<Emphasis Type="Italic">Teucrium polium</Emphasis> Complex with Molybdate Enhance Cultured Islets Secretory Function

Islet transplantation has become a promising treatment in the therapy of type 1 diabetes. Its function improvement, after isolation and before transplantation, is crucial because of their loss both in number and function of islets after isolation procedures. Trace elements sodium orthovanadate (SOV) and sodium molybdate (SM), as well as medicinal plant Teucrium polium L. (TP), showed and possessed high beneficial antioxidative potential and even hypoglycemic properties via their effect on islets. We evaluated the effect of these components in combination on cultured islet function in order to improve pancreatic islet transplantation. Rat pancreatic islets were cultured for 24 h then incubated with different concentrations of TP (0.01 and 0.1 mg/mL) alone and in combination with SOV (1 mM) or SM (1 mM). Insulin concentration in buffer media was measured as islet secretory function. Administration of TP (0.01 mg/mL), SM, and SOV alone or in combination with each other significantly increased insulin secretion at high glucose concentration (16.7 mM); insulin secretion was significantly greater in the group containing both TP and SM than other treated groups (p < 0.05). The combination of the mentioned trace elements especially molybdate with TP could improve islet cells function before transplantation.     

Tail-associated structural protein gp61 of Staphylococcus aureus phage φMR11 has bifunctional lytic activity

A tailed bacteriophage, φMR11 (siphovirus), was selected as a candidate therapeutic phage against Staphylococcus aureus infections. Gene 61, one of the 67 ORFs identified, is located in the morphogenic module. The gene product (gp61) has lytic domains homologous to CHAP (corresponding to an amidase function) at its N-terminus and lysozyme subfamily 2 (LYZ2) at its C-terminus. Each domain of gp61 was purified as a recombinant protein. Both the amidase [amino acids (aa) 1–150] and the lysozyme (aa 401–624) domains but not the linker domain (aa 151–400) caused efficient lysis of S . aureus . Immunoelectron microscopy localized gp61 to the tail tip of the φMR11 phage. These data strongly suggest that gp61 is a tail-associated lytic factor involved in local cell-wall degradation, allowing the subsequent injection of φMR11 DNA into the host cytoplasm. Staphylococcus aureus lysogenized with φMR11 was also lysed by both proteins. Staphylococcus aureus strains on which φMR11 phage can only produce spots but not plaques were also lysed by each protein, indicating that gp61 may be involved in 'lysis from without'. This is the first report of the presence of a tail-associated virion protein that acts as a lysin, in an S. aureus phage.     

Towards the mechanism and comparative effect of diphenyl diselenide, diphenyl ditelluride and ebselen under various pathophysiological conditions in rat's kidney preparation

As an extension of our previous work we not only evaluated the relationship between acidosis and lipid peroxidation in rat's kidney homogenate, but also determined for the first time the potential anti-oxidant activity of diphenyl diselenide, diphenyl ditelluride and ebselen at a range of pH values (7.4–5.4). Because of the pH dependency of iron redox cycling, pH and iron need to be well controlled and for the reason we tested a number of pH values (from 7.4 to 5.4) to get a closer idea about the role of iron under various pathological conditions. Acidosis increased rate of lipid peroxidation in the absence Fe (II) in kidney homogenates especially at pH 5.4. This higher extent of lipid peroxidation can be explained by; the mobilized iron which may come from reserves where it is weakly bound. Addition of iron (Fe) chelator desferoxamine (DFO) to reaction medium completely inhibited the peroxidation processes at all studied pH values including acidic values (5.8–5.4). In the presence of Fe (II) acidosis also enhanced detrimental effect of Fe (II) especially at pH (6.4–5.4). Diphenyl diselenide significantly protected lipid peroxidation at all studied pH values, while ebselen offered only a small statistically non-significant protection. The highest anti-oxidant potency was observed for diphenyl ditelluride. These differences in potencies were explained by the mode of action of these compounds using their catalytic anti-oxidant cycles. However, changing the pH of the reaction medium did not alter the anti-oxidant activity of the tested compounds. This study provides evidence for acidosis catalyzed oxidative stress in kidney homogenate and for the first time anti-oxidant potential of diphenyl diselenide and diphenyl ditelluride not only at physiological pH but also at a range of acidic values.     

Photochemical covalent binding of urocanic acid to polynucleic acids

Photolysis of E-[ring-2-14C]urocanic acid (UA) with native or denatured calf thymus DNA leads to covalent binding of the radiolabel to the nucleic acid. A similar observation is made upon photolysis of the labeled UA with the polyribonucleotides, in which case a strong preference is observed for binding to poly[U]. DNA or poly[U], which had been reacted with UA and purified by dialysis and multiple precipitations, releases UA upon further irradiation with 254 nm light (as expected for cyclobutane adducts). Quantum efficiencies for binding of the UA to native DNA have been measured at 308 and 266 nm and are 0.30 x 10(-5) and 1.3 x 10(-4), respectively, at comparable reactant concentrations. The large increase at the shorter wavelength (where DNA absorption is more competitive) is taken as evidence for the primary role of a DNA excited state in initiating the binding reaction(s).     

Effect of Foliar Application of Silicon and Salicylic Acid on Regulation of Yield and Nutritional Responses of Greenhouse Cucumber Under High Temperature

Plant nutrition management is known as an efficient strategy to control environmental constraints. This experiment was conducted in a climate control greenhouse with a hydroponic system. The high temperature (36 °C?±?1) was imposed on the pots after fruit formation. The studied factors were silicon in 2 concentrations (0 and 4 parts per thousand (ppt)) and salicylic acid in 3 concentrations (0, 0.5, and 1 mM). They were sprayed on cucumber plants 3 times and under high-temperature conditions to evaluate if they can regulate and improve the yield and quality of cucumber fruit under high-temperature conditions or not. The results showed that all treatments significantly improved the nutritional status, total yield, and fruit quality (including marketable yield (i.e., fruits that can be sold due to their good shape) and nitrate content). Under high-temperature conditions, foliar application of silicon had the highest effect on the increase of total yield and marketable fruit yield (respectively, 36.14% and 40.29% increase compared to the control treatment). Micro-nutrients concentrations in the leaf were significantly increased by Si but a reverse status happened for salicylic acid. Under high temperatures, both treatments also significantly decreased the nitrate content of the fresh matter of fruit but silicon was the superior treatment. Silicon and salicylic acid, respectively, had positive effects on mitigation of adverse effects of high temperature on cucumber plants. These findings suggest the use of these treatments under high-temperature conditions in greenhouse cucumber production.

Graphical Abstract

N–No₃ content in dry matter of leaf (left) and fresh matter of fruit (right) affected by different treatments. *SaA0–SiA4: 4 ppt Si; SaA0.5–SiA0: 0.5 mM SA; SaA0.5–SiA4: 0.5 mM SA?+?4 ppt Si; SaA1–SiA0: 1 mM SA; SaA1–SiA4: 1 mM SA?+?4 ppt Si; control: without any SA and Si applications. Means in the same column followed by the same letter are not significantly different according to DMRT at (P?≤?0.05)

     

Macrophylloside, a flavone glucoside from Primula macrophylla

A new flavone glucoside macrophylloside has been isolated from the whole plant of Primula macrophylla and its structure was determined by spectroscopic methods as 2′-hydroxy-7-O-β- -glucopyranosyloxyflavone. Sitosterol glucoside was also isolated for the first time from this plant.