Comparative study of lung toxicity of E-cigarette ingredients to investigate E-cigarette or vaping product associated lung injury.

No comparative study has yet been performed on the respiratory effects of individual E-cigarette ingredients. Here, lung toxicity of individual ingredients of E-cigarette products containing nicotine or tetrahydrocannabinol was investigated. Mice were intratracheally administered propylene glycol (PG), vegetable glycerin (VG), vitamin E acetate (VEA), or nicotine individually for two weeks. Cytological and histological changes were noticed in PG- and VEA-treated mice that exhibited pathophysiological changes which were associated with symptoms seen in patients with symptoms of E-cigarette or Vaping Use-Associated Lung Injuries (EVALI) or E-cigarette users. Compared to potential human exposure situations, while the VEA exposure condition was similar to the dose equivalent of VEA content in E-cigarettes, the PG condition was about 47-137 times higher than the dose equivalent of the daily PG intake of E-cigarette users. These results reveal that VEA exposure is much more likely to cause problems related to EVALI in humans than PG. Transcriptomic analysis revealed that PG exposure was associated with fibrotic lung injury via the AKT signaling pathway and M2 macrophage polarization, and VEA exposure was associated with asthmatic airway inflammation via the mitogen-activated protein kinase signaling pathway. This study provides novel insights into the pathophysiological effects of individual ingredients of E-cigarettes.

Vaping additives cannabinoid oil and vitamin E acetate adhere to and damage the human airway epithelium.

E-cigarette, or vaping product use-associated lung injury (EVALI), is a severe respiratory disorder that caused a sudden outbreak of hospitalized young people in 2019. Using cannabis oil containing vaping products, including vitamin E acetate contaminants, was found to be strongly associated with EVALI. However, the underlying tissue impacts of the condition are still largely unknown. Here, we focused on the vehicle cannabinoid oil (CBD oil) and contaminant vitamin E acetate (VEA) effects on airway epithelial cells. Primary human bronchial epithelial (HBE) cultures were exposed to e-liquid aerosols that contained CBD oil and VEA in combination or the common e-liquid components PG/VG with and without nicotine. Cell viability analysis indicated dramatically increased cell death counts after 3 days of CBD exposure, and this effect was even higher after CBD + VEA exposure. Microscopic examination of the cultures revealed cannabinoid and VEA depositions on the epithelial surfaces and cannabinoid accumulation in exposed cells, followed by cell death. These observations were supported by proteomic analysis of the cell secretions that exhibited increases in known markers of airway epithelial toxicity, such as xenobiotic enzymes, factors related to oxidative stress response, and cell death indicators. Overall, our study provides insights into the association between cannabinoid oil and vitamin E acetate vaping and lung injury. Collectively, our results suggest that the adherent accumulation of CBD oil on airway surfaces and the cellular uptake of both CBD oil- and VEA-containing condensates cause elevated metabolic stress, leading to increased cell death rates in human airway epithelial cultures.

Thermal Degradants Identified from the Vaping of Vitamin E Acetate.

Studies have suggested that vitamin E acetate (VEA), when used in an electronic vaping device, undergoes thermal degradation and is considered one of the main contributors in e-cigarette or vaping product use-associated lung injury (EVALI). Using a Borgwaldt 5.1 linear smoker, a SVS250 Electronic Vaporizer and two types of tank systems, VEA was analyzed for degradation products produced via the Cooperation Centre for Scientific Research Relative to Tobacco method 81 when the filter containing vaporized VEA was extracted using acetonitrile. Two of the major products identified were 2,3,5,6-tetramethyl-1,4-benzoquinone and 2,6,10,14-tetramethyl-1-pentadecene, which were confirmed using analytical standards and gas chromatography-high-resolution mass spectrometry (GC-HRMS). Additional synthesis of 4-acetoxy-2,3,5,6-tetramethyl-2,4-cyclohexadienone and subsequent characterization using nuclear magnetic resonance and GC-HRMS suggested that this is not one of the products produced. Identification of these degradants will allow future studies to quantify and examine the degradants in vivo and in vitro as biomarkers for exposure and toxicity assessment.

Compiling Evidence for EVALI: A Scoping Review of In Vivo Pulmonary Effects After Inhaling Vitamin E or Vitamin E Acetate.

BACKGROUND: Vitamin E acetate (VEA) has come under significant scrutiny due to its association with E-cigarette or vaping product use-associated lung injury (EVALI). Various theoretical mechanisms have been proposed for toxicity, including tocopherol (vitamin E)-mediated surfactant damage, recruitment of inflammation, and pyrolysis of acetate to the pulmonary irritant ketene. OBJECTIVE: Characterize studies in mammals evaluating inhaled VEA, vitamin E analogues, or pyrolyzed acetate that describe subsequent effects on the lung. ELIGIBILITY: Research in all languages from time of inception to October 1, 2020, regarding mammals (human or animal) exposed to inhaled vitamin E analogues, or any compound containing acetate administered via inhalation after pyrolysis, and subsequent description of pulmonary effect. SOURCES OF EVIDENCE: Ovid MEDLINE, Scopus, and Web of Science Core Collection. RESULTS: In total, 786 unique articles were identified. After duplicate reviewer screening, 16 articles were eligible for inclusion. Tocopherol was evaluated in 68.8% (11/16) of the studies, VEA in 18.8% (3/16), and both VEA and tocopherol were evaluated in 12.5% (2/16). Of the five studies evaluating VEA, it was given by pyrolysis in 60.0% (3/5). No human studies were identified. All included trials were conducted on non-human mammals: 75.0% (12/16) rodent models and 25.0% (4/16) sheep models. Outcomes assessed were heterogeneous and included 57 unique outcomes. CONCLUSIONS: Several questions still exist regarding the pulmonary toxicity of inhaled tocopherol and VEA. More studies are needed to determine whether tocopherol alone (i.e., without acetate) can cause pulmonary injury. Additionally, further studies of VEA should evaluate the impact that pyrolysis and co-administration with other compounds, such as tetrahydrocannabinol, have on the toxic potential of VEA.

Chemical Emissions From Heated Vitamin E Acetate-Insights to Respiratory Risks From Electronic Cigarette Liquid Oil Diluents Used in the Aerosolization of Δ9-THC-Containing Products.

As of February 18, 2020, the e-cigarette, or vaping, product use associated lung injury (EVALI) outbreak caused the hospitalization of a total of 2,807 patients and claimed 68 lives in the United States. Though investigations have reported a strong association with vitamin E acetate (VEA), evidence from reported EVALI cases is not sufficient to rule out the contribution of other chemicals of concern, including chemicals in either THC or non-THC products. This study characterized chemicals evolved when diluent oils were heated to temperatures that mimic e-cigarette, or vaping, products (EVPs) to investigate production of potentially toxic chemicals that might have caused lung injury. VEA, vitamin E, coconut, and medium chain triglyceride (MCT) oil were each diluted with ethanol and then tested for constituents and impurities using a gas chromatograph mass spectrometer (GC/MS). Undiluted oils were heated at 25°C (control), 150°C, and 250°C in an inert chamber to mimic a range of temperatures indicative of aerosolization from EVPs. Volatilized chemicals were collected using thermal desorption tubes, analyzed using a GC/MS, and identified. Presence of identified chemicals was confirmed using retention time and ion spectra matching with analytic standards. Direct analysis of oils, as received, revealed that VEA and vitamin E were the main constituents of their oils, and coconut and MCT oils were nearly identical having two main constituents: glycerol tricaprylate and 2-(decanoyloxy) propane-1,3-diyl dioctanoate. More chemicals were measured and with greater intensities when diluent oils were heated at 250°C compared to 150°C and 25°C. Vitamin E and coconut/MCT oils produced different chemical emissions. The presence of some identified chemicals is of potential health consequence because many are known respiratory irritants and acute respiratory toxins. Exposure to a mixture of hazardous chemicals may be relevant to the development or exacerbation of EVALI, especially when in concert with physical damage caused by lung deposition of aerosols produced by aerosolizing diluent oils.

E-cigarette or Vaping Product Use-Associated Lung Injury Produced in an Animal Model From Electronic Cigarette Vapor Exposure Without Tetrahydrocannabinol or Vitamin E Oil.

E-cigarette or vaping product use-associated lung injury was recognized in the United States in the summer of 2019 and is typified by acute respiratory distress, shortness of breath, chest pain, cough, and fever, associated with vaping. It can mimic many of the manifestations of coronavirus disease 2019 (COVID-19). Some investigators have suggested that E-cigarette or vaping product use-associated lung injury was due to tetrahydrocannabinol or vitamin E acetate oil mixed with the electronic cigarette liquid. In experimental rodent studies initially designed to study the effect of electronic cigarette use on the cardiovascular system, we observed an E-cigarette or vaping product use-associated lung injury-like condition that occurred acutely after use of a nichrome heating element at high power, without the use of tetrahydrocannabinol, vitamin E, or nicotine. Lung lesions included thickening of the alveolar wall with foci of inflammation, red blood cell congestion, obliteration of alveolar spaces, and pneumonitis in some cases; bronchi showed accumulation of fibrin, inflammatory cells, and mucus plugs. Electronic cigarette users should be cautioned about the potential danger of operating electronic cigarette units at high settings; the possibility that certain heating elements may be deleterious; and that E-cigarette or vaping product use-associated lung injury may not be dependent upon tetrahydrocannabinol, vitamin E, or nicotine.

Characterization and Cytotoxicity of Polyprenol Lipid and Vitamin E-TPGS Hybrid Nanoparticles for Betulinic Acid and Low-Substituted Hydroxyl Fullerenol in MHCC97H and L02 Cells.

BACKGROUND: This study demonstrated an innovative formulation including the polyprenol (GBP) lipid and vitamin E-TPGS hybrid nanoparticles (NPs) which was aimed to control the transfer of betulinic acid (BA) and low-substituted hydroxyl fullerenol (C60(OH)n). Additionally, it developed BA-C60(OH)n-GBP-TPGS-NPs delivery system and researched the anti-hepatocellular carcinoma (HCC) effects. MATERIALS AND METHODS: The NPs were prepared by nanoprecipitation with ultrasonic-assisted emulsification (UAE) method. It was characterized by scanning electronic microscopy (SEM), transmission electron microscopy (TEM), FTIR spectrum, size distribution and zeta potential. Physical and chemical properties were evaluated through measurement of drug release, stability studies, drug loading efficiency (DE) and encapsulation efficiency (EE). Biological activities were evaluated through measurement of MTT assay, lactate dehydrogenase leakage assay (LDH), cell proliferation assays, cell apoptosis analysis, comet assay, wound healing assay, cell invasion and Western blot analysis. RESULTS AND CONCLUSIONS: The NPs exhibited clear distribution characteristics, improved solubility and stability. BA and C60(OH)n for the NPs displayed a biphasic release pattern with sustained drug release properties. The mixture of C60(OH)n with different hydroxyl groups may have a certain effect on the stability of the NPs system itself. The NPs could effectively inhibit MHCC97H cell proliferation, migration and invasion in vitro. Combined use of C60(OH)n and BA in GBP lipids may improve the inhibit effect of C60(OH)n or BA against HCC cells and reduce cytotoxicity and genotoxicity of C60(OH)n for normal cells. We concluded that one of the important mechanisms of BA-C60(OH)n-GBP-TPGS-NPs inhibiting MHCC97H cells is achieved by up-regulating the expression of Caspase-3, Caspase-8 and Caspase-9.

E-cigarette, or Vaping, Product Use-Associated Lung Injury Among Clusters of Patients Reporting Shared Product Use - Wisconsin, 2019.

On July 10, 2019, Wisconsin Department of Health Services (WDHS) was notified of five previously healthy adolescents with severe lung injuries who reported use of e-cigarette, or vaping, products before symptom onset. As of December 31, 2019, 105 confirmed or probable cases of e-cigarette, or vaping, product use-associated lung injury (EVALI)* had been reported to WDHS . Three social clusters (A, B, and C), comprising eight EVALI patients (cluster A = two patients, cluster B = three, and cluster C = three) were identified. WDHS investigated these clusters with standard and follow-up interviews; laboratory analysis of e-cigarette, or vaping, products; and analysis of bronchoalveolar lavage (BAL) fluid. All eight patients reported daily use of tetrahydrocannabinol (THC)-containing e-cigarette, or vaping, product cartridges (THC cartridges) in the month preceding symptom onset. All THC cartridges were purchased from local illicit dealers, and all patients reported using THC cartridges labeled as "Dank Vapes," among other illicit brand names. At least two members of each cluster reported frequent sharing of THC cartridges before symptom onset. All eight patients also reported daily use of nicotine-containing e-cigarette, or vaping, products. Vitamin E acetate (VEA) was detected in all five THC cartridges tested from two patients, and in BAL fluid from two other patients. These findings suggest that THC cartridges containing VEA and sold on the illicit market were likely responsible for these small clusters of EVALI. Based on information presented in this and previous reports (1,2) CDC recommends not using THC-containing e-cigarette, or vaping, products, especially those obtained from informal sources such as friends, family, or in-person or online dealers (1). VEA is strongly linked to the EVALI outbreak and should not be added to e-cigarette, or vaping, products (1).

Update: Characteristics of a Nationwide Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injury - United States, August 2019-January 2020.

Since August 2019, CDC, the Food and Drug Administration (FDA), state and local health departments, and public health and clinical stakeholders have been investigating a nationwide outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) (1). This report updates patient demographic characteristics, self-reported substance use, and hospitalization dates for EVALI patients reported to CDC by states, as well as the distribution of emergency department (ED) visits related to e-cigarette, or vaping, products analyzed through the National Syndromic Surveillance Program (NSSP). As of January 14, 2020, a total of 2,668 hospitalized EVALI cases had been reported to CDC. Median patient age was 24 years, and 66% were male. Overall, 82% of EVALI patients reported using any tetrahydrocannabinol (THC)-containing e-cigarette, or vaping, product (including 33% with exclusive THC-containing product use), and 57% of EVALI patients reported using any nicotine-containing product (including 14% with exclusive nicotine-containing product use). Syndromic surveillance indicates that ED visits related to e-cigarette, or vaping, products continue to decline after sharply increasing in August 2019 and peaking in September 2019. Clinicians and public health practitioners should remain vigilant for new EVALI cases. CDC recommends that persons not use THC-containing e-cigarette, or vaping, products, especially those acquired from informal sources such as friends, family members, or from in-person or online dealers. Vitamin E acetate is strongly linked to the EVALI outbreak and should not be added to any e-cigarette, or vaping, products (2). However, evidence is not sufficient to rule out the contribution of other chemicals of concern, including chemicals in either THC- or non-THC-containing products, in some reported EVALI cases.

Co-carcinogenic effects of vitamin E in prostate.

A large number of basic researches and observational studies suggested the cancer preventive activity of vitamin E, but large-scale human intervention trials have yielded disappointing results and actually showed a higher incidence of prostate cancer although the mechanisms underlying the increased risk remain largely unknown. Here we show through in vitro and in vivo studies that vitamin E produces a marked inductive effect on carcinogen-bioactivating enzymes and a pro-oxidant status promoting both DNA damage and cell transformation frequency. First, we found that vitamin E in the human prostate epithelial RWPE-1 cell line has the remarkable ability to upregulate the expression of various phase-I activating cytochrome P450 (CYP) enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), giving rise to supraphysiological levels of reactive oxygen species. Furthermore, our rat model confirmed that vitamin E in the prostate has a powerful booster effect on CYP enzymes associated with the generation of oxidative stress, thereby favoring lipid-derived electrophile spread that covalently modifies proteins. We show that vitamin E not only causes DNA damage but also promotes cell transformation frequency induced by the PAH-prototype benzo[a]pyrene. Our findings might explain why dietary supplementation with vitamin E increases the prostate cancer risk among healthy men.

Topical anesthesia therapy using lidocaine-loaded nanostructured lipid carriers: tocopheryl polyethylene glycol 1000 succinate-modified transdermal delivery system.

PURPOSE: Transdermal drug delivery of local anesthetics using lipid nanoparticles could enhance lipophilic drugs permeation through the stratum corneum, improve drug diffusion to deeper skin, and exert good therapeutic effects. The purpose of this study was to engineer a Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS)-modified cationic nanostructured lipid carriers (NLC) for the delivery of lidocaine (LID; TPGS/LID-NLC). MATERIALS AND METHODS: TPGS/LID-NLC was prepared by solvent diffusion method. The particle size, polydispersity index, zeta potential, drug entrapment efficiency, drug loading, stability, drug release, and cytotoxicity were tested to evaluate the basic characters of NLC. In vitro skin permeation and in vivo anesthesia effect in an animal model were further investigated to determine the therapeutic efficiency of the system. RESULTS: TPGS/LID-NLC had a particle size of 167.6±4.3 nm, a zeta potential of +21.2±2.3 mV, an entrapment efficiency of 85.9%±3.1%, and a drug loading of 11.5%±0.9%. A sustained release pattern was achieved by TPGS/LID-NLC, with 81.2% of LID released at 72 hours. In vitro permeation study showed that the steady-state fluxes (Jss), permeability coefficient (Kp), and cumulative drug permeation Qn at 72 hours (Q72) of TPGS/LID-NLC were 15.6±1.8 µg/cm2/hour, 10.3±0.9 cm/hour (×10-3), and 547.5±23.6 µg/cm2, respectively, which were significantly higher than the nonmodified NLC and free drug groups. In vivo anesthesia effect of TPGS/LID-NLC was the most remarkable and long acting among the formulations tested, which could be concluded by the most considerable maximum possible effect from 10 to 120 minutes during the whole research. CONCLUSION: The most prominent in vitro permeation efficiency and in vivo anesthetic effect of TPGS/LID-NLC could be the evidence that TPGS-modified NLC could function as a promising drug delivery system for prolonged and efficient local anesthetic therapy.

Improving the biopharmaceutical attributes of mangiferin using vitamin E-TPGS co-loaded self-assembled phosholipidic nano-mixed micellar systems.

The current research work encompasses the development, characterization, and evaluation of self-assembled phospholipidic nano-mixed miceller system (SPNMS) of a poorly soluble BCS Class IV xanthone bioactive, mangiferin (Mgf) functionalized with co-delivery of vitamin E TPGS. Systematic optimization using I-optimal design yielded self-assembled phospholipidic nano-micelles with a particle size of < 60 nm and > 80% of drug release in 15 min. The cytotoxicity and cellular uptake studies performed using MCF-7 and MDA-MB-231 cell lines demonstrated greater kill and faster cellular uptake. The ex vivo intestinal permeability revealed higher lymphatic uptake, while in situ perfusion and in vivo pharmacokinetic studies indicated nearly 6.6- and 3.0-folds augmentation in permeability and bioavailability of Mgf. In a nutshell, vitamin E functionalized SPNMS of Mgf improved the biopharmaceutical performance of Mgf in rats for enhanced anticancer potency.

A novel multifunctional biomedical material based on polyacrylonitrile: Preparation and characterization.

Wet spun microfibers have great potential in the design of multifunctional controlled release materials. Curcumin (Cur) and vitamin E acetate (Vit. E Ac) were used as a model drug system to evaluate the potential application of the drug-loaded microfiber system for enhanced delivery. The drugs and polyacrylonitrile (PAN) were blended together and spun to produce the target drug-loaded microfiber using an improved wet-spinning method and then the microfibers were successfully woven into fabrics. Morphological, mechanical properties, thermal behavior, drug release performance characteristics, and cytocompatibility were determined. The drug-loaded microfiber had a lobed "kidney" shape with a height of 50-100 µm and width of 100-200 µm. The addition of Cur and Vit. E Ac had a great influence on the surface and cross section structure of the microfiber, leading to a rough surface having microvoids. X-ray diffraction and Fourier transform infrared spectroscopy indicated that the drugs were successfully encapsulated and dispersed evenly in the microfilament fiber. After drug loading, the mechanical performance of the microfilament changed, with the breaking strength improved slightly, but the tensile elongation increased significantly. Thermogravimetric results showed that the drug load had no apparent adverse effect on the thermal properties of the microfibers. However, drug release from the fiber, as determined through in-vitro experiments, is relatively low and this property is maintained over time. Furthermore, in-vitro cytocompatibility testing showed that no cytotoxicity on the L929 cells was found up to 5% and 10% respectively of the theoretical drug loading content (TDLC) of curcumin and vitamin E acetate. This study provides reference data to aid the development of multifunctional textiles and to explore their use in the biomedical material field.

Antifungal efficacy of itraconazole-loaded TPGS-b-(PCL-ran-PGA) nanoparticles.

This research was conducted to formulate biodegradable itraconazole (ITZ)-loaded d-a-tocopheryl polyethylene glycol 1000 succinate-b-poly(e-caprolactone-ran-glycolide) (TPGS-b-(PCL-ran-PGA); TPP) nanoparticles (NPs) (designed as ITZ-loaded TPP NPs) to improve antifungal efficacy. ITZ-loaded TPP NPs were prepared by a modified double-emulsion method, and their size distribution, morphology, zeta potential, drug encapsulation efficiency, drug-release profile, and antifungal effects were characterized. The cytotoxicity of ITZ-loaded-TPP NPs on HeLa cells and fibroblasts was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The in vivo antifungal activity of ITZ-loaded-TPP NPs was examined in mice by administrating 5×10(5) colony forming units of Candida albicans through the tail vein. The survival rate and survival time of the mice was observed. The fungal count and pathology of lung tissue was analyzed. The data showed that ITZ-loaded-TPP NPs have size of 265±5.8 nm, zeta potential of -31±0.5 mV, high encapsulation efficiency (95%), and extended drug-release profile. ITZ-loaded-TPP NPs at a high concentration of 25 mg/mL had no cytotoxicity on HeLa cells and fibroblasts. Furthermore, ITZ-loaded-TPP NPs achieved a higher level of antifungal activity both in vitro and in vivo. The survival rate and duration was higher in mice treated by ITZ-loaded-TPP NPs than in the other groups (P<0.05). In conclusion, ITZ-loaded-TPP NPs significantly improved ITZ bioavailability by increasing its aqueous dispersibility and extending the duration of drug release, thereby improving the antifungal efficacy of the ITZ agent.

Preparation, in vitro and in vivo evaluation of polymeric nanoparticles based on hyaluronic acid-poly(butyl cyanoacrylate) and D-alpha-tocopheryl polyethylene glycol 1000 succinate for tumor-targeted delivery of morin hydrate.

Herein, we describe the preparation of a targeted cellular delivery system for morin hydrate (MH), based on a low-molecular-weight hyaluronic acid-poly(butyl cyanoacrylate) (HA-PBCA) block copolymer. In order to enhance the therapeutic effect of MH, D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) was mixed with HA-PBCA during the preparation process. The MH-loaded HA-PBCA "plain" nanoparticle (MH-PNs) and HA-PBCA/TPGS "mixed" nanoparticles (MH-MNs) were concomitantly characterized in terms of loading efficiency, particle size, zeta potential, critical aggregation concentration, and morphology. The obtained MH-PNs and MH-MNs exhibited a spherical morphology with a negative zeta potential and a particle size less than 200 nm, favorable for drug targeting. Remarkably, the addition of TPGS resulted in about 1.6-fold increase in drug-loading. The in vitro cell viability experiment revealed that MH-MNs enhanced the cytotoxicity of MH in A549 cells compared with MH solution and MH-PNs. Furthermore, blank MNs containing TPGS exhibited selective cytotoxic effects against cancer cells without diminishing the viability of normal cells. In addition, the cellular uptake study indicated that MNs resulted in 2.28-fold higher cellular uptake than that of PNs, in A549 cells. The CD44 receptor competitive inhibition and the internalization pathway studies suggested that the internalization mechanism of the nanoparticles was mediated mainly by the CD44 receptors through a clathrin-dependent endocytic pathway. More importantly, MH-MNs exhibited a higher in vivo antitumor potency and induced more tumor cell apoptosis than did MH-PNs, following intravenous administration to S180 tumor-bearing mice. Overall, the results imply that the developed nanoparticles are promising vehicles for the targeted delivery of lipophilic anticancer drugs.

Enhanced antifungal effects of amphotericin B-TPGS-b-(PCL-ran-PGA) nanoparticles in vitro and in vivo.

BACKGROUND: Amphotericin B (AMB) is a polyene antibiotic with broad spectrum antifungal activity, but its clinical toxicities and poor solubility limit the wide application of AMB in clinical practice. Recently, new drug-loaded nanoparticles (NPs) - diblock copolymer D-α-tocopheryl polyethylene glycol 1000 succinate-b-poly(ε-caprolactone-ran-glycolide) (PLGA-TPGS) - have received special attention for their reduced toxicity, and increased effectiveness of drug has also been reported. This study aimed to develop AMB-loaded PLGA-TPGS nanoparticles (AMB-NPs) and evaluate their antifungal effects in vitro and in vivo. METHODS: AMB-NPs were prepared with a modified nanoprecipitation method and then characterized in terms of physical characteristics, in vitro drug release, stability, drug-encapsulation efficiency, and toxicity. Finally, the antifungal activity of AMB-NPs was investigated in vitro and in vivo. RESULTS: AMB-NPs were stable and spherical, with an average size of around 110 nm; the entrapment efficacy was closed to 85%, and their release exhibited a typically biphasic pattern. The actual minimum inhibitory concentration of AMB-NPs against Candida albicans was significantly lower than that of free AMB, and AMB-NPs were less toxic on blood cells. In vivo experiments indicated that AMB-NPs achieved significantly better and prolonged antifungal effects when compared with free AMB. CONCLUSION: The AMB-PLGA-TPGS NP system significantly improves the AMB bioavailability by improving its antifungal activities and reducing its toxicity, and thus, these NPs may become a good drug carrier for antifungal treatment.

Acute toxicity of subcutaneously administered vitamin E isomers delta- and gamma-tocotrienol in mice.

The toxicity of parenterally administered vitamin E isomers, delta-tocotrienol (DT3) and gamma-tocotrienol (GT3), was evaluated in male and female CD2F1 mice. In an acute toxicity study, a single dose of DT3 or GT3 was administered subcutaneously in a dose range of 200 to 800 mg/kg. A mild to moderately severe dermatitis was observed clinically and microscopically in animals at the injection site at doses above 200 mg/kg. The severity of the reaction was reduced when the drug concentration was lowered. Neither drug produced detectable toxic effects in any other tissue at the doses tested. Based on histopathological analysis for both DT3 and GT3, and macroscopic observations of inflammation at the injection site, a dose of 300 mg/kg was selected as the lowest toxic dose in a 30-day toxicity study performed in male mice. At this dose, a mild skin irritation occurred at the injection site that recovered completely by the end of the experimental period. At a dose of 300 mg/kg of DT3 or GT3, no adverse effects were observed in any tissues or organs.

Synergistic effect of combined treatment with gamma-tocotrienol and statin on human malignant mesothelioma cells.

The present study is the first to demonstrate the synergetic effect of statins (atorvastatin and simvastatin) and gamma-tocotrienol (γ-T3) on human malignant mesothelioma (MM). Statin + γ-T3 combinations induced greater cell growth inhibition more than each single treatment via inhibition of mevalonate pathway, a well-known target of both γ-T3 and statins. γ-T3 was necessary for endoplasmic reticulum stress markers CHOP and GRP78, whereas an intrinsic apoptotic marker, caspase 3 activation was induced only in the presence of statins. Overall, the combination of γ-T3 and statins could be useful for MM therapy and functions in a complementary style.

δ- and γ-tocotrienols induce classical ultrastructural apoptotic changes in human T lymphoblastic leukemic cells.

Tocotrienols are isomers of the vitamin E family, which have been reported to exert cytotoxic effects in various cancer cells. Although there have been some reports on the effects of tocotrienols in leukemic cells, ultrastructural evidence of tocotrienol-induced apoptotic cell death in leukemic cells is lacking. The present study investigated the effects of three isomers of tocotrienols (alpha, delta, and gamma) on a human T lymphoblastic leukemic cell line (CEM-SS). Cell viability assays showed that all three isomers had cytotoxic effects (p < 0.05) on CEM-SS cells with delta-tocotrienol being the most potent. Transmission electron microscopy showed that the cytotoxic effects by delta- and gamma-tocotrienols were through the induction of an apoptotic pathway as demonstrated by the classical ultrastructural apoptotic changes characterized by peripheral nuclear chromatin condensation and nuclear fragmentation. These findings were confirmed biochemically by the demonstration of phosphatidylserine externalization via flow cytometry analysis. This is the first study showing classical ultrastructural apoptotic changes induced by delta- and gamma-tocotrienols in human T lymphoblastic leukemic cells.

Regulation of xenobiotic metabolism, the only signaling function of alpha-tocopherol?

There is growing concern based on meta-analyses of clinical trials using vitamin E supplements that these supplements increase the risk of all-cause mortality in humans. My laboratory has been investigating the metabolism and disposition of "excess" vitamin E. This review focuses on the various mechanisms that prevent vitamin E intoxication. Non-alpha-tocopherols are aggressively metabolized thereby preventing their tissue accumulation and limiting increases in their plasma concentrations. Moreover, "excess" alpha-tocopherol is also metabolized and its concentrations are limited. The mechanisms for this limitation do not seem to be specific for vitamin E, but rather are general xenobiotic pathways. We suggest that the most relevant cytochrome P450-mediated pathway is the one that is most important for the regulation and activation of vitamin K, specifically the one dependent on CYP4F2.