Effects of different UV radiation on photoprotective pigments and antioxidant activity of the hot‐spring cyanobacterium Leptolyngbya cf. fragilis

UV‐induced synthesis/accumulation of photoprotective pigments and antioxidant activity were investigated in the hot‐spring cyanobacterium Leptolyngbya cf. fragilis. The results indicated that UV radiation may induce biosynthesis of carotenoids, allophycocyanin, phycoerythrin, and scytonemin while phycocyanin degrades in response to longtime UV radiation. Moreover, pigment composition of L. cf. fragilis was significantly altered with increasing UV radiation times, probably due to destruction and resynthesis of accessory pigments as an adaptation strategy to UV stress. The in vitro antioxidant analysis of different extracts of UV treated cyanobacteria exhibited concentration‐dependent antioxidant activity. Ethyl acetate extract of 72 h UV treatment showed maximum total antioxidant activity (IC50 = 71.73 ± 5.3 μg mL^?1) followed by ethyl acetate control (non‐UV irradiated) extract (IC50 = 109.43 ± 2.76 μg mL^?1). This is the first report for the UV‐induced synthesis of photoprotective pigments and their antioxidant activity in L. cf. fragilis.     

Model studies for isolation of G-quadruplex-forming DNA sequences through a pull-down strategy with macrocyclic polyoxazole

G-quadruplexes (G4s) are non-B DNA structures present in guanine-rich regions of gene regulatory areas, promoters and CpG islands, but their occurrence and functions remain incompletely understood. Thus, methodology to identify G4 sequences is needed. Here, we describe the synthesis of a novel cyclic hepta-oxazole compound, L1Bio-7OTD (1), bearing a biotin affinity-tag as a tool to pull down G4 structures from mixtures of G4-forming and non G4-forming DNA sequences. We confirmed that it could pull down G4s associated with telomeres, bcl-2 gene, and c-kit gene.     

Effects of crocin in reducing DNA damage,inflammation, and oxidative stress in multiple sclerosis patients: A double‐blind,randomized, and placebo‐controlled trial

Multiple sclerosis (MS) is an autoimmune disease in which the immune system attacks the nerve cells, resulting in neurological disorders. Oxidative stress, free radicals, and neuritis have important roles in MS pathogenesis. Here, we aim to evaluate the effect of crocin on inflammatory markers, oxidative damage, and deoxyribonucleic acid (DNA) damage in the blood of patients with MS. A total of 40 patients were divided into two groups, drug and placebo‐treated groups, using random assignment. Participants of the intervention and control groups received two crocin capsules or placebo per day for 28 days, respectively. Findings revealed a significant decrease in the level of important pathogenic factors in MS, including lipid peroxidation, DNA damage, tumor necrosis factor‐alpha, and interleukin 17 as well as a significant increase in the total antioxidant capacity in the serum of patients treated with crocin compared with the placebo group. Our results suggest the beneficial and therapeutic effects of crocin in MS.     

Growth Behavior and Fatty Acid Production of Probiotics,Pediococcus acidilactici and Lactococcus lactis,at Different Concentrations of Fructooligosaccharide: Studies Validating Clinical Efficacy of Selected Synbiotics on Growth Performance of Caspian Roach (Rutilus frisii kutum) Fry

Probiotics and Antimicrobial Proteins - Growth behavior and production of short-chain fatty acid (SCFA) of two probiotics, Pediococcus acidilactici and Lactococcus lactis, each at...     

Comparison of expression optimization of new derivative of staphylokinase (SAK-2RGD-TTI) with the rSAK

Staphylokinase (SAK) is a promising thrombolytic agent for the treatment of patients suffering from blood-clotting disorders. To increase the potency of SAK and to minimize vessel reocclusion, a new construct bearing SAK motif fused to tsetse thrombin inhibitor (TTI) via a 20-amino acid linker with 2 RGD (2 × arginine-glycine-aspartic acid inhibiting platelet aggregation via attachment to integrin receptors of platelet) was codon optimized and expressed comparatively in Pichia pastoris GS115 as a Mut⁺ strain and KM71H as a Mut^s strain. Fusion protein was optimized in terms of best expression condition and fibrinolytic activity and compared with the rSAK. Expression level of the designed construct reached up to 175 mg/L of the culture medium after 72-hr stimulation with 2.5% methanol and remained steady for 3–4 days. The highest expression was obtained at the range of 2–3% methanol. The SAK-2RGD-TT (relative activity >82%) was more active at 25–37 °C than rSAK (relative activity of 93%). Further, it showed relative activity >80% at pH ranges of 7–9. Western blot analysis showed two bands of nearly 27 and 24 kDa at ratio of 5 to 3, respectively. The specific fibrinolytic activity of the SAK-2RGD-TTI was measured as 8,269 U/mg, and 19,616 U/mg for the nonpurified and purified proteins, respectively. Deglycosylation by using tunicamycin in culture medium resulted in higher fibrinolytic activity of SAK-2RGD-TTI (2.2 fold). Consequently, compared to the rSAK, at the same equimolar proportion, addition of RGD and TTI fragments could increase fibrinolytic activity. Also, P. pastoris can be considered as an efficient host for overexpression of the soluble SAK-2RGD-TTI with high activity without requiring a complicated purification procedure.     

Magnetoelectric nanocomposite scaffold for high yield differentiation of mesenchymal stem cells to neural-like cells

While the differentiation factors have been widely used to differentiate mesenchymal stem cells (MSCs) into various cell types, they can cause harm at the same time. Therefore, it is beneficial to propose methods to differentiate MSCs without factors. Herein, magnetoelectric (ME) nanofibers were synthesized as the scaffold for the growth of MSCs and their differentiation into neural cells without factors. This nanocomposite takes the advantage of the synergies of the magnetostrictive filler, CoFe₂O ₄ nanoparticles (CFO), and piezoelectric polymer, polyvinylidene difluoride (PVDF). Graphene oxide nanosheets were decorated with CFO nanoparticles for a proper dispersion in the polymer through a hydrothermal process. After that, the piezoelectric PVDF polymer, which contained the magnetic nanoparticles, underwent the electrospun process to form ME nanofibers, the ME property of which has the potential to be used in areas such as tissue engineering, biosensors, and actuators.