Rate control analysis of the translation initiation pathway in S. cerevisiae

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A new portable toluidine blue/aptamer complex-on-polyethyleneimine-coated gold nanoparticles-based sensor for label-free electrochemical detection of alpha-fetoprotein

The quantification of alpha-fetoprotein (AFP) as a potential liver cancer biomarker which is generally found in ultratrace level is of significance in biomedical diagnostics. Therefore, it is challenging to find a strategy to fabricate a highly sensitive electrochemical device towards AFP detection through electrode modification for signal generation and amplification. This work shows the construction of a simple, reliable, highly sensitive, and label-free aptasensor based on polyethyleneimine-coated gold nanoparticles (PEI-AuNPs). A disposable ItalSens screen-printed electrode (SPE) is employed for fabricating the sensor by successive modifying with PEI-AuNPs, aptamer, bovine serum albumin (BSA), and toluidine blue (TB), respectively. The AFP assay is easily performed when the electrode is inserted into a small Sensit/Smart potentiostat connected to a smartphone. The readout signal of the aptasensor derives from the electrochemical response of TB intercalating into the aptamer-modified electrode after binding with the target. The decrease in current response of the proposed sensor is proportional to the AFP concentration due to the restriction of the electron transfer pathway of TB by a number of insulating AFP/aptamer complexes on the electrode surface. PEI-AuNPs improve SPE’s reactivity and provide a large surface area for aptamer immobilization whereas aptamer provides selectivity to the target AFP. Consequently, this electrochemical biosensor is highly sensitive and selective for AFP analysis. The developed assay reveals a linear range of detection from 10 to 50000 pg mL−1 with R2 = 0.9977 and provided a limit of detection (LOD) of 9.5 pg mL−1 in human serum. With its simplicity and robustness, it is anticipated that this electrochemical-based aptasensor will be a benefit for the clinical diagnosis of liver cancer and further developed for other biomarkers analysis

Iron (III)-Quercetin Complex: Synthesis, Physicochemical Characterization, and MRI Cell Tracking toward Potential Applications in Regenerative Medicine

In cell therapy, contrast agents T1 and T2 are both needed for the labeling and tracking of transplanted stem cells over extended periods of time through magnetic resonance imaging (MRI). Importantly, the metal-quercetin complex via coordination chemistry has been studied extensively for biomedical applications, such as anticancer therapies and imaging probes. Herein, we report on the synthesis, characterization, and labeling of the iron (III)-quercetin complex, “IronQ,” in circulating proangiogenic cells (CACs) and also explore tracking via the use of a clinical 1.5 Tesla (T) MRI scanner. Moreover, IronQ had a paramagnetic T1 positive contrast agent property with a saturation magnetization of 0.155 emu/g at 1.0 T and longitudinal relaxivity (r1) values of 2.29 and 3.70 mM−1s−1 at 1.5 T for water and human plasma, respectively. Surprisingly, IronQ was able to promote CAC growth in conventional cell culture systems without the addition of specific growth factors. Increasing dosages of IronQ from 0 to 200 μg/mL led to higher CAC uptake, and maximum labeling time was achieved in 10 days. The accumulated IronQ in CACs was measured by two methodologies, an inductively coupled plasma optical emission spectrometry (ICP-EOS) and T1-weighted MRI. In our research, we confirmed that IronQ has excellent dual functions with the use of an imaging probe for MRI. IronQ can also act as a stimulating agent by favoring circulating proangiogenic cell differentiation. Optimistically, IronQ is considered beneficial for alternative labeling and in the tracking of circulation proangiogenic cells and/or other stem cells in applications of cell therapy through noninvasive magnetic resonance imaging in both preclinical and clinical settings

Sequence analysis of mitochondrial DNA hypervariable region I in Thai individuals

<div><p>Nucleotide sequence analysis of hypervariable region I (HVRI) in human mitochondrial DNA (mtDNA) was investigated in 100 unrelated Thai individuals. A total of 85 variable sites and 423 base substitutions, which consisted of 390 nucleotide transitions and 33 nucleotide transversions were found. The following nucleotide substitutions were found: 48% at 16,223, 31% at 16,304, 30% at 16,332, and 26% at 16,129, respectively. Transition from T to C (43.7%) was the most frequent substitution. The nucleotide insertions were found at two sites with T at position 16,188 and C at position 16,194. Eighty-two haplotypes were investigated of which 72 haplotypes were unique. The most frequent haplotypes (16,108T-16,129A-16,162G-16,172C-16,304C and 16,260T-16,298C-16,355T-16,362C) were observed. From position 16,180 to 16,193, thirteen patterns of polycytosine or C-stretch were observed, whereas 68 Thai individuals were found to be similar to the references. The genetic diversity, random match probability, and discrimination power were estimated to be 0.9943, 0.0156, and 0.9844, respectively.</p></div

Pentagalloyl Glucose- and Ethyl Gallate-Rich Extract from Maprang Seeds Induce Apoptosis in MCF-7 Breast Cancer Cells through Mitochondria-Mediated Pathway

Bouea macrophylla Griffith, locally known as maprang, has important economic value as a Thai fruit tree. The maprang seed extract (MPSE) has been shown to exhibit antibacterial and anticancer activities. However, the bioactive constituents in MPSE and the molecular mechanisms underlying these anticancer activities remain poorly understood. This study aims to identify the active compounds in MPSE and to investigate the mechanisms involved in MPSE-induced apoptosis in MCF-7 treated cancer cells. The cytotoxic effect was determined by MTT assay. The apoptosis induction of MPSE was evaluated in terms of ROS production, mitochondrial membrane potential depolarization, and apoptosis-related gene expression. The compounds identified by HPLC and LC/MS analysis were pentagalloyl glucose, ethyl gallate, and gallic acid. MPSE treatment decreased cell proliferation in MCF-7 cells, and MPSE was postulated to induce G2/M phase cell cycle arrest. MPSE was found to promote intracellular ROS production in MCF-7 treated cells and to also influence the depolarization of mitochondrial membrane potential. In addition, MPSE treatment can lead to increase in the Bax/Bcl-2 gene expression ratio, suggesting that MPSE-induced apoptosis is mitochondria-dependent pathway. Our results suggest that natural products obtained from maprang seeds have the potential to target the apoptosis pathway in breast cancer treatments

Response of Stemona alkaloid production in Stemona sp. to chitosan and yeast extract elicitors

The experiments were purposed to investigate the effect of chitosan and yeast extract on Stemona alkaloid production in Stemona sp. culture. Both elicitors enhanced Stemona alkaloid production over the control. Treatment with chitosan at a concentration of 25 mg/L for 1 week resulted in the highest production of Stemona alkaloids. It was found that 1\u27, 2\u27-didehydrostemofoline and stemofoline production was 2.65 fold and 2.95 fold higher than the control, respectively

Mutagenicity, antimutagenicity and tyrosinase inhibition activity of hydroglycol extracts from Terminalia chebula Retzius, Terminalia bellerica Roxb and Rafflesia kerrii Meijer

The hydroglycolic extracts from Terminalia chebula Retzius, Terminalia bellerica Roxb and Rafflesia kerrii Meijer were investigated for total phenolic content (TPC), cytotoxicity, mutagenicity, antimutagenicity and antityrosinase for safety assessment as novel botanical-based cosmeceutical ingredients. These plant extracts showed TPC between 14.90 ± 0.02 and 112.40 ± 0.08 mg GAE g-1 of extract when using the Folin-Ciocalteu method. The cytotoxicity study revealed that the 50% cytotoxicity dose (CD50) towards normal mouse fibroblast L929 and mouse melanoma B16F10 cell lines was 5.43 ± 0.18 - 39.39 ± 0.14 mg mL-1 and 4.35 ± 0.33 - 58.23 ± 0.18 mg mL-1, respectively. In genotoxicity investigation, it was found that all extracts were not mutagenic at the concentrations up to 87.34 mg 0.1 mL-1 when tested with Salmonella typhimurium strains TA98 and TA100 in the presence and absence of metabolic activation (S9 microsomal fraction). The extracts were further tested for antimutagenic activity against 2-aminoanthracene (2-AA) and 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide (AF-2) which were used as the tested mutagens. Interestingly, all hydroglycolic extracts exhibited the inhibitory effect on the mutagenicity after being induced by 2AA and AF-2 in S. typhimurium strains TA98 and TA100 in the presence and absence of metabolic activation. All plant extracts were further investigated for tyrosinase inhibitory activity. Results showed that all extracts possessed tyrosinase inhibitory activity with 50% inhibitory concentration values (IC50) of 1.27 ± 0.49 - 39.96 ± 0.21 mg mL-1. Overall studies including their antimutagenicity and antityrosinase activities suggest that the hydroglycolic extracts of these three plants may be used as potential candidates for skin-care cosmeceutical ingredients