Vascular Permeability In Rats Research Articles

Notoginsenoside R2 induces colonic microvascular injuries via regulating the Rap1GAP/PI3K/Akt signaling pathway.

BackgroundNotoginsenoside R2 (NGR2) is an important active saponin molecule of Panax Notoginseng (PN), but its effect on regulating angiogenesis is unclear. Here, we investigated the role of NGR2 in angiogenesis in vivo and in vitro.MethodsNGR2 was administered to rats by intragastric administration for 7 days. The colonic histopathology and microvessel density (MVD) were observed and evaluated under an inverted microscope. The colonic mucosal permeability (MP) and vascular permeability (VP) were evaluated by measuring the transmittance of FD-4 and the vascular leakage of Evans blue, respectively. The serum IL-2, TNF-ɑ, IL-4, IL-10, VEGFA165, and VEGFA121 levels were detected with ELISA. In vitro, pHUVECs were cultured and treated with NGR2. The mechanism of NGR2 in angiogenesis was assessed by VEGFA165, LY294002, silencing, and overexpression plasmids of Rap1GAP in vitro. The cell viability, cell proliferation, tube formation, and concentration of intracellular pyruvate and lactic acid of pHUVECs were measured after 24 h. The expression of proteins was detected with western blotting.ResultsNGR2 could significantly induce inflammatory injuries in the colonic mucosa and microvessels. Both MP and VP in rats treated with NGR2 increased in proportion to the serum VEGFA165 and VEGFA121 level, the ratio of VEGFA165/VEGFA121, and the concentration of intracellular pyruvate and lactic acid. In vitro, NGR2 reduced cell viability, proliferation, and tube formation, and enhanced the intracellular glycolysis of pHUVECs. Furthermore, the cell viability, proliferation, and tube formation of pHUVECs were inhibited by NGR2 via blocking the Rap1GAP/PI3K/Akt signaling pathway.ConclusionsNGR2 could induce colonic mucosal microvascular injuries and promoted the intracellular glycolysis of pHUVECs via blocking the Rap1GAP/PI3K/Akt signaling pathway.

An engineered tetra-valent antibody fully activates the Tie2 receptor with comparable potency to its natural ligand angiopoietin-1

Activation of the tyrosine kinase with Ig and epidermal growth factor homology domain 2 (Tie2) receptor by angiopoietin-1 (Ang1) is critical for vascular stabilization: it promotes survival signal transduction via auto-phosphorylation and reduces vascular permeability by strengthening tight junctions between endothelial cells. Thus, Tie2/Ang1 signaling is a promising therapeutic target for vascular diseases. However, in vivo use of existing Tie2 signaling modulators, such as recombinant Ang1, is restricted by limitations in manufacturability and stability. Here, we present a novel engineered tetra-valent agonistic antibody, ASP4021, which can specifically and fully activate the Tie2 receptor in an equivalent manner to Ang1. ASP4021 induced Tie2 self-phosphorylation and inhibited apoptosis in a human primary endothelial cell line. Additionally, single administration of ASP4021 significantly suppressed mustard-oil-induced vascular permeability in rats. ASP4021 may thus be a potential therapeutic candidate for diseases associated with vascular weakness such as diabetic retinopathy, diabetic macular edema and critical limb ischemia.

Evaluation of analgesic and anti-inflammatory activities and molecular docking analysis of steroidal lactones from Datura stramonium L.

BackgroundDatura stramonium L. is widely used across the world for its therapeutic potential to treat inflammatory disorders. The current work was designed to isolate and identify steroidal lactones from D. stramonium leaves and evaluate their anti-inflammatory and analgesic properties. MethodsSeveral compounds were isolated from D. stramonium leaves and characterized by nuclear magnetic resonance and high-resonance electron spray ionization mass spectrometry techniques. Further, anti-inflammatory properties of these compounds were evaluated by in vitro assays, such as release of NO and pro-inflammatory cytokines by lipopolysaccharide (LPS)-activated J774A.1 macrophages. Using in vivo models, anti-inflammatory and analgesic effects were examined by mouse tail-flick, carrageenan-induced inflammation in rat paw model, vascular permeability in rats, and acetic acid-induced writhing in mice. The docking studies were performed for assessing the binding efficiency of the test compounds with cyclooxygenase-1 (COX-1) and COX-2, lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), inducible nitric oxide synthases (iNOS) and nuclear factor-κB (NF-κB). ResultsThree lactones were isolated and confirmed as daturalactone (D1), 12-deoxywithastramonolide (D23), and daturilin (D27). Further, the isolated compounds showed nitric oxide inhibition and pro-inflammatory cytokines released by LPS-activated J774A.1 macrophages. The in vivo results suggest that D1, D23 and D27 (20 mg/kg) were able to reduce the pain and inflammation in various animal models. The docking analysis showed that these three compounds actively bind with COX-1, COX-2, LOX-1, NF-κB, and iNOS, validating the anti-inflammatory effects of the lactones. ConclusionThese findings demonstrate substantial anti-inflammatory and analgesic properties of D. stramonium-derived lactones and their potential as anti-inflammatory agents to treat chronic inflammatory ailments.

Effects of salidroside injection on pulmonary vascular permeability in rats with septic shock induced lung injury induced by lipopolysaccharide

Effects of salidroside injection on pulmonary vascular permeability in rats with septic shock induced lung injury induced by lipopolysaccharide

ANTI-INFLAMMATORY ACTIVITY OF CURCUMIN AND CAPSAICIN AUGMENTED IN COMBINATION

Objective: Dietary curcumin and capsaicin are well known for their health beneficial potencies. The current study was done to assess the anti-inflammatory activity of curcumin, capsaicin and their combination by employing in vitro and in vivo models.Methods: We investigated the protective effect of curcumin, capsaicin and their combination using in vitro heat induced human red blood cell (HRBC) membrane stabilisation, in vivo 3% agar induced leukocyte mobilisation and acetic acid induced vascular permeability assay.Results: Curcumin, capsaicin and their combination exhibited concentration dependent protective effect against heat-induced HRBC membrane destabilisation, while combined curcumin and capsaicin restored 87.0±0.64 % membrane stability and it is found to be better than curcumin, capsaicin and diclofenac sodium (75.0±0.25. 72±0.9 and 80.0±0.31 %) protective effect. In agar suspension induced leukocyte mobilization assay, the combined curcumin and capsaicin had shown 39.5±1.58 % of inhibition compared to individual curcumin and capsaicin, which showed moderate inhibition of 16.0±3.14 and 21.6±2.17 % respectively. Besides, the combined curcumin and capsaicin had shown highly significant inhibition of acetic acid-induced vascular permeability in rats (62.0±3.14 %), whereas individual curcumin and capsaicin showed moderate inhibition of vascular permeability with 36.0±2.41 and 43.0±1.92 % respectively.Conclusion: This study demonstrates the significant anti-inflammatory property of combined curcumin and capsaicin at half of the individual concentration of curcumin and capsaicin.

Prolyl-glycyl-proline (PGP) Peptide Prevents an Increase in Vascular Permeability in Inflammation

This study was aimed at investigating the effect of prolyl-glycyl-proline (PGP) tripeptide on vascular permeability in rats with an inflammation. It was found that the peptide reduces the rat paw edema induced by a subcutaneous administration of histamine to the same extent as the conventional anti-inflammatory agent diclofenac. However, an assessment of the relative expression level of the cox-2 gene at the inflammation focus using real-time PCR showed that, in contrast to diclofenac, PGP does not affect the cox-2 gene expression. This is indicative of the fact that they have different mechanisms of action. We used the model of acute peritonitis induced by an intraperitoneal injection of thioglycolate to demonstrate that the inflammatory response of an organism is accompanied by increased vascular permeability in the tissues of the stomach and small intestine. Pre-administration (30 minutes before the induction of the inflammation) of PGP prevented this increase, whereby the level of vascular permeability, exudate volume in the peritoneal cavity, and the amount of the Evans Blue dye in this exudate remained at the control level. Therefore, these results suggest that the anti-inflammatory action of PGP is based on its ability to prevent an increase in vascular permeability.

Endothelin ETA Receptor Blockade, by Activating ETB Receptors, Increases Vascular Permeability and Induces Exaggerated Fluid Retention.

Endothelin (ET) receptor antagonists have been associated with fluid retention. It has been suggested that, of the two endothelin receptor subtypes, ETB receptors should not be blocked, because of their involvement in natriuresis and diuresis. Surprisingly, clinical data suggest that ETA-selective antagonists pose a greater risk of fluid overload than dual antagonists. The purpose of this study was to evaluate the contribution of each endothelin receptor to fluid retention and vascular permeability in rats. Sitaxentan and ambrisentan as ETA-selective antagonists and bosentan and macitentan as dual antagonists were used as representatives of each class, respectively. ETA-selective antagonism caused a dose-dependent hematocrit/hemoglobin decrease that was prevented by ETB-selective receptor antagonism. ETA-selective antagonism led to a significant blood pressure reduction, plasma volume expansion, and a greater increase in vascular permeability than dual antagonism. Isolated vessel experiments showed that ETA-selective antagonism increased vascular permeability via ETB receptor overstimulation. Acutely, ETA-selective but not dual antagonism activated sympathetic activity and increased plasma arginine vasopressin and aldosterone concentrations. The hematocrit/hemoglobin decrease induced by ETA-selective antagonism was reduced in Brattleboro rats and in Wistar rats treated with an arginine vasopressin receptor antagonist. Finally, the decrease in hematocrit/hemoglobin was larger in the venous than in the arterial side, suggesting fluid redistribution. In conclusion, by activating ETB receptors, endothelin receptor antagonists (particularly ETA-selective antagonists) favor edema formation by causing: 1) fluid retention resulting from arginine vasopressin and aldosterone activation secondary to vasodilation, and 2) increased vascular permeability. Plasma volume redistribution may explain the clinical observation of a hematocrit/hemoglobin decrease even in the absence of signs of fluid retention.

The role of central and peripheral D2R receptors in the mechanism of colonic vascular permeability during experimental colitis in rats

We investigated the involvement of central and peripheral D2 dopaminergic receptors in the mechanism of vascular permeability in rat's colon during experimental ulcerative colitis. Ulcerative colitis was induced in male white inbred rats by 6 % iodoacetamide enema. For the investigation of central and peripheral D2R, separate and joint injections of D2R antagonist domperidone (2 mg/100 g, per os) and D2R agonist quinpirole (1 mg/100 g, per os) were applied. Central D2R were destroyed by neurotoxin injection – 6OHDA. Colonic vascular permeability was measured by colonic extravasation of 1,5 % Evans blue. It was observed that blockade of peripheral D2R decreased colonic vascular permeability, while simultaneous activation of central D2R and inhibition of peripheral D2R have additive positive effect in prevention of increased colonic vascular permeability during experimental colitis.

Effects of beta-hydroxybutyrate on brain vascular permeability in rats with traumatic brain injury

This study investigates the effect of beta-hydroxybutyrate (BHB) on blood–brain barrier (BBB) integrity during traumatic brain injury (TBI) in rats. Evans blue (EB) and horseradish peroxidase (HRP) were used as determinants of BBB permeability. Glutathione (GSH) and malondialdehyde (MDA) levels were estimated in the right (injury side) cerebral cortex of animals. The gene expression levels for occludin, glucose transporter (Glut)-1, aquaporin4 (AQP4) and nuclear factor-kappaB (NF-κB) were performed, and Glut-1 and NF-κB activities were analyzed. BHB treatment decreased GSH and MDA levels in intact animals and in those exposed to TBI (P<0.05). Glut-1 protein levels decreased in sham, BHB and TBI plus BHB groups (P<0.05). NF-κB protein levels increased in animals treated with BHB and/or exposed to TBI (P<0.05). The expression levels of occludin and AQP4 did not significantly change among experimental groups. Glut-1 expression levels increased in BHB treated and untreated animals exposed to TBI (P<0.05). While NF-κB expression levels increased in animals in TBI (P<0.01), a decrease was noticed in these animals upon BHB treatment (P<0.01). In animals exposed to TBI, EB extravasation was observed in the ipsilateral cortex regardless of BHB treatment. Ultrastructurally, BHB attenuated but did not prevent the presence of HRP in brain capillary endothelial cells of animals with TBI; moreover, the drug also led to the observation of the tracer when used in intact rats (P<0.01). Altogether, these results showed that BHB not only failed to provide overall protective effects on BBB in TBI but also led to BBB disruption in healthy animals.

Dopamine receptor 2 activation inhibits ovarian vascular endothelial growth factor secretion in an ovarian hyperstimulation syndrome (OHSS) animal model: implications for treatment of OHSS with dopamine receptor 2 agonists

To explore whether a dopamine receptor 2 agonist (D2-ag) can prevent ovarian hyperstimulation syndrome (OHSS) in a rat model by decreasing ovarian vascular endothelial growth factor (VEGF) production. Experimental study in an OHSS animal model. University-affiliated infertility center. Immature Wistar rats. Immature rats were stimulated with gonadotropins to mimic OHSS and treated with a D2-ag and/or D2-antagonists (D2-ant). Vascular permeability (VP) was measured at the endpoint, and ovaries were collected to assess the effects of these drugs on VEGF production. VP was estimated by measuring the peritoneal extravasation of a previously injected dye. Ovarian VEGF mRNA expression and VEGF protein levels were assessed by quantitative real-time PCR and Western blots, respectively. The D2-ag exerted a reduction in VP that was associated with a drastic decrease in VEGF protein production in OHSS rat ovaries. The effects of this D2-ag on VP and VEGF protein levels were partially reversed by concomitant administration of a D2-ant. Ovarian VEGF mRNA expression levels were unaffected by these drugs in OHSS rats. D2-ags prevent increased VP in OHSS rats by decreasing ovarian VEGF production, very likely through a D2-mediated post-transcriptional mechanism. Given the dose-dependent inhibitory effect of D2-ags on ovarian VEGF production reported herein, we infer that current OHSS therapies used in humans may be improved by increasing the intraovarian concentration of D2-ags in these patients.

Fatty acid composition, anti-inflammatory and analgesic activities of Hibiscus sabdariffa Linn. seeds

Hibiscus (H.) sabdariffa (commonly known as “Karkadeh” in Arabic) is widely used in various pharmacological applications in Sudan. The present study was carried out to investigate the antiinflammatory and analgesic activities of H. sabdariffa seed extracts using rat models. In acute antiinflammatory models, oral administration of petroleum ether extract of H. sabdariffa seeds inhibited the hind paw edema (p<0.01) which was induced by carrageenan. The petroleum ether extract exhibited significant (p<0.01) inhibition of vascular permeability in rats induced by intraperitoneal injection of acetic acid (0.6%). In cotton pellet granuloma method, the petroleum ether extract of H. sabdariffa seed showed significant inhibition of granuloma. The extract reduced (p<0.001) abdominal constrictions which was induced by injection of acetic acid (0.7%). Analysis of seed oil of H. sabdariffa using Gas Chromatography revealed the presence of three fatty acids; these were linolelaidic acid, arachidic acid, and palmitic acid. In conclusion, H. sabdariffa seeds possess anti-inflammatory and analgesic activities in rat model.

β-Defensins Activate Human Mast Cells via Mas-Related Gene X2

Human β-defensins (hBDs) stimulate degranulation in rat peritoneal mast cells in vitro and cause increased vascular permeability in rats in vivo. In this study, we sought to determine whether hBDs activate murine and human mast cells and to delineate the mechanisms of their regulation. hBD2 and hBD3 did not induce degranulation in murine peritoneal or bone marrow-derived mast cells (BMMC) in vitro and had no effect on vascular permeability in vivo. By contrast, these peptides induced sustained Ca(2+) mobilization and substantial degranulation in human mast cells, with hBD3 being more potent. Pertussis toxin (PTx) had no effect on hBD-induced Ca(2+) mobilization, but La(3+) and 2-aminoethoxydiphenyl borate (a dual inhibitor of inositol 1,4,5-triphosphate receptor and transient receptor potential channels) caused substantial inhibition of this response. Interestingly, degranulation induced by hBDs was substantially inhibited by PTx, La(3+), or 2-aminoethoxydiphenyl borate. Whereas human mast cells endogenously express G protein-coupled receptor, Mas-related gene X2 (MrgX2), rat basophilic leukemia, RBL-2H3 cells, and murine BMMCs do not. Silencing the expression of MrgX2 in human mast cells inhibited hBD-induced degranulation, but had no effect on anaphylatoxin C3a-induced response. Furthermore, ectopic expression of MrgX2 in RBL-2H3 and murine BMMCs rendered these cells responsive to hBDs for degranulation. This study demonstrates that hBDs activate human mast cells via MrgX2, which couples to both PTx-sensitive and insensitive signaling pathways most likely involving Gαq and Gαi to induce degranulation. Furthermore, murine mast cells are resistant to hBDs for degranulation, and this reflects the absence of MrgX2 in these cells.

Caffeic acid phenethyl ester attenuates IgE-induced immediate allergic reaction

Caffeic acid phenethyl ester (CAPE) is the active component of honey bee propolis extracts. The results of the current study demonstrate that CAPE attenuated immunoglobulin (Ig)E-mediated allergic response in mast cells. Oral administration of CAPE inhibited IgE-mediated passive cutaneous anaphylaxis. CAPE effectively reduced both histamine and serotonin (5-HT)-induced vascular permeability in rats. CAPE also reduced histamine and leukotrienes (LTs) release from isolated rat peritoneal mast cells. Moreover, CAPE suppressed contraction induced by histamine (3 × 10(-8)-3 × 10(-5) M), 5-HT (3 × 10(-9)-10(-6) M) and adenosine (3 × 10(-8)-10(-5) M) in guinea pig tracheal zigzag. These findings provide evidence that CAPE may serve as an effective therapeutic agent for allergic diseases.

Agmatine induces gastric protection against ischemic injury by reducing vascular permeability in rats

To investigate the effect of administration of agmatine (AGM) on gastric protection against ischemia reperfusion (I/R) injury. Three groups of rats (6/group); sham, gastric I/R injury, and gastric I/R + AGM (100 mg/kg, i.p. given 15 min prior to gastric ischemia) were recruited. Gastric injury was conducted by ligating celiac artery for 30 min and reperfusion for another 30 min. Gastric tissues were histologically studied and immunostained with angiopoietin 1 (Ang-1) and Ang-2. Vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1) were measured in gastric tissue homogenate. To assess whether AKt/phosphatidyl inositol-3-kinase (PI3K) mediated the effect of AGM, an additional group was pretreated with Wortmannin (WM) (inhibitor of Akt/PI3K, 15 μg/kg, i.p.), prior to ischemic injury and AGM treatment, and examined histologically and immunostained. Another set of experiments was run to study vascular permeability of the stomach using Evan's blue dye. AGM markedly reduced Evan's blue dye extravasation (3.58 ± 0.975 μg/stomach vs 1.175 ± 0.374 μg/stomach, P < 0.05), VEGF (36.87 ± 2.71 pg/100 mg protein vs 48.4 ± 6.53 pg/100 mg protein, P < 0.05) and MCP-1 tissue level (29.5 ± 7 pg/100 mg protein vs 41.17 ± 10.4 pg/100 mg protein, P < 0.01). It preserved gastric histology and reduced congestion. Ang-1 and Ang-2 immunostaining were reduced in stomach sections of AGM-treated animals. The administration of WM abolished the protective effects of AGM and extensive hemorrhage and ulcerations were seen. AGM protects the stomach against I/R injury by reducing vascular permeability and inflammation. This protection is possibly mediated by Akt/PI3K.

The Sesame Lignan Sesamin Attenuates Vascular Permeability in Rats with Streptozotocin-Induced Diabetes: Involvement of Oxidative Stress

Background: Cardiovascular disorders are a major cause of morbidity and mortality in diabetic patients. Increased vascular permeability is a hallmark of diabetic vasculopa- thy, and the administration of natural products with antioxidant activity could restore vascular function. Objectives: In this study, the effect of chronic treatment with sesamin on vascular per- meability in rats with streptozotocin (STZ)-induced diabetes was investigated. Materials and Methods: Male diabetic rats received sesamin at a dose of either 10 or 20 mg/kg for 7 weeks, beginning 1 week after diabetes induction. Vascular permeability was estimated by measuring Evans blue dye extravasation. Oxidative stress markers, including malondialdehyde (MDA) and superoxide dismutase (SOD) activity, were also measured in aortic tissue. Results: Extravasation of Evans blue dye increased significantly in the diabetic group compared to that in the control group (p < 0.05), and treatment with sesamin signifi- cantly and dose-dependently decreased this extravasation (p < 0.05). Diabetic rats also had elevated malondialdehyde (MDA) and reduced superoxide dismutase (SOD) activ- ity (p < 0.005-0.001), and chronic treatment with sesamin (20 mg/kg) significantly re- versed the elevated MDA content (p < 0.05) and reduced SOD activity (p < 0.05). Conclusions: Chronic treatment of diabetic rats with sesamin could dose-dependently improve aortic permeability, partly through the attenuation of oxidative stress in aor- tic tissue. ARTICLE INFO

Prevention of the Onset of Ovarian Hyperstimulation Syndrome (OHSS) in the Rat After Ovulation Induction with a Low Molecular Weight Agonist of the LH Receptor Compared with hCG and rec-LH

Ovarian hyperstimulation syndrome (OHSS) incidentally occurs in controlled ovarian stimulation protocols and is associated with human chorionic gonadotropin (hCG) administration. OHSS is caused by increased vascular permeability (VP) and thought to be mediated by hypersecretion of vascular endothelial growth factor (VEGF) by granulosa cells. Low molecular weight (LMW)-LH agonists have a similar mode of action but a shorter half-life compared with hCG, which could potentially lead to a clinical benefit in reducing the risk for OHSS in controlled ovarian stimulation protocols. The objective of this study is to investigate the role of an orally active LMW-LH agonist in OHSS induction compared with recombinant LH (rec-LH) and hCG. Immature rats were hyperstimulated with pregnant mare serum gonadotropin, and ovulation was induced by hCG, rec-LH or a LMW-LH agonist. The degree of VP was determined by Evans Blue in the abdominal cavity. Ovaries were weighed, and VEGF concentration in the ovary was determined. Pregnant mare serum gonadotropin stimulation followed by single-dose hCG or rec-LH resulted in clear enlargement of the ovaries and increased VP and VEGF levels. However, ovulation induction with a single dose of the LMW-LH agonist did not result in increased VP and VEGF levels, and even multiple dosing to mimic a longer exposure did not induce OHSS symptoms. In conclusion, we demonstrated that the oral LMW-LH agonist did not induce VP in rat, indicative for OHSS, possibly due to reduced VEGF production. If this is translatable to human, this could potentially represent a clinical benefit in reducing the risk for OHSS when using these compounds in controlled ovarian stimulation protocols.

Isolation from bovine plasma of a protein that enhances vascular permeability in rats.

Isolation from bovine plasma of a protein that enhances vascular permeability in rats.

Analgesic and anti-inflammatory activities in rats of alpha-(3,5-di-t-butyl-4-hydroxybenzylidene)-gamma-butyrolactone (KME-4), and its intestinal damage.

alpha-(3,5-Di-t-butyl-4-hydroxybenzylidene)-gamma-butyrolactone (KME-4), an anti-inflammatory drug, possesses analgesic activity in rat models. In the acetic acid-induced writhing test, the oral ED50 values for KME-4, indomethacin, naproxen and ibuprofen were 5.2, 3.8, 7.0 and 18.6 mg kg-1, respectively, and the relative order of potency of these drugs correlated with their inhibitory effect on acetic acid-induced vascular permeability in rats. KME-4 also had analgesic activity in the tests of Randall-Selitto and adjuvant arthritic flexion, but the dose required was greater than that needed in the writhing test. KME-4 (10 mg kg-1 day-1 orally) has a preventive effect against adjuvant-induced arthritis in rats, and its efficacy was more potent than indomethacin (2 mg kg-1 day-1) as judged from various parameters determined. When administered orally to rats once daily for 12 days, KME-4 caused perforating ulceration of the small intestine but this action was less potent than the effect of indomethacin, naproxen and ibuprofen.

Anti-inflammatory and antinociceptive activities of Euterpe oleracea Mart., Arecaceae, oil

The oil of the fruits of Euterpe oleracea Mart., Arecaceae (OEO), was evaluated in models of inflammation and hyperalgesia in vivo to study its effects on these conditions. The experimental models contained the writhing test in mice, rat paw edema, granuloma test in rats, vascular permeability in rats, cell migration to the peritoneal cavity in rats and ear erythema induced by croton oil in mice. Doses of 500, 1000 and 1500 mg/kg of OEO were administered orally. The observed number of writhes was inhibited by 33.67, 45.88 and 55.58%, respectively. OEO produced a dose-dependent effect, with linear correlation coefficient R=0.99 (y=0.0219x+23.133), and the median effective dose found was 1226.8 mg/kg. The oral administration of 1226.8 mg/kg of OEO inhibited carrageenan-induced edema by 29.18% (p<0.05) when compared to the control group. The daily administration of OEO for six days inhibited the formation of granulomatous tissue by 36.66% (p<0.01). In ear erythema induced by croton oil, OEO presented a significant inhibition (37.9%). In the vascular permeability test, treatment with OEO decreased the response to histamine, inhibiting vascular permeability by 54.16%. In carrageenan-induced peritonitis, OEO reduced the number of neutrophils migrating compared to the control group by 80.14%. These results suggested that OEO has anti-inflammatory and antinociceptive activities, probably of peripheral origin and linked to prostaglandin biosynthesis inhibition.

Effect of Chlorogenic acid on mast cell-dependent anaphylactic reaction

Chlorogenic acid (CGA), a naturally occurring polyphenol compound, has a number of biological activities. However, roles of CGA in the mast cell-dependent anaphylactic reaction have not been fully examined. In the present study, the effect and mechanism of CGA on mast cell-dependent anaphylactic reaction were investigated using in vivo and in vitro models. CGA inhibited compound 48/80-induced systemic anaphylactic shock in mice and skin vascular permeability in rats. CGA also inhibited anti-dinitrophenyl (DNP) IgE-mediated passive cutaneous anaphylaxis (PCA). Moreover, CGA dose-dependently reduced histamine and TNF-α release from RBL-2H3 cells activated by anti-DNP IgE. Pretreatment with CGA suppressed IgE–antigen complex induced calcium uptake into RBL-2H3 cells. When CGA was added, the level of intracellular cyclic adenosine monophosphate (cAMP) in RBL-2H3 cells was significantly elevated compared with the untreated cells. Decreased calcium uptake and increased cAMP level might be involved in the inhibitory effect of CGA on mast cell activation. These results suggest a possible therapeutic application of CGA in allergic diseases.