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This study was conducted to isolate and identify thermophilic and thermotolerant bacteria from Jordanian hot springs and to determine hydrolytic, antimicrobial, and anticancer activities of the isolates. Thirty bacterial isolates were recovered from water samples of five main local hot springs. Nineteen of the isolated colonies were light yellow and circular to rhizoid on nutrient agar; cells were Gram-positive, endospore-forming, and rod-shaped. Eleven isolates were Gram-negative non-spore forming rods. It was found that 21 isolates met the criteria of moderate thermophiles; all isolates were grown aerobically (JA5 was facultative anaerobes) at 40-60 °C, pH 6-9, and 0-4% salt concentration and most of these isolates were reacted positively with catalase and oxidase. The remaining nine isolates were thermotolerant. Depending on the 16S rRNA gene sequences of the isolates, it was found that 19 thermophilic isolates have 97-100% sequence homology to the genus Bacillus; eight isolates were closely related to the thermophilic genus Geobacillus showing 97-100% homology to G. stearothermophilus ATCC 7953. The isolate JM2 shares 99% sequence homology with Thermomonas hydrothermalis. Remarkably, it was found that the 16S rDNA sequence of isolate JZ9 were highly similar (99% identity) to the thermophilic bacterium Caldimonas hydrothermale. To our knowledge, this is the first record of Caldimonas isolation from Jordanian hot springs. A wide spectrum of hydrolytic activities for protease, lipase, xylanase, cellulase, amylase, and pectinase was detected from the obtained isolates. It was found that JM1, JS3, and JZ11 isolates produced all tested enzymatic activities. Antimicrobial activities were only exhibited by three isolates (thermophilic JH1 and JM11 and thermotolerant JS3). Results indicated that three thermophilic Bacillus isolates (JA2, JM11, and JM12) produced selective cytotoxicity against human leukemia cell line K562. Therefore, many of the obtained isolates in this study can be considered as a promising source of effective agents that may be used for medical, pharmaceutical, and industrial purposes. [ABSTRACT FROM AUTHOR]

Cancer is a worldwide health problem and is the second leading cause of death after heart disease. Due to the high cost and severe side effects associated with chemotherapy treatments, natural products with anticancer therapeutic potential may play a promising role in anticancer therapy. The purpose of this study was to investigate the cytotoxic and apoptotic characteristics of the aqueous Drimia maritima bulb extract on Caco-2 and COLO-205 colorectal cancer cells. In order to reach such a purpose, the chemical composition was examined using the GC-MS method, and the selective antiproliferative effect was determined in colon cancer cell lines in normal gingival fibroblasts. The intracellular ROS, mitochondrial membrane potential, and gene expression changes in selected genes (CASP8, TNF-α, and IL-6 genes) were assessed to determine the molecular mechanism of the antitumor effect of the extract. GC-MS results revealed the presence of fifty-seven compounds, and Proscillaridin A was the predominant secondary metabolite in the extract. The IC50 of D. maritima bulb extract on Caco-2, COLO-205, and the normal human gingival fibroblasts were obtained at 0.9 µg/mL, 2.3 µg/mL, and 13.1 µg/mL, respectively. The apoptotic effect assay indicated that the bulb extract induced apoptosis in both colon cancer cell lines. D. maritima bulb extract was only able to induce statistically significant ROS levels in COLO-205 cells in a dose-dependent manner. The mitochondrial membrane potential (MMP) revealed a significant decrease in the MMP of Caco-2 and COLO-205 to various concentrations of the bulb extract. At the molecular level, RT-qPCR was used to assess gene expression of CASP8, TNF-α, and IL-6 genes in Caco-2 and COLO-205 cancer cells. The results showed that the expression of pro-inflammatory genes TNF-α and IL-6 were upregulated. The apoptotic initiator gene CASP8 was also upregulated in the Caco-2 cell line and did not reach significance in COLO-205 cells. These results lead to the conclusion that D. maritima extract induced cell death in both cell lines and may have the potential to be used in CRC therapy in the future. [ABSTRACT FROM AUTHOR]

Highly dispersed nanoporous Au rods have been prepared from arc melted Ag70Au30 alloy using site-selective electrochemical potential controlled dealloying method followed by Au anodizing process. The microstructure studies using scanning electron microscope and atomic force microscope indicate that selective removal of Ag from the Ag70Au30, precursor results in the formation of bi-continuous three-dimensional network structures with uniform pores and Au ligaments diameter of 6 nm. The noticeable features present in the optical studies of highly dispersed nanoporous Au rods using UV—Vis spectroscopy are two absorption bands peaking at 477 and 546 nm with overlapping of these bands at 520 nm. The antimicrobial testing by Agar well diffusion method reveals that the dispersed porous Au rods have greater inhibitory effect against both Gram-positive and Gram-negative bacterial strains. The results obtained provide opportunities to design and manipulate nanoporous Au rods at atomic level to achieve antimicrobial efficacy for biomedical applications. [ABSTRACT FROM AUTHOR]