The role of BDNF transcription in the antidepressant-like effects of 18ß-glycyrrhetinic acid in a chronic social defeat stress model.

BACKGROUND: Xiaoyaosan (XYS), a traditional Chinese medicine formulation, has been used in the treatment of depression. However, no studies have yet identified the active compounds responsible for its antidepressant effects in the brain. STUDY DESIGN: We investigated the antidepressants effects of XYS and identified 18ß-glycyrrhetinic acid (18ß-GA) as the primary compound present in the brain following XYS injection. Furthermore, we explored the molecular mechanisms underlying the antidepressant-like effects of both XYS and 18ß-GA. METHODS: To investigate the antidepressant-like effects of XYS and elucidate the associated molecular mechanisms, we employed various methodologies, including cell cultures, the chronic social defeat stress (CSDS) model, behavioral tests, immunoprecipitation, quantitative PCR (qPCR) assays, Western blotting assays, luciferase assays, chromatin immunoprecipitation (ChIP) assays, immunofluorescence staining, and dendritic spine analysis. RESULTS: We identified 18ß-GA as the primary compound in the brain following XYS injection. In vitro, 18ß-GA was found to bind with ERK (extracellular signal-regulated kinase), subsequently activating ERK kinase activity toward both c-Jun and cAMP response element binding protein (CREB). Moreover, 18ß-GA activated brain-derived neurotrophic factor (BDNF) transcription by stimulating nuclear factor-erythroid factor 2-related factor 2 (Nrf2), c-Jun, and CREB, while also inhibiting methyl CpG binding protein 2 (MeCP2) both in vitro and in vivo. Chronic intraperitoneal (i.p.) administration of 18ß-GA exhibited prophylactic antidepressant-like effects in a CSDS model, primarily by activating BDNF transcription in the medial prefrontal cortex (mPFC). Interestingly, a single i.p. injection of 18ß-GA produced rapid and sustained antidepressant-like effects in CSDS-susceptible mice by engaging the BDNF-tropomyosin receptor kinase B (TrkB) signaling pathway in the mPFC. CONCLUSION: These findings suggest that the activation of BDNF transcription in the mPFC underlies the antidepressant-like effects of 18ß-GA, a key component of XYS in the brain.

Photosynthetic Toxicity of Enrofloxacin on Scenedesmus obliquus in an Aquatic Environment.

Aquaculture facilities are a potential source of antibiotics in aquatic environments, having adverse effects on the algae species. In this study, the toxicity induced by enrofloxacin (ENR) on the algae Scenedesmus obliquus was evaluated. The uptake of ENR and the change in the growth and photosynthesis of algae were analyzed. At the exposure doses of 10-300 µg/L, the accumulated levels of ENR in algae were 10.61-18.22 µg/g and 12.09-18.34 µg/g after 48 h and 96 h of treatment, respectively. ENR inhibited the growth of algae, with a concentration for 50% effect of 119.74 µg/L, 53.09 µg/L, 64.37 µg/L, and 52.64 µg/L after 24 h, 48 h, 72 h and 96 h of treatment, respectively, indicating the self-protection and repair ability of algae in a short period of time. Furthermore, the chlorophyll contents decreased in all treatment groups, and the photosynthetic system Ⅱ parameters decreased in a dose-dependent manner under ENR stress, suggesting that ENR caused a disorder in the electron transport of the photosynthesis of algae, and the carbon fixation and assimilation processes were thus damaged. These results indicate that ENR poses a considerable risk to aquatic environments, affects the carbon sinks, and even has an adverse effect on human health.

First records of the genus Phrurotimpus Chamberlin amp; Ivie, 1935 from China, with two new species and one new combination (Araneae: Phrurolithidae).

The genus Phrurotimpus Chamberlin Ivie, 1935, previously known only from the Nearctic, is found in Asia for the first time, with species recorded from the Yunnan Province of China. Two new species are described from both sexes, P. daliensis sp. n. and P. baoshanensis sp. n., and one new combination, P. lasiolepis (Fu, Chen Zhang, 2016) comb. n., are reported in this study.

Drug-free contact lens based on quaternized chitosan and tannic acid for bacterial keratitis therapy and corneal repair.

Bacterial keratitis (BK) and related inflammatory diseases causes irreversible damage to the corneal tissue. In this study, a novel polyacrylamide semi-interpenetrating network hydrogel including quaternized chitosan and tannic acid (PAM-QCS-TA) were used to construct a novel antibacterial and antioxidant contact lens. The obtained hydrogels showed high water content (>85%), swelling resistance, light transmittance (>90%) and adjustable mechanical property. Both quantitative and qualitative antibacterial experiments against Staphylococcus aureus and Escherichia coli (E. coli) indicated excellent sterilization function especially against E. coli (almost 100%). Due to the presence of tannin acid, it showed obvious antioxidant properties, which relieved oxidative stress and protect cells from reactive oxygen species-induced cytotoxicity. Animal experiments also indicated the shortened treatment time of BK (only 3 days) as well as the protection of eye tissue structure. Therefore, such drug-free antibacterial and antioxidant contact lens avoiding the development of drug resistance is a potential candidate in ocular infectious and inflammatory diseases treatment.

3-Dimensional hollow graphene balls for voltammetric sensing of levodopa in the presence of uric acid.

The development of novel nanomaterials brings new opportunity and challenge for high sensing detection of biomolecules. The authors describe the preparation of 3-dimentional hollow graphene balls (3D HGBs) using nickel nanoparticles (Ni-NPs) as the template. The Ni-NPs were synthesized by chemical reduction of nickel chloride and then graphene was coated onto their surface via carburization and carbonization. After etching Ni-NPs, 3D HGBs with few layers and a typical size of 100 nm were obtained. They were sprayed onto indium tin oxide glass to obtain a working electrode for electrochemical determination of levodopa in the presence of uric acid. Due to the unique hollow porous structure of the 3D HGBs, the electrode exhibits a sensitivity of 0.69 µA·µM-1·cm-2 and a 1 µM limit of detection. It is selective, reproducible and stable. It was applied to the determination of levodopa in spiked human plasma samples and it is of potential use in clinical research. Graphical abstract Schematic presentation of the preparation of 3-dimensional hollow graphene balls (HGBs) by using nickel nanoparticles as a template that can be removed by etching. The HGBs were sprayed onto indium tin oxide (ITO) glass to obtain a working electrode that has a sensitivity of 0.69 µA⋅µM-1·cm-2 and a 1 µM limit of detection for the determination of levodopa.