Incorporating valsartan in sesame oil enriched self-nanoemulsifying system-loaded liquisolid tablets to improve its bioavailability.

Valsartan (VST) is a poorly soluble antihypertensive drug characterized by its limited dissolution rate and low bioavailability. This study aims to improve VST solubility and dissolution rate via developing liquisolid tablets (LSTs) containing a self-nanoemulsifying drug delivery system (SNEDDS), which is expected to enhance VST bioavailability. This aim was achieved via two designs of experiment. The first was the simplex-lattice design to optimize VST-loaded-SNEDDS using sesame oil, Tween 80, and polyethylene glycol 400. The second was the 32-3-level factorial design to optimize the liquisolid system using the SNEDDS-loaded VST and Neusilin®US2 as a carrier and fumed silica as a coating material. Different excipient ratios (X1) and varioussuper-disintegrants (X2) were also used in developing the optimized VST-LSTs. Thein vitrodissolution of VST from LSTs was compared with the marketed product (Diovan®). Non-compartmental analysis of plasma data after extravascular input with the linear trapezoidal method was used to calculate thepharmacokinetic parameters of the optimized VST-LSTs compared with the marketed tablet in male Wistar rats. The optimized SNEDDS compromised 24.9% sesame oil, 33.3% surfactant, and 41.8% cosurfactant, giving 173.9 nm size and 63.9 mg/ml loading capacity. Also, the SNEDDS-loaded VST tablet revealed good quality attributes with the release of 75% of its content in 5 min and 100% within 15 min. On the other hand, the marketed product took 1 h for the entire drug to be released.Moreover, the maximum plasma concentration (Cmax) of the optimizedVST-LSTwas6585.33 ng/ml within 1 h (Tmax), compared to 2884.67 ng/ml within 2 h of the marketed tablet.The relative bioavailability of the SNEDDS-loaded VST tablet was 213.7% compared to that of the marketed tablet, indicating that this formulation approach could be applied for increasing solubility, dissolution behavior in GIT, and bioavailability of poorly water-soluble drugs.

Hybrid nanoparticulate system of Fluvastatin loaded phospholipid, alpha lipoic acid and melittin for the management of colon cancer.

As a hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, Fluvastatin (FLV) is used for reducing low-density lipoprotein (LDL) cholesterol as well as to prevent cardiovascular problems. FLV showed cell line cytotoxicity and antitumor effect. Melittin (MEL) exhibits antineoplastic activity and is known to be promising as a therapeutic option for cancer patients. The aim of this work was to investigate the combination of FLV with MEL loaded hybrid formula of phospholipid (PL) with alpha lipoic acid (ALA) nanoparticles to maximize anticancer tendencies. This study examines the optimization of the prepared formulation in order to minimize nanoparticles size and maximize zeta potential to potentiate cytotoxic potentialities in colon cancer cells (Caco2), cell viability, cell cycle analysis and annexin V were tested. In addition to biological markers as P53, Bax, bcl2 and Caspase 3 evaluation The combination involving FLV PL ALA MEL showed enhanced cytotoxic potentiality (IC50 = 9.242 ± 0.35 µg/mL), about twofold lower, compared to the raw FLV (IC50 = 21.74 ± 0.82 µg/mL). According to studies analyzing cell cycle, optimized FLV PL ALA MEL was found to inhibit Caco2 colon cancer cells more significantly than other therapeutic treatments, wherein a higher number of cells were found to accumulate over G2/M and pre-G1 phases, whereas G0/G1/S phases witnessed the accumulation of a lower number of cells. The optimized formulation may pave the way for a novel and more efficacious treatment for colon cancer.

The Encapsulation of Febuxostat into Emulsomes Strongly Enhances the Cytotoxic Potential of the Drug on HCT 116 Colon Cancer Cells.

Febuxostat (FBX) is a drug able to inhibit xanthine oxidase and reduce uric acid production commonly used for the treatment of hyperuricemia in subjects suffering from gout. Several studies have also been directed at its use as anti-cancer drug during the last years, opening a window for its off-label use. In the present study, an optimized formulation in terms of vesicle size and drug release, obtained by encapsulation of FBX into the emulsomes (FBX-EMLs), was evaluated for its cytotoxic potential in human colorectal carcinoma (HCT 116) cells. The optimized FBX-EMLs formula had an improved half maximal inhibitory concentration (IC50), about 4-fold lower, compared to the free drug. The cell cycle analysis showed a significant inhibition of the HCT 116 cells proliferation following FBX-EMLs treatment compared to all the other conditions, with a higher number of cells accumulating on G2/M and pre-G1 phases, paralleled by a significant reduction of cells in G0/G1 and S phases. The optimized formula was also able to significantly increase the percentage of cell population in both early and late stages of apoptosis, characterized by a higher intracellular caspase-3 concentration, as well as percentage of necrotic cells. Lastly, the FBX ability to decrease the mitochondrial membrane potential was enhanced when the drug was delivered into the EMLs. In conclusion, the new formulation of FBX into EMLs improved all the parameters related to the anti-proliferative activity and the toxic potential of the drug towards colorectal cancer cells.

Brain iron loading impairs DNA methylation and alters GABAergic function in mice.

Iron deficiency is closely associated with altered GABA metabolism and affective behavior. While mutation in the hemochromatosis ( HFE) gene disrupts iron homeostasis and promotes oxidative stress that increases the risk of neurodegeneration, it is largely unknown whether HFE mutation modifies GABAergic homeostasis and emotional behavior. The goal of our study was to investigate the impact of HFE on GABAergic neurochemistry and redox-epigenetic regulation in the brain using H67D HFE-mutant mice that recapitulates the H63D-HFE mutation in humans. H67D mice displayed elevated redox-active iron levels in the brain by 32% compared to age-matched wild-type mice. Moreover, the H67D brain had increased isoprostane and decreased glutathione, indicating elevated oxidative stress. Additionally, the H67D brain had decreased global methylation and attenuated DNA methyltransferase (DNMT) activity. Direct addition of iron to purified DNMT in vitro decreased enzyme activity in a concentration-dependent manner. Last, H67D mice exhibited decreased anxiety-like behavior, which was associated with increased expression of the GABAA receptor α2 subunits by 93%, and these changes were also observed in H67D mice fed a low-iron diet. Taken together, our results suggest a putative role of HFE in regulating labile iron status in the brain, and mutation in H67D perturbs redox-methylation status, contributing to GABAergic dysfunction.-Ye, Q., Trivedi, M., Zhang, Y., Böhlke, M., Alsulimani, H., Chang, J., Maher, T., Deth, R., Kim, J. Brain iron loading impairs DNA methylation and alters GABAergic function in mice.

Microdialysis-directed Intra-tumor Pharmacokinetic Modeling of Methotrexate in Mice and Humans.

PURPOSE: To develop a quantitative pharmacokinetic model to characterize the disposition of methotrexate (MTX) at tumor site in tumor-bearing mice and to predict MTX concentrations in the human tumor. METHODS: The plasma profiles of MTX were obtained from normal mice, while microdialysis technique was employed to characterize the time course of MTX in tumor from breast tumor-bearing mice. Disposition profiles of plasma and tumor were analyzed by a hybrid physiologically-based pharmacokinetic (hPBPK) model that incorporates physiologically-relevant parameters such as tumor blood flow and volume, while plasma concentrations were used as a forcing input into the vascular-interstitial spaces of the tumor. The plasma profiles were initially described by a biexponential decay model to obtain a forcing function that enters into the vascular-interstitial spaces in the tumor. Using a defined forcing function, the tumor free concentrations were fitted to the hPBPK model. Based on the model developed, sensitivity analysis was conducted with a perturbation of PK parameters to predict different scenarios of intratumoral MTX transport. The relevant physiological PK parameters from the mouse model were then scaled-up and utilized to simulate human tumor concentrations. RESULTS: The mouse hPBPK model adequately characterized the concentration-time profiles of MTX in both plasma and tumor and produced various transfer rate constants between plasma and tumor. Our model was also able to reasonably predict MTX concentrations in the human tumor when human physiological data were utilized. CONCLUSIONS: The hPBPK model was able to quantitatively characterize the atypical transport of MTX in the tumor, supporting the idea that microdialysis is a valuable tool to study tumor biodistribution of drugs and to predict tumor concentrations in humans based on the pre-clinical data. This information can ultimately aid in the development of anticancer drugs with improved PK profiles. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Role of fatty acid composites in the toxicity of titanium dioxide nanoparticles used in cosmetic products.

It has been recognized that the use of nanoparticles (NPs) in the cosmetic industry results in products with better efficacy and functionality. However, recent advances in molecular toxicology have revealed that NP exposure can promote cytotoxicity and oxidative damage, which has raised health concerns in the use of NPs in personal care products. Nevertheless, the mechanistic basis for the toxicity and safety of cosmetic NPs is poorly understood. The goal of the study was to determine the cytotoxicity and intracellular distribution of titanium dioxide (TiO2) NPs containing fatty acid composites (palmitoleic acid, palmitic acid, stearic acid and oleic acid) commonly used in cosmetic products. Two types of cells, human fibroblast skin cells and adenocarcinoma lung cells, were exposed to either bare TiO2 NPs or TiO2 NPs mixed with fatty acids for up to 48 hr. NMR analysis confirmed that the fatty acid composites remained in the NPs after wash. The cytotoxicity of TiO2 NPs was determined by cell viability measurement using quantitative confocal microscopy, and the localization of two different forms of TiO2 NPs were assessed using electron spectroscopic imaging with transmission electron microscopy. TiO2 NPs containing fatty acids posed significantly reduced cytotoxicity (80-88% decreases) than bare NPs in both cell types. Furthermore, there was less intracellular penetration of the NPs containing fatty acid composites compared with bare NPs. These results provide important insights into the role of fatty acids in protecting the cells from possible toxicity caused by NPs used in the production of cosmetic products.

Effect of Hfe Deficiency on Memory Capacity and Motor Coordination after Manganese Exposure by Drinking Water in Mice.

Excess manganese (Mn) is neurotoxic. Increased manganese stores in the brain are associated with a number of behavioral problems, including motor dysfunction, memory loss and psychiatric disorders. We previously showed that the transport and neurotoxicity of manganese after intranasal instillation of the metal are altered in Hfe-deficient mice, a mouse model of the iron overload disorder hereditary hemochromatosis (HH). However, it is not fully understood whether loss of Hfe function modifies Mn neurotoxicity after ingestion. To investigate the role of Hfe in oral Mn toxicity, we exposed Hfe-knockout (Hfe (-/-)) and their control wild-type (Hfe (+/+)) mice to MnCl2 in drinking water (5 mg/mL) for 5 weeks. Motor coordination and spatial memory capacity were determined by the rotarod test and the Barnes maze test, respectively. Brain and liver metal levels were analyzed by inductively coupled plasma mass spectrometry. Compared with the water-drinking group, mice drinking Mn significantly increased Mn concentrations in the liver and brain of both genotypes. Mn exposure decreased iron levels in the liver, but not in the brain. Neither Mn nor Hfe deficiency altered tissue concentrations of copper or zinc. The rotarod test showed that Mn exposure decreased motor skills in Hfe (+/+) mice, but not in Hfe (-/-) mice (p = 0.023). In the Barns maze test, latency to find the target hole was not altered in Mn-exposed Hfe (+/+) compared with water-drinking Hfe (+/+) mice. However, Mn-exposed Hfe (-/-) mice spent more time to find the target hole than Mn-drinking Hfe (+/+) mice (p = 0.028). These data indicate that loss of Hfe function impairs spatial memory upon Mn exposure in drinking water. Our results suggest that individuals with hemochromatosis could be more vulnerable to memory deficits induced by Mn ingestion from our environment. The pathophysiological role of HFE in manganese neurotoxicity should be carefully examined in patients with HFE-associated hemochromatosis and other iron overload disorders.