Honokiol ameliorates cigarette smoke-induced damage of airway epithelial cells via the SIRT3/SOD2 signalling pathway.

Cigarette smoking can cause damage of airway epithelial cells and contribute to chronic obstructive pulmonary disease (COPD). Honokiol is originally isolated from Magnolia obovata with multiple biological activities. Here, we investigated the protective effects of honokiol on cigarette smoke extract (CSE)-induced injury of BEAS-2B cells. BEAS-2B cells were treated with 300 mg/L CSE to construct an in vitro cell injury model, and cells were further treated with 2, 5 and 10 µM honokiol, then cell viability and LDH leakage were analysed by CCK-8 and LDH assay kits, respectively. Apoptosis was detected by flow cytometry analysis. ELISA was used to measure the levels of tumour necrosis factor (TNF)-ɑ, IL-1ß, IL-6, IL-8 and MCP-1. The results showed that honokiol (0.5-20 µM) showed non-toxic effects on BEAS-2B cells. Treatment with honokiol (2, 5 and 10 µM) reduced CSE (300 mg/L)-induced decrease in cell viability and apoptosis in BEAS-2B cells. Honokiol also decreased CSE-induced inflammation through inhibiting expression and secretion of inflammatory cytokines, such as TNF-ɑ, IL-1ß, IL-6, IL-8 and MCP-1. Moreover, honokiol repressed CSE-induced reactive oxygen species (ROS) production, decrease of ATP content and mitochondrial biogenesis, as well as mitochondrial membrane potential. Mechanistically, honokiol promoted the expression of SIRT3 and its downstream target genes, which are critical regulators of mitochondrial function and oxidative stress. Silencing of SIRT3 reversed the protective effects of honokiol on CSE-induced damage and mitochondrial dysfunction in BEAS-2B cells. These results indicated that honokiol attenuated CSE-induced damage of airway epithelial cells through regulating SIRT3/SOD2 signalling pathway.

Effect of Domestication on Nonvolatile Flavor Substances in Mud Crabs (Scylla paramamosain): A Way to Improve the Quality of Commercial Crabs.

In this study, the best domestication time for mud crabs (Scylla paramamosain) that were domesticated in the same region was explored. MC crabs (Mang Cai City, Vietnam), TS crabs (Taishan City, Guangdong Province, China), and NB crabs (Ningbo City, Zhejiang Province, China) were used as experiment groups, which were all domesticated in the Sanmen area for 28 days. Then, free amino acids and flavor nucleotides in muscles and hepatopancreas were determined. In MC and NB crabs, flavor amino acids in hepatopancreas and equivalent umami concentration (EUC) of flavor nucleotides in the hepatopancreas and muscles were lower than those of CK1 and CK3 crabs before domestication (0 day). There was no significant difference between MC and CK1 and between NB and CK3 crabs after 28 days of domestication. The content of umami amino acids, the total content of flavor nucleotides, and EUC in the hepatopancreas in TS crabs were lower than those in CK2 crabs and were still lower than those in CK2 crabs after 28 days of domestication. Therefore, it takes at least a month to domesticate mud crabs. The theoretical basis and technical reference for the directional cultivation of the flavor quality of mud crabs were provided in this study..

Temperature potentially induced distinctive flavor of mud crab Scylla paramamosain mediated by gut microbiota.

Many factors affect the flavor of crabs. However, impact of temperature on flavor has not been reported. Here, we examined Scylla paramamosain collected within the main four producing areas in China from north sampling point (NP) and south sampling point (SP), respectively. The contents of flavouring-related substances in hepatopancreas, muscles and gonads were determined by high-performance liquid chromatography (HPLC). Meanwhile, high-throughput sequencing of 16S RNA gene was used to reveal the diversity distribution of gut microbiota at each sample collection point. Comparisons among flavor substances of edible parts, the implied higher temperature in SP may be beneficial to the accumulation of flavor substances in gonads, while lower temperature in NP may be beneficial to the accumulation of flavor substances in muscles and hepatopancreas. The gut microbiota of crabs, was analyzed via 16S rRNA gene sequencing. The results of gut microbiota showed that there were significant differences in the distribution of gut microbiota in NP and SP. The microbiota composition of SP has a high distribution richness and no absolute dominant bacteria, while NP has absolute dominant bacteria and its microbiota richness was lower than SP. The results of redundancy analysis (RDA) showed that there was a significant correlation between temperature and the relative abundance of gut microbiota, and a significant correlation between gut microbiota and the content of flavor substances. This study indicates that temperature may be one of the main factors for the differences of flavor substances between SP and NP, which was most probably mediated by gut microbiota. Further exploration is needed with laboratory experiments in which the environment is more precisely controlled if these views are to be determined.

High-throughput sequencing reveals the core gut microbiota of the mud crab (Scylla paramamosain) in different coastal regions of southern China.

BACKGROUND: Scylla paramamosain is a commercially important mud crab. The microbiota is a community that inhabits the crab intestine, and is important for physiological functional and host health. RESULTS: Proteobacteria, Firmicutes, Bacteroidetes, Tenericutes, Spirochaetae and Fusobacteria were the dominant phyla of the 36 representative phyla. Eleven genera of the 820 representative genera were considered as core gut microbiota and were distributed in the five dominant phyla. The core genus of the Proteobacteria included Arcobacter, Photobacterium, Vibrio, Shewanella and Desulfovibrio. The other four phyla contained one or two genera. Male and female crab samples had two different core genera, (male samples: Psychrilyobacter & Lactococcus; female samples: Clostridium_sensu_stricto_11 and Candidatus_Bacilloplasma). CONCLUSIONS: This is the first time core intestinal microbiota have been identified in crab from nine coastal regions of southern China. This study provides sequencing data related to the gut microbiota of S. paramamosain, and may contribute to probiotic development for S. paramamosain aquaculture industries.

Comparing the performances of circular ponds with different impellers by CFD simulation and microalgae culture experiments.

In this study, a numerical simulation using computational fluid dynamics (CFD) was used to investigate the hydrodynamic characteristics of circular ponds with three different impellers (hydrofoil, four-pitched-blade turbine, and grid plate). The reliability of the CFD model was validated by particle image velocimetry (PIV). Hydrodynamic analyses were conducted to evaluate the average velocity magnitude along the light direction (Uz), turbulence properties, average shear stress, pressure loss and the volume percentage of dead zone inside circular ponds. The simulation results showed that Uz value of hydrofoil was 58.9, 40.3, and 28.8% higher than those of grid plate with single arm, grid plate with double arms and four-pitched blade turbines in small-scale circular ponds, respectively. In addition, hydrofoil impeller with down-flow operation had outstanding mixing characteristics. Lastly, the results of Chlorella pyrenoidosa cultivation experiments indicated that the biomass concentration of hydrofoil impeller with down-flow operation was 65.2 and 88.8% higher than those of grid plate with double arms and four-pitched-blade turbine, respectively. Therefore, the optimal circular pond mixing system for microalgae cultivation involved a hydrofoil impeller with down-flow operation.