The interaction of a thiosemicarbazone derived from R - (+) - limonene with lipid membranes

Interaction of novel N-acridine thiosemicarbazones with lipid membrane: NMR and molecular dynamics simulations

NMR and molecular dynamics simulations revealed differences in the localization of the novel thiosemicarbazones: 2-benzoyl ((E)-N-(acridin-9-yl)-2-(phenyl(pyridin-2-yl)methylene)hydrazine-1-carbothioamide (AOBP) and 2-dipyridyl ((E)-N-(acridin-9-yl)-2-(di(pyridin-2-yl)methylene)hydrazine-1-carbothioamide (AODP) within the lipid membrane. It turned out that both thiosemicarbazones can penetrate inside the membrane, but AOBP is able to pass into the center of the hydrophobic region of the lipid bilayer, while AODP is distributed closer to the surface and freely leaves the membrane into the aqueous environment. The presence of cholesterol was also found to prevent both thiosemicarbazones from penetrating the membrane. The mechanism of anti-proliferative activity of some TSCs is related to the penetration through the lysosomal membrane and formation of cytotoxic copper complexes, which generate ROS resulting in lysosomal membrane permeabilization and cell death. Hydrophobic drugs, including TSCs, could penetrate through lysosomal membrane via passive diffusion, thus the affinity of drug to the hydrophobic interior of the lipid membrane could be important for their activity. Since the mechanism of thiosemicarbazones anticancer activity is associated with their penetration into lysosomes, the results obtained are important for a better understanding of the mechanisms of activity of these compounds and the development of new drug agents.

Synergic effects of DL-limonene, R-limonene, and cisplatin on AKT, PI3K, and mTOR gene expression in MDA-MB-231 and 5637 cell lines

The anticancer and cytotoxic effects of DL-Limonene and R-Limonene are well-documented. However, the role of natural compounds in enhancing the efficacy of platinum-based drugs like Cisplatin (CisPt) remains debated. This study aims to boost Cisplatin's impact on breast (MDA-MB-231) and bladder (5637) cancer cells using DL-Limonene and R-Limonene. Different concentrations of DL-Limonene, R-Limonene, and Cisplatin, combined, were used to treat MDA-MB-231 and 5637 cells in this experimental study. The cell's viability was evaluated using an MTT assay. AnnexinV- PI staining was applied to evaluate the percentage of apoptotic cells. Cytotoxicity results showed that combining DL-Limonene, R-Limonene, and Cisplatin significantly improved outcomes in MDA-MB-231 cells (P < 0.05). Annexin/PI staining revealed apoptosis rates of 74 %, 28 %, 43 %, 81 %, and 91 % for Cisplatin40, R-Limonen1000, DL-Limonen1000, R-Limonen1000/DL-Limonen1000, and the combined treatment, respectively, versus 13 % in the control. The combination also resulted in the greatest reduction of AKT, PI3K, and mTOR gene expression. Our results show that R-Limonene and DL-Limonene enhance Cisplatin's cancer-inhibiting effects in breast and bladder cancer cell lines. These compounds may be promising for combination therapy, potentially allowing for lower doses of chemotherapy and reducing side effects like nephrotoxicity.

Spectroscopic behavior of bufotenine and bufotenine N-oxide: Solvent and pH effects and interaction with biomembrane models

Bufotenine is a fluorescent analog of Dimethyltryptamine (DMT) that has been widely studied due to its psychedelic properties and biological activity. However, little is known about its spectroscopic properties in different media. Thus, we present in this work, for the first time, the spectroscopic behavior of bufotenine and bufotenine N-oxide by means of their fluorescence properties. Both molecules exhibit changes in optical absorption and emission spectra with variations in pH of the medium and in different solvents. Assays in the presence of biomembranes models, like micelles and liposomes, were also performed. In surfactants titration experiments, the spectral shift observed in fluorescence shows the interaction of both molecules with pre-micellar structures and with micelles. Steady state anisotropy measurements show that both bufotenine and bufotenine N-oxide, in the studied concentration range, interact with liposomes without causing changes in the fluidity of the lipid bilayer. These results can be useful in studies that aim at searching for new compounds, inspired by bufotenine and bufotenine N-oxide, with relevant pharmacological activities and also in studies that use these molecules as markers of psychiatric disorders.

In-plane and out-of-plane gigahertz sound velocities of saturated and unsaturated phospholipid bilayers from cryogenic to room temperatures

Here, we examined the gigahertz sound velocities of hydrated multibilayers of saturated (1,2-dimyristoyl-sn-glycero-3-phosphocholine, DMPC) and unsaturated (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC) phospholipids by Brillouin spectroscopy. Out-of-plane and in-plane (lateral) phonons were studied independently of each other. Similar strong temperature dependences of the sound velocities were found for phonons of both types. The sound velocities in the low-temperature limit were two-fold higher than that at physiological temperatures; a significant part of the changes in sound velocity occurs in the solid-like gel phase. The factors that may be involved in the peculiar behavior of sound velocity include changes in the chain conformational state, relaxation susceptibility, changes in the elastic modulus at infinite frequencies, and lateral packing of molecules.

Mandarin essential oil as an antimicrobial in ethanolic fermentation: Effects on Limosilactobacillus fermentum and Saccharomyces cerevisiae

The antibacterial activity of citrus essential oils (EOs) in the context of combating Limosilactobacillus fermentum, one of the most important bacterial contaminants in the bioethanol production industry, has never been explored previously. Industrial processes usually utilize sulfuric acid for cell treatment to decrease bacterial contamination. However, due to the hazardous nature of sulfuric acid, an alternative to it is highly desirable. Therefore, in the present study, the efficacy of Fremont IAC 543 mandarin EO against a strain of L. fermentum (ATCC® 9338™) was evaluated under proliferative/non-proliferative conditions, in both pure culture and co-culture with an industrial strain of Saccharomyces cerevisiae. The mandarin EO exhibited higher effectiveness against L. fermentum compared to that against S. cerevisiae under non-proliferative conditions (added to water rather than to culture medium). At the concentration of 0.05%, the EO was as effective as the acid solution with pH 2.0 in reducing the count of L. fermentum almost 5 log CFU mL^-1 cycles, while the concentration of 0.1% led to the complete loss of bacterial culturability. When L. fermentum was co-cultured with S. cerevisiae, the efficacy of the EO against the bacterial strain was reduced. However, despite this reduced efficacy in co-culture, mandarin EO may be considered effective in combating L. fermentum and could be applied in processes where this bacterium proves to be unfavorable and does not interact with S. cerevisiae.