Characterisation, in-vitro and in-vivo evaluation of valproic acid-loaded nanoemulsion for improved brain bioavailability

OBJECTIVE: This study was aimed to investigate the potential of formulated valproic acid-encapsulated nanoemulsion (VANE) to improve the brain bioavailability of valproic acid (VPA). METHODS: Valproic acid-encapsulated nanoemulsions were formulated and physically characterised (osmolarity, viscosity, drug content, drug encapsulation efficiency). Further investigations were also conducted to estimate the drug release, cytotoxic profile, in-vitro blood-brain barrier (BBB) permeability, pharmacokinetic parameter and the concentration of VPA and VANE in blood and brain. KEY FINDINGS: Physical characterisation confirmed that VANE was suitable for parenteral administration. Formulating VPA into nanoemulsion significantly reduced the cytotoxicity of VPA. In-vitro drug permeation suggested that VANEs crossed the BBB as freely as VPA. Pharmacokinetic parameters of VANE-treated rats in plasma and brain showed F3 VANE had a remarkable improvement in AUC, prolongation of half-life and reduction in clearance compared to VPA. Given the same extent of in-vitro BBB permeation of VPA and VANE, the higher bioavailability of VANE in brain was believed to have due to higher concentration of VANE in blood. The brain bioavailability of VPA was improved by prolonging the half-life of VPA by encapsulating it within the nanoemulsion-T80. CONCLUSIONS: Nanoemulsion containing VPA has alleviated the cytotoxic effect of VPA and improved the plasma and brain bioavailability for parenteral delivery of VPA

Ultrasonic emulsification of parenteral valproic acid-loaded nanoemulsion with response surface methodology and evaluation of its stability

Response surface methodology (RSM) was used to optimize the formulation of a nanoemulsion for central delivery following parenteral administration. A mixture of medium-chain triglyceride (MCT) and safflower seed oil (SSO) was determined as a sole phase from the emulsification properties. Similarly, a natural surfactant (lecithin) and non-ionic surfactant (Tween 80) (ratio 1:2) were used in the formulation. A central composite design (CCD) with three-factor at five-levels was used to optimize the processing method of high energy ultrasonicator. Effects of pre-sonication ultrasonic intensity (A), sonication time (B), and temperature (C) were studied on the preparation of nanoemulsion loaded with valproic acid. Influence of the aforementioned specifically the effects of the ultrasonic processing parameters on droplet size and polydispersity index were investigated. From the analysis, it was found that the interaction between ultrasonic intensity and sonication time was the most influential factor on the droplet size of nanoemulsion formulated. Ultrasonic intensity (A) significantly affects the polydispersity index value. With this optimization method, a favorable droplet size of a nanoemulsion with reasonable polydispersity index was able to be formulated within a short sonication time. A valproic acid loaded nanoemulsion can be obtained with 60% power intensity for 15 min at 60 °C. Droplet size of 43.21 ± 0.11 nm with polydispersity index of 0.211 were produced. The drug content was then increased to 1.5%. Stability study of nanoemulsion containing 1.5% of valproic acid had a good stability as there are no significant changes in physicochemical aspects such as droplet size and polydispersity index. With the characteristisation study of pH, viscosity, transmission electron microscope (TEM) and stability assessment study the formulated nanoemulsion has the potential to penetrate blood–brain barrier in the treatment of epilepsy

The oyster genome reveals stress adaptation and complexity of shell formation

The Pacific oyster Crassostrea gigas belongs to one of the most species-rich but genomically poorly explored phyla, the Mollusca. Here we report the sequencing and assembly of the oyster genome using short reads and a fosmid-pooling strategy, along with transcriptomes of development and stress response and the proteome of the shell. The oyster genome is highly polymorphic and rich in repetitive sequences, with some transposable elements still actively shaping variation. Transcriptome studies reveal an extensive set of genes responding to environmental stress. The expansion of genes coding for heat shock protein 70 and inhibitors of apoptosis is probably central to the oyster's adaptation to sessile life in the highly stressful intertidal zone. Our analyses also show that shell formation in molluscs is more complex than currently understood and involves extensive participation of cells and their exosomes. The oyster genome sequence fills a void in our understanding of the Lophotrochozoa. © 2012 Macmillan Publishers Limited. All rights reserved

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population.

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (P interaction  = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications

Development, characterisation and translocation of valproic acid-encapsulated nanoemulsion across blood-brain barrier

Valproic acid (VPA) is a widely used antiepileptic drug (AED) for epilepsy especially in generalized and absence seizures. However, VPA has high plasma protein binding (90 % - 95 %) so only low amount of free VPA were able to reach the brain. An increase in therapeutic dose is not feasible as it will further aggravate the toxicity problem because VPA has a narrow therapeutic window range of 50-150 μg/mL in plasma. The presence of brain-to-blood efflux transporter in blood-brain barrier (BBB)further reduces the bioavailability of VPA in the brain. Taken together, the efficacy of VPA in treating epilepsy is hampered by high plasma protein binding nature, narrow therapeutic window and low brain bioavailability. The currently marketed parenteralVPA only enhances the solubility of the drug in water. Therefore in this study, a formulation of parenteral nanoemulsion of VPA was developed to reduce the clearance of VPA, to improve the tolerable concentration of VPA and the brain bioavailability of VPA. In our study, valproic acid-encapsulated nanoemulsions (VANE) were formulated by dispersing an oil phase containing VPA and lecithin into an aqueous phase containing tween 80 (T80). Among all types of oils studied, safflower seed oil was used as an oil phase in VANE as it formed the smallest droplet size of VANE. Alpha-tocopherol were also added into the oil phase to reduce the lipid peroxidation of oil phase in VANE. To further reduce the droplet size of VANE, the optimum processing conditions of ultrasonicator were studied (temperature, energy intensity and time) and used to further emulsify the VANE. Next, four VANEs with different percent composition (F1, F2, F3 and F4) were formulated to study the effect of oil phase content and drug-to-oil phase ratio on the physical properties of VANE (droplet size, polydispersity index (PDI) and zeta potential). Eventually, two nanoemulsions namely F3 VANE and F4 VANE out of these four formulations were selected to be studied in the following studies as they had higher drug content at desirable physical characteristic (droplet size <200 nm, PDI <0.2). Both VANEs had physiologically compatible pH (around 8), osmolarity and viscosity. Both VANEs were spherical in shape and encapsulated more than 97% of VPA. Stability studies showed that F3 VANE was more stable than F4 VANE as F3 VANE showed only little changes in droplet size and PDI at storage of high temperature (45 °C) over five months. The in vitro drug release also indicated F3 VANE had more and faster VPA release compared to F4 VANE. This was probably due to lower surfactant-to-oil ratio and higher percentage of oil in F3 VANE, exhibited less barrier for VPA release. F3 VANE (IC50: 633.19 μg/mL) also had less cytotoxic effect on hCMEC/D3 cells compared to F4 VANE (IC50: 402.69 μg/mL). Next, the in vitro BBB model was successfully developed with appropriate optimization and characterization. It was then used to assess the in vitro drug penetrability of F3 and F4 VANE where both VANEs penetrated the in vitro BBB as freely as VPA. Comparing both of the VANEs, F3 VANE was physically and biologically more attractive as it had higher drug content, better stability and less cytotoxic effect. Hence, only VPA and F3 VANE were studied in vivo studies. F3 VANE had improved the total bioavailability of VPA, reduced the clearance of VPA, and prolonged the half life of VPA in the blood from F3-treated rats compared to VPA-treated rats. The improvement of bioavailability of F3 VANE in the brain was also observed. This is possibly due to (a) higher bioavailability of F3 VANE in blood (b) lower clearance rate of F3 VANE in the brain by possible inhibition of T80 to P-gp. Overall, F3 VANE had successfully reduced the cytotoxicity of VPA, the clearance of VPA and prolonged the half-life of VPA in the blood, subsequently improved the brain bioavailability of VPA significantly

Preclinical anticancer activity of Typhonium flagelliforme (Lodd.) Blume and its potential mechanism: A systematic review

Objective: To assess the potential of Typhonium flagelliforme (Lodd.) Blume (T. flagelliforme, Bian Yan Li Tou Jian), a traditional Chinese medicinal plant, as an anticancer agent in a systematic review of preclinical research. Methods: Seven databases, namely, Scopus, PubMed, Web of Science, ScienceDirect, LILACS, EBSCO Medline, and Mendeley were thoroughly searched from their inception up until September 8, 2023. Peer-reviewed English language studies that conducted in vitro and in vivo investigations of T. flagelliforme extracts, fractions, or isolated compounds were included. Clinical trials and non-original peer-reviewed reports were excluded. The effectiveness of T. flagelliforme on various cancer cells, tumor sizes, and mechanisms was qualitatively assessed. The quality of evidence was assessed using the ToxRTool by three independent raters, and their consistency was verified. Results: The search included 27 studies: 22 in vitro, four in vivo, and one involving both. T. flagelliforme extracts were shown to be effective against leukemic, breast, colorectal, and lung cancers. Most studies had “Reliable with Restrictions” scores. T. flagelliforme induced apoptosis by halting the cell cycle, activating caspase-3/-9, cleaving PARP, fragmenting DNA, reducing survivin, decreasing ROS, suppressing COX-2 and HSP70, and inhibiting the NF-κB pathway. When combined with interferon, T. flagelliforme exerts antiangiogenic effects. Conclusion: Although T. flagelliforme shows promising activity against cancer, its efficacy as a standalone anticancer treatment remains uncertain. It appears to be better suited as complementary or combined therapy. The lack of conclusive evidence could be attributed to suboptimal study design, incomplete reporting, and inadequate inclusion of proper positive controls and statistical analyses across multiple articles

Depression, anxiety, and stress among university students in Selangor, Malaysia during COVID-19 pandemics and their associated factors.

IntroductionThis study aims to assess the impacts of COVID-19 pandemics among university students in Malaysia, by identifying the prevalence of depression, anxiety and stress among them and their respective predictors.MethodologyAn online cross-sectional study was conducted via non-probabilistic convenience sampling. Data were collected on sociodemographic characteristics, lifestyle, COVID-19 related influences. Mental health status was assessed with depression, anxiety, and stress scale (DASS-21).Results388 students participated this study (72.4% female; 81.7% Bachelor's student). The prevalence of moderate to severe depression, anxiety and stress among university students are 53.9%, 66.2% and 44.6%, respectively. Multivariable logistic regression analysis found that the odds of depression were lower among students who exercise at least 3 times per week (OR: 0.380, 95% CI: 0.203-0.711). The odd ratio of student who had no personal history of depression to had depression, anxiety and stress during this pandemic was also lower in comparison (OR: 0.489, 95% CI: 0.249-0.962; OR: 0.482, 95% CI: 0.241-0.963; OR: 0.252, 95% CI: 0.111-0.576). Surprisingly, students whose are currently pursuing Master study was associated with lower stress levels (OR: 0.188, 95% CI: 0.053-0.663). However, student who had poorer satisfaction of current learning experience were more likely to experience stress (OR: 1.644, 95% CI: 1.010-2.675).LimitationsIt is impossible to establish causal relationships between variables on mental health outcomes, and there is a risk of information bias.ConclusionThe prevalence of mental health issues among university students is high. These findings present essential pieces of predictive information when promoting related awareness among them

Investigations of amphiphilic butylglyceryl-functionalized dextran nanoparticles for topical delivery

Toward the development of colloidal systems that can enhance transdermal permeation of hydrophilic actives, a material combining the non‐toxic of dextran with alkylglycerols permeation enhancing property has been designed. To this purpose, a range of amphiphilic butylglyceryl dextrans (DEX‐OX4) was synthesized via modification with n‐butylglycidyl ether with a degree of functionalization in the range 6.3%–35.7%. A reduced viscosity and an increased molecular weight of DEX‐OX4 were recorded when compared to the starting material. DEX‐OX4 was formulated into nanocarriers and loaded with α‐arbutin prior to characterization—the nanoparticles (180–220 nm size) were found to be close‐to‐spherical, stable at pH 5 and 7, with a loading capacity of 11.7%. Slower release of α‐arbutin from the nanoparticles was demonstrated when tested in acidic media. Lack of toxicity at application‐relevant concentrations and increased permeation were demonstrated by nanoparticles in vitro results against immortalized skin human keratinocytes cells (HaCaT)