Copper nanoparticles synthesized by polyol process used to control hematophagous parasites

The present study was based on assessments of the anti-parasitic activities of the hematophagous (blood feeding) larvae of malaria vector, Anopheles subpictus Grassi, filariasis vector, Culex quinquefasciatus, Say (Diptera: Culicidae), and the larvae of cattle tick Rhipicephalus (Boophilus) microplus, Canestrini (Acari: Ixodidae). The metallic copper nanoparticles (Cu NPs) synthesized by polyol process from copper acetate as precursor and Tween 80 were used as both the medium and the stabilizing reagent. The efficacy of synthesized Cu NPs was tested against the larvae of blood-sucking parasites. UV-vis spectra characterization was performed, and peak was observed at 575 nm, which is the characteristic to the surface plasmon bond of Cu NPs. The strong surface plasmon absorption band observed at 575 nm may be due to the formation of non-oxidized Cu NPs. X-ray diffraction (XRD) spectral data showed concentric rings corresponding to the 26.79 (111), 34.52 (200), and 70.40 (220) reflections. XRD spectrum of the copper nanoparticles exhibited 2θ values corresponding to the copper nanocrystal. No peaks of impurities are observed in XRD data. The scanning electron micrograph (SEM) showed structures of irregular polygonal, cylindrical shape, and the size range was found to be 35–80 nm. The size of the Cu NPs was measured by atomic force microscope (AFM) in non-contact mode. For imaging by AFM, the sample was suspended in acetone and spins coated on a silicon wafer. The line profile image was drawn by the XEI software and the horizontal line at 6 μm on a 2D AFM image. Research has demonstrated that metallic nanoparticles produce toxicity in aquatic organisms that is due largely to effects of particulates as opposed to release of dissolved ions. Copper acetate solution tested against the parasite larvae exposed to varying concentrations and the larval mortality was observed for 24 h. The larval percent mortality observed in synthesized Cu NPs were 36, 49, 75, 93,100; 32, 53, 63, 73, and 100 and 36, 47, 69, 88, 100 at 0.5, 1.0, 2.0, 4.0, and 8.0 mg/L against A. subpictus, C. quinquefasciatus and R. microplus, respectively. The larval percent mortality shown in copper acetate solution were 16, 45, 57, 66 and 100, 37, 58, 83, 87, and 100 and 41, 59, 79, 100, and 100 at 10, 20, 30, 40, and 50 mg/L against A. subpictus, C. quinquefasciatus, and R. microplus, respectively. The maximum efficacy was observed in Cu NPs and copper acetate solution against the larvae of A. subpictus, C. quinquefasciatus, and R. microplus with LC₅₀ and r ² values of 0.95 and 23.47, 1.01 and 15.24, and 1.06 and 14.14 mg/L with r ² = 0.766; 0.957 and 0.908; 0.946; and 0.816 and 0.945, respectively. The control (distilled water) showed nil mortality in the concurrent assay. The chi-square value was significant at p ≤ 0.05 level. This is the first report on anti-parasitic activity of the synthesized Cu NPs and copper acetate solution.     

Synaptotagmin I and IV are differentially regulated in the brain by the recreational drug 3,4-methylenedioxymethamphetamine (MDMA)

3,4-Methylenedioxymethamphetamine (MDMA or Ecstasy) is a widely abused drug. In brains of mice exposed to MDMA, we recently detected altered expression of several cDNAs and genes by using the differential display polymerase chain reaction (PCR) method. Expression of one such cDNA, which exhibited 98% sequence homology with the synaptic vesicle protein synaptotagmin IV, decreased 2 h after MDMA treatment. Herein, the effect of MDMA on expression of both synaptotagmin I and IV was studied in detail, since the two proteins are functionally interrelated. PCR analyses (semi-quantitative and real-time) confirmed that upon treatment with MDMA, expression of synaptotagmin IV decreased both in the midbrain and frontal cortex of mice. Decreases in the protein levels of synaptotagmin IV were confirmed by Western immunoblotting with anti-synaptotagmin IV antibodies. In contrast, the same exposure to MDMA increased expression of synaptotagmin I in the midbrain, a region rich in serotonergic neurons, but not in the frontal cortex. This differential expression was confirmed at the protein level with anti-synaptotagmin I antibodies. MDMA did not induce down- or up-regulation of synaptotagmin IV and I, respectively, in serotonin transporter knockout mice (-/-) that are not sensitive to MDMA. Therefore, psychoactive drugs, such as MDMA, appear to modulate expression of synaptic vesicle proteins, and possibly vesicle trafficking, in the brain.     

Antiulcerogenic activity of hydroalcoholic fruit extract of Pithecellobium dulce in different experimental ulcer models in rats

Ethnopharmacological relevance

The ethnopharmacological importance of Pithecellobium dulce is evidenced by its traditional use for gastric complications. The aim of the study is to evaluate the gastroprotective activity and the mechanism of action of hydroalcoholic fruit extract of P. dulce (HAEPD) in rats by using chemical and stress induced ulcer models.

Materials and methods

Gastric ulcer was induced by administering alcohol (or) acetylsalicylic acid (or) hypothermic restraint stress to rats pretreated with HAEPD (200 mg/kg b wt for 30 day). Volume of gastric fluid, pH, acidity, activities of pepsin, H⁺, K⁺-ATPase, myeloperoxidase, mucin content, nucleic acids, glycoproteins and prostaglandin E₂ (PGE₂) levels were assessed in gastric tissues.

Results

Ulcer score was significantly minimized in HAEPD administered animals. pH and acidity of gastric fluid were significantly minimized and the mucin, PGE₂ levels were significantly maintained in drug pre administered animals. The activities of H⁺, K⁺- ATPase and myeloperoxidase were found to be significantly elevated in ulcer control animals and found to be decreased in drug pretreated animals. The cell proliferation was found to be enhanced in drug received animals. The total protein bound carbohydrate to total protein ratio was found to be significantly maintained by HAEPD. The effects were found to be comparable with that of standard drug omeprazole.

Conclusion

It is concluded that HAEPD possess a potent antiulcer activity probably by acting as cytoprotective and antiacid secretory agent.     

Antihyperglycemic effect of the fruit-pulp of Eugenia jambolana in experimental diabetes mellitus

The oral antihyperglycemic effect of the water and ethanolic extracts of the fruit-pulp of Eugenia jambolana (EJ) was investigated in alloxan-induced diabetic with fasting blood glucose between 120 and 250 mg/dl as well as severely diabetic rabbits (fasting blood glucose above 250 mg/dl). Water extract was found to be more effective than the ethanolic extract in reducing fasting blood glucose and improving blood glucose in glucose tolerance test. Chromatographic purification of the water extract yielded not only two hypoglycaemic fractions (F-III more active than F-IV) but indicated the presence of hyperglycemic compounds (F-I and F-II) also in the water extract of Eugenia jambolana fruits. When administered as a single dose of 25 mg/kg of body weight; F-III could reduce fasting blood glucose from 174.0 +/- 4.6 to 137.3 +/- 5.4 mg/dl in diabetic (21% fall) and from 266.0 +/- 5.4 to 202.2 +/- 5.2 mg/dl in severely diabetic rabbits (24% fall). After treatment of diabetic and severely diabetic rabbits daily once with 25mg/kg, body weight with F-III for 7 and 15 days, respectively, there was fall in fasting blood glucose (38% diabetic; 48% severely diabetic) and improvement in blood glucose during glucose tolerance test (48%) in diabetic rabbits. Further, there was increase in the plasma insulin levels in both diabetic (24.4%) and severely diabetic rabbits (26.3%). The in vitro studies with pancreatic islets showed that the insulin release was nearly two and half times more than that in untreated diabetic rabbits. The mechanism of action of FIII fraction appears to be both pancreatic by stimulating release of insulin and extra pancreatic by directly acting on the tissues.     

Diabetes impairs hippocampal function through glucocorticoid-mediated effects on new and mature neurons

Many organ systems are adversely affected by diabetes, including the brain, which undergoes changes that may increase the risk of cognitive decline. Although diabetes influences the hypothalamic-pituitary-adrenal axis, the role of this neuroendocrine system in diabetes-induced cognitive dysfunction remains unexplored. Here we demonstrate that, in both insulin-deficient rats and insulin-resistant mice, diabetes impairs hippocampus-dependent memory, perforant path synaptic plasticity and adult neurogenesis, and the adrenal steroid corticosterone contributes to these adverse effects. Rats treated with streptozocin have reduced insulin and show hyperglycemia, increased corticosterone, and impairments in hippocampal neurogenesis, synaptic plasticity and learning. Similar deficits are observed in db/db mice, which are characterized by insulin resistance, elevated corticosterone and obesity. Changes in hippocampal plasticity and function in both models are reversed when normal physiological levels of corticosterone are maintained, suggesting that cognitive impairment in diabetes may result from glucocorticoid-mediated deficits in neurogenesis and synaptic plasticity.     

Palmar Type of Median Artery as a Source of Superficial Palmar Arch: A Cadaveric Study with Its Clinical Significance

The superficial palmar arch (SPA) and its contributing arteries are highly variable. The palmar type of median artery (PMA) can be involved in the formation of the SPA by replacing the superficial palmar branch of the radial artery (RA) or the ulnar artery (UA). The present study was undertaken to investigate the presence of the PMA and its contribution in the formation of SPA in 42 cadavers (84 upper limbs) of Indian origin. When there was a PMA, its outer diameter was measured in the carpal tunnel. The PMA was found in 13 upper limbs (15.4%), and of these ten incidences (11.9%), the PMA took part in the formation of SPA, and in three instances (3.5%), the PMA did not make up part of the SPA. Out of the ten cases in which the PMA contributed to the formation of SPA, in six cases (7.1%), the PMA anastomosed with the UA; in three cases (3.5%), the PMA anastomosed with both the UA and the RA, and in one incidence (1.1%), the PMA joined the arteria radialis indicis (deep branch of the RA) to complete the SPA. The outer diameters of the median arteries varied between 0.8 and 2.6 mm with the mean value of 1.7 mm. The present study concludes that the median–ulnar type of SPA was the most common type of SPA when the PMA was encountered as a source of superficial arterial arcade of the hand, followed by the radial–median–ulnar type. The vascular patterns found in this study are important to hand surgeons. The present study of PMA origin, course, and its contribution to the SPA will add to the existing knowledge of the vascular anatomy of forearm and hand.     

Mutagenesis studies of the major benzo[a]pyrene N2-dG adduct in a 5'-TG versus a 5'-UG sequence: removal of the methyl group causes a modest decrease in the [G->T/G->A] mutational ratio

The potent mutagen/carcinogen benzo[a]pyrene (B[a]P) is metabolically activated to (+)-anti-B[a]PDE, which induces a full spectrum of mutations primarily at the G:C base pairs (e.g. GC-->TA, GC-->AT, etc.). Each of these mutations can be induced by its major adduct [+ta]-B[a]P-N(2)-dG, where DNA sequence context appears to influence both the quantitative and qualitative pattern of mutagenesis. We noted previously that 5'-TG sequences tend to have a higher fraction of G-->T mutations for both [+ta]-B[a]P-N(2)-dG and (+)-anti-B[a]PDE in comparison with 5'-CG, 5'-GG or 5'-AG sequences. To investigate a possible structural element for this trend, the role (if any) of the methyl group on the 5'-T is considered. Using adduct site-specific means, the [G-->T/G-->A] mutational ratio for [+ta]-B[a]P-N(2)-dG is determined to be approximately 1.08 in a 5'-TGT sequence, and approximately 0.60 in a 5'-UGT sequence. (G-->C mutations are minor.) Although this modest approximately 1.8-fold decrease in [G-->T/G-->A] ratio is statistically significant (P = 0.03), it suggests that the methyl group on the 5'-T is not the main reason why a 5'-T tends to enhance G-->T mutations. This study was prompted by an adduct conformational hypothesis, which predicted that the removal of the methyl group in a 5'-TG sequence would lower the fraction of G-->T mutations; however, the approximately 1.8-fold decrease is too small to do additional experiments to assess whether this conformational hypothesis, or other hypotheses, are the true cause of the decrease, which is discussed in this paper.     

Toll-like receptor 2 mediates inflammatory cytokine induction but not sensitization for liver injury by Propioni- bacterium acnes

Recognition of Gram-positive bacteria by Toll-like receptor 2 (TLR2) induces activation of proinflammatory pathways. In mice, sensitization with the Gram-positive Propionibacterium acnes followed by a challenge with the TLR4 ligand, lipopolysaccharide (LPS), results in fulminant hepatic failure. Here, we investigated the role of TLR2 in liver sensitization to LPS-induced injury. Stimulation of Chinese hamster ovary cells and peritoneal macrophages with heat-killed P. acnes required expression of TLR2 but not of TLR4, suggesting that P. acnes was a TLR2 ligand. Cell activation by P. acnes was myeloid differentiation primary-response protein 88 (MyD88)-dependent, and it was augmented by coexpression of CD14 in mouse peritoneal macrophages. In vitro, P. acnes behaved as a TLR2 ligand and induced TLR4 hetero- and TLR2 homotolerance in peritoneal macrophages. In vivo priming of wild-type mice with P. acnes, but not with the selective TLR2 ligands peptidoglycan and lipotheicoic acid, resulted in hepatocyte necrosis, hyperelevated serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, interferon-gamma (IFN-gamma), and IL-12 (p40/p70), and increased RNA expression of proinflammatory cytokines (IL-12p40, IL-1alpha, IL-6, IL-1beta, IL-18, IFN-gamma) in the liver after a LPS challenge. Furthermore, P. acnes priming sensitized TLR2-deficient (TLR2-/-) but not MyD88-/- mice to LPS-induced injury, evidenced by hepatocyte necrosis, increased levels of serum TNF-alpha, IFN-gamma, IL-6, and liver proinflammatory cytokine mRNA expression. IFN-gamma, a cytokine sensitizing to endotoxin, was induced by P. acnes in splenocytes of TLR2-/- and TLR9-/- but not MyD88-/- mice. These results suggest that although P. acnes triggers TLR2-mediated cell activation, TLR2-independent but MyD88-dependent mechanisms mediate in vivo sensitization by P. acnes for LPS-induced liver injury.