Suzana Beatriz Veríssimo de Mello

Effect of isolated fractions of Harpagophytum procumbens D.C. (devil's claw) on COX-1, COX-2 activity and nitric oxide production on whole-blood assay.

The present study evaluates the effect of isolated fractions of Harpagophytum procumbens (devils claw) on cyclooxygenase (COX‐1 and COX‐2) activities and NO production using a whole blood assay. The activity of COX‐1 was quantified as platelet thromboxane B2 production in blood clotting and COX‐2 as prostaglandin E2 production in LPS‐stimulated whole blood. Total NO2−/NO3− concentration was determined by Griess reaction in LPS stimulated blood. Assays were performed by incubation of isolated fractions obtained by flash chromatography monitored with HPLC, TLC and identified by 1HNMR, containing different amounts of harpagoside with blood from healthy donors. Indomethacin and etoricoxib were the positive controls of COX‐1 and COX‐2 Inhibition. Data shows that fraction containing the highest concentration of harpagoside inhibited indistinctively COX‐1 and COX‐2 (37.2 and 29.5% respectively) activity and greatly inhibited NO production (66%). In contrast the fraction including iridoid pool increased COX‐2 and did not alter NO and COX‐1 activities. The fraction containing cinnamic acid was able to reduce only NO production (67%). Our results demonstrated that the harpagoside fraction is the main responsible for the effect of devils claw on these enzyme activities. However, other components from devils claw crude extract could antagonize or increase the synthesis of inflammatory mediators. Copyright

Pro and Antiinflammatory Properties of Toxins from Animal Venoms

Accidents evoked by venomous animals are common in tropical regions. In Brazil, envenomation evoked by snakes, spiders and scorpions are an important public health problem. Their venoms are composed of a great number of toxins, which are capable of acting on tissue and plasma components with consequent toxic and pharmacological effects. On the other hand, the diversity of venom composition makes them important source of toxins that can be employed as scientific tools. Here we describe the mechanisms of anti and pro-inflammatory properties of toxins of Bothrops and Crotalus genus snakes and Loxosceles and Phoneutria genus spider venoms. The emphasis was to summarise, both in vivo and in vitro, studies that focused on the action of phospholipases, metalloproteinases and sphingomyelinase D on vascular and cellular aspects of the process as well as the complex network of chemical mediators involved.

Exercise training can attenuate the inflammatory milieu in women with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by chronic inflammation. This study sought to assess the effects of an exercise training program on cytokines and soluble TNF receptors (sTNFRs) in response to acute exercise in SLE women. Eight SLE women and 10 sex-, age-, and body mass index-comparable healthy controls (HC) participated in this study. Before and after a 12-wk aerobic exercise training program, cytokines and sTNFRs were assessed at rest and in response to single bouts of acute moderate/intense exercise. HC performed the acute exercise bouts only at baseline. After the exercise training program, there was a decrease in resting TNFR2 levels (P = 0.025) and a tend to reduction interleukin (IL)-10 levels (P = 0.093) in SLE. The resting levels of IL-6, IL-10, and TNF-α after the exercise training in SLE reached HC levels (P > 0.05). In response to a single bout of acute moderate exercise, the area under the curve (AUC) of IL-10 was significantly reduced after the exercise training program in SLE (P = 0.043), and the AUC of IL-10, IL-6, TNF-α, and sTNFR1 of SLE approached control values (P > 0.05). In response to a single bout of acute intense exercise, the AUC of IL-10 was significantly reduced in SLE (P = 0.015). Furthermore, the AUC of sTNFR2 tended to decrease after exercise training program in SLE (P = 0.084), but it did not reach control values (P = 0.001). An aerobic exercise training program attenuated the inflammatory milieu in SLE women, revealing a novel homeostatic immunomodulatory role of exercise in an autoimmunity condition.

Role of kinins and nitric oxide on the rabbit arthritis induced by Bothrops jararaca venom.

The effects of the nitric oxide synthase inhibitor N(omega)Nitro-L-arginine-methyl ester (L-NAME) and of the bradykinin B(2) receptor antagonist HOE 140 were evaluated in the inflammatory reaction induced by Bothrops jararaca venom (BjV) in New Zealand White rabbits. Arthritis was induced by injecting 0.5 ml of a sterile solution of BjV (1-64 microg/ml) into the knee intraarticular cavity. The contralateral joint was injected with bovine serum albumin (BSA) diluted in sterile saline. At selected times thereafter (4, 24 and 48 h), the vascular permeability and the leukocyte influx in both the synovial fluid and synovium were evaluated. BjV caused a dose-dependent increase in both leukocyte influx and protein extravasation which reached a maximal response at 16 microg. Bothrops jararaca venom also induced the increase in the leukocyte accumulation in the synovium and in the concentration of both NO(2)/NO(3) in the synovial fluid. Chronic administration of L-NAME (20 mg/kg/day in the drinking water for 2 weeks) markedly reduced the leukocyte accumulation (90%), protein leakage (44%), and NO(2)/NO(3) (50%) levels in the synovial fluid, measured at the 4th h. Hoe 140, given i.v. (0.3 mg/kg, 30 min before) also reduced leukocyte accumulation (75%), protein leakage (48%), and NO(2)/NO(3) (79%) levels in the synovial fluid, measured at the 4th h. Similar results were obtained with acute administration of L-NAME (30 mg/kg, i.v., 30 min before). These results indicate that arthritis induced by BjV is triggered by kinin formation and that the increase in both vascular permeability and leukocyte accumulation is modulated by NO release.

Anti-inflammatory effect of bee venom on antigen-induced arthritis in rabbits: Influence of endogenous glucocorticoids

AIM OF THE STUDY This study assessed the involvement of endogenous glucocorticoids (GCs) in the anti-arthritic properties of bee venom (BV) on antigen-induced arthritis (AIA) in rabbits. MATERIALS AND METHODS BV (1.5-6 microg/kg/day) was injected for 7 days before AIA induction, whereas the control group received sterile saline. The total and differential leukocyte count, PGE(2) levels in synovial fluid and synovial membrane cell infiltrate were evaluated. The contribution of GCs to BV action was assessed in rabbits treated with BV plus metyrapone, an inhibitor of GC synthesis, or RU-38 486, a steroid antagonist. RESULTS Treatment with BV (1.5 microg/kg/day) reduced the leukocyte count and PGE(2) level (18571+/-1909 cells/mm(3) and 0.49+/-0.05 ng/mL, respectively) as well as the cellular infiltrate compared with the control group (40968+/-5248 cells/mm(3) and 2.92+/-0.68 ng/mL, p<0.05). The addition of metyrapone to BV treatment completely reversed the inhibition of AIA, whereas RU-38 486 was ineffective. CONCLUSION Our data show that bee venom treatment prevents the development of antigen-induced arthritis in rabbits through the action of GCs.

Effect of topical clay application on the synthesis of collagen in skin: an experimental study

Background.  Clay is often used in cosmetic treatments, although little is known about its action.

In vivo blockade of Ca+2-dependent nitric oxide synthases impairs expressions of L-selectin and PECAM-1

Interactions of leukocytes with endothelium play a role for the immune system modulated by endogenous agents, such as glucocorticoids and nitric oxide (NO). Glucocorticoids inhibit leukocyte-endothelial interactions whereas the role of NO is still controversial. In this study, the activity of Ca(+2)-dependent nitric oxide synthases was in vivo blocked in male Wistar rats by given l-NAME, 20mgkg(-1) for 14 days dissolved in drinking water and expression of adhesion molecules involved in leukocyte-endothelial interactions was investigated. Expressions of L-selectin and PECAM-1 in peripheral leukocytes and PECAM-1 in endothelial cells were reduced by l-NAME treatment. Only L-selectin expression was controlled at transcriptional levels. These effects were not dependent on endogenous glucocorticoids, as corticosterone levels were not altered in l-NAME-treated rats. Our results show that NO, produced at physiological levels, controls expression of constitutive adhesion molecules expressions in cell membranes by different mechanisms of action.

Pharmacological characterisation of arthritis induced by Bothrops jararaca venom in rabbits: a positive cross talk between bradykinin, nitric oxide and prostaglandin E2

BACKGROUND: Our previous results showed that nitric oxide (NO) and bradykinin (BK) mediate the arthritis induced by Bothrops jararaca venom (BjV) in rabbits. In this study, we investigated the contribution of each receptor of BK as well as the inter-relationship between NO and eicosanoids in BjV-induced arthritis. METHODS: The arthritis was induced in rabbits with 16 microg of BjV injected intra-articularly. Prostaglandin E2 (PGE2), thromboxane B2 (TxB2), leukotriene B4 (LTB4) (radioimmunoassay) and nitrite/nitrate concentrations (NO2/NO3) (Griess reaction) were evaluated in the synovial fluid 4 h later. The animals were prior treated with NO synthase inhibitor (L-NAME; 20 mg/kg/day for 14 days), the B2 antagonist of BK (HOE-140) and the B1 antagonist of BK (des-Arg9[Leu8]-bradykinin), both at a dose of 0.3mg/kg, 30 min prior to the venom injection. RESULTS: Data show that L-NAME and HOE-140 treatment were equally able to reduce PGE2 and NO2/NO3 levels without interfering with TxB2 and LTB4 production. On the contrary, the B1 antagonist of BK inhibited TxB2 and LTB4 production, and did not alter PGE2 and NO metabolites levels in the inflamed joint. DISCUSSIONS: The results presented clarify the contribution of the kinin system, mainly through the B2 receptor, to the local inflammatory response induced by BjV, as well as its positive interaction with PGE2 and NO production.

The effect of methotrexate on the bone healing of mandibular condylar process fracture: An experimental study in rats

BACKGROUND Methotrexate (MTX) is an anti-metabolite used in rheumatology and oncology. High doses are indicated for oncological treatment, whereas low doses are indicated for chronic inflammatory diseases. This study evaluated the effect of two MTX treatment schedules on the bone healing of the temporomandibular joint fracture in rats. METHODS Seventy-five adult male Wistar rats were used to generate an experimental unilateral medially rotated condylar fracture model that allows an evaluation of bone healing and the articular structures. The animals were subdivided into three groups that each received one of the following treatments intraperitoneally: saline (1 mL/week), low-dose MTX (3 mg/kg/week) and high-dose MTX (30 mg/kg). The histological study comprised fracture site and temporomandibular joint evaluations and bone neoformation was evaluated by histomorphometric analysis. A biochemical parameter of bone formation was also assessed. RESULTS When compared with saline, high-dose MTX delayed bone fracture repairs. In this latter group, after 90 days, the histological analysis revealed atrophy of the fibrocartilage and the presence of fibrous tissue in the joint space. The histomorphometric analysis revealed diminished bone neoformation. The alkaline phosphatase levels also decreased after MTX treatment. CONCLUSION It was concluded that high-dose MTX impaired mandibular condyle repair and induced degenerative articular changes.

Serum adipocytokine profile and metabolic syndrome in young adult female dermatomyositis patients

OBJECTIVES: To analyse the frequency of metabolic syndrome in young adult female dermatomyositis patients and its possible association with clinical and laboratory dermatomyositis-related features and serum adipocytokines. METHOD: This cross-sectional study included 35 dermatomyositis patients and 48 healthy controls. Metabolic syndrome was defined according to the 2009 Joint Interim Statement. RESULTS: Patient age was comparable in the dermatomyositis and control groups, and the median disease duration was 1.0 year. An increased prevalence of metabolic syndrome was detected in the dermatomyositis group (34.3% vs. 6.3%; p=0.001). In addition, increased serum adiponectin and resistin levels were noted in contrast to lower leptin levels. In dermatomyositis patients, adipocytokine levels were correlated with the levels of total cholesterol, low-density cholesterol, triglycerides and muscle enzymes. A comparison of dermatomyositis patients with (n=12) and without (n=23) syndrome metabolic revealed that adipocytokine levels were also correlated with age, and that dermatomyositis patients with metabolic syndrome tended to have more disease activity despite similar adipocytokine levels. CONCLUSIONS: Metabolic syndrome is highly prevalent in young adult female dermatomyositis patients and is related to age and disease activity. Moreover, increased serum adiponectin and resistin levels were detected in dermatomyositis patients, but lower serum leptin levels were observed.