adverse effect possible together can be more beneficial than pharmaceutical monotherapy for fostering balanced brain functioning. Nutraceutical provides a specific composition of effective macronutrients and micronutrients that are difficult to synthesize in the laboratory. Numerous elements of rice fibers in rice bran are characterized as natural anti-oxidant and having potential anti-inflammatory activity. The rice bran captures interest among the researchers as it is widespread, affordable, and rich in nutrients including protein, fat, carbohydrates, bioactive components, and dietary fiber. This review covers the neuroprotective multiplicity of rice bran and its constituents to deter pathological conditions of the brain and to facilitate balanced brain functioning at the same time.

Effects of vitamin E on neurodegenerative diseases: an update

Vitamin E deficiency is associated with many neurological problems. Although the mechanisms of vitamin E action in neurodegenerative diseases are not clear, there are many possible mechanisms. Examples of such mechanisms are the protective effects of vitamin E against oxidative stress damage and its suppressive role in the expression of many genes involved in the development of neurodegeneration. Many studies have evaluated the relationship between vitamin E intake or vitamin E levels in body fluids and neurodegenerative diseases. Some studies concluded that vitamin E can play a protective role in neurodegeneration with respect to diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), stroke and amyotrophic lateral sclerosis (ALS). Vitamin E supplementation was also associated with risk factors for some neurodegenerative diseases. In this review, we discuss the possible effects of vitamin E on the development and course of AD, PD, stroke and ALS, and the potential mechanisms involved.

Vitamin E deficiency is associated with many neurological problems. Although the mechanisms of vitamin E action in neurodegenerative diseases are not clear, there are many possible mechanisms. Examples of such mechanisms are the protective effects of vitamin E against oxidative stress damage and its suppressive role in the expression of many genes involved in the development of neurodegeneration. Many studies have evaluated the relationship between vitamin E intake or vitamin E levels in body fluids and neurodegenerative diseases. Some studies concluded that vitamin E can play a protective role in neurodegeneration with respect to diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), stroke and amyotrophic lateral sclerosis (ALS). Vitamin E supplementation was also associated with risk factors for some neurodegenerative diseases. In this review, we discuss the possible effects of vitamin E on the development and course of AD, PD, stroke and ALS, and the potential mechanisms involved.

Cognitive function improvement with astaxanthin and tocotrienol intake: a randomized, double-blind, placebo-controlled study

We examined the effects of the mixed ingestion of astaxanthin derived from Haematococcus pluvialis and tocotrienols on the cognitive function of healthy Japanese adults who feel a memory decline. Forty-four subjects were randomly but equally assigned to the astaxanthin-tocotrienols or placebo group. An astaxanthin-tocotrienols or placebo capsule was taken once daily before or after breakfast for a 12-week intervention period. The primary outcome was composite memory from the Cognitrax cognitive test, and the secondary outcomes were other cognitive functions and subjective symptoms for memory. Each group included 18 subjects in the efficacy analysis (astaxanthin-tocotrienols group, 55.4 ± 7.9 years; placebo group, 54.6 ± 6.9 years). The astaxanthin-tocotrienols group showed a significant improvement in composite memory and verbal memory in Cognitrax at Δ12 weeks compared with the placebo group. Additionally, the astaxanthin-tocotrienols group showed a significant improvement in the subjective symptom of "During the last week, have you had trouble remembering people's names or the names of things?" compared with the placebo group after 12 weeks. No adverse events were observed in this study. The results demonstrated that taking an astaxanthin-tocotrienols combination improves the composite memory and verbal memory of Japanese adults who feel a memory decline (UMIN 000031758).

Potential Role of Tocotrienols on Non-Communicable Diseases: A Review of Current Evidence

Tocotrienol (T3) is a subfamily of vitamin E known for its wide array of medicinal properties. This review aimed to summarize the health benefits of T3, particularly in prevention or treatment of non-communicable diseases (NCDs), including cardiovascular, musculoskeletal, metabolic, gastric, and skin disorders, as well as cancers. Studies showed that T3 could prevent various NCDs, by suppressing 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in the mevalonate pathway, inflammatory response, oxidative stress, and alternating hormones. The efficacy of T3 in preventing/treating these NCDs is similar or greater compared to tocopherol (TF). TF may lower the efficacy of T3 because the efficacy of the combination of TF and T3 was lower than T3 alone in some studies. Data investigating the effects of T3 on osteoporosis, arthritis, and peptic ulcers in human are limited. The positive outcomes of T3 treatment obtained from the preclinical studies warrant further validation from clinical trials.

Tocotrienols and Cancer: From the State of the Art to Promising Novel Patents

BACKGROUND

Tocotrienols (TTs) are vitamin E derivatives naturally occurring in several plants and vegetable oils. Like Tocopherols (TPs), they comprise four isoforms, α, β, γ and δ, but unlike TPs, they present an unsaturated isoprenoid chain. Recent studies indicate that TTs provide important health benefits, including neuroprotective, anti-inflammatory, anti-oxidant, cholesterol lowering and immunomodulatory effects. Moreover, they have been found to possess unique anti-cancer properties.

OBJECTIVE

The purpose of this review is to present an overview of the state of the art of TTs role in cancer prevention and treatment, as well as to describe recent patents proposing new methods for TTs isolation, chemical modification and use in cancer prevention and/or therapy.

METHODS

Recent literature and patents focusing on TTs anti-cancer applications have been identified and reviewed, with special regard to their scientific impact and novelty.

RESULTS

TTs have demonstrated significant anti-cancer activity in multiple tumor types, both in vitro and in vivo. Furthermore, they have shown synergistic effects when given in combination with standard anti-cancer agents or other anti-tumor natural compounds. Finally, new purification processes and transgenic sources have been designed in order to improve TTs production, and novel TTs formulations and synthetic derivatives have been developed to enhance their solubility and bioavailability.

CONCLUSION

The promising anti-cancer effects shown by TTs in several preclinical studies may open new opportunities for therapeutic interventions in different tumors. Thus, clinical trials aimed at confirming TTs chemopreventive and tumor-suppressing activity, particularly in combination with standard therapies, are urgently needed.

Vitamin E and Alzheimer's disease: what do we know so far?

Vitamin E has been proposed as a potential clinical intervention for Alzheimer's disease (AD) given the plausibility of its various biological functions in influencing the neurodegenerative processes associated with the condition. The tocopherol and tocotrienol isoforms of vitamin E have multiple properties including potent antioxidant and anti-inflammatory characteristics, in addition to influences on immune function, cellular signalling and lowering cholesterol. Several of these roles offer a theoretical rationale for providing benefit for the treatment of AD-associated pathology. Diminished circulating concentrations of vitamin E have been demonstrated in individuals with AD. Reduced plasma levels have furthermore been associated with an increased risk of AD development while intake, particularly from dietary sources, may limit or reduce the rate of disease progression. This benefit may be linked to synergistic actions between vitamin E isoforms and other micronutrients. Nevertheless, randomised trials have found limited and inconsistent evidence of vitamin E supplementation as an effective clinical intervention. Thus, despite a strong rationale in support of a beneficial role for vitamin E for the treatment of AD, the evidence remains inconclusive. Several factors may partly explain this discrepancy and represent the difficulties of translating complex laboratory evidence and dietary interactions into clinical interventions. Methodological design limitations of existing randomised trials and restrictions to supplementation with a single vitamin E isoform may also limit the influence of effect. Moreover, several factors influence individual responsiveness to vitamin E intake and recent findings suggest variation in the underlying genetic architecture attenuates vitamin E biological availability and activity which likely contributes to the variation in clinical responsiveness and the failure of randomised trials to date. Importantly, the clinical safety of vitamin E remains controversial and warrants further investigation.

The Role of Tocotrienol in Preventing Male Osteoporosis-A Review of Current Evidence

Male osteoporosis is a significant but undetermined healthcare problem. Men suffer from a higher mortality rate post-fracture than women and they are marginalized in osteoporosis treatment. The current prophylactic agents for osteoporosis are limited. Functional food components such as tocotrienol may be an alternative option for osteoporosis prevention in men. This paper aims to review the current evidence regarding the skeletal effects of tocotrienol in animal models of male osteoporosis and its potential antiosteoporotic mechanism. The efficacy of tocotrienol of various sources (single isoform, palm and annatto vitamin E mixture) had been tested in animal models of bone loss induced by testosterone deficiency (orchidectomy and buserelin), metabolic syndrome, nicotine, alcoholism, and glucocorticoid. The treated animals showed improvements ranging from bone microstructural indices, histomorphometric indices, calcium content, and mechanical strength. The bone-sparing effects of tocotrienol may be exerted through its antioxidant, anti-inflammatory, and mevalonate-suppressive pathways. However, information pertaining to its mechanism of actions is superficial and warrants further studies. As a conclusion, tocotrienol could serve as a functional food component to prevent male osteoporosis, but its application requires validation from a clinical trial in men.