Heat stress delays detoxification of phenanthrene in the springtail Folsomia candida.

Climate change has intensified the occurrence of heat waves, resulting in organisms being exposed to thermal and chemical stress at the same time. The effects of mild heat shock combined with sublethal concentrations of phenanthrene (PHE) on defense mechanisms in springtails Folsomia candida were investigated. The transcription of Heat Shock Protein 70 (HSP70) was significantly upregulated by heat shock but tended to reach the control levels after 42 h of recovery. The transcription of cytochrome P450 3A13 (CYP3A13) was upregulated 3-13 fold by PHE but suppressed by heat shock. The suppression by heat shock might contribute to the reduced detoxification of PHE during high-temperature exposure. In line with this, we found that the internal PHE concentration was approximately 70% higher in heat-shocked springtails than in animals kept at control temperature. In general, the transcription of genes encoding enzymes of detoxification phase Ⅱ (glutathione S-transferase 3) and phase Ⅲ (ABC transporter 1) and the activity of antioxidant defense enzymes (superoxide dismutase and catalase) were less influenced than genes encoding phase I detoxification mechanisms (CYP3A13). These results indicate that heat shock delays the detoxification of PHE in springtails.

Antisense Oligonucleotides Conjugated with Lipophilic Compounds: Synthesis and In Vitro Evaluation of Exon Skipping in Duchenne Muscular Dystrophy.

Our groups previously reported that conjugation at 3'-end with ursodeoxycholic acid (UDCA) significantly enhanced in vitro exon skipping properties of ASO 51 oligonucleotide targeting the human DMD exon 51. In this study, we designed a series of lipophilic conjugates of ASO 51, to explore the influence of the lipophilic moiety on exon skipping efficiency. To this end, three bile acids and two fatty acids have been derivatized and/or modified and conjugated to ASO 51 by automatized solid phase synthesis. We measured the melting temperature (Tm) of lipophilic conjugates to evaluate their ability to form a stable duplex with the target RNA. The exon skipping efficiency has been evaluated in myogenic cell lines first in presence of a transfection agent, then in gymnotic conditions on a selection of conjugated ASO 51. In the case of 5'-UDC-ASO 51, we also evaluated the influence of PS content on exon skipping efficiency; we found that it performed better exon skipping with full PS linkages. The more efficient compounds in terms of exon skipping were found to be 5'-UDC- and 5',3'-bis-UDC-ASO 51.

Hexane extract of green tea (Camellia sinensis) leaves is an exceptionally rich source of squalene.

Squalene is a cancer chemo-preventive and skin protective agent with high commercial demand. Here, we report for the first time that the green tea (Camellia sinensis) leaves is a surprisingly rich plant-based source of squalene. Young and tender leaves and old and turf leaves were collected at four different collecting seasons (April-August). Lipophilic compounds in the leaves and commercial green teas were extracted with hexane. The squalene contents in the hexane extracts varied greatly with the types of the leaves and collecting seasons. The hexane extract of turf leaves contained significantly higher contents of squalene than the extract of tender leaves. The hexane extract of the turf leaves collected in August contained the highest content of squalene (29.2 g/kg extract). This represents the first report on the qualitative and quantitative information on squalene in green tea leaves.

SPC Liposomes as Possible Delivery Systems for Improving Bioavailability of the Natural Sesquiterpene ß-Caryophyllene: Lamellarity and Drug-Loading as Key Features for a Rational Drug Delivery Design.

The natural sesquiterpene ß-caryophyllene (CRY) has been highlighted to possess interesting pharmacological potentials, particularly due to its chemopreventive and analgesic properties. However, the poor solubility of this sesquiterpene in aqueous fluids can hinder its uptake into cells, resulting in inconstant responses of biological systems, thus limiting its application. Therefore, identifying a suitable pharmaceutical form for increasing CRY bioavailability represents an important requirement for exploiting its pharmacological potential. In the present study, the ability of soybean phosphatidylcholine (SPC) liposomes to improve bioavailability and absorption of CRY in cancer cells has been evaluated. Liposomal formulations of CRY, differing for lamellarity (i.e., unilamellar and multilamellar vesicles or ULV and MLV) and for the drug loading (i.e., 1:0.1, 1:0.3 and 1:0.5 mol/mol between SPC and CRY) were designed with the aim of maximizing CRY amount in the liposome bilayer, while avoiding its leakage during storage. The low-loaded formulations significantly potentiated the antiproliferative activity of CRY in both HepG2 and MDA-MB-468 cells, reaching a maximum IC50 lowering (from two to five folds) with 1:0.3 and 1:0.1 SPC/CRY MLV. Conversely, increasing liposome drug-loading reduced the ability for CRY release, likely due to a possible interaction between SPC and CRY that affects the membrane properties, as confirmed by physical measures.

Influence of body composition on disposition of the highly fat distributed compound as analysed by physiologically based pharmacokinetic (PBPK) modeling and simulation.

A recent study suggested that the pharmacokinetics (PK) of highly fat distributed compounds can be affected by acute changes in the volume of adipose tissue. The present study investigates possible influences of body composition on the disposition of the highly lipophilic compound TAK-357 in two rat strains. Physiologically based PK (PBPK) modeling and simulation was applied on single and multiple dose PK data of TAK-357 in obese Wistar fatty rats and Wistar lean rats having approximately 45% and 13% body fat, respectively. The observed effects of an elevated fat mass in Wistar fatty rats on the plasma concentrations appeared to be partly compensated for by other differences between the two rat strains. A decrease in the tissue to blood partition coefficients under high body fat conditions was identified as another factor contributing to the difference in PK. A higher lipid content in the plasma in high body fat animals may result in relatively lower tissue to blood partition coefficients. PBPK-based simulations indicate that the plasma concentrations of lipophilic compounds in high body fat conditions can differ by up to two-times at steady-state. This confirms that there is only a small impact of body composition change on the plasma concentration of highly lipophilic drugs and that the need for therapeutic dose adjustments may be limited.

Characterization of dietary fucoxanthin from Himanthalia elongata brown seaweed.

This study explored Himanthalia elongata brown seaweed as a potential source of dietary fucoxanthin which is a promising medicinal and nutritional ingredient. The seaweed was extracted with low polarity solvents (n-hexane, diethyl ether, and chloroform) and the crude extract was purified with preparative thin layer chromatography (P-TLC). Identification, quantification and structure elucidation of purified compounds was performed by LC-DAD-ESI-MS and NMR (1H and 13C). P-TLC led purification yielded 18.6mg/g fucoxanthin with 97% of purity based on the calibration curve, in single-step purification. LC-ESI-MS (parent ion at m/z 641 [M+H-H2O]+) and NMR spectra confirmed that the purified band contained all-trans-fucoxanthin as the major compound. Purified fucoxanthin exhibited statistically similar (p>0.05) DPPH scavenging capacity (EC50: 12.9µg/mL) while the FRAP value (15.2µg trolox equivalent) was recorded lower (p<0.05) than the commercial fucoxanthin. The promising results of fucoxanthin purity, recovery and activity suggested that H. elongata seaweed has potential to be exploited as an alternate source for commercial fucoxanthin production.

Impact of acute fat mobilisation on the pharmacokinetics of the highly fat distributed compound TAK-357, investigated by physiologically based pharmacokinetic (PBPK) modeling and simulation.

In a dog toxicokinetic study, an unusual plasma concentration increase of the highly lipophilic compound TAK-357 was observed 2 weeks after termination of a 2-week repeated dosing in one dog with acute body weight loss. The present study investigates the cause of this increase. A physiologically based pharmacokinetic (PBPK) model was constructed using the rat and dog pharmacokinetic data. Using the constructed model, the TAK-357 concentration profile in the case of body weight change was simulated. The PBPK model-derived simulation suggested that redistribution from adipose tissues to plasma due to a loss of body fat caused the observed concentration increase of TAK-357 in dog plasma. The analysis demonstrates that the disposition of a highly lipophilic and fat-distributed compound can be affected by acute changes in adipose tissue mass. PBPK modeling and simulation proved to be efficient tools for the quantitative hypothesis testing of apparently atypical PK phenomena resulting from acute physiological changes.