Blog Archives
The effect of dual-functional hyaluronic acid-vitamin E succinate micelles on targeting delivery of doxorubicin.
Wang J, Ma W, Guo Q, Li Y, Hu Z, Zhu Z, Wang X, Zhao Y, Chai X, Tu P.
Int J Nanomedicine. 2016 Nov 7;11:5851-5870. eCollection 2016.
Abstract
Tumor-targeted delivery system has been developed as an attractive strategy for effective tumor therapy. In this study, in order to enhance the antitumor effects of doxorubicin (DOX), amphiphilic hyaluronic acid (HA)-conjugated vitamin E succinate (VES) copolymers (HA-VES) with different degrees of substitution (DS) were prepared with synergistic antitumor effects and active targeting activities, and utilized as nanocarriers for the efficient delivery of DOX. DOX-loaded HA-VES polymeric micelles (HA-VES/DOX) self-assembled from dual-functional HA-VES copolymer and exhibited excellent loading efficiency and superior colloidal stability. In vitro, HA-VES/DOX displayed enhanced cytotoxicity with synergistic anticancer effects of HA-VES copolymer, high apoptosis-inducing activities of tumor cells, and reversal effects of DOX on multidrug resistance, in comparison with DOX. Also, in vitro cellular uptake and subcellular localization studies revealed that HA-VES/DOX could more efficiently internalize into cancer cells and selectively release DOX within lysosomes, thereby enhancing the distribution of DOX in nuclei and facilitating its interactions with DNA. Specifically, HA-VES/DOX decreased the activity of CD44 mRNA and improved the targeting efficiency on MCF-7 cells, based on the active recognition between HA and CD44 receptor. More importantly, HA-VES/DOX displayed better tumor accumulation and targeting, and enhanced antitumor efficacy with reduced systemic toxicity in 4T1 tumor-bearing mice. In summary, the developed HA-VES-based drug delivery system, which increased drug targeting on the tumor site and exhibited preferable anticancer activity, could hold great potential as an effective and promising strategy for efficient tumor therapy.
Development of novel HDL-mimicking α-tocopherol-coated nanoparticles to encapsulate nerve growth factor and evaluation of biodistribution.
Prathipati P, Zhu J, Dong X.
Eur J Pharm Biopharm. 2016 Nov;108:126-135. doi: 10.1016/j.ejpb.2016.08.005. Epub 2016 Aug 12.
Abstract
Nerve Growth Factor (NGF) is one of the members of the neurotrophin family with multifaceted functions. However, clinical application of NGF is hurdled by the challenge on formulation development. The objective of this study was to develop novel high-density lipoproteins (HDL)-mimicking nanoparticles (NPs) coated with α-tocopherol to incorporate NGF by a self-assembly approach. The NPs were prepared by an optimized self-assembly method that is simple and scalable. The composition of HDL-mimicking NPs was optimized. The prototype of the HDL-mimicking α-tocopherol-coated NPs contained phosphatidylserine (a negative charged phospholipid) and d-α-Tocopheryl polyethylene glycol succinate (a source of vitamin E) to enhance the entrapment efficiency of apolipoprotein A-I in the NPs. The entrapment efficiency of apolipoprotein A-I was about 30%. The NPs had particle size about 200nm with a relatively narrow size distribution. Finally, cationic ion-pair agents were optimized to form ion-pairs with NGF to facilitate the incorporation of NGF into the NPs. Protamine sodium salt USP formed an optimal ion-pair complex with NGF. The results showed that the novel HDL-mimicking α-tocopherol-coated NPs successfully encapsulated NGF with over 65% entrapment efficiency by using this ion-pair strategy. In vitro release studies demonstrated a slow release of NGF from NGF NPs in PBS containing 5% BSA at 37°C for 72 h. Further biodistribution studies showed that intravenously injected NGF NPs significantly increased NGF concentration in plasma and decreased the uptake in liver, spleen and kidney, compared to free NGF in mice.
Effects of omega-3 fatty acid plus alpha-tocopherol supplementation on malnutrition-inflammation score, biomarkers of inflammation and oxidative stress in chronic hemodialysis patients.
Asemi Z, Soleimani A, Shakeri H, Mazroii N, Esmaillzadeh A.
Int Urol Nephrol. 2016 Nov;48(11):1887-1895. Epub 2016 Aug 23.
Abstract
The current study was carried out to assess the effects of omega-3 fatty acid and alpha-tocopherol co-supplementation on malnutrition-inflammation score (MIS), biomarkers of inflammation and oxidative stress in chronic hemodialysis (HD) patients.
In a randomized double-blind placebo-controlled clinical trial, 120 patients with chronic HD were included. Patients were randomly allocated into four groups to receive: (1) 1250 mg/day omega-3 fatty acid containing 600 mg EPA and 300 mg DHA + alpha-tocopherol placebo (n = 30); (2) 400 IU/day alpha-tocopherol + omega-3 fatty acids placebo (n = 30); (3) 1250 mg omega-3 fatty acids/day + 400 IU/day alpha-tocopherol (n = 30); and (4) omega-3 fatty acids placebo + alpha-tocopherol placebo (n = 30) for 12 weeks.
After 12 weeks of intervention, all three groups of alpha-tocopherol only, individual omega-3 fatty acids, and combined omega-3 fatty acids and alpha-tocopherol experienced a significant improvements in MIS compared with the placebo group; however, improvements were much greater in the individual omega-3 fats (-1.4 ± 1.4) and combined omega-3 fats and alpha-tocopherol (-1.1 ± 2.3) groups compared with alpha-tocopherol group alone (-0.5 ± 1.7, P = 0.004). Furthermore, both individual and combined intervention with omega-3 fats and alpha-tocopherol led to a significant increase in plasma nitric oxide (NO) (combined group: +17.6 ± 29.3; alpha-tocopherol: +43.1 ± 36.3; omega-3 fats: +31.0 ± 40.0; and placebo: -0.5 ± 18.5 µmol/L, respectively, P < 0.001) and total antioxidant capacity (TAC) (+64.9 ± 113.6, +53.0 ± 144.6, +57.6 ± 157.8 and -69.9 ± 215.1 mmol/L, respectively, P = 0.004) levels.
Overall, omega-3 fatty acids and alpha-tocopherol co-supplementation for 12 weeks among HD patients improved MIS, plasma NO and TAC levels. Future studies with longer duration of the intervention are needed to confirm the validity of our findings. CLINICAL REGISTRATION: www.irct.ir as IRCT201410245623N28.
Egg Consumption Increases Vitamin E Absorption from Co-Consumed Raw Mixed Vegetables in Healthy Young Men.
Kim JE, Ferruzzi MG, Campbell WW.
Nutr. 2016 Nov;146(11):2199-2205. Epub 2016 Sep 21.
Abstract
Most people living in the United States underconsume vitamin E, and dietary approaches to increase the absorption of vitamin E may help individuals to meet their body’s needs. In this study, we assessed the effect of adding cooked whole egg to a raw mixed-vegetable salad on α-tocopherol and γ-tocopherol absorption.
With the use of a randomized-crossover design, 16 healthy young men [mean ± SD age: 24 ± 4 y; mean ± SD body mass index (in kg/m2): 24 ± 2] consumed the same salad (all served with 3 g canola oil) with no egg [control (CON)], with 75 g cooked egg [low egg (LE)], or with 150 g cooked egg [high egg (HE)]; a 1-wk dietary washout period was included between trials. For the first 7 d of each trial, participants consumed a low-vitamin E diet to reduce plasma vitamin E concentrations. Blood was collected hourly for 10 h and the triacylglycerol-rich lipoprotein fractions (TRLs) were isolated. α-Tocopherol and γ-tocopherol concentrations in TRLs were analyzed and composite areas under the curve (AUCs) were calculated.
Results showed that the consumption of cooked whole eggs is an effective way to increase the absorption of α-tocopherol and γ-tocopherol from a co-consumed meal that naturally contains vitamin E, such as a raw mixed-vegetable salad, in healthy young men. This trial was registered at clinicaltrials.gov as NCT01951313.
Brain Health, Oxidative Stress & Vitamin E
The brain acts as a control center that regulates the human body’s biological events such as respiration and metabolism processes. When compared to other organs, the brain requires higher amount of oxygen to meet metabolic demands1 but it possesses lower antioxidant capacity. Since the brain contains a high content of polyunsaturated fatty acids (PUFAs), it is very susceptible to free radical-mediated oxidative stress that affects brain health negatively.2 Therefore, lipid soluble antioxidants such as vitamin E (tocopherols and tocotrienols) are crucial to minimize oxidative stress.
Role of Noncovalent Sulfur···Oxygen Interactions in Phenoxyl Radical Stabilization: Synthesis of Super Tocopherol-like Antioxidants.
Menichetti S, Amorati R, Meoni V, Tofani L, Caminati G, Viglianisi C.
Org Lett. 2016 Nov 4;18(21):5464-5467. Epub 2016 Oct 18.
Abstract
Noncovalent sulfur···oxygen interactions can increase the stability of chalcogen ortho-substituted phenoxyl radicals. This effect contributes to transforming the 7-hydroxybenzo[b]thiophene moiety in a privileged structural motif to enhance the activity of phenolic antioxidants. A cascade of five consecutive electrophilic reactions occurring in one pot afforded potent and biocompatible α-tocopherol-like antioxidants.
Peroxisome proliferator-activated receptor γ down-regulation mediates the inhibitory effect of d-δ-tocotrienol on the differentiation of murine 3T3-F442A preadipocytes.
Torabi S, Yeganehjoo H, Shen CL, Mo H.
Nutr Res. 2016 Nov 3. pii: S0271-5317(16)30204-4. doi: 10.1016/j.nutres.2016.11.001. [Epub ahead of print]
Abstract
Tocotrienols accelerate the degradation of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase that catalyzes the biosynthesis of mevalonate; the latter is essential for preadipocyte differentiation. Tocotrienols also down-regulate peroxisome proliferator-activated receptor γ (PPARγ), a key regulator of adipocyte differentiation. We hypothesized that mevalonate deprivation and PPARγ down-regulation mediate d-δ-tocotrienol-induced inhibition of adipocyte differentiation. The objectives of this study were to determine the effect of d-δ-tocotrienol on 3T3-F442A preadipocyte differentiation and the involvement of PPARγ and mevalonate. Murine 3T3-F442A preadipocytes were incubated with d-δ-tocotrienol (2.5-10 μmol/L) for 8 days. AdipoRed assay and Oil Red O staining showed that d-δ-tocotrienol dose-dependently reduced the intracellular triglyceride content. Concomitantly, d-δ-tocotrienol dose-dependently inhibited glucose uptake by 3T3-F442A cells and the expression of GLUT4, HMG CoA reductase, and p-Akt proteins. The effects of d-δ-tocotrienol on intracellular triglyceride content and glucose uptake were attenuated by rosiglitazone, an agonist of PPARγ, but not supplemental mevalonate (100 μmol/L). In contrast, mevalonate, but not rosiglitazone, reversed the effects of lovastatin, a competitive inhibitor of HMG CoA reductase shown to inhibit adipocyte differentiation via mevalonate deprivation. Trypan blue staining revealed no changes in cell viability after a 48-hour incubation of 3T3-F442A cells with d-δ-tocotrienol (0-80 μmol/L), suggesting that the adipogenesis-suppressive activity of d-δ-tocotrienol was independent of cytotoxicity. In conclusion, these findings demonstrate the antiadipogenic effect of d-δ-tocotrienol via PPARγ down-regulation.
A naturally occurring mixture of tocotrienols inhibits the growth of human prostate tumor, associated with epigenetic modifications of cyclin-dependent kinase inhibitors p21 and p27.
Huang Y, Wu R, Su ZY, Guo Y, Zheng X, Yang CS, Kong AN.
J Nutr Biochem. 2016 Nov 4;40:155-163. doi: 10.1016/j.jnutbio.2016.10.019. [Epub ahead of print]
Abstract
Tocotrienols, members of the vitamin E family, have three unsaturated bonds in their side chains. Recently, it has been suggested that the biological effects of tocotrienols may differ from that of tocopherols. Several in vitro studies have shown that tocotrienols have stronger anticancer effects than tocopherols. VCaP cell line used in this study is from a vertebral bone metastasis from a patient with prostate cancer. Eight-week-old male NCr(-/-) nude mice were subcutaneously injected with VCaP-luc cells in matrigel and then administered a tocotrienol mixture for 8 weeks. The tocotrienol mixture inhibited the growth of human prostate tumor xenografts in a dose-dependent manner. The concentrations of tocotrienols and their metabolites were significantly increased in treatment groups. Tocotrienols inhibited prostate tumor growth by suppressing cell proliferation, which was associated with the induction of the cyclin-dependent kinase (CDK) inhibitors p21 and p27. In addition, tocotrienol treatment was associated with elevated H3K9 acetylation levels at proximal promoter regions of p21 and p27 and with decreased expression of histone deacetylases. Tocotrienols inhibited human prostate tumor growth, associated with up-regulation of the CDK inhibitors p21 and p27. Elevated expression of p21 and p27 could be partly due to the suppressed expression of HDACs.
Atheroprotective effects of pure tocotrienol supplementation in the treatment of rabbits with experimentally induced early and established atherosclerosis.
Rahman TA, Hassim NF, Zulkafli N, Muid S, Kornain NK, Nawawi H.
Food Nutr Res. 2016 Oct 28;60:31525. doi: 10.3402/fnr.v60.31525.
Abstract
Atherosclerosis is the main cause of coronary artery disease -related deaths worldwide. The atheroprotective properties of pure tocotrienols (T3) in the absence of alpha-tocopherol (α-TCP) in vitamin E has not been extensively examined. This study aims to determine the atheroprotective properties of T3 in early and established atherosclerosis rabbits. The findings suggest the possible atheroprotective role T3 plays as an adjunct supplementation to standard treatment in the prevention of CAD.