No abstract

Comparing macrophage-derived cytokine and nitric oxide (NO) profiles in type I and type II diabetes mellitus (DM); and determining whether thymoquinone (TQ) has any modulatory effect were the main objectives of the present study. Peritoneal macrophages have been collected from Otsuka Long-Evans Tokushima Fatty (OLETF) as a model for type II DM and its control Long-Evans Tokushima Otsuka (LETO) rats, as well as from streptozotocin (STZ)-injected LETO ones as a model for type I DM. The cells were cultured and incubated with or without TQ (10 microM) in the absence or presence of lipopolysaccharide (LPS; 1 microg/ml). The same parameters have been also assessed in sera of the used animals with or without TQ treatment (3 mg/kg) under both LPS-stimulated (10 mg/kg) and unstimulated conditions. Nitrite, IL-1beta and TNF-alpha were significantly higher in macrophage supernatants and sera of the acutely affected STZ-LETO rats either with or without LPS stimulation compared to corresponding controls. On the other hand, chronically diabetic OLETF rats' macrophage supernatants showed significant decreases of IL-1beta and TNF-alpha levels upon LPS stimulation or even without stimulation (IL-1beta); and insignificant increase in nitrite concentration, which turned significant upon LPS stimulation. Sera of these animals, however, showed significant increase in TNF-alpha level. TQ normalised the elevated nitrite and cytokine profiles both in vitro and in vivo, yet had no significant effect on the already decreased parameters in chronically affected OLETF rats. These data suggest that there is a tendency for macrophage inflammatory products to increase in acute type I and to decrease in chronic type II DM; and that TQ has the potential to normalise the elevated levels of these macrophage-derived inflammatory mediators.

No abstract

1 The object of the present study was to clarify the neurotransmitters controlling membrane responses to electrical field stimulation (EFS) in the longitudinal smooth muscle cells of the chicken anterior mesenteric artery. 2 EFS (5 pulses at 20 Hz) evoked a depolarization of amplitude 19.772.1 mV, total duration 29.673.1 s and latency 413.0767.8 ms. This depolarization was tetrodotoxin (TTX)-sensitive and its amplitude was partially decreased by atropine (0.5 mM); however, its duration was shortened by further addition of prazosin (10 mM). 3 Atropine/prazosin-resistant component was blocked by the nonspecific purinergic antagonist, suramin, in a dose-dependent manner, indicating that this component is mediated by the neurotransmitter adenosine 5 0 -triphosphate (ATP).4 Neither desensitization nor blocking of P2X receptor with its putative receptor agonist a,bmethylene ATP (a,b-MeATP, 1 mM) and its antagonist pyridoxalphosphate-6-azophenyl-2 0 ,4 0 -disulfonic (PPADS, up to 50 mM), had significant effect on the purinergic depolarization. In contrast, either desensitization or blocking of P2Y receptor with its putative agonist 2-methylthioATP (2-MeSATP, 1 mM) and its antagonist Cibacron blue F3GA (CBF3GA, 10 mM) abolished the purinergic depolarization, indicating that this response is mediated through P2Y but not P2X receptor. 5 The purinergic depolarization was inhibited by pertussis toxin (PTX, 600 ng ml À1). Furthermore, it was significantly inhibited by a phospholipase C (PLC) inhibitor, U-73122 (10 mM), indicating that the receptors involved in mediating the purinergic depolarization are linked to a PTX-sensitive G-protein, which is involved in a PLC-mediated signaling pathway. 6 Data of the present study suggest that the EFS-induced excitatory membrane response occurring in the longitudinal smooth muscle of the chicken anterior mesenteric artery is mainly purinergic in nature and is mediated via P2Y purinoceptors.

This study was designed to provide laboratory evidence supporting the hematopoietic effect of Beta vulgaris (beet) leaf aqueous extract in phenylhydrazine-induced anemia model in albino rats. Extraction of the leaves/stalks was done by maceration in 30% hydro-ethanol for 48 h. An intraperitoneal injection of 20 mg/kg phenylhydrazine was applied for two consecutive days to develop hemolytic anemia on the 4th day after the 1st injection in 24 of 30 male albino rats. The animals were divided into 5 groups and received the following treatments: standard (ferrous ascorbate + folic acid; 13.5 + 0.135 mg/kg), B. vulgaris extract (100 and 200 mg/kg), or left untreated (normal and diseased controls). Blood samples were taken at 0, 4, 8, and 12 days of the experiment for hematological and clinico-chemical analysis. Beet leaf extract significantly restored the levels of red blood cells, white blood cells, hemoglobin, and hematocrit in dose- and time-dependent manners. Blood indices have been significantly corrected. Erythropoietin level was maintained at higher levels. Erythrocytic membrane oxidation biomarker (malondialdehyde) level was significantly reduced compared to the anemic untreated group. The extract exhibited potent, concentration (4–512 μg/mL)-dependent antioxidant activity indicated by the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, with IC50 value of 37.91 μg/mL. Beet leaf extract resulted in detection of flavonoid and phenolic compounds that may underlie its hematinic properties. These findings may indicate B. vulgaris as a good natural source for pharmaceutical preparations with hematopoietic effects and treatment of anemia and/or associated conditions.

No abstract

Rotavirus non-structural protein (NSP) 4 can induce aqueous secretion in the gastrointestinal tract of neonatal mice through activation of an age-and Ca 2+ -dependent plasma membrane anion permeability. Accumulating evidence suggests that nitric oxide (NO) plays a role in the modulation of aqueous secretion and the barrier function of intestinal cells. This study investigated transcriptional changes in inducible NO synthase (iNOS), an enzyme responsible for NO production, after rotavirus infection in mice and after treatment of intestinal cells with NSP4. Diarrhoea was observed in 5-day-old CD-1 mice from days 1 to 3 after inoculation with 10 7 focus-forming units of different rotavirus strains. Ileal iNOS mRNA expression was induced as early as 6 h post-inoculation, before the onset of clinical diarrhoea in infected mice, and was upregulated during the course of rotavirus-induced diarrhoea. Ex vivo treatment of ilea excised from CD-1 suckling mice with NSP4 resulted in upregulation of ileal iNOS mRNA expression within 4 h. Furthermore, NSP4 was able to induce iNOS expression and NO production in murine peritoneal macrophages and RAW264.7 cells. The specificity of NSP4 inducibility was confirmed by the inhibitory effect of anti-NSP4 serum. Using a series of truncated NSP4s, the domain responsible for iNOS induction in macrophages was mapped to the reported enterotoxin domain, aa 109-135. Thus, rotavirus infection induces ileal iNOS expression in vivo and rotavirus NSP4 also induces iNOS expression in the ileum and macrophages. Together, these findings suggest that NO plays a role in rotavirus-induced diarrhoea. INTRODUCTIONRotavirus, the most common mammalian enteric viral pathogen, exclusively infects differentiated epithelial cells of intestinal villi in infants and young animals (Kapikian & Chanock, 1990). Rotavirus infection in mammals is associated with blunting of the intestinal villi and mild infiltration of mononuclear cells in lamina propria (Greenberg et al., 1994). Rotavirus non-structural protein 4 (NSP4) and a synthetic peptide corresponding to aa ) have been shown to cause diarrhoea in suckling mice (Ball et al., 1996;Mori et al., 2002). NSP4 as a viral enterotoxin induces age-and Ca 2+ -dependent movement of halide ions across the plasma membrane in the initial cyclic nucleotide-independent pathway (Dong et al., 1997;Morris et al., 1999). Apart from the direct action of NSP4 on the mucosa at the onset of rotavirus diarrhoea, secondary mechanisms triggered by rotavirus replication and/or NSP4 are thought to sustain the diarrhoeal response. These mechanisms include mucosal destruction (Davidson & Barnes, 1979;Greenberg et al., 1994), villus ischaemia (Osborne et al., 1991), alteration of paracellular permeability and of expression of digestive enzymes (Jourdan et al., 1998;Dickman et al., 2000), and activation of the enteric nervous system (ENS) (Lundgren et al., 2000). The latter may explain how comparatively few infected cells at the villus tips can induce secretion of electrolytes and water fro...

The present study is aimed at utilization of novel and classical kidney function biomarkers to evaluate the nephroprotective potential of Carica papaya leaf extract (CPLE) in gentamicin nephrotoxicity model in albino rats. The used classical biomarkers were urea and creatinine; while the new biomarkers were Kidney injury molecule-1 (KIM-1) and Clusterin. Forty-five male albino rats were assigned into five groups and subjected to different treatments for nine consecutive days (vehicles; gentamicin, 100 mg/kg, subcutaneously; ascorbic acid, 200 mg/kg, orally; CPLE, 150 and 300 mg/kg b wt., orally). Three rats/group were killed on days 3, 6, and 9 for blood and tissue samples for renal and oxidation markers. Gentamicin resulted in significant increase in urea and creatinine only by the end of the experimental course; while the novel biomarkers were evident as early as 3 days upon gentamicin injection. When concurrently administered with gentamicin, CPLE significantly protected kidney tissues against gentamicin nephrotoxic effects indicated by decrement of both the novel and the classical standard biomarkers, in a dose-dependent manner. CPLE-mediated protection was attributed to its antioxidant potential indicated by significant inhibition of malondialdehyde (MDA) levels in both serum and kidney homogenates. The results were further supported by histopathological examination that revealed considerable amelioration of the pathological microscopic alterations induced by repeated gentamicin injection. Phytochemical analysis of CPLE indicated presence of tannins and flavonoids. These data may suggest CPLE, based on improvement of both classical and novel renal markers, as a highly potent nephroprotective and antioxidant from natural source that could be a good remedy in conditions associated with renal disorders.