Effects of anode materials on the performance and anode microbial community of soil microbial fuel cell.

Five soil microbial fuel cells (SMFCs) with graphite felt, aluminium sheet, activated carbon fibre felt, graphite paper and carbon cloth as anodes were constructed using the petroleum hydrocarbon polluted soils as substrates. After 115 days of operation, the SMFC with graphite felt anode performed the best in both bioelectricity output and removal of target pollutants, with the bioelectricity output parameters of 345 mV for stable voltage, 24.0 mW/m2 for power density and 774 Ω for internal resistance, and the removal rates of 59.14 % for total petroleum hydrocarbon, 61.65 % for anthracene, and 55.92 % for pyrene, respectively. The conductivity of the material was the key factor affecting the electron transfer rate of the anode, which determined the electric acclimation and screening intensity of SMFC to soil microbes, leading to the growth and succession of the electricigens-dominanted anode microbial community with various abundances of phyla and genera. The surface structure of the anode material played a critical role in the internal resistance of SMFC through affecting the mass transfer of substrate and metabolites, and it might also change the abundance of microbes especially those non-electricigens on the community through different adhesion.

Cytotoxic Activities of Total Saponins from Plena Clematis on Human Tumor Cell Lines In Vitro.

OBJECTIVE: To investigate the anti-proliferative effects of saponins prepared from Plena Clematis (PC) cultured in Fujian Province, China on 4 human tumor cell lines and its possible anti-tumor mechanism. METHODS: The growth inhibition assays of saponins on human esophageal squamous carcinoma cell line (EC9706), human hepatoma cell line (HepG-2), human oral cancer cell line (KB) and human gastric cancer cell line (BGC-823) were evaluated in vitro by thiazolyl blue (MTT) method. The inhibitory effects on EC9706 treated with different concentrations of saponins (15.62, 31.25, 62.50, 125, 250 and 500 µg/mL) were performed in vitro by MTT method. The morphology and nuclear staining with acridine orange/ethidium bromide of EC9706 cells treated with saponins were illustrated under an inverted phase fluorescence microscope. The apoptotic effects of saponins were further evaluated by annexin-V/propidium iodide dual staining experiment to examine the occurrence of phosphatidylserine externalization onto the cell surface by a flflow cytometer. RESULTS: MTT assay showed that the saponins could inhibit the proliferation of 4 tumor cell lines. Among them, the maximum inhibition rate of 73.1% was detected in EC9706 cells at the saponins concentration of 250 µg/mL for 24 h. Further investigation indicated that the saponins induced EC9706 cells apoposis. The EC9706 cells presented apoptotic characteristics when treated with saponins, including that the morphologies of EC9706 cells were appeared round-shaped with higher refraction, and the cell nuclear stained orange with EB after 250 µg/mL saponins exposure. The flow cytometry analysis results showed that the induction of cell cycle arrest in apoptotic system may participate in the anti-proliferative activity of saponins on EC9706 cells. CONCLUSION: The saponins from PC exhibited significant cytotoxicity against human EC9706, KB, BGC-823, and HepG-2 cells and might be beneficial to development of ethnic pharmaceutical plant for potential anti-tumor drugs.

Cytotoxic Activities of Total Saponins from Plena Clematis on Human Tumor Cell Lines In Vitro / 中国结合医学杂志

OBJECTIVE@#To investigate the anti-proliferative effects of saponins prepared from Plena Clematis (PC) cultured in Fujian Province, China on 4 human tumor cell lines and its possible anti-tumor mechanism.@*METHODS@#The growth inhibition assays of saponins on human esophageal squamous carcinoma cell line (EC9706), human hepatoma cell line (HepG-2), human oral cancer cell line (KB) and human gastric cancer cell line (BGC-823) were evaluated in vitro by thiazolyl blue (MTT) method. The inhibitory effects on EC9706 treated with different concentrations of saponins (15.62, 31.25, 62.50, 125, 250 and 500 μg/mL) were performed in vitro by MTT method. The morphology and nuclear staining with acridine orange/ethidium bromide of EC9706 cells treated with saponins were illustrated under an inverted phase fluorescence microscope. The apoptotic effects of saponins were further evaluated by annexin-V/propidium iodide dual staining experiment to examine the occurrence of phosphatidylserine externalization onto the cell surface by a flflow cytometer.@*RESULTS@#MTT assay showed that the saponins could inhibit the proliferation of 4 tumor cell lines. Among them, the maximum inhibition rate of 73.1% was detected in EC9706 cells at the saponins concentration of 250 μg/mL for 24 h. Further investigation indicated that the saponins induced EC9706 cells apoposis. The EC9706 cells presented apoptotic characteristics when treated with saponins, including that the morphologies of EC9706 cells were appeared round-shaped with higher refraction, and the cell nuclear stained orange with EB after 250 μg/mL saponins exposure. The flow cytometry analysis results showed that the induction of cell cycle arrest in apoptotic system may participate in the anti-proliferative activity of saponins on EC9706 cells.@*CONCLUSION@#The saponins from PC exhibited significant cytotoxicity against human EC9706, KB, BGC-823, and HepG-2 cells and might be beneficial to development of ethnic pharmaceutical plant for potential anti-tumor drugs.

Establishment of Cell-Based Neuroglobin Promoter Reporter Assay for Neuroprotective Compounds Screening.

Neuroglobin (Ngb) has been demonstrated to be neuroprotective against stroke and neurodegenerative diseases, thus upregulating Ngb might be a novel approach for neuroprotection. In this study we aimed to establish cell-based Ngb reporter systems for screening neuroprotective compounds targeting Ngb upregulation. We developed both mouse and human stable Ngb reporter systems containing a luciferase reporter gene directed by mouse and human Ngb promoter, respectively. To validate these reporter systems, we used them to screen a pool of natural plant compounds. RT-PCR was used to verify the Ngb-upregulating effects of selected compounds, and neurotoxicity assay was used to test their neuroprotection effects in primary cultured neurons. We identified polydatin, genistein, daidzein, biochanin A and formononetin that can upregulate both mouse and human Ngb promoter activity. RT-PCR confirmed that polydatin, genistein and formononetin significantly increased Ngb mRNA expression in primary neurons. Furthermore, formononetin significantly decreased oxygen-glucose deprivation (OGD)-induced neurotoxicity. Moreover, inhibition of cAMP response element-binding protein (CREB) showed that CREB is required for formononetin-induced Ngb upregulation. These results suggest that these Ngb reporter systems are suitable for neuroprotective compound screening, which will be used to screen larger compound libraries for more potent neuroprotectants. This preliminary study will facilitate the development of Ngb-targeted therapeutics for stroke and neurodegenerative diseases.