Influence of Ce3+ Substitution on Antimicrobial and Antibiofilm Properties of ZnCexFe2-xO4 Nanoparticles (X = 0.0, 0.02, 0.04, 0.06, and 0.08) Conjugated with Ebselen and Its Role Subsidised with γ-Radiation in Mitigating Human TNBC and Colorectal Adenocarcinoma Proliferation In Vitro

Cancers are a major challenge to health worldwide. Spinel ferrites have attracted attention due to their broad theranostic applications. This study aimed at investigating the antimicrobial, antibiofilm, and anticancer activities of ebselen (Eb) and cerium-nanoparticles (Ce-NPs) in the form of ZnCexFe2-XO4 on human breast and colon cancer cell lines. Bioassays of the cytotoxic concentrations of Eb and ZnCexFe2-XO4, oxidative stress and inflammatory milieu, autophagy, apoptosis, related signalling effectors, the distribution of cells through the cell-cycle phases, and the percentage of cells with apoptosis were evaluated in cancer cell lines. Additionally, the antimicrobial and antibiofilm potential have been investigated against different pathogenic microbes. The ZOI, and MIC results indicated that ZnCexFe2-XO4; X = 0.06 specimen reduced the activity of a wide range of bacteria and unicellular fungi at low concentration including P. aeruginosa (9.5 mm; 6.250 µg/mL), S. aureus (13.2 mm; 0.390 µg/mL), and Candida albicans (13.5 mm; 0.195 µg/mL). Reaction mechanism determination indicated that after ZnCexFe2-xO4; X = 0.06 treatment, morphological differences in S.aureus were apparent with complete lysis of bacterial cells, a concomitant decrease in the viable number, and the growth of biofilm was inhibited. The combination of Eb with ZFO or ZnCexFe2-XO4 with γ-radiation exposure showed marked anti-proliferative efficacy in both cell lines, through modulating the oxidant/antioxidant machinery imbalance, restoring the fine-tuning of redox status, and promoting an anti-inflammatory milieu to prevent cancer progression, which may be a valuable therapeutic approach to cancer therapy and as a promising antimicrobial agent to reduce the pathogenic potential of the invading microbes.

Gasping for Sulfide: A Critical Appraisal of Hydrogen Sulfide in Lung Disease and Accelerated Aging

Hydrogen sulfide (H₂S) is a gaseous signaling molecule involved in a plethora of physiological and pathological processes. It is primarily synthesized by cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase as a metabolite of the transsulfuration pathway. H₂S has been shown to exert beneficial roles in lung disease acting as an anti-inflammatory and antiviral and to ameliorate cell metabolism and protect from oxidative stress. H₂S interacts with transcription factors, ion channels, and a multitude of proteins via post-translational modifications through S-persulfidation ("sulfhydration"). Perturbation of endogenous H₂S synthesis and/or levels have been implicated in the development of accelerated lung aging and diseases, including asthma, chronic obstructive pulmonary disease, and fibrosis. Furthermore, evidence indicates that persulfidation is decreased with aging. Here, we review the use of H₂S as a biomarker of lung pathologies and discuss the potential of using H₂S-generating molecules and synthesis inhibitors to treat respiratory diseases. Furthermore, we provide a critical appraisal of methods of detection used to quantify H₂S concentration in biological samples and discuss the challenges of characterizing physiological and pathological levels. Considerations and caveats of using H₂S delivery molecules, the choice of generating molecules, and concentrations are also reviewed. Antioxid. Redox Signal. 35, 551-579.

A small molecule targeting glutathione activates Nrf2 and inhibits cancer cell growth through promoting Keap-1S-glutathionylation and inducing apoptosis

The level of glutathione (GSH) is increased in many cancer cells. Consuming intracellular GSH by chemical small molecules that specifically target GSH is a new strategy to treat cancer. Recently, we synthesized and proved that a new compound 2-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)cyclohexa-2,5-diene-1,4-dione (PBQC) could target to and consume intracellular GSH specifically, but, it is not clear if PBQC can affect cancer cell growth and the activity of the nuclear factor-erythroid 2-related factor 2 (Nrf2) which is a key factor involved in regulation of cancer cell growth. In this study, we addressed these questions. We found that PBQC suppressed cancer cell growth through increasing the activity of Nrf2, while it did not inhibit normal vascular endothelial cell growth. Furthermore, we demonstrated that PBQC can cause Keap-1 protein S-glutathionylation and promote Nrf2 nuclear translocation as well as the expression of pro-apoptosis genes. As a result, the cancer cells underwent apoptosis. Here, we provide a new Nrf2 activator, PBQC that can promote the expressions of pro-apoptosis genes downstream Nrf2. The data suggest that PBQC is a potential lead-compound for development of new anti-cancer drugs.

The level of glutathione (GSH) is increased in many cancer cells.