Bioactivity Studies of Hesperidin and XAV939.

The present work aimed to evaluate the reactivity of natural bioflavonoid hesperidin (HSP) and synthetically derived XAV939 (XAV) against human hepatocellular carcinoma (HepG2), human breast cancer (MDA-MB231) cancer cell lines, and related molecular and pathological profiles. Data recorded revealed that the cytotoxic potential of the tested products was found to be cell type- and concentration-dependent. The half-maximal inhibitory concentration (IC50) value of the HSP-XAV mixture against MDA-MB231 was significantly decreased in the case of using the HSP-XAV mixture against the HepG2 cell line. Also, there was a significant upregulation of the phosphotumor suppressor protein gene (P53) and proapoptotic genes such as B-cell lymphoma-associated X-protein (Bax, CK, and Caspase-3), while antiapoptotic gene B-cell lymphoma (Bcl-2) was significantly downregulated compared with the untreated cell control. The cell cycle analysis demonstrated that DNA accumulation was detected mainly during the G2/M phase of the cell cycle accompanied with the elevated reactive oxygen species level in the treatment of HepG2 and MDA-MB231 cell lines by the HSP-XAV mixture, more significantly than that in the case of cell control. Finally, our finding suggests that both HSP and XAV939 and their mixture may offer an alternative in human liver and breast cancer therapy.

Protonation Equilibria of N-Acetylcysteine.

The acid base protonation equilibria of N-acetylcysteine (Nac) and its equilibrium constants in water solutions were determined by the Hyperquad 2008 software assessment from the pH potentiometry data, which provides a diversity of statistics presentations. The effect of a number of organic solvents on the acid base protonation processes was also examined. The solution equilibria of N-acetylcysteine (Nac) were studied at T = 298.15 K in water (w 1) + organic liquid mixtures [100 w 2 = 0, 20, 40, 60, and 80%] with an ionic strength of I = 0.16 mol·dm-3 NaNO3. Also, the organic solvent's influence was studied based on the Kamlet-Taft linear solvation energy relationship. The experimental results were compared with theoretical ones obtained via the Gaussian 09 calculation computer program. The protonation equilibria of Nac were found to be important in the progress of separation systems in aqueous and non-aqueous ionic solutions. Nac showed a likely good metal dibasic chelating bioligand as the DFT calculations proved two binding sites. Spectrophotometry evaluation was also done for N-acetylcysteine bioligands at various pH values in water solutions then its absorbance ratio was measured.

In vitro evaluation of electroporated gold nanoparticles and extremely-low frequency electromagnetic field anticancer activity against Hep-2 laryngeal cancer cells.

INTRODUCTION: The extremely-low frequency electromagnetic field (ELFEMF) has been proposed for use in cancer therapy since it was found that magnetic waves interfere with many biological processes. Gold nanoparticles (Au-NPs) have been widely used for drug delivery during cancer in vitro studies due to their low cytotoxity and high biocompatibility. The electroporation of cancer cells in a presence of Au-NPs (EP Au-NPs) can induce cell apoptosis, alterations of cell cycle profile and morphological changes. The impact of ELFEMF and EP Au-NPs on morphology, cell cycle and activation of apoptosis-associated genes on Hep-2 laryngeal cancer cell line has not been studied yet. MATERIALS AND METHODS: ELFEMF on Hep-2 cells were carried out using four different conditions: 25/50 mT at 15/30 min, while Au-NPs were used as direct contact (DC) or with electroporation (EP, 10 pulses at 200V, equal time intervals of 4 sec). MTT assay was used to check the toxicity of DC Au-NPs. Expression of CASP3, P53, BAX and BCL2 genes was quantified using qPCR. Cell cycle was analyzed by flow cytometry. Hematoxylin and eosin (HE) staining was used to observe cell morphology. RESULTS: Calculated IC50 of DC Au-NPs 24.36 µM (4.79 µg/ml) and such concentration was used for further DC and EP AuNPs experiments. The up-regulation of pro-apoptotic genes (CASP3, P53, BAX) and decreased expression of BCL2, respectively, was observed for all analyzed conditions with the highest differences for EP AuNPs and ELFEMF 50 mT/30 min in comparison to control cells. The highest content of cells arrested in G2/M phase was observed in ELFEMF-treated cells for 30 min both at 25 or 50 mT, while the cells treated with EP AuNPs or ELFEMF 50 mT/15 min showed highest ratios of apoptotic cells. HE staining of electroporated cells and cells exposed to ELFEMF's low and higher frequencies for different times showed nuclear pleomorphic cells. Numerous apoptotic bodies were observed in the irregular cell membrane of neoplastic and necrotic cells with mixed euchromatin and heterochromatin. CONCLUSIONS: Our observations indicate that treatment of Hep-2 laryngeal cancer cells with ELFEMF for 30 min at 25-50 mT and EP Au-NPs can cause cell damage inducing apoptosis and cell cycle arrest.

Feruloyl esterases as biotechnological tools: current and future perspectives.

Feruloyl esterases represent a diverse group of hydrolases catalyzing the cleavage and formation of ester bonds between plant cell wall polysaccharide and phenolic acid. They are widely distributed in plants and microorganisms. Besides lipases, a considerable number of microbial feruloyl esterases have also been discovered and overexpressed. This review summarizes the latest research on their classification, production, and biophysicochemical properties. Special emphasis is given to the importance of that type of enzyme and their related phenolic ferulic acid compound in biotechnological processes, and industrial and medicinal applications.

How does chromatin package DNA within nucleus and regulate gene expression?

The human body is made up of 60 trillion cells, each cell containing 2 millions of genomic DNA in its nucleus. How is this genomic deoxyribonucleic acid [DNA] organised into nuclei? Around 1880, W. Flemming discovered a nuclear substance that was clearly visible on staining under primitive light microscopes and named it 'chromatin'; this is now thought to be the basic unit of genomic DNA organization. Since long before DNA was known to carry genetic information, chromatin has fascinated biologists. DNA has a negatively charged phosphate backbone that produces electrostatic repulsion between adjacent DNA regions, making it difficult for DNA to fold upon itself. In this article, we will try to shed light on how does chromatin package DNA within nucleus and regulate gene expression?

Microbial production of four biodegradable siderophores under submerged fermentation.

Four siderophore analogues were isolated and purified from Escherichia coli, Bacillus spp. ST13, and Streptomyces pilosus microorganisms under some specific submerged fermentation conditions. In order to evaluate the highest production of this siderophore analogues through the growth, a rapid spectrophotometric screening semi-quantitative method was used, in which interestingly the analogues were isolated in its own form not its iron chelate. After chromatographic separation, the chemical structures of the isolated and purified siderophores were illustrated using detailed spectroscopic techniques. The biodegradation studies were done on that four novel isolated and purified siderophores following OECD protocols. In addition, the bioactivities of these siderophores and their iron complexes were examined and evaluated.

Expression of feruloyl esterase from Aspergillus awamori in Escherichia coli: Characterization and crystal studies of the recombinant enzyme.

This paper describes cloning, expression, characterization and crystallization of feruloyl esterase from Aspergillus awamori. The gene coding for feruloyl esterase from A. awamori was amplified, cloned, and expressed in Escherichia coli. The recombinant enzyme was purified, characterized and used for crystallization. Its X-ray crystallographic data were collected and explained using molecular replacement theory. Also, the tertiary structure of the recombinant enzyme-ferulic acid complex was also determined.