Ultrathin Two-Dimensional BiOCl-Bi2 S3 -Cu2 S Ternary Heterostructures with Enhanced LSPR effect for NIR Photonic Bacterial Disinfection.

Photonic disinfection, particularly near-infrared (NIR) light triggered antibacterial, has emerged as a highly promising solution for combating pathogenic microbes due to its spatiotemporal operability, safety, and low cost of apparatus. However, it remains challenging to construct NIR-responsive antibacterial agents with high light-converting efficacy and elucidate synergistic mechanisms. In this work, ultrathin two-dimensional (2D) BiOCl-Bi2 S3 -Cu2 S ternary heterostructures that can efficiently kill drug-resistant bacteria were synthesized by doping 0D Bi2 S3 and Cu2 S nanoparticles in the 2D BiOCl nanosheets via a facile one-pot hydrothermal method. Notably, the incorporation of Cu2 S nanoparticles bestows strong NIR light-harvesting capability to the composite nanosheets due to their localized surface plasmon resonance (LSPR). Upon NIR light illumination, the BiOCl-Bi2 S3 -Cu2 S nanosheets can achieve enhanced photonic hyperthermia and reaction oxygen species (ROS) generation, serving as single light-activated bi-functional photothermal/photodynamic therapeutics. High-speed hot electrons and large local electronic fields caused by LSPR might play an important role in thermal vibrations and effective carrier separations, respectively. Benefiting from the unique ternary heterostructures, both the photothermal conversion and ROS generation efficacy of BiOCl-Bi2 S3 -Cu2 S nanosheets are significantly improved compared to the binary BiOCl-Cu2 S or BiOCl-Bi2 S3 nanosheets. Accordingly, the ternary composite nanosheets can effectively kill bacteria via the NIR-driven photonic disinfection mechanism. This work presents a new type of 2D composite nanosheets with ternary heterostructures for NIR photonic disinfection.

NIR-Triggered Multi-Mode Antitumor Therapy Based on Bi2 Se3 /Au Heterostructure with Enhanced Efficacy.

Of all the reaction oxygen species (ROS) therapeutic strategies, NIR light-induced photocatalytic therapy (PCT) based on semiconductor nanomaterials has attracted increasing attention. However, the photocatalysts suffer from rapid recombination of electron-hole pairs due to the narrow band gaps, which are greatly restricted in PCT application. Herein, Bi2 Se3 /Au heterostructured photocatalysts are fabricated to solve the problems by introducing Au nanoparticles (NPs) in situ on the surface of the hollow mesoporous structured Bi2 Se3 . Owing to the lower work function of Au NPs, the photo-induced electrons are easier to transfer and assemble on their surfaces, resulting in the increased separation of the electron-hole pairs with efficient ROS generation. Besides, Bi2 Se3 /Au heterostructures also enhance the photothermal efficiency due to the effective orbital overlaps with accelerated electron migrations according to density functional theory calculations. Moreover, the PLGA-PEG and the doxorubicin (DOX) are introduced for photothermal-triggered drug release in the system. The Bi2 Se3 /Au heterostructures also displays excellent infrared thermal (IRT) and computed tomography (CT) dual-modal imaging property for promising cancer diagnosis. Collectively, Bi2 Se3 /Au@PLGA-PEG-DOX exhibits prominent tumor inhibition effect based on synchronous PTT, PCT and chemotherapy triggered by NIR light for efficient antitumor treatment.

Effect of Exercise Intensity on Neurotrophic Factors and Blood-Brain Barrier Permeability Induced by Oxidative-Nitrosative Stress in Male College Students.

We investigated the effects of aerobic exercise intensity on oxidative-nitrosative stress, neurotrophic factor expression, and blood-brain barrier (BBB) permeability. Fifteen healthy men performed treadmill running under low-intensity (LI), moderate-intensity (MI), and high-intensity (HI) conditions. Blood samples were collected immediately before exercise (IBE), immediately after exercise (IAE), and 60 min after exercise (60MAE) to examine oxidative-nitrosative stress (reactive oxygen species [ROS]; nitric oxide [NO]), neurotrophic factors (brain-derived neurotrophic factor [BDNF]; nerve growth factor [NGF]), and blood-brain barrier (BBB) permeability (S-100ß; neuron-specific enolase). ROS concentration significantly increased IAE and following HI (4.9 ± 1.7 mM) compared with that after LI (2.8 ± 1.4 mM) exercise (p < .05). At 60MAE, ROS concentration was higher following HI (2.5 ± 1.2 mM) than after LI (1.5 ± 0.5 mM) and MI (1.4 ± 0.3 mM) conditions (p < .05). Plasma NO IAE increased significantly after MI and HI exercise (p < .05). Serum BDNF, NGF, and S-100b levels were significantly higher IAE following MI and HI exercise (p < .05). BDNF and S-100b were higher IAE following MI (29.6 ± 3.4 ng/mL and 87.1 ± 22.8 ng/L, respectively) and HI (31.4 ± 3.8 ng/mL and 100.6 ± 21.2 ng/L, respectively) than following LI (26.5 ± 3.0 ng/mL and 64.8 ± 19.2 ng/L, respectively) exercise (p < .05). 60MAE, S-100b was higher following HI (71.1 ± 14.5 ng/L) than LI (56.2 ± 14.7 ng/L) exercise (p < .05). NSE levels were not significantly different among all intensity conditions and time points (p > .05). Moderate- and/or high-intensity exercise may induce higher oxidative-nitrosative stress than may low-intensity exercise, which can increase peripheral neurotrophic factor levels by increasing BBB permeability.

Ursolic acid plays a protective role in obesity-induced cardiovascular diseases.

The metabolic disturbance of obesity is one of the most common risk factors of atherosclerosis. Resistin, an obesity-induced adipokine, can induce the expression of cell adhesion molecules and the attachment of monocytes to endothelial cells, which play an important role in the development of atherosclerosis. Ursolic acid, a pentacyclic triterpenoid found in fruits and many herbs, exhibits an array of biological effects such as anti-inflammatory and antioxidative properties. The aim of this study was to investigate the potential underlying mechanisms of the effect of ursolic acid on resistin-induced adhesion of U937 cells to human umbilical vein endothelial cells (HUVECs). Our data indicated that ursolic acid suppressed the adhesion of U937 to HUVECs and downregulated the expression of adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1), intracellular cell adhesion molecule-1 (ICAM-1), and E-selectin, in resistin-induced HUVECs by decreasing the production of intracellular reaction oxygen species (ROS) and attenuating the nuclear translocation of NFκB. Ursolic acid appeared to inhibit resistin-induced atherosclerosis, suggesting that ursolic acid may play a protective role in obesity-induced cardiovascular diseases.

Sex steroids have opposing effects on heart rate of juveniles, Gambusia holbrooki.

Abstract: Built on our recent work that heart rates (HRs) and function in Gambusia holbrooki are sexually dimorphic, this study assessed whether the species is an appropriate model to study sex-hormone effects on heart physiology. With a hypothesis that 17ß-estradiol (E2) and 17α-methyltestosterone (MT) regulate the HR of juvenile G. holbrooki in a sex-specific manner, genetic males and females were treated with E2 and MT, respectively, and the HR; (bpm) was measured an hour following treatment using light-cardiogram. Results showed the HRs (bpm) of both sexes were significantly (P < 0.05) altered compared to controls. Specifically, the E2 accelerated HR in the males and conversely MT decelerated the HR in the females. The normal expression levels of estrogen (erα and erß) and G protein-coupled estrogen (gper) receptor genes were significantly higher (P < 0.05) in female than male hearts. Interestingly, the activity of the erß in the heart of the MT-treated females reversed and was significantly lower (P < 0.05) than those of males while erα and gper were non-responsive. In contrast, significant down- and up-regulation of erα and gper, respectively, occurred in the liver of MT-treated females. Morphological observations suggest that MT caused hepatomegaly, somewhat resembling an inflating balloon, perhaps induced by the accumulation of unexpelled gases. E2-induced ventricular angiogenesis in males was likely due to an influx of blood supply caused by the increased HRs. Collectively, the results demonstrate that the juvenile G. holbrooki heart readily responds to E2/MT in a sex-specific manner.

Synthesis of oxygen vacancy-enriched N/P co-doped CoFe2O4 for high-efficient degradation of organic pollutant: Mechanistic insight into radical and nonradical evolution.

Oxygen vacancy-enriched N/P co-doped cobalt ferrite (NPCFO) was synthesized using ionic liquid as N and P sources, and then the catalytic performance and mechanism of NPCFO upon peroxymonosulfate (PMS) activation for the degradation of organic pollutants were investigated. The as-synthesized NPCFO-700 exhibited excellent catalytic performance in activating PMS, and the degradation rate constant of 4-chlorophenol (4-CP) increased with the increase of OV concentration in NPCFO-x. EPR analysis confirmed the existence of ·OH, SO4·-, and 1O2 in the NPCFO-700/PMS system, in which OV could induce the generation of 1O2 by PMS adsorption and successive capture, and also served as electronic transfer medium to accelerate the redox cycle of M2+/M3+ (M denotes Co or Fe) for the generation of radical to synergistically degrade organic pollutants. In addition, the contribution of free radical and nonradical to 4-CP degradation was observed to be strongly dependent on solution pH, and SO4·- was the major ROS in 4-CP degradation under acid and alkaline condition, while 1O2 was involved in the degradation of 4-CP under neutral condition due its selective oxidation capacity, as evidenced by the fact that such organic pollutants with ionization potential (IP) below 9.0 eV were more easily attacked by 1O2. The present study provided a novel insight into the development of transition metal-based heterogeneous catalyst containing massive OV for high-efficient PMS activation and degradation of organic pollutants.

A new isoflavonol and other constituents from Cameroonian propolis and evaluation of their anti-inflammatory, antifungal and antioxidant potential.

Propolis is rich in diverse bioactive compounds. Propolis samples were collected from three localities of Cameroon and used in the study. Column chromatography separation of propolis MeOH:DCM (50:50) extracts yielded a new isoflavonol, 2-hydroxy-8-prenylbiochanin A (1) alongside 2',3'-dihydroxypropyltetraeicosanoate (2) and triacontyl p-coumarate (3) isolated from propolis for first time together with seven compounds: ß-amyrine (4), oleanolic acid (5), ß-amyrine acetate (6), lupeol (7), betulinic acid (8), lupeol acetate (9) and lupenone (10). These compounds were tested for their inhibitory effect on oxidative burst where intracellular reactive oxygen species (ROS) were produced from zymosan stimulated human whole blood phagocytes and on production of nitric oxide (NO) from lipopolysaccharide (LPS) stimulated J774.2 mouse macrophages. The cytotoxicity of these compounds was evaluated on NIH-3 T3 normal mouse fibroblast cells, antiradical potential on 2,2-diphenyl-1-picrylhydrazylhydrazyl (DPPH·) as well as their anti-yeast potential on four selected candida species. Compound 1 showed higher NO inhibition (IC50 = 23.3 ± 0.3 µg/mL) than standard compound L-NMMA (IC50 = 24.2 ± 0.8 µg/mL). Higher ROS inhibition was shown by compounds 6 (IC50 = 4.3 ± 0.3 µg/mL) and 9 (IC50 = 1.1 ± 0.1 µg/mL) than Ibuprofen (IC50 = 11.2 ± 1.9 µg/mL). Furthermore, compound 1 displayed moderate level of cytotoxicity on NIH-3 T3 cells, with IC50 = 5.8 ± 0.3 µg/mL compared to the cyclohexamide IC50 = 0.13 ± 0.02 µg/mL. Compound 3 showed lower antifungal activity on Candida krusei and Candida glabrata, MIC of 125 µg/mL on each strain compared to 50 µg/mL for fuconazole. The extracts showed low antifungal activities ranging from 250 to 500 µg/mL on C. albicans, C. krusei and C. glabrata and the values of MIC on Candida parapsilosis were 500 µg/mL and above. DPPH* scavenging activity was exhibited by compounds 1 (IC50 = 15.653 ± 0.335 µg/mL) and 3 (IC50 = 89.077 ± 24.875 µg/mL) compared to Vitamin C (IC50 = 3.343 ± 0.271 µg/mL) while extracts showed moderate antiradical activities with IC50 values ranging from 309.31 ± 2.465 to 635.52 ± 11.05 µg/mL. These results indicate that compounds 1, 6 and 9 are potent anti-inflammatory drug candidates while 1 and 3 could be potent antioxidant drugs.

Inhibition of autophagy modulates astaxanthin and total fatty acid biosynthesis in Chlorella zofingiensis under nitrogen starvation.

The present study showed that inhibition of autophagy significantly increased cellular levels of reactive oxygen species in Chlorella zofingiensis under nitrogen starvation. This was accompanied with increased expression of PSY, and enhanced accumulation of astaxanthin after 48h of cultivation. Nevertheless, the proportion of astaxanthin in secondary carotenoids remained unchanged. Meanwhile, the expression level of ACCase was also elevated in the 3-MA-treated cells compared to the control despite a >20% lower content of fatty acid in the former than the latter. This phenomenon might be due to inhibition of recycling of cellular components by 3-MA and suggests the potential involvement of post-transcriptional regulation in fatty acid biosynthesis. In summary, our work has been the first to report a potentially important role of autophagy in fatty acid and astaxanthin accumulation in C. zofingiensis under stress conditions. The findings might provide valuable insights to guide further research in this area.

Selenocysteine antagonizes oxygen glucose deprivation-induced damage to hippocampal neurons.

Designing and/or searching for novel antioxidants against oxygen glucose deprivation (OGD)-induced oxidative damage represents an effective strategy for the treatment of human ischemic stroke. Selenium is an essential trace element, which is beneficial in the chemoprevention and chemotherapy of cerebral ischemic stroke. The underlying mechanisms for its therapeutic effects, however, are not well documented. Selenocysteine (SeC) is a selenium-containing amino acid with neuroprotective potential. Studies have shown that SeC can reduce irradiation-induced DNA apoptosis by reducing DNA damage. In this study, the in vitro protective potential and mechanism of action of SeC against OGD-induced apoptosis and neurotoxicity were evaluated in HT22 mouse hippocampal neurons. We cultured HT22 cells in a glucose-free medium containing 2 mM Na2S4O2, which formed an OGD environment, for 90 minutes. Findings from MTT, flow cytometry and TUNEL staining showed obvious cytotoxicity and apoptosis in HT22 cells in the OGD condition. The activation of Caspase-7 and Caspase-9 further revealed that OGD-induced apoptosis of HT22 cells was mainly achieved by triggering a mitochondrial-mediated pathway. Moreover, the OGD condition also induced serious DNA damage through the accumulation of reactive oxygen species and superoxide anions. However, SeC pre-treatment for 6 hours effectively inhibited OGD-induced cytotoxicity and apoptosis in HT22 cells by inhibiting reactive oxygen species-mediated oxidative damage. Our findings provide evidence that SeC has the potential to suppress OGD-induced oxidative damage and apoptosis in hippocampal neurons.

A Core-Shell-Satellite Structured Fe3 O4 @g-C3 N4 -UCNPs-PEG for T1 /T2 -Weighted Dual-Modal MRI-Guided Photodynamic Therapy.

Reactive oxygen species (ROS) produced in the specific tumor site plays the key role in photodynamic therapy (PDT). Herein, a multifunctional nanoplatform is designed by absorbing ultrasmall upconversion nanoparticles (UCNPs) on mesoporous graphitic-phase carbon nitride (g-C3 N4 ) coated superparamagnetic iron oxide nanospheres, then further modified with polyethylene glycol (PEG)molecules (abbreviated as Fe3 O4 @g-C3 N4 -UCNPs-PEG). The inert g-C3 N4 layer between Fe3 O4 core and outer UCNPs can substantially depress the quenching effect of Fe3 O4 on the upconversion emission. Upon near-infrared (NIR) laser irradiation, the UCNPs convert the energy to the photosensitizer (g-C3 N4 layer) through fluorescence resonance energy transfer process, thus producing a vast amount of ROS. In vitro experiment exhibits an obvious NIR-triggered cell inhibition due to the cellular uptake of nanoparticles and the effective PDT efficacy. Notably, this platform is responsive to magnetic field, which enables targeted delivery under the guidance of an external magnetic field and supervises the therapeutic effect by T1 /T2 -weighted dual-modal magnetic resonance imaging. Moreover, in vivo therapeutic effect reveals that the magnetism guided accumulation of Fe3 O4 @g-C3 N4 -UCNPs-PEG can almost trigger a complete tumor inhibition without any perceived side effects. The experiments emphasize that the excellent prospect of Fe3 O4 @g-C3 N4 -UCNPs-PEG as a magnetic targeted platform for PDT application.