Tocotrienols for bone health: a translational approach

The Effects of Tocotrienol on Gut Microbiota: A Scoping Review

Gut dysbiosis has been associated with many chronic diseases, such as obesity, inflammatory bowel disease, and cancer. Gut dysbiosis triggers these diseases through the activation of the immune system by the endotoxins produced by gut microbiota, which leads to systemic inflammation. In addition to pre-/pro-/postbiotics, many natural products can restore healthy gut microbiota composition. Tocotrienol, which is a subfamily of vitamin E, has been demonstrated to have such effects. This scoping review presents an overview of the effects of tocotrienol on gut microbiota according to the existing scientific literature. A literature search to identify relevant studies was conducted using PubMed, Scopus, and Web of Science. Only original research articles which aligned with the review's objective were examined. Six relevant studies investigating the effects of tocotrienol on gut microbiota were included. All of the studies used animal models to demonstrate that tocotrienol altered the gut microbiota composition, but none demonstrated the mechanism by which this occurred. The studies induced diseases known to be associated with gut dysbiosis in rats. Tocotrienol partially restored the gut microbiota compositions of the diseased rats so that they resembled those of the healthy rats. Tocotrienol also demonstrated strong anti-inflammatory effects in these animals. In conclusion, tocotrienol could exert anti-inflammatory effects by suppressing inflammation directly or partially by altering the gut microbiota composition, thus achieving its therapeutic effects.

The Role of Tocotrienol in Arthritis Management—A Scoping Review of Literature

Arthritis is a cluster of diseases impacting joint health and causing immobility and morbidity in the elderly. Among the various forms of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA) are the most common. Currently, satisfying disease-modifying agents for arthritis are not available. Given the pro-inflammatory and oxidative stress components in the pathogenesis of arthritis, tocotrienol, a family of vitamin E with both anti-inflammatory and antioxidant properties, could be joint-protective agents. This scoping review aims to provide an overview of the effects of tocotrienol on arthritis derived from the existing scientific literature. A literature search using PubMed, Scopus and Web of Science databases was conducted to identify relevant studies. Only cell culture, animal and clinical studies with primary data that align with the objective of this review were considered. The literature search uncovered eight studies investigating the effects of tocotrienol on OA (n = 4) and RA (n = 4). Most of the studies were preclinical and revealed the positive effects of tocotrienol in preserving joint structure (cartilage and bone) in models of arthritis. In particular, tocotrienol activates the self-repair mechanism of chondrocytes exposed to assaults and attenuates osteoclastogenesis associated with RA. Tocotrienol also demonstrated strong anti-inflammatory effects in RA models. The single clinical trial available in the literature showcases that palm tocotrienol could improve joint function among patients with OA. In conclusion, tocotrienol could be a potential anti-arthritic agent pending more results from clinical studies.

Ameliorative Effect of Tocotrienols on Perimenopausal-Associated Osteoporosis-A Review

Osteoporosis, or bone loss, is a disease that affects many women globally. As life expectancy increases, the risk of osteoporosis in women also increases, too, and this will create a burden on the healthcare and economic sectors of a country. Osteoporosis was once thought to be a disease that would occur only after menopause. However, many studies have shown that osteoporosis may develop even in the perimenopausal stage. Due to the erratic levels of estrogen and progesterone during the perimenopausal stage, studies suggest that women are exposed to the risk of developing osteoporosis even at this stage. The erratic hormonal changes result in the production of proinflammatory mediators and cause oxidative stress, which leads to the progressive loss of bone-building activities. Tocotrienols, members of vitamin E, have many health-promoting properties. Due to their powerful anti-oxidative and anti-inflammatory properties, tocotrienols have shown positive anti-osteoporotic properties in post-menopausal studies. Hence, we propose here that tocotrienols could also possibly alleviate perimenopausal osteoporosis by discussing in this review the connection between inflammatory mediators produced during perimenopause and the risk of osteoporosis. Tocotrienols could potentially be an anti-osteoporotic agent, but due to their low bioavailability, they have not been as effective as they could be. Several approaches have been evaluated to overcome this issue, as presented in this review. As the anti-osteoporotic effects of tocotrienols were mostly studied in post-menopausal models, we hope that this review could pave the way for more research to be done to evaluate their effect on peri-menopausal models so as to reduce the risk of osteoporosis from an earlier stage.

Untargeted muscle tissue metabolites profiling in young, adult, and old rats supplemented with tocotrienol-rich fraction

The greatest significant influence on human life span and health is inevitable ageing. One of the distinguishing characteristics of ageing is the gradual decrease of muscle mass and physical function. There has been growing evidence that tocotrienol can guard against age-associated chronic diseases and metabolic disorders. This study aimed to elucidate the effects of tocotrienol-rich fraction (TRF) on muscle metabolomes and metabolic pathways in ageing Sprague Dawley (SD) rats. Three months, 9 months, and 21 months old male SD rats were divided into control and treated groups with 10 rats per group. Rats in control and treated groups were given 60 mg/kg body weight/day of palm olein and 60 mg/kg body weight/day of TRF, respectively, via oral gavage for 3 months. Muscle performance was assessed at 0 and 3 months of treatment by measuring muscle strength and function. Our results showed that TRF treatment caused a significant increase in the swimming time of the young rats. Comparison in the control groups showed that metabolites involved in lipid metabolisms such as L-palmitoyl carnitine and decanoyl carnitine were increased in ageing. In contrast, several metabolites, such as 3-phosphoglyceric acid, aspartic acid and aspartyl phenylalanine were decreased. These findings indicated that muscle metabolomes involved in lipid metabolism were upregulated in aged rats. In contrast, the metabolites involved in energy and amino acid metabolism were significantly downregulated. Comparison in the TRF-supplemented groups showed an upregulation of metabolites involved in energy and amino acid metabolism. Metabolites such as N6-methyl adenosine, spermine, phenylalanine, tryptophan, aspartic acid, histidine, and N-acetyl neuraminic acid were up-regulated, indicating promotion of amino acid synthesis and muscle regeneration. Energy metabolism was also improved in adult and old rats with TRF supplementation as indicated by the upregulation of nicotinamide adenine dinucleotide and glycerol 3-phosphate compared to the control group. In conclusion, the mechanism underlying the changes in skeletal muscle mass and functions in ageing was related to carbohydrate, lipid and amino acid metabolism. Tocotrienol supplementation showed beneficial effects in alleviating energy and amino acid synthesis that may promote the regeneration and renewal of skeletal muscle in ageing rats.

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.

Tocotrienol Supplementation Led to Higher Serum Levels of Lysophospholipids but Lower Acylcarnitines in Postmenopausal Women: A Randomized Double-Blinded Placebo-Controlled Clinical Trial

Osteoporosis is a major health problem in postmenopausal women. Herein we evaluated the effects of 12-week tocotrienols (TT) supplementation on serum metabolites in postmenopausal, osteopenic women. Eighty-nine participants (59.7 ± 6.8 yr, BMI 28.7 ± 5.7 kg/m²) were assigned to 3 treatments: placebo (860 mg olive oil/day), 300mg TT (300 mg TT/day), and 600mg TT (600 mg TT/day) for 12 weeks. TT consisted of 90% δ-TT and 10% γ-TT. In this metabolomic study, we evaluated the placebo and 600mgTT at baseline and 12 weeks. As expected, TT and its metabolite levels were higher in the supplemented group after 12 weeks. At baseline, there were no differences in demographic parameters or comprehensive metabolic panels (CMP). Metabolomics analysis of serum samples revealed that 48 biochemicals were higher and 65 were lower in the 600mg TT group at 12 weeks, compared to baseline. The results confirmed higher serum levels of tocotrienols and lysophospholipids, but lower acylcarnitines and catabolites of tryptophan and steroids in subjects given 600mg TT. In summary, 12-week TT supplementation altered many serum metabolite levels in postmenopausal women. The present study supports our previous findings that TT supplementation helps reduce bone loss in postmenopausal osteopenic women by suppressing inflammation and oxidative stress. Furthermore, the body incorporates TT which restructures biomembranes and modifies phospholipid metabolism, a response potentially linked to reduced inflammation and oxidative stress.

Therapeutic potential of annatto tocotrienol with self-emulsifying drug delivery system in a rat model of postmenopausal bone loss

Tocotrienol has been shown to prevent bone loss in animal models of postmenopausal osteoporosis, but the low oral bioavailability might limit its use. A self-emulsifying drug delivery system (SEDDS) could increase the bioavailability of tocotrienol. However, evidence of this system in improving the skeletal effects of tocotrienol is scanty. This study aims to evaluate the therapeutic efficacy of annatto tocotrienol with SEDDS in a rat model of postmenopausal bone loss. Ten-month-old female Sprague Dawley rats were randomized into six groups. The baseline group was euthanatized at the onset of the study. Four other groups underwent ovariectomy to induce estrogen deficiency. The sham underwent similar surgery procedure, but their ovaries were retained. Eight weeks after surgery, the ovariectomized rats received one of the four different regimens orally daily: (a) SEDDS, (b) annatto tocotrienol [60 mg/kg body weight (b.w.)] without SEDDS, (c) annatto-tocotrienol (60 mg/kg b.w.) with SEDDS, (d) raloxifene (1 mg/kg b.w.). After eight weeks of treatment, blood was collected for the measurement of delta-tocotrienol level and oxidative stress markers. The rats were euthanized and their bones were harvested for the evaluation of the bone microstructure, calcium content and strength. Circulating delta-tocotrienol level was significantly higher in rats receiving annatto tocotrienol with SEDDS compared to the group receiving unformulated annatto-tocotrienol (p < 0.05). Treatment with unformulated or SEDDS-formulated annatto tocotrienol improved cortical bone thickness, preserved bone calcium content, increased bone biomechanical strength and increased antioxidant enzyme activities compared with the ovariectomized group (p < 0.05). Only SEDDS-formulated annatto tocotrienol improved trabecular microstructure, bone stiffness and lowered malondialdehyde level (p < 0.05 vs the ovariectomized group). The improvement caused by annatto tocotrienol was comparable to raloxifene. In conclusion, SEDDS improves the bioavailability and skeletal therapeutic effects of annatto tocotrienol in a rat model of postmenopausal bone loss. This formulation should be tested in a human clinical trial to validate its efficacy.

Osteoprotective effect of green tea polyphenols and annatto-extracted tocotrienol in obese mice is associated with enhanced microbiome vitamin K2 biosynthetic pathways

The role of the gut microbiome in bone health has received significant attention in the past decade. We investigated the effects of green tea polyphenols (GTP) and annatto-extracted tocotrienols (AT) on bone properties and gut microbiome in obese mice. Male mice were assigned to a two (no AT vs. 400 mg/kg diet AT) × two (no GTP vs. 0.5% w/v GTP) factorial design, namely control, G, T, and G+T group respectively, for 14 weeks. The 4th lumbar vertebra (LV-4) and femur were harvested for bone microstructural analysis using μ-CT. Microbiome analysis using 16S rRNA gene sequencing of cecal feces was performed. AT increased bone volume at distal femur. GTP increased serum procollagen type 1 N-terminal propeptide concentration, bone volume at the distal femur and the LV-4, and trabecular number at distal femur; whereas GTP decreased trabecular separation at distal femur. Interactions between GTP and AT were observed in serum C-terminal telopeptide of type I collagen level (control>G=T=G+T) as well as the cortical bone area (control<G=T=G+T) and thickness (T≥G+T≥G≥control) at femur mid-diaphysis. Redundancy analysis showed a significant difference in the gut microbiome profile among different groups and the relative abundance of Akkermansia muciniphila, Clostridum saccharogumia, and Subdoligranulum variabile was increased in the GTP- and AT-supplemented groups. Functional profiling of the gut microbiome showed the combination of GTP and AT induced biosynthetic pathways for vitamin K₂. Our results suggest that GTP and AT supplementation benefits bone properties in obese mice through modifying gut microbiome composition and function.

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.

Beneficial effects of δ-tocotrienol against oxidative stress in osteoblastic cells: studies on the mechanisms of action

Purpose

Natural antioxidants are considered as promising compounds in the prevention/treatment of osteoporosis. We studied the ability of purified δ-tocotrienol (δ-TT) isolated from a commercial palm oil (Elaeis guineensis) fraction to protect osteoblast MC3T3-E1 and osteocyte MLO-Y4 cells against tert-butyl hydroperoxide (t-BHP)-induced oxidative damage and the mechanisms involved in its protective action in MC3T3-E1.

Methods

MC3T3-E1 and MLO-Y4 cells were treated with δ-TT (1.25–20 µg/ml for 2 h) followed by t-BHP at 250 µM or 125 µM for 3 h, respectively. MTT test was used to measure cell viability. Apoptotic cells were stained with Hoechst-33258 dye. Intracellular ROS levels were measured by dichlorofluorescein CM-DCFA. The OPT fluorimetric assay was used to detect the reduced glutathione to oxidized glutathione ratio (GSH/GSSG) contents.

Results

δ-TT significantly prevented the effects of t-BHP on cell viability and apoptosis reaching a maximum protective activity at 10 and 5 µg/ml in MC3T3-E1 and MLO-Y4 cells, respectively. This protective effect was due to a reduction of intracellular ROS levels and an increase in the defense systems shown by the increase in the GSH/GSSG. GSH loss induced by an inhibitor of GSH synthesis significantly reduced the δ-TT-positive effect on ROS levels. δ-TT prevention of oxidative damage was completely removed by combined treatment with the specific inhibitors of PI3K/AKT (LY294002) and Nrf2 (ML385).

Conclusions

The δ-TT protective effect against oxidative damage in MC3T3-E1 cells is due to a reduction of intracellular ROS levels and an increase of the GSH/GSSG ratio, and involves an interaction between the PI3K/Akt–Nrf2 signaling pathways.

Isolated Compounds from Turpinia formosana Nakai Induce Ossification

Bone metabolism is a homeostatic process, imbalance in which leads to the onset of diseases such as osteoporosis and osteopenia. Although several drugs are currently available to treat such conditions, they are associated with severe side effects and do not enhance bone formation. Thus, identifying alternative treatment strategies that focus on enhancing bone formation is essential. Herein, we explored the osteogenic potential of Turpinia formosana Nakai using human osteoblast (HOb) cells. The plant extract was subjected to various chromatographic techniques to obtain six compounds, including one new compound: 3,3′-di-O-methylellagic acid-4-O-α-l-arabinofuranoside (1). Compounds 3,3′-di-O-methylellagic acid-4-O-α-l-arabinofuranoside (1), gentisic acid 5-O-β-d-(6′-O-galloyl) glucopyranoside (2), strictinin (3), and (-)-epicatechin-3-O-β-d-allopyranoside (6) displayed no significant cytotoxicity toward HOb cells, and thus their effects on various osteogenic markers were analyzed. Results showed that 1–3 and 6 significantly increased alkaline phosphatase (ALP) activity up to 120.0, 121.3, 116.4, and 125.1%, respectively. Furthermore, 1, 2, and 6 also markedly enhanced the mineralization process with respective values of up to 136.4, 118.9, and 134.6%. In addition, the new compound, 1, significantly increased expression levels of estrogen receptor-α (133.4%) and osteogenesis-related genes of Runt-related transcription factor 2 (Runx2), osteopontin (OPN), bone morphogenetic protein (BMP)-2, bone sialoprotein (BSP), type I collagen (Col-1), and brain-derived neurotropic factor (BDNF) by at least 1.5-fold. Our results demonstrated that compounds isolated from T. formosana possess robust osteogenic potential, with the new compound, 1, also exhibiting the potential to enhance the bone formation process. We suggest that T. formosana and its isolated active compounds deserve further evaluation for development as anti-osteoporotic agents.

Effects of Palm Oil Tocotrienol-Rich Fraction (TRF) and Carotenes in Ovalbumin (OVA)-Challenged Asthmatic Brown Norway Rats

Synthetic therapeutic drugs for asthma, a chronic airway inflammation characterised by strong eosinophil, mast cell, and lymphocyte infiltration, mucus hyper-production, and airway hyper-responsiveness, exhibit numerous side effects. Alternatively, the high antioxidant potential of palm oil phytonutrients, including vitamin E (tocotrienol-rich fractions; TRF) and carotene, may be beneficial for alleviating asthma. Here, we determined the therapeutic efficacy of TRF, carotene, and dexamethasone in ovalbumin-challenged allergic asthma in Brown Norway rats. Asthmatic symptoms fully developed within 8 days after the second sensitization, and were preserved throughout the time course via intranasal ovalbumin re-challenge. Asthmatic rats were then orally administered 30 mg/kg body weight TRF or carotene. TRF-treated animals exhibited reduced inflammatory cells in bronchial alveolar lavage fluid. TRF- and carotene-treated rats exhibited notable white blood cell reduction comparable to that from dexamethasone. TRF- and carotene-treatment also downregulated pro-inflammatory markers (IL-β, IL-6, TNF-α), coincident with anti-inflammatory marker IL-4 and IL-13 upregulation. Treatment significantly reduced asthmatic rat plasma CRP and IgE, signifying improved systemic inflammation. Asthmatic lung histology displayed severe edema and inflammatory cell infiltration in the bronchial wall, whereas treated animals retained healthy, normal-appearing lungs. The phytonutrients tocotrienol and carotene thus exhibit potential benefits for consumption as nutritional adjuncts in asthmatic disease.

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.

Report on the 2nd International Symposium on Phytochemicals in Medicine and Food (4-7 April 2017, FuZhou, China)

The second International Symposium on Phytochemicals in Medicine and Food (2-ISPMF), organized by the Phytochemical Society of Europe (PSE), the Phytochemical Society of Asia (PSA) and the International Society for Chinese Medicine (ISCM), was held on 4-7 April 2017 in FuZhou, China. This symposium created a stage for more than 290 scientists from 33 countries to discuss the latest research in phytochemicals for food and human health. The program comprised 14 plenary lectures, 27 invited talks, 49 short oral presentations, a graduate student forum consisting of 22 oral presentations, and more than 110 posters. 2-ISPMF received supports from several international journals.

The Role of Vitamin E in Preventing and Treating Osteoarthritis - A Review of the Current Evidence

Osteoarthritis is a debilitating disease of the joint involving cartilage degeneration and chondrocytes apoptosis. Oxidative stress is one of the many proposed mechanisms underpinning joint degeneration in osteoarthritis. The current pharmacotherapies emphasize pain and symptomatic management of the patients but do not alter the biological processes underlying the cartilage degeneration. Vitamin E is a potential agent to prevent or treat osteoarthritis due to its antioxidant and anti-inflammatory effects. This review aims to summarize the current evidence on the relationship between vitamin E and osteoarthritis derived from preclinical and human studies. Cellular studies showed that vitamin E mitigated oxidative stress in cartilage explants or chondrocyte culture invoked by mechanical stress or free radicals. Animal studies suggested that vitamin E treatment prevented cartilage degeneration and improve oxidative status in animal models of osteoarthritis. Low circulating or synovial vitamin E was observed in human osteoarthritic patients compared to healthy controls. Observational studies also demonstrated that vitamin E was related to induction or progression of osteoarthritis in the general population. Vitamin E supplementation might improve the outcomes in patients with osteoarthritis, but negative results were also reported. Different isomers of vitamin E might possess distinct anti-osteoarthritic effects. As a conclusion, vitamin E may retard the progression of osteoarthritis by ameliorating oxidative stress and inflammation of the joint. Further studies are warranted to develop vitamin E as an anti-osteoarthritis agent to reduce the global burden of this disease.

Annatto-extracted tocotrienols improve glucose homeostasis and bone properties in high-fat diet-induced type 2 diabetic mice by decreasing the inflammatory response

Diabetes is a risk factor for osteoporosis. Annatto-extracted tocotrienols (TT) have proven benefits in preserving bone matrix. Here, we evaluated the effects of dietary TT on glucose homeostasis, bone properties, and liver pro-inflammatory mRNA expression in high-fat diet (HFD)-induced type 2 diabetic (T2DM) mice. 58 male C57BL/6 J mice were divided into 5 groups: low-fat diet (LFD), HFD, HFD + 400 mgTT/kg diet (T400), HFD + 1600 mgTT/kg diet (T1600), and HFD + 200 mg metformin/kg (Met) for 14 weeks. Relative to the HFD group, both TT-supplemented groups (1) improved glucose homeostasis by lowering the area under the curve for both glucose tolerance and insulin tolerance tests, (2) increased serum procollagen I intact N-terminal propeptide (bone formation) level, trabecular bone volume/total volume, trabecular number, connectivity density, and cortical thickness, (3) decreased collagen type 1 cross-linked C-telopeptide (bone resorption) levels, trabecular separation, and structure model index, and (4) suppressed liver mRNA levels of inflammation markers including IL-2, IL-23, IFN-γ, MCP-1, TNF-α, ITGAX and F4/80. There were no differences in glucose homeostasis and liver mRNA expression among T400, T1600, and Met. The order of osteo-protective effects was LFD ≥T1600 ≥T400 = Met >HFD. Collectively, these data suggest that TT exerts osteo-protective effects in T2DM mice by regulating glucose homeostasis and suppressing inflammation.

A 12-week evaluation of annatto tocotrienol supplementation for postmenopausal women: safety, quality of life, body composition, physical activity, and nutrient intake

BACKGROUND

Evidence suggests that tocotrienols may benefit bone health in osteopenic women. However, their safety in this population has never been investigated. This study was to evaluate the safety of a 12-week supplementation of annato tocotrienol in postmenopausal osteopenic women, along with effects of the supplementation on quality of life, body composition, physical activity, and nutrient intake in this population.

METHODS

Eighty nine postmenopausal osteopenic women were randomly assigned to 3 treatment arms: (1) Placebo (430 mg olive oil/day), (2) Low tocotrientol (Low TT) (430 mg tocotrienol/day from DeltaGold 70 containing 300 mg tocotrienol) and (3) High tocotrienol (High TT) (860 mg tocotrienol/day from DeltaGold 70 containing 600 mg tocotrienol) for 12 weeks. DeltaGold 70 is an extract from annatto seed with 70% tocotrienol consisting of 90% delta-tocotrienol and 10% gamma-tocotrienol. Safety was examined by assessing liver enzymes (aspartate aminotransferase, alanine aminotransferase), alkaline phosphatase, bilirubin, kidney function (blood urea nitrogen and creatinine), electrolytes, glucose, protein, albumin, and globulin at 0, 6, and 12 weeks. Serum tocotrienol and tocopherol concentrations were assessed and pills counted at 0, 6, and 12 weeks. Quality of life, body composition, physical activity, and dietary macro- and micro-nutrient intake were evaluated at 0 and 12 weeks. A mixed model of repeated measures ANOVA was applied for analysis.

RESULTS

Eighty seven subjects completed the study. Tocotrienol supplementation did not affect liver or kidney function parameters throughout the study. No adverse event due to treatments was reported by the participants. Tocotrienol supplementation for 6 weeks significantly increased serum delta-tocotrienol level and this high concentration was sustained to the end of study. There was no difference in serum delta-tocotrienol levels between the Low TT and the High TT groups. No effects of tocotrienol supplementation were observed on quality of life, body composition, physical activity, and nutrient intake.

CONCLUSIONS

Annatto-derived tocotrienol up to 600 mg per day for 12 weeks appeared to be safe in postmenopausal osteopenic women, particularly in terms of liver and kidney functions. Tocotrienol supplementation for 12 weeks did not affect body composition, physical activity, quality of life, or intake of macro- and micro-nutrients in these subjects.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02058420 .

TITLE

Tocotrienols and bone health of postmenopausal women.

Annatto-derived tocotrienol stimulates osteogenic activity in preosteoblastic MC3T3-E1 cells: a temporal sequential study

PURPOSE

Annatto-derived tocotrienol (AnTT) has been shown to improve bone formation in animal models of osteoporosis. However, detailed studies of the effects of AnTT on preosteoblastic cells were limited. This study was conducted to investigate the osteogenic effect of AnTT on preosteoblast MC3T3-E1 cells in a time-dependent manner.

MATERIALS AND METHODS

Murine MC3T3-E1 preosteoblastic cells were cultured in the different concentrations of AnTT (0.001-1 µg/mL) up to 24 days. Expression of osteoblastic differentiation markers was measured by qPCR (osterix [OSX], collagen 1 alpha 1 [COL1α1], alkaline phosphatase [ALP], and osteocalcin [OCN]) and by fluorometric assay for ALP activity. Detection of collagen and mineralized nodules was done via Direct Red staining and Alizarin Red staining, respectively.

RESULTS

The results showed that osteoblastic differentiation-related genes, such as OSX, COL1α1, ALP, and OCN, were significantly increased in the AnTT-treated groups compared to the vehicle group in a time-dependent manner (P<0.05). Type 1 collagen level was increased from day 3 to day 15 in the AnTT-treated groups, while ALP activity was increased from day 9 to day 21 in the AnTT-treated groups (P<0.05). Enhanced mineralization was observed in the AnTT-treated groups via increasing Alizarin Red staining from day 3 to day 21 (P<0.05).

CONCLUSION

Our results suggest that AnTT enhances the osteogenic activity by promoting the bone formation-related genes and proteins in a temporal and sequential manner.

Protective Effects of Selected Botanical Agents on Bone

Osteoporosis is a serious health problem affecting more than 200 million elderly people worldwide. The early symptoms of this disease are hardly detectable. It causes progressive bone loss, which ultimately renders the patients susceptible to fractures. Osteoporosis must be prevented because the associated fragility fractures result in high morbidity, mortality, and healthcare costs. Many plants used in herbal medicine contain bioactive compounds possessing skeletal protective effects. This paper explores the anti-osteoporotic properties of selected herbal plants, including their actions on osteoblasts (bone forming cells), osteoclasts (bone resorbing cells), and bone remodelling. Some of the herbal plant families included in this review are Berberidaceae, Fabaceae, Arecaceae, Labiatae, Simaroubaceaea, and Myrsinaceae. Their active constituents, mechanisms of action, and pharmaceutical applications were discussed. The literature shows that very few herbal plants have undergone human clinical trials to evaluate their pharmacological effects on bone to date. Therefore, more intensive research should be performed on these plants to validate their anti-osteoporotic properties so that they can complement the currently available conventional drugs in the battle against osteoporosis.

Tocotrienol supplementation suppressed bone resorption and oxidative stress in postmenopausal osteopenic women: a 12-week randomized double-blinded placebo-controlled trial

Tocotrienols have shown bone-protective effect in animals. This study showed that a 12-week tocotrienol supplementation decreased concentrations of bone resorption biomarker and bone remodeling regulators via suppressing oxidative stress in postmenopausal osteopenic women.

INTRODUCTION

Tocotrienols (TT) have been shown to benefit bone health in ovariectomized animals, a model of postmenopausal women. The purpose of this study was to evaluate the effect of 12-week TT supplementation on bone markers (serum bone-specific alkaline phosphatase (BALP), urine N-terminal telopeptide (NTX), serum soluble receptor activator of nuclear factor-kappaB ligand (sRANKL), and serum osteoprotegerin (OPG)), urine calcium, and an oxidative stress biomarker (8-hydroxy-2'-deoxyguanosine (8-OHdG)) in postmenopausal women with osteopenia.

METHODS

Eighty-nine postmenopausal osteopenic women (59.7 ± 6.8 year, BMI 28.7 ± 5.7 kg/m²) were randomly assigned to three groups: (1) placebo (430 mg olive oil/day), (2) low TT (430 mg TT/day, 70% purity), and (3) high TT (860 mg TT/day, 70% purity). TT, an extract from annatto seed with 70% purity, consisted of 90% delta-TT and 10% gamma-TT. Overnight fasting blood and urine samples were collected at baseline, 6, and 12 weeks for biomarker analyses. Eighty-seven subjects completed the 12-week study.

RESULTS

Relative to the placebo group, there were marginal decreases in serum BALP level in the TT-supplemented groups over the 12-week study period. Significant decreases in urine NTX levels, serum sRANKL, sRANKL/OPG ratio, and urine 8-OHdG concentrations and a significant increase in BALP/NTX ratio due to TT supplementation were observed. TT supplementation did not affect serum OPG concentrations or urine calcium levels throughout the study period. There were no significant differences in NTX level, BALP/NTX ratio, sRANKL level, and sRANKL/OPG ratio between low TT and high TT groups.

CONCLUSIONS

Twelve-week annatto-extracted TT supplementation decreased bone resorption and improved bone turnover rate via suppressing bone remodeling regulators in postmenopausal women with osteopenia. Such osteoprotective TT's effects may be, in part, mediated by an inhibition of oxidative stress.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02058420.

TITLE

Tocotrienols and bone health of postmenopausal women.