Jonatas Zeni Klafke

Identification of the Plant Steroid α-Spinasterol as a Novel Transient Receptor Potential Vanilloid 1 Antagonist with Antinociceptive Properties

The transient receptor potential vanilloid 1 (TRPV1) receptor is relevant to the perception of noxious information and has been studied as a therapeutic target for the development of new analgesics. The goal of this study was to perform in vivo and in vitro screens to identify novel, efficacious, and safe TRPV1 antagonists isolated from leaves of the medicinal plant Vernonia tweedieana Baker. All of the fractions and the hydroalcoholic extract produced antinociception in mice during the capsaicin test, but the dichloromethane fraction also had antioedematogenic effect. Among the compounds isolated from the dichloromethane fraction, only α-spinasterol reduced the nociception and edema induced by capsaicin injection. Moreover, α-spinasterol demonstrated good oral absorption and high penetration into the brain and spinal cord of mice. α-Spinasterol was able to displace [3H]resiniferatoxin binding and diminish calcium influx mediated by capsaicin. Oral administration of the dichloromethane fraction and α-spinasterol also produced antinociceptive effect in the noxious heat-induced nociception test; however, they did not change the mechanical threshold of naive mice. The treatment with α-spinasterol did not produce antinociceptive effect in mice systemically pretreated with resiniferatoxin. In addition, α-spinasterol and the dichloromethane fraction reduced the edema, mechanical, and heat hyperalgesia elicited by complete Freunds adjuvant paw injection. The dichloromethane fraction and α-spinasterol did not affect body temperature or locomotor activity. In conclusion, α-spinasterol is a novel efficacious and safe antagonist of the TRPV1 receptor with antinociceptive effect.

Antiplatelet, Antithrombotic, and Fibrinolytic Activities of Campomanesia xanthocarpa

In a previous work based on popular belief, Campomanesia xanthocarpa Berg., popularly known as “guavirova”, showed to have a potential effect in the control of a number of conditions associated with cardiovascular diseases. The aim of the present work was to investigate the effects of C. xanthocarpa extract (CXE) on antiplatelet, antithrombotic and fibrinolytic activities in mice and in human blood. Mice were treated orally for 5 days with CXE or acetylsalicylic acid and at the end of the treatment period animals were challenged for bleeding, acute thromboembolism and ulcerogenic activity. In addition, we have assessed the prothrombin time and activated partial thromboplastin time (aPTT) after oral administration. In in vitro assays, antiplatelet effects of CXE was evaluated on platelet aggregation, and fibrinolytic activity of the extract was observed by mice or human artificial blood clot degradation. Platelet citotoxicity of the extract was also determined by the LDH assay. Results demonstrated that CXE has a significant protective effect on thrombosis. It also inhibits platelet aggregation without demonstrating cytotoxicity on platelets. CXE slightly prolonged aPTT and showed no ulcerogenic activity after oral administration. In addition, CXE showed a fibrinolytic activity. Thus, C. xanthocarpa showed antiplatelet, antithrombotic and fibrinolytic activities in mice.

Anti-inflammatory and antioxidant effects of Aloe saponaria Haw in a model of UVB-induced paw sunburn in rats.

Ultraviolet B (UVB) irradiation mainly affects biological tissues by inducing an increase in reactive oxygen species (ROS) production which leads to deleterious outcomes for the skin, including pain and inflammation. As a protective strategy, many studies have focused on the use of natural products. The aim of this study was to investigate the effects of Aloe saponaria on nociceptive, inflammatory, and oxidative parameters in a model of UVB-induced sunburn in adult male Wistar rats. Sunburned animals were topically treated with vehicle (base cream), 1% silver sulfadiazine (positive control) or A. saponaria (10%) once a day for 6days. UVB-induced nociception (allodynia and hyperalgesia), inflammation (edema and leukocyte infiltration) and oxidative stress (increases in H2O2, protein carbonyl levels and lipid peroxidation and a decrease in non protein thiol content) were reduced by both A. saponaria and sulfadiazine topical treatment. Furthermore, A. saponaria or its constituents aloin and rutin reduced the oxidative stress induced by H2O2 in skin homogenates in vitro. Our results demonstrate that topical A. saponaria treatment displayed anti-nociceptive and anti-inflammatory effects in a UVB-induced sunburn model, and these effects seem to be related to its antioxidant components.

Mortalidade por doenças circulatórias e evolução da saúde da família no Brasil: um estudo ecológico

O objetivo deste estudo foi analisar a mortalidade por doencas circulatorias paralelamente a evolucao da Estrategia Saude da Familia no Brasil. Estudo ecologico, retrospectivo, baseado na evolucao temporal da ESF e nas taxas de mortalidade por doencas circulatorias no Brasil. Foi realizada uma descricao da razao de cobertura habitante x ESF e dos indicadores de saude relacionados a mortalidade por doencas circulatorias. Para a associacao estatistica utilizou-se o teste de Correlacao de Spearman. Houve aumento populacional no Brasil em 15%, evolucao de 761% no numero de ESF e 5% de aumento na mortalidade por doencas circulatorias. A razao populacao x ESF passou de 52.838 (1998) para 7.084 (2006) pessoas assistidas por ESF. As regioes norte e nordeste apresentaram crescimento nas taxas de mortalidade por doencas circulatorias e em 21 (81%) estados houve correlacao positiva entre mortalidade por doencas circulatorias e ESF (r: > 0,7; p < 0,01). Por fim, considera-se a ESF uma importante politica publica de saude, tendo obtido resultados exitosos no Brasil desde a sua implementacao. Entretanto, em um contexto geral, sua expansao nao influenciou a reducao da mortalidade por doencas circulatorias, tendo apresentado aumento deste indicador no pais.

Gallic acid functions as a TRPA1 antagonist with relevant antinociceptive and antiedematogenic effects in mice

The transient receptor potential ankyrin 1 (TRPA1) has been identified as a relevant target for the development of novel analgesics. Gallic acid (GA) is a polyphenolic compound commonly found in green tea and various berries and possesses a wide range of biological activities. The goal of this study was to identify GA as a TRPA1 antagonist and observe its antinociceptive effects in different pain models. First, we evaluated the ability of GA to affect cinnamaldehyde-induced calcium influx. Then, we observed the antinociceptive and antiedematogenic effects of GA (3–100 mg/kg) oral administration after the intraplantar (i.pl.) injection of TRPA1 agonists (allyl isothiocyanate, cinnamaldehyde, or hydrogen peroxide—H2O2) in either an inflammatory pain model (carrageenan i.pl. injection) or a neuropathic pain model (chronic constriction injury) in male Swiss mice (25–35 g). GA reduced the calcium influx mediated by TRPA1 activation. Moreover, the oral administration of GA decreased the spontaneous nociception triggered by allyl isothiocyanate, cinnamaldehyde, and H2O2. Carrageenan-induced allodynia and edema were largely reduced by the pretreatment with GA. Moreover, the administration of GA was also capable of decreasing cold and mechanical allodynia in a neuropathic pain model. Finally, GA was absorbed after oral administration and did not produce any detectable side effects. In conclusion, we found that GA is a TRPA1 antagonist with antinociceptive properties in relevant models of clinical pain without detectable side effects, which makes it a good candidate for the treatment of painful conditions.

Role of peripheral polyamines in the development of inflammatory pain

Polyamines (putrescine, spermidine and spermine) are aliphatic amines that are produced by the action of ornithine decarboxylase (ODC) in a rate-limiting and protein kinase C (PKC)-regulated step. Because high levels of polyamines are found in the synovial fluid of arthritic patients, the aim of the present study was to identify the role of peripherally produced polyamines in a model of inflammatory pain induced by adjuvant. The subcutaneous injection of Complete Freunds adjuvant (CFA, 50 μL/paw) caused the development of mechanical allodynia and edema. Moreover, it increased ODC expression and activity and PKC activation. Administration of the selective ODC inhibitor DFMO (10 μmol/paw) attenuated the development of allodynia and edema and decreased ODC activity in both control and CFA-treated animals. Furthermore, administration of the PKC inhibitor GF109203X (1 nmol/paw) reduced allodynia and ODC activity in animals injected with CFA. A subcutaneous injection of putrescine (10 μmol/paw), spermidine (3-10 μmol/paw) or spermine (0.3-3 μmol/paw) into the rat paw also caused mechanical allodynia and edema. The present results suggest that endogenously synthesized polyamines are involved in the development of nociception and edema caused by an adjuvant. Moreover, polyamine production in inflammatory sites seems to be related to an increase in ODC activity stimulated by PKC activation. Thus, controlling polyamine synthesis and action could be a method of controlling inflammatory pain.

Natural Products with Antiplatelet Action

BACKGROUND Complex hemostatic mechanisms are involved in the pathophysiology of various diseases, including cardiovascular diseases. Among them, dysregulation of platelet activity is linked to the progression of atherosclerosis and mainly involves platelet aggregation and a decrease in blood flow in the vascular endothelium. The major platelet activation pathways mediated by agonists involve the arachidonic acid pathway, adenosine diphosphate pathway, serotonin pathway, nitric oxide pathway, and action of free radicals on molecules involved in platelet aggregation. These mechanisms have been widely studied and discussed because they are inhibited by the use of medicinal plants in complementary and alternative medicine, thus reducing platelet aggregation. RESULTS Of the main plants discussed in this review, which have antiplatelet activity, some include saffron, garlic, green tea, St. Johns wort, ginger, ginkgo biloba, ginseng, and guavirova. These herbal medicines have phytochemical components, which are directly related to the antiplatelet activity of the plant, such as flavonoids, curcumins, catechins, terpenoids, polyphenols, and saponins. While the majority of the medicinal plants mentioned here were native to the Asian continents, some are distributed worldwide, and found to a smaller extent throughout the American continent, European continent, Mediterranean, African continent, and the Middle East. CONCLUSION This review showed that several plants and/or compounds exhibit anti-platelet activity, and are therefore potential research targets for developing drugs to treat diseases related to aggregation disorders.

Association between hypertriglyceridemia and protein oxidation and proinflammatory markers in normocholesterolemic and hypercholesterolemic individuals

BACKGROUND Although hypercholesterolemia is a well-established risk factor for coronary heart disease, evidence suggests that increased triglyceride (TG) concentrations are also an independent risk factor. TG concentrations >150mg/dl are observed nearly twice as often in subjects with atherosclerosis. We assessed the association between hypertriglyceridemia and protein oxidation and proinflammatory markers in normocholesterolemic and hypercholesterolemic individuals. METHODS We included 127 volunteers enrolled in Cruz Alta, RS, Brazil. The patients were stratified based on total cholesterol and TG concentrations for analysis of associations with inflammation (high-sensitivity C-reactive protein - hs-CRP), endothelial dysfunction (nitric oxide - NOx) and oxidative stress (advanced oxidation protein products - AOPPs; ischemia-modified albumin - IMA). Correlations between variables were determined and multiple regression analysis was employed to investigate whether some variables correlate with TG concentrations. RESULTS Hypertriglyceridemia was related to oxidative stress and proinflammatory markers in individuals independent of total cholesterol concentrations. Moreover, the results indicate a stronger association of tested biomarkers with TG concentrations than with total cholesterol. The results indicate a positive correlation between oxidative stress and TG concentrations in the sera of hypercholesterolemia subjects. AOPPs and IMA concentrations were associated with the presence of hypertriglyceridemia in a manner that was independent of age, gender, hypertension and diabetes mellitus disease, smoking habits, sedentary lifestyle, BMI, waist circumference, LDL, HDL and total cholesterol concentrations. CONCLUSIONS We speculate that TG concentrations can reflect the enhancement of protein oxidation and proinflammation.

Biomarkers of Subclinical Atherosclerosis and Natural Products as Complementary Alternative Medicine

Cardiovascular diseases (CVD) are considered the leading cause of morbidity and mortality from chronic diseases in the world. In addition, about 20% of first and recurrent acute myocardial infarctions (MI) are silent. In this context, subclinical atherosclerosis culminates in evident CVD, through the evolution of early risk factors such as hypercholesterolemia, hypertriglyceridemia and others. The main problem in CVD is related to the long-time between the start of the subclinical atherosclerosis and the manifestation of the disease. The identification of subjects at risk of such events is obviously substantial, since identification leads to implementation and compliance with effective preventive measures that reduce such risk. In this sense, this review demonstrates biomarkers as an alternative to early detection of subclinical atherosclerosis. One of the proposed biomarkers is the Ischemia-modified albumin (IMA), being considered a promising biochemical biomarker for atherosclerotic conditions. Another marker that is gaining strength and is associated with the IMA are the advanced oxidation protein products (AOPP), its measurement provides information on the level of exposure to potentially harmful changes to proteins and metabolic control. And last but not least we have nitric oxide as an early marker mainly related to endothelial dysfunction. In this review also is evidenced the use of the Campomanesia xanthocarpa, a plant native to southern region from Brazil extensively used as complementary and alternative medicine, and natural products to reduce protein oxidation and improve the availability of nitric oxide and consequently vascular function, reducing the risk for development of CVD.