IMmunosuppressants and TGF-β1 accelerated and prolonged the nitric oxide/oxyradicals-dependent suppression by dexamethasone in paw edema of mice

Dexamethasone (Dex, 0.3 mg/Kg, S.c.) did not suppress histamine and ischemic paw edema of mice up to 1 hr. However, given TGF-β1 (0.3 μ g/Kg, I.p.), Dex suppression appeared early as 30 min (36% and 42%). When Dex (0.1 mg/Kg, S.c.) was injected 6 hr before the assay, Dex alone, TGF-β1 ± Dex, FK506 (10 mg/kg, oral)± Dex, cyclosporin A (CsA, 30 mg/kg, oral) ± Dex, rapamycin (Rapa, 10 mg/Kg, I.p.) ± Dex, deoxyspergualin (DSP, 10 mg/Kg, I.p.) ± Dex, did not suppress the edemata (less than 11 %). Nevertheless, if Dex and TGF-β1 were dosed together with one of these immunosuppressants, suppressions of histamine and ischemic edema were 53%, 45% (FK506), 45%, 49% (CsA), 44%, 48% (Rapa) and 39%, 51% (DSP), respectively. Glucocorticoid (GC) receptor (GR) complex contains heat shock proteins such as hsp56 (or CsA-binding protein: CyP-40), hsp70 and hsp90. FK506, Rapa and TGF-β1 receptor I (TR-I) bind FK-binding protein-12 (FKBP-12). FK506 and Rapa bind also hsp56. CsA binds CyP-40. DSP binds hsp70 and/or hsp90. These bindings might change or stabilize the conformation of GR complex resulting in edema suppressions. Nitric oxide synthase (NOS) inhibitors, superoxide dismutase (SOD), catalase, mannitol and cycloheximide, reversed the edema suppressions by TGF-β1 ± immunosuppressant at 30 min and 6 hr after Dex. Endogenous NO, Or and/or · OH seemed to be essential for edema suppressions. Our demonstration in vivo may offer a theoritical support for clinicians to adopt combination therapy of immunosuppressant(s) and GC.     

Antiinflammatory effect of a protein kinase C inhibitor (K-252a) on the development of the dextran-induced paw edema in the rat (preliminary results).

The effect of a metabolite of Nocardiopsis sp. as a protein kinase C inhibitor from microbial origin was investigated on the onset and development of dextran-induced paw edema in the rat. It was published that this compound (K-252a) interferes with histamine release from mast cells, while dextran-induced paw and nose edema are induced by vasoactive agents, like histamine etc., released from the disrupted mast cells. The antiinflammatory effect of the K-252a is effectuated by the inhibition of protein kinase C. Groups of male Wistar rats with 180-200 g b.w. were used; each group consisted of 10-10 rats. The following groups were consisted: rats given orally DMSO (control), rats given 1 mg/kg, or 3 mg/kg b.w. of K-252a dissolved in DMSO and given p.o. one hour before dextran injection. Dextran (BDH Chem. LTD, molW: 200.000, England) was injected intraperitoneally in 10% solution, in a dose of one ml/100 g b.w. Volume of the hind leg was measured by a mercury plethysmometer. Time-sequence of the edema was followed. Increase in volume of hind leg paw was related to its 0-min volume in %. Results were analyzed by the Kruskal-Wallis-test. Edema of the legs and noses appeared in each of the control rats in one hour. The 1 mg/kg dose of K-252a retarded the appearance of the edema by 1 hour, the 3 mg/kg dose, however, prevented its onset for 4 hours.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diazepam effects on carrageenan-induced inflammatory paw edema in rats: role of nitric oxide

High doses of diazepam (10.0-20.0 mg/kg) were shown to reduce the volume of acute inflammatory paw edema in rats as a response to carrageenan administration. This effect was attributed to an action of diazepam on the peripheral-type benzodiazepine receptor (PBR) present in the adrenal and/or immune/inflammatory cells. The present study was undertaken to analyze the involvement of nitric oxide (NO) on the effects of diazepam on carrageenan-induced paw edema in rats (CIPE) and to look for the presence of PBR and inducible/constitutive NO synthases (NOS) on slices taken from the inflamed paws of diazepam-treated rats. For that, an acute inhibition of NO biosynthesis was achieved using 50.0 mg/kg No mega-nitro-L-arginine (L-NAME), L-arginine (300.0 mg/kg), the true precursor of NO, and D-arginine (300.0 mg/kg), its false substrate, were also used. The following results were obtained: (1) diazepam (10.0 and 20.0 mg/kg) decreased CIPE values in a dose- and time-dependent way; (2) diazepam effects on CIPE were increased by L-NAME pretreatment; (3) treatment with L-arginine but not with D-arginine reverted at least in part the decrements of CIPE values observed after diazepam administration; (4) PBR were found in endothelial and inflammatory cells that migrated to the inflammatory site at the rat paw; (5) confocal microscopy showed the presence of both PBR and NOS in endothelial and inflammatory cells taken from inflamed paw tissues of rats treated with diazepam a finding not observed in tissues provided from rats treated with diazepam's control solution. These results suggest an important role for NO on the effects of diazepam on CIPE. Most probably, these effects reflect a direct action of diazepam on PBR present in the endothelium of the microvascular ambient and/or on immune/inflammatory cells. An action like that would lead, among other factors, to a decrease in NO, generated by NO synthase, and thus in the mechanisms responsible for CIPE.     

Absence of effect of chronic angiotensin II type 1 receptor blockade on endogenous kinin concentrations-induced paw edema model in the rat.

The effects of chronic treatment with losartan. an AT1 receptor antagonist, on the tissue content of bradykinin (BK) and des-Arg9-BK and on their pharmacological effects were examined in the carrageenan-induced paw edema model (0.5% solution, 50 microl/paw) in the rat. These effects were compared with those of angiotensin-converting enzyme inhibitors (ACEi). For this purpose, rats were chronically treated with losartan (3, 10 and 30 mg/kg/day) and enalapril or quinapril (1 mg/kg/day). Endogenous BK and des-Arg9-BK tissue contents at the site of local inflammation were measured by highly sensitive and specific enzyme immunoassays. Losartan 3 mg/kg/day for 7, 14 and 28 days had no significant effect on carrageenan-induced paw edema, but both losartan 10 and 30 mg/kg/day for 14 days significantly increased the hindpaw volume by 50% at 3 h and by 59% at 5 h. These effects, similar to those measured for ACEi, were inhibited by icatibant, a B2 kinin receptor antagonist (32.5 nmol/paw), that reduced carrageenan-induced paw edema to the level seen in vehicle-treated rats. In the same model, and contrary to ACEi, losartan 3, 10 and 30 mg/kg/day for 14 days had no significant effect on endogenous BK and des-Arg9-BK levels in the local inflammatory site or on circulating and tissue ACE activities. These results show, at least in that model, that the potentiating effects of losartan on carrageenan-induced paw edema are independent of the concentrations of endogenous kinins.     

Anti-inflammatory effect of the hydralcoholic extract of Zingiber officinale rhizomes on rat paw and skin edema.

Plant extracts have been used for centuries as a popular mode of treatment for several health disorders. Over the last ten years, the study of those extracts has attracted attention in different fields of the biological sciences. Ginger, the rhizome of Zingiber officinale Roscoe (Zingiberaceae), is a commom constituent of diet worldwide and it has been reported that its extracts present some pharmacological activities. Here we investigate the effects of the crude hydralcoholic extract of ginger rhizomes on the classical models of rat paw and skin edema. The carrageenan-, compound 48/80- or serotonin-induced rat paw edema were inhibited significantly by the intraperitoneal administration of alcoholic ginger extract. Ginger extract was also effective in inhibiting 48/80-induced rat skin edema at doses of 0.6 and 1.8 mg/site. Rat skin edema induced by substance P or bradikinin was not affected by treatment with Z. officinalle extract. The intraperitoneal administration of ginger extract (186 mg/kg(-1) body wt.) 1 h prior to serotonin injections, reduced significantly the serotonin-induced rat skin edema. Our results demonstrated that crude extract of Zingiber officinale was able to reduce rat paw and skin edema induced by carrageenan, 48/80 compound and serotonin. The antiedematogenic activity seems to be related, at least partially, to an antagonism of the serotonin receptor.     

A pharmacologic analysis of the action of platelet-activating factor in the induction of hindpaw edema in the rat

Platelet-activating factor (PAF), a phospholipid product of neutrophils, alveolar macrophages, monocytes, and platelets and an important mediator of inflammatory reactions, was studied for its ability to evoke hindpaw edema in the rat. PAF caused edema, peaking at 1 hr and gradually declining over the next 2 hr. The H₁ and H₂ antihistamines, mepyramine and cimetidine, the serotonin/histamine antagonists, cyrpoheptadine, and the serotonin antagonist, methysergide, were ineffective in reducing PAF-induced paw edema. Indomethacin, acetylsalicylic acid, and dexamethasone did not inhibit the peak edematous response but significant reduction was noted with only dexamethasone at 3 hr. Prazosin and propranolol did not prevent PAF-induced edema, whereas, yohimbine, phentolamine, rauwolscine, verapamil and theophylline partially inihibited edema. Clonidine and guanfacine did not induce edema when injected into the rat hindpaw. These results suggest that PAF elicits edema at₂₊ vascular sites of the rat hindpaw which are partially dependent on extracellular Ca movement, are not due to -1 or -2,-adrenoreceptor stimulation, histamine, serotonin, of photaglandin activity, and demonstrates variable sensitivities to agents blocking Ca²⁺ entry. Inhibition of specific PAF-sensitive receptors await the discovery of specific PAF antagonists.     

Evaluation of the anti-inflammatory activity of riparin II (O-methil-N-2-hidroxi-benzoyl tyramine) in animal models

Riparin II (RipII), an alkamide isolated from the green fruit of Aniba riparia, was tested in the various animal models of inflammation to investigate its anti-inflammatory activity. Male Wistar rats (180–240 g) were treated with RipII by gavage at doses 25 or 50 mg/kg, before initiating the inflammatory responses. The tests used were paw edema induced by carrageenan, dextran, histamine or serotonin; peritonitis induced by carrageenan and fMLP, as well as the measurement of MPO activity, TNF-α and Il-1β amount in the peritoneal fluid. In the animal models of carrageenan and dextran-induced paw edema, the animals treated with RipII showed lower edema than those of the control group. Treatment with RipII also reduced the paw edema induced by histamine but not serotonin. In the carrageenan-induced peritonitis model, treatment with RipII reduced leukocyte migration, the MPO activity and the amount of TNF-α and IL-1β in the peritoneal fluid. In summary, these results indicate that RipII has an anti-inflammatory activity in chemical models of acute inflammation. RipII might be directly or indirectly inhibiting the activity, production or release of pro-inflammatory mediators involved in the generation of the pain associated with inflammation.     

Preliminary studies on phospholipase A2-induced mouse paw edema as a model to evaluate antiinflammatory agents

Phospholipase A2 (PLA2) is a key component of the inflammatory process because of its role in the generation of eicosanoids and platelet-activating factor (PAF). Manipulation of PLA2 activity offers a novel therapeutic approach for the development of antiinflammatory agents; however, there is a need for a suitable in vivo model. Injection of 1 microgram of snake venom PLA2 (A. piscivorus piscivorus, D-49) into the mouse hind footpad produced a significant three- to four-fold rise in paw edema within 10 min, compared to the saline control. Edema formation depended on enzyme concentration and appeared specific for PLA2 since edema was negated by enzyme pretreatment with p-bromophenacyl bromide, a nonspecific PLA2 inhibitor. Moreover, injection of a protein such as bovine serum albumin did not result in significant edema. Coinjection of phenidone (lipoxygenase inhibitor, 50 micrograms), indomethacin (cyclooxygenase inhibitor, 50 micrograms), cyproheptadine (antihistamine/antiserotonin, 50 micrograms), aristolochic acid (putative PLA2 inhibitor, 100 micrograms), or kadsurenone (PAF antagonist, 50 micrograms) with PLA2 (1 microgram/paw) resulted in partial reduction (44.5, 34.2, 54.7, 64, and 50% inhibition, respectively) of edema formation. Oral administration of cyproheptadine (10 mg/kg), indomethacin (10 mg/kg), BW 755c (100 mg/kg), or dexamethasone (1 mg/kg) 1-3 h before challenge also decreased PLA2-induced edema (63.0, 30.1, 47.8, or 62.5% inhibition, respectively). The data suggest that mouse paw edema resulting from PLA2 injection is a multicomponent event, influenced by both autacoids and lipid mediators of inflammation.     

Endothelium-dependent vasorelaxation is inhibited by in vivo depletion of vascular thiol levels: Role of endothelial nitric oxide synthase

Thiols like glutathione may serve as reducing co-factors in the production of nitric oxide (NO) and protect NO from inactivation by radical oxygen species. Depletion of thiol compounds reduces NO-mediated vascular effects in vitro and in vivo. The mechanisms underlying these actions are not clear, but may involve decreased synthesis of NO and/or increased degradation of NO. This study investigates the effect of glutathione depletion on the response to NO-mediated vasodilation induced by acetylcholine (Ach, 10 μg/kg), endothelial NO synthase (eNOS) activity and potential markers of vascular superoxide anion (O^·-₂) production in conscious chronically catheterized rats. Thiol depletion induced by buthionine sulfoximine (BSO, 1 g ip within 24 h) decreased the hypotensive effect of Ach by 30% (MAP reduction before BSO 27 ± 3 mmHg, 19 ± 3 mmHg after BSO, (mean ± SEM), p < .05n = 8). The impaired effect of Ach was associated with a significant reduction in eNOS activity (control: 7.7 ± 0.8, BSO: 3.9 ± 0.4 pmol/min/mg protein (p < .05), n = 6). In contrast, neither NADH/NADPH driven membrane-associated oxidases nor lucigenin reductase activity were significantly (p < .05) affected by BSO (BSO: 4415 ± 123, control: 4105 ± 455 counts/mg, n = 6) in rat aorta. It is concluded that in vivo thiol depletion results in endothelial dysfunction and a reduced receptor-mediated vascular relaxation. This effect is caused by reduced endothelial NO formation.     

Intrinsic prostacyclin contributes to exudation induced by bradykinin or carrageenin: a study on the paw edema induced in IP-receptor-deficient mice

To prove that prostaglandin I2 (PGI2) is a major prostaglandin involved in bradykinin-induced exudation, we examined carrageenin- or bradykinin-induced paw edema in prostacyclin receptor-deficient mice (IPKO). Paw volume of wild-type mice (IPWT) increased gradually 5-6 hr after the carrageenin injection in a similar manner as in ICR mice, but the swelling in IPKO mice was significantly smaller (about 60% of the IPWT volume). Indomethacin, at 10 mg/kg, suppressed the swelling of the IPWT paw to the level of the non-pretreated IPKO, which was not affected by indomethacin, confirming the previous result that PGI2 is a major prostaglandin involved in the swelling. The paw edema of IPWT and IPKO was significantly attenuated by the nonpeptide bradykinin B2-receptor antagonist FR173657, at 30 mg/kg, to the same level of swelling, indicating kinin involvement. Injection of bradykinin (1.2 nmole) into the paw caused rapid edema, which peaked around 15 min in both mice. However, the edema induced in IPKO was smaller and almost at the same level as that elicited in the indomethacin-treated IPWT, suggesting that edema induced by bradykinin includes the intrinsic effect of PGI2. Concomitant injection of carbacyclin with bradykinin caused enhancement of edema in IPWT mice but not in IPKO mice, indicating that intrinsic PGI2 could cause enhancement of bradykinin- or even carrageenin-induced edema formation. These results clearly demonstrate that bradykinin released by carrageenin may be a key mediator to induce PGI2 formation, and both autacoids work together to induce enhanced inflammatory exudation.     

Mechanisms Involved in the Anti-Inflammatory Action of a Polysulfated Fraction from Gracilaria cornea in Rats

The anti-inflammatory mechanisms of the sulfated polysaccharidic fraction obtained from red marine alga Gracilaria cornea (Gc-FI) were investigated using a paw edema model induced in rats by different inflammatory agents (carrageenan, dextran, serotonin, bradykinin, compound 48/80 or L-arginine). Gc-FI at the doses of 3, 9 or 27 mg/kg, subcutaneously - s.c., significantly inhibited rat paw edema induced by carrageenan and dextran, as confirmed by myeloperoxidase and Evans’ blue assessments, respectively. Gc-FI (9 mg/kg, s.c.) inhibited rat paw edema induced by histamine, compound 48/80 and L-arginine. Additionally, Gc-FI (9 mg/kg, s.c.) inhibited Cg-induced edema in animals with intact mast cells but did not inhibit that with degranulated mast cells by compound 48/80, revealing a protective role on mast cell membranes. Gc-FI down-regulated the IL-1β, TNF-α and COX-2 mRNA and protein levels compared with those of the carrageenan group, based on qRT-PCR and immunohistochemistry analyses. After inhibition with ZnPP IX, a specific heme oxygenase-1 (HO-1) inhibitor, the anti-inflammatory effect of Gc-FI was not observed in Cg-induced paw edema, suggesting that the anti-inflammatory effect of Gc-FI is, in part, dependent on the integrity of the HO-1 pathway. Gc-FI can target a combination of multiple points involved in inflammatory phenomena.     

Analgesic effect of the midazolam-induced anesthesia in different doses on the patients after the thoracoscopic resection of lung cancer

ObjectiveTo elaborate the analgesic efficiency of midazolam-induced anesthesia in different doses on the patients following the thoracoscopic resection of lung cancer.MethodsNinety patients undergoing thoracoscopic resection of lung cancer between August 2017 and July 2018 were randomized in the observation group (n = 45) and the control group (n = 45). Patients in observation group underwent the anesthesia induced by 0.1 mg/kg midazolam, while for the control group, the dose was adjusted to 0.05 mg/kg. Then, we compared the levels of inflammatory factors, SaO₂, average of arterial pressure and changes in heart rate before and after surgery (48 h) to analyze the efficacy.ResultsAt the postoperative 48 h, patients in the observation group had lower levels of inflammatory factors when comparing with their counterparts in the control group [IL-6, IL-8, IL-1β and TNF-α: (58.44 ± 3.22) μg/L, (2.04 ± 0.26) μg/L, (2.98 ± 0.44) μg/L, (5.33 ± 0.77) μg/L v.s. (96.44 ± 4.54) μg/L, (3.23 ± 0.33) μg/L, (3.77 ± 0.44) μg/L, (7.64 ± 0.99) μg/L] (P < 0.05). Meanwhile, those in the observation group had a lower SaO₂, average arterial pressure and heart rate [(93.79 ± 1.08)%, (93.22 ± 3.46) mmHg, (87.55 ± 2.35) beat/min v.s. (97.13 ± 1.03)%, (96.44 ± 4.03) mmHg, (91.05 ± 2.89) beat/min] (P < 0.05). However, no statistical significance was identified in the differences of the bleeding amount, surgical time and anesthesia time between two groups (P > 0.05), while the eye-opening time and the extubation time in the observation group were all shorter than those in the control group (P < 0.05). Similarly, the postoperative pain scores, total doses of propofol and remifentanil were also lowered (P < 0.05).ConclusionFor patients of thoracoscopic resection of lung cancer, midazolam-induced anesthesia (0.1 mg/kg) performs better than 0.5 mg/kg in inhibiting the inflammatory responses, with significant reduction in the dose of anesthetics, thereby stabilizing the status of patients in perioperative period and mitigating the postoperative pains. Thus, it is potential candidate.     

Attenuation of carrageenan-induced hind paw edema and plasma TNF-α level by Philippine stingless bee (Tetragonula biroi Friese) propolis

Despite decades-long existence of the Philippine stingless bee industry, the biological activity of propolis from this native bee species (Tetragonula biroi Friese) remains poorly understood and sparingly investigated. Herein, we examined the potential anti-inflammatory efficacy of Philippine stingless bee propolis using the lambda (λ)-carrageenan-induced mice model of hind paw edema. Thirty (30), six-week-old, male ICR mice were randomly assigned into three treatment groups (n=10/group) as follows: distilled water group, diclofenac sodium group (10 mg/kg), and propolis group (100 mg/kg). All treatment were administered an hour prior to the injection of the phlogistic agent. As observed at 3 h post-injection, λ-carrageenan remarkably evoked the classical signs of hind paw edema exemplified grossly by swelling and hyperemia. The ameliorative effect of propolis became apparent at the onset of 6 h post-injection with a statistically significant finding evident at the 24-h period. This gross attenuation histologically correlated to a considerable and specific reduction of the dermal edema, which mirrored those of the diclofenac sodium group. Furthermore, both propolis and diclofenac sodium significantly attenuated the λ-carrageenan-induced increase in the protein expression levels of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) depicting more than two-fold decrement relative to the distilled water group. Altogether, these suggest that Philippine stingless bee propolis also exhibited a promising in vivo anti-inflammatory property, which can be partly mediated through the inhibition of TNF-α.     

Histamine-induced changes in rat tracheal goblet cell mucin store and mucosal edema

The pathology of chronic asthma in human and mouse is characterized by inflammation and remodeling of airway tissues. As a result of repeated inflammatory insults to the lower airways, smooth muscle thickening, mucin secretion and airway hyperreactivity may develop. In ovalbumin (OVA)-sensitized mice with repeated challenges with OVA to the lower airways, the trachea and bronchi are characterized by goblet cell hyperplasia and mucus hypersecretion from goblet cells. Previous study reports that intravenous (i.v.) application of a high dose of capsaicin releases tachykinin from capsaicin-sensitive nerves, producing acute plasma leakage and mucosal edema formation and causing depletion of mucin granules in goblet cells that results in a reduction in the number and size of Alcian blue (AB)-positive goblet cells in the rat trachea within a few minute after capsaicin application. Histamine is an important non-neural mediator of asthma from mast cells. The present study investigated whether i.v. application of a high dose of histamine (18 μmol/ml/kg) could result in these acute changes and the similar time-course changes in rat trachea. The tracheal whole mounts stained with chloroacetate esterase reagent and AB and tracheal methacrylate sections stained with AB and periodic acid-Schiff reagent were used for evaluation of histological and cellular changes. At 5 min after histamine application, mucosal leaky venules were numerous and subepithelial edema ratio (% of length of edema along the mucosal epithelial circumference of tracheal cross section) was found to be 48.2 ± 4.9, which was greater (P < 0.01) than saline-treated rats. But, the number of AB-positive goblet cells, 2,030 ± 170/mm² of mucosal surface epithelium, was similar to saline-treated group (P > 0.05). One day later, edema ratio remained large and the number of AB-positive goblet cells was 1,140 ± 150/mm² epithelium, reduced to half the number of the group at 5 min after histamine (P < 0.01). It is suggested that mucus hypersecretion occurred at this time point. At 3 or 5 days after histamine, edema ratio gradually decreased. The number of AB-positive goblet cells continued to remain small on day 3. On day 5 after histamine, the number of AB-positive goblet cells restored to the level of rat group at 5 min after histamine application. At 7 days after histamine, edema ratio returned to the level of saline-treated group. It is concluded that degranulation and thinning of tracheal goblet cells and mucus hypersecretion lagged behind histamine-induced acute plasma leakage and edema, and restoration of mucin store in goblet cells was associated with remission of mucosal edema.     

Anticoagulant activity, paw edema and pleurisy induced carrageenan: Action of major types of commercial carrageenans

Considering the use of commercials carrageenans as a model for inflammation, the aim this work is a comparative study these compounds in the pro-inflammatory action by ear edema and pleurisy and to analyze their anticoagulant activity. Paw edema was induced by injecting kappa, iota and lambda carrageenans in saline solution into the hind paw of male Wistar rats (p < 0.05). The three types of carrageenans showed different volume in pleural exudates, characterized by fluid accumulation, a large number of neutrophils and raised NO production (p < 0.001). The activated partial thromboplastin time (aPTT) for kappa and iota carrageenans (100 μg) was 240 s and 132 s, respectively. Lambda carrageenan was the most potent anticoagulant at 240 s (20 μg). These carragenans demonstrated no anticoagulant action using the PT test in vitro. Histological analysis in paw edema demonstrated that iota and lambda carrageenans showed major cellular infiltration in relation to kappa. Thus, quantitative evaluation of inflammation demonstrated that iota and lambda carrageenans have higher inflammatory potential than do kappa carrageenans.     

Prostacyclin-induced hypothermia: Involvement of central histamine H2-receptors

Some of the biological activities of prostacyclin (PGI₂) are known to be mediated through cyclic AMP (cAMP). The purpose of this study was to assess the involvement of histamine and serotonin receptors as well as cAMP in the PGI₂-induced hypothermia in conscious guinea pig. Intracerebroventricular administration of 50–500 μg/kg PGI₂ produced a dose-related hypothermia, whereas its stable metabolite 6-keto prostaglandin F₁α had an insignificant effect. Low central doses (10–50 μg/kg) of dibutyryl cAMP (DBC) were hyperthermic, but high doses (100–500 μg/kg) caused hypothermia. Theophylline and low doses of DBC given centrally attenuated the PGI₂-induced hypothermia. Mepyramine and methysergide did not antagonize the effects of PGI₂ or DBC. However, central administration of metiamide (10–100 μg/kg) attenuated the hypothermic responses to both PGI₂ and DBC. These results suggest that histamine H₂-receptors are involved in the hypothermia induced by PGI₂.     

Antitumor and toxicologic properties of the organometallic anticancer agent vanadocene dichloride

We report here on the antineoplastic, toxicologic, and transmembrane transfer properties of vanadocene dichloride (VDC), a representative metallocene dihalide. VDC is cytotoxic to HEp-2 human epidermoid carcinoma cells, in vitro, in a dose dependent manner, with a D_o value (dose increment reducing the survival fraction by 1/e) of 0.530 ± 0.005 μg/ml. Under similar experimental conditions, the D_o for cisplatin (CDDP) against these cells is 0.46 ± 0.08 μg/ml. In a murine mammary adenocarcinoma (TA3Ha) system, 125 μg/ml VDC inhibits the tumor-forming ability of 10⁵ cells upon i.p. inoculation into syngeneic Strain A mice. The transmembrane transfer rate constants for the metal uptake of VDC and CDDP by TA3Ha cells in vitro were found to be 3.3 ± 0.8 × 10⁻⁴ min⁻¹ and 12 ± 2.0 × 10^t-4 min⁻¹, respectively. In vivo studies with TA3Ha cells show that two i.p. treatments of 20, 40, and 60 mg/kg VDC increase the host survival by 30, 50, and 90%, respectively. Under similar conditions, 2, 4, and 6 mg/kg CDDP (equitoxic dose levels) prolong the host survival 50, 75, and 83%, respectively. Morphological, blood urea nitrogen level, and serum creatinine level data for Strain A mice treated with 60 mg/kg VDC give no evidence of renal or small intestinal damage. However, changes in the liver consistent with fatty cell degeneration are observed in these mice.     

Determination of puerarin in biological samples and its application to a pharmacokinetic study by flow‐injection chemiluminescence

A simple and sensitive flow injection–chemiluminescence (FI–CL) method has been developed for the determination of puerarin, based on the fact that puerarin can greatly inhibit CL of the luminol–H₂O₂–haemoglobin system. The inhibition of CL intensity was linear to the logarithm of the concentration of puerarin in the range 0.08–10.0 μg/mL (r² = 0.9912). The limit of detection was 0.05 μg/mL (3σ) and the relative standard deviation (RSD) for 1.0 μg/mL (n = 11) of puerarin solution was 1.4%. Coupled with solid‐phase extraction (SPE) as the sample pretreatment, the determination of puerarin in biological samples and a preliminary pharmocokinetic study of puerarin in rats were performed. The recoveries for plasma and urine at three different concentrations were 89.2–110.0% and 91.4–104.8%, respectively. The pharmacokinetics of puerarin in plasma of rat coincides with the two‐compartment open model. The T_1/2α, T_1/2β, CL/F, V_Z/F, AUC_{(0 – t)}, MRT_{(0 – ∞)}, T_max and C_max were 0.77 ± 0.21 h, 7.55 ± 2.64 h, 2.43 ± 1.02 L/kg/h, 11.40 ± 3.45 L/kg, 56.67 ± 10.65 mg/h/L, 5.04 ± 2.78 h, 1.00 ± 0.35 h and 19.70 ± 4.67 μg/mL, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

Evaluation of anti-inflammatory activity of Vernonia cinerea Less. extract in rats.

The methanol extract of the whole plant of Vernonia cinerea Less. was evaluated for its anti-inflammatory activity in acute (carrageenin, histamine and serotonin induced rat paw edema) and a chronic model (cotton pouch induced granuloma). The methanol extract (250 and 500 mg/kg(-1) p.o.) exhibited significant activity (p < 0.001) against all phlogistic agents used in a dose dependant manner. In the chronic model (cotton pouch granuloma method) the methanol extract exhibited significant anti-inflammatory activity. All these effects were compared with standard drug phenylbutazone (100 mg/kg(-1) p.o.).