Polyethylene terephthalate nanoplastics cause oxidative stress induced cell death in Saccharomyces cerevisiae.

Polyethylene terephthalate (PET) is a common plastic widely used in food and beverage packaging that poses a serious risk to human health and the environment due to the continual rise in its production and usage. After being produced and used, PET accumulates in the environment and breaks down into nanoplastics (NPs), which are then consumed by humans through water and food sources. The threats to human health and the environment posed by PET-NPs are of great concern worldwide, yet little is known about their biological impacts. Herein, the smallest sized PET-NPs so far (56 nm) with an unperturbed PET structure were produced by a modified dilution-precipitation method and their potential cytotoxicity was evaluated in Saccharomyces cerevisiae. Exposure to PET-NPs decreased cell viability due to oxidative stress induction revealed by the increased expression levels of stress response related-genes as well as increased lipid peroxidation. Cell death induced by PET-NP exposure was mainly through apoptosis, while autophagy had a protective role.

Antioxidant, antidiabetic effects and polyphenolic contents of propolis from Siirt, Turkey.

Propolis, a natural product collected by honeybees from various plant sources, has gained significant attention due to its diverse bioactive compounds and potential therapeutic properties. To further explore its contents and biological activities, this study aimed to analyze the phenolic compounds in Siirt propolis extracts obtained using different solvents, namely ethanol, water, and ethanol-water mixtures. The primary objective of this research was to investigate the phenolic profile, as well as the antidiabetic and antioxidant activities of the propolis extracts. Chemical profiling of extracts was performed using LC-MS/MS. The antioxidant potential of the propolis extracts was evaluated through free radical scavenging methods, including DPPH and ABTS assays. As a result of these analyses, propolis extracts showed moderate radical scavenging potential with 13.86%-35.72% for DPPH and 33.62%-62.50% for ABTS at a concentration of 30 µg mL-1, respectively. This radical scavenging potential of the extracts sheds light on its ability to combat oxidative stress, which is implicated in the development of diabetes, and its potential effects on cellular health. Additionally, the study assessed the antidiabetic properties of the propolis extracts by examining their inhibition effects on α-amylase and α-glycosidase enzymes. Extracts with high phenolic content showed a high inhibitory effect against α-glucosidase with an IC50 of 5.72 ± 0.83 µg mL-1. This research provided significant findings regarding the potential use of propolis in the treatment of diabetes and related metabolic disorders.

An update comprehensive review on the status of COVID-19: vaccines, drugs, variants and neurological symptoms.

Various recently reported mutant variants, candidate and urgently approved current vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), many current situations with severe neurological damage and symptoms as well as respiratory tract disorders have begun to be reported. In particular, drug, vaccine, and neutralizing monoclonal antibodies (mAbs) have been developed and are currently being evaluated in clinical trials. Here, we review lessons learned from the use of novel mutant variants of the COVID-19 virus, immunization, new drug solutions, and antibody therapies for infections. Next, we focus on the B 1.1.7, B 1.351, P.1, and B.1.617 lineages or variants of concern that have been reported worldwide, the new manifestations of neurological manifestations, the current therapeutic drug targets for its treatment, vaccine candidates and their efficacy, implantation of convalescent plasma, and neutralization of mAbs. We review specific clinical questions, including many emerging neurological effects and respiratory tract injuries, as well as new potential biomarkers, new studies in addition to known therapeutics, and chronic diseases of vaccines that have received immediate approval. To answer these questions, further understanding of the burden kinetics of COVID-19 and its correlation with neurological clinical outcomes, endogenous antibody responses to vaccines, pharmacokinetics of neutralizing mAbs, and action against emerging viral mutant variants is needed.

Synthesis of Oleanolic Acid Analogues and Their Cytotoxic Effects on 3T3 Cell Line.

BACKGROUND: Oleanolic acid (OA) is a known natural compound with many important biological activities. Thirteen oleanolic acid derivatives linked at C-3 and C-28 were synthesized and their structures were confirmed by 1H- and 13C NMR and mass spectral analyses. Among them, compounds 4, 6, 8-10, 12, 13 were synthesized for the first time. They were evaluated for their cytotoxic activity. They showed proliferative effect at low concentrations while cytotoxic effect was observed at high concentrations in a dose dependent manner. METHODS: We have first synthesized compounds 1 and 2 from the reaction of methyl iodide and OA. Compound 1 was reduced with LiAlH4 to give compound 3, and compound 2 gave compound 9 with MOMBr as a new compound. The compound 10 was then obtained from the reduction of compound 9 with LiAlH4 as a new oleanolic acid derivative. A diol derivative 11 was synthesized from OA and LiAlH4 at the room temperature. Compound 4 was obtained from the reaction of compound 3 with CBr4 as a new analogue of OA, and the reduction of compound 4 afforded compound 5 as a known product. In addition, we synthesized compounds 6-8 from compound 3 using MsCl, MeI and p-nitrobenzoyl chloride, respectively, in good yields. Compounds 6 and 8 are new analogues of OA. The new compounds 12 and 13 were also synthesized starting from OA using with MOMBr and TBDMSiCl as the reagents. The all synthesized compounds were purified by using column chromatography and/or crystallization. RESULTS: In the present study, thirteen OA derivatives linked at C-28 and (or) C-3 were synthesized and evaluated for their cytotoxic activity on 3T3 cell lines which are the standard fibroblast cell lines, derived from Swiss albino mouse embryo tissue. 3T3 cell viability was observed at low concentrations of the tested triterpenoids while they displayed anti-proliferative effect at higher concentrations. CONCLUSION: Oleanolic acid 28-methyl ester (2) showed fairly different behavior from all the other compounds tested and found to be the least cytotoxic compound. However, at 200 µM concentration, it exhibited the same cytotoxicity with compounds 3, 9 and 10 around 58-59%. Among the tested 13 compounds, 7 exhibited the most drastic decline for the viability from 12,5 µM to 25 µM concentration. Compound 6 displayed the most cytotoxic effect, almost in all concentrations, particularly at 6.25 and 25 µM concentrations while the highest cytotoxic effect at 50 µM was observed for compound 11 among all the tested triterpenoids. As a result, all the tested OA derivatives showed proliferative effect at 1,56 µM although no proliferative effect was observed for OA. Moreover, OA exhibited higher cytotoxic effect than its derivatives, particularly at higher concentrations (50, 100, 200 µM) with an exception for compound 11. Because, the latter showed highest proliferative effect at lowest concentration, and highest anti-proliferative effect at highest concentration which surpassed all the OA derivatives.