Effects of Artemisia annua L. (Asteracea) on nutritional physiology and enzyme activities of elm leaf beetle, Xanthogaleruca luteola Mull. (Coleoptera: Chrysomellidae)

Methanolic extract of Artemisia annua L., a weed collected around paddy fields in north of Iran, was investigated for its toxic effects on: feeding, growth, fecundity, fertility including the biochemical characteristics of elm leaf beetle Xanthogaleruca luteola Mull. The toxicity tests indicate that insecticidal effect was 2.4-fold higher in 3rd instar larvae than in adults. The LC₅₀ was 48% and 43.77% of a methanolic leaf extract at 24 and 48 h, respectively. The feeding deterrence was highest at 10% concentration and lowest at 0.625% for 3rd instar larvae and adults during the first 24 h and decreased thereafter. Larval duration significantly increased at higher concentrations. Larval treatment with 10% methanolic extract resulted in deformed adults (adultoids) with drastic changes in gross morphology of female reproductive system. Food digestion and assimilation significantly decreased in adults. Larval duration and adult fecundity and fertility were also significantly reduced. Twenty-four hours after treating 3rd instar larva with the extract the levels of glucose, protein, urea, uric acid, α-amylase, alkaline phosphatase, alanine amino transferase and aspartate amino transferase significantly changed. However, at 48 h the extract lost its potency. The extract did not effect the level of cholesterol in treated larva. These results indicate that Artemisia annua L. extract contains inhibitors of key metabolic pathways that may be useful in future control of the elm leaf beetle.     

Adsorption of Cationic Dyes on a Magnetic 3D Spongin Scaffold with Nano-Sized Fe3O4 Cores

The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe₃O₄ cores is reported here for the first time. The formation of this magnetic spongin–Fe₃O₄ composite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) (TGA-DTA), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyses. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of well-dispersed spherical nanoparticles tightly bound to the spongin scaffold. The magnetic spongin–Fe₃O₄ composite showed significant removal efficiency for two cationic dyes (i.e., crystal violet (CV) and methylene blue (MB)). Adsorption experiments revealed that the prepared material is a fast, high-capacity (77 mg/g), yet selective adsorbent for MB. This behavior was attributed to the creation of strong electrostatic interactions between the spongin–Fe₃O₄ and MB or CV, which was reflected by adsorption mechanism evaluations. The adsorption of MB and CV was found to be a function of pH, with maximum removal performance being observed over a wide pH range (pH = 5.5–11). In this work, we combined Fe₃O₄ nanoparticles and spongin scaffold properties into one unique composite, named magnetic spongin scaffold, in our attempt to create a sustainable absorbent for organic wastewater treatment. The appropriative mechanism of adsorption of the cationic dyes on a magnetic 3D spongin scaffold is proposed. Removal of organic dyes and other contaminants is essential to ensure healthy water and prevent various diseases. On the other hand, in many cases, dyes are used as models to demonstrate the adsorption properties of nanostructures. Due to the good absorption properties of magnetic spongin, it can be proposed as a green and uncomplicated adsorbent for the removal of different organic contaminants and, furthermore, as a carrier in drug delivery applications.     

Proteolytic enzymes reactions on wool yarn and surfactants effects on the enzyme treatment

In this study, the effects of enzymes on wool yarn in the presence of different salts (ammonium sulfate, sodium tetraborate, and di-sodium hydrogen phosphate) were investigated. Alcalase 2,5 LDX and Savinase 16 LEX were selected as proteolytic enzymes. In addition, the effects of surfactants (Sandozin NRW, Irgasol NA, Erkantol NR, and Sandozin EH) on the enzyme treatment of wool yarn were evaluated. The results indicated that the effects of enzymes on wool yarn were greatest in the presence of sodium tetraborate. Furthermore, the properties of wool yarn such as weight loss, strength loss, and hairiness were influenced by these surfactants. The SEM images of the treated samples confirmed the obtained results.     

Interaction of phosphodiesterase 5 inhibitor with malathion on rat brain mitochondrial-bound hexokinase activity

The main objective of this study was to investigate the possible protective effect of pentoxifylline as a phosphodiesterase 5 inhibitor used as a cardiovascular medication on malathion-induced changes on rat mitochondrial-bound hexokinase activity.Animals in four various groups received moderate toxic dose of malathion (200 mg/kg/day), effective dose of pentoxifylline (50 mg/kg/day) alone and in combination, and the control group that received only vehicle. All administrations were done intraperitoneally for one week. At the end of the experiment, the brain was removed and the mitochondria were isolated. Hexokinase (HK) activity, cellular lipid peroxidation (LPO) and total antioxidant capacity (TAC) were analyzed in brain mitochondria.Malathion noticeably decreased TAC and increased HK activity and LPO in the mitochondria whereas pentoxifylline significantly restored malathion-induced changes in LPO, HK, and TAC.The results of the present study indicate that phosphodiesterase 5 inhibition remarkably protects brain mitochondria from malathion-induced changes on HK activity and oxidative stress.     

Effect of ovariectomy on reference memory version of Morris water maze in young adult rats

Background: The effect of ovariectomy and accompanying sudden loss of circulating gonad hormones on spatial learning performance in the young adult rats was examined. We hypothesized that spatial learning and memory in a considerable number of women who undergo a surgical menopause and estrogen deprivation before their natural menopause be impaired. Methods: In this study, we used 26 Wistar rats (approximately five months of age) and divided them into two groups: intact and ovariectomized (OVX). They were tested for spatial reference memory in Morris water maze 6 weeks after OVX. Results: The results showed that the performance of OVX group in the water maze was significantly lower than the control group. Although, mean path length decreased across blocks in both groups, OVX rats had significantly longer path length than controls across blocks 2-6 (P<0.05). OVX rats had lower percent of total time spent in target quarter than controls in probe trials (P<0.05). Body weight gain was significant only in OVX group during the experiment (P<0.05). Plasma estrogen significantly decreased after OVX (P<0.05). Conclusion: This finding provides further evidence for the role of estrogen, a gonadal steroid hormone, in the manipulation of functions related to learning and memory. It is suggested that estrogen loss following OVX impaired spatial reference memory in young adult rats. Our results suggest that it is necessary to protect women who undergo a surgical menopause before their natural menopause from cognition impairments.     

Practical methods for increasing light interception efficiency and root growth in soybean

Determining the effect of different sources of nitrogen and weeds on two varieties of soybean, an experiment was conducted out at research station of Tabriz University, Iran. Treatments were two varieties (Williams and Harcor), four nitrogen levels (two levels of symbiotic bacteria and two levels of urea) and weeds (with and without control). Results showed that three various factors can significantly change the Photosynthetically Active Radiation (PAR) amount at different layers of canopy. Solar radiation decreased in a vertical profile of canopy because of increasing Leaf Area Index (LAI). At the bottom level of canopy only 6% of total arrived PAR was recorded. Increasing LAI caused a sharp decrease in Light Interception Efficiency (LIE) in the canopy. Weeds significantly affected root nodules in dry and fresh weights. So, in weedy condition of soybean canopy, accumulation of dry matter decreases due to decline in LIE. On the other hand, weeds can strongly affect on nodules activity and decrease potential of nitrogen fixation by symbiosis bacteria.     

Ileal relaxation induced by Mentha longifolia (L.) leaf extract in rat

The effect of Mentha longifolia (L.) leaf hydroalcoholic extract (MLE) was examined on rat ileal smooth muscle contractions. Last portion of ileum from male adult Wistar rat was mounted in an organ bath containing Tyrode solution. The tissue was contracted by carbachol (CCh, 10 microM), KCl (60 mM) and BaC12 (4 mM) and then MLE (0.0625-1 mg mL(-1)) was added to the bath cumulatively. The effect of MLE on KCl-induced contraction was examined after tissue incubation with propranolol (1 microM), naloxone (1 microM) and N omega-nitro-L-arginine methyl ester (L-NAME, 100 microM). The effect of MLE on CaCl2-induced ileal contraction in Ca(2+)-free with high potassium Tyrode solution was also evaluated. The role of potassium channels was examined by ileum incubation (5 mim) with tetraethylammonium (TEA, 1 mM). The results showed that KCl-, CCh and BaCl2-induced ileal contractions were inhibited (p < 0.001) by cumulative concentrations of MLE with the same potency. In addition, MLE (0.25-1 mg mL(-1)) inhibited (p < 0.01) ileal contractions induced by CaCl2 (0.45-2.7 mM) in a concentration-related manner. The antispasmodic effect of MLE was affected neither by propranolol, L-NAME nor by naloxone. The MLE concentration-response curve was shifted to the right (p < 0.05) by tissue incubation with TEA. From results it may be suggested that Mentha longifolia hydroalcoholic leaf extract induces its spasmolytic activity mainly through disturbance in calcium mobilization and partly by potassium channels activation. Present results show that Mentha longifolia leaf extract exerts relaxant effects on intestinal smooth muscle, consistent with the traditional use of the plant to treat gastrointestinal disorders such as diarrhea and colic.     

Use of Selection Indices Based on Multivariate Analysis for Improving Grain Yield in Rice

In order to study selection indices for improving rice grain yield, a cross was made between an Iranian traditional rice (Oryza sativa L.) variety, Tarommahalli and an improved indica rice variety, Khazar in 2006. The traits of the parents (30 plants), F1 (30 plants) and F2 generations (492 individuals) were evaluated at the Rice Research institute of Iran (RRII) during 2007. Heritabilities of the number of panicles per plant, plant height, days to heading and panicle exsertion were greater than that of grain yield. The selection indices were developed using the results of multivariate analysis. To evaluate selection strategies to maximize grain yield, 14 selection indices were calculated based on two methods (optimum and base) and combinations of 12 traits with various economic weights. Results of selection indices showed that selection for grain weight, number of panicles per plant and panicle length by using their phenotypic and/or genotypic direct effects (path coefficient) as economic weights should serve as an effective selection criterion for using either the optimum or base index.     

Effect of chronic intracerebroventricluar administration of lipopolysaccharide on connexin43 protein expression in rat hippocampus

Background: Hippocampal damages, which are accompanied by inflammation, are among the main causes of epilepsy acquisition. We previously reported that chronic intracerebroventricular (i.c.v.) injection of lipopolysaccharide (LPS) modulates epileptogenesis in rats. There is a network of gap junction channels in the hippocampus that contribute to epileptogenesis. Gap junction channels are formed by oligomeric protein subunits called connexins (Cx). Astrocytic Cx43 and neuronal Cx36 are expressed in the hippocampus. In order to find out the possible role of gap junctions in seizure-modulating effect of LPS and neuroinflammation, we studied the effect of central administration of LPS on expression of Cx36 and Cx43 in rat hippocampus. Methods: LPS, 2.5 µg/rat/day, was injected i.c.v. to male Wistar rats for 14 days. mRNA and protein abundance of Cx36, Cx43 and IL1-β were measured in rat hippocampus by real time-PCR, Western blot and ELISA techniques, at the beginning, in the middle, and at the end of the treatment period. Results: IL1-β protein level was significantly increased 6 h after first injection of LPS. Cx36 and Cx43 mRNA expression did not alter during chronic administration of LPS. A selective decrease in Cx43 protein expression was observed after 7 injections of LPS. Conclusion: It is suggested that Cx43 containing gap junctions in the hippocampus is down-regulated in response to chronic injection of LPS. This event can inhibit propagation of toxic and noxious molecules to neighboring cells and modulate hippocampal excitability and epileptogenesis. Key Words: Connexin36 (Cx36), Connexin43 (Cx43), Interleukin-1β (IL1-β )     

Electrodeposition of homogeneous and adherent polypyrrole/Na<Superscript>+</Superscript>-cloisite nanocomposite on iron electrodes

In this work homogeneous and adherent nanocomposite of polypyrrole (PPY) with Na⁺-Cloisite nanoclays was successfully prepared by insitu electropolymerization of pyrrole monomer in the presence of Na⁺-Cloisite nanoclays. Formation of nanocomposite and incorporation of nanoclays in polypyrrole matrix was endorsed and characterized by FTIR spectroscopy studies, X-ray diffraction (XRD) pattern and scanning electron microscopy (SEM). The X-ray difraction patterns showed that PPY was intercalated between clay layers in the order of nanoscale. The morphology of the resulted nanocomposite was studied by scanning electron micrograph (SEM). Cyclic voltammetry experiments were carried out in different electrolytes and showed that nanocomposite is electroactive, while conductivity of the nanocomposite derived from four point probe technique indicated that the resulted nanocomposite is conductive. The anticorrosive properties of a thin layer coating of PPY/Na⁺-Cloisite nanocomposite on iron coupons was evaluated and compared with pure polypyrrole coating. According to the results in various corrosive environments PPY/Na⁺-Cloisite nanocomposite has enhanced corrosion protection effect in comparison to pure polypyrrole coating. It was observed that the corrosion protection effect was due to the dispersion of nanoclays in polymer matrix, which results in the increase in the corrosion potential and decrease in corrosion current and corrosion rate.