RESUMO No Brasil, a família Malvaceae está representada por aproximadamente 200 espécies e algumas foram descritas como gastroproteroras. Pavonia alnifolia A.St.-Hil. (Malvaceae) foi selecionada após uma abordagem quimiossistemática, considerando-se sua potencial capacidade em prevenir lesões gástricas. Assim, a atividade gastroprotetora do extrato etanólico de caules de P. alnifolia foi avaliada utilizando o modelo de indução aguda da lesão gástrica por etanol acidificado em camundongos. Além disso, foram quantificados o teor de flavonóides, pelo método de cloreto de alumínio, e de polifenóis, pelo método Folin-Ciocalteu, uma vez que a relação desses componentes com a proteção gástrica foi evidenciada. Os ensaios apontaram redução acentuada das lesões gástricas em camundongos tratados com o extrato da planta em todas as doses ensaiadas (10, 100 e 300 mg/kg). Esse efeito pode estar relacionado com a presença de polifenóis, cujo teor encontrado foi 74,3 ± 7,5 μg equivalente de pirogalol/mg do material vegetal examinado e 82,7 ± 7,1 μg equivalente de pirogalol /mg da amostra no extrato preparado por percolação e teor de flavonoides totais, que por sua vez apresentou um resultado de 17,1 ± 1,4 μg/mg de extrato. O extrato apresentou proteção da mucosa gástrica e este efeito pode estar relacionado à presença dos polifenóis e flavonóides encontrados.

ABSTRACT In Brazil, the Malvaceae family is represented by at about 200 species. Some of those species are known as gastro protective ones. The Pavonia alnifolia A.St.-Hil (Malvaceae) was selected after a chemosystematic approach. The gastro preventive activity of the ethanol extract of stems Pavonia alnifolia was evaluated through the use of the Ethanol:chlroridric acid model on mice. The quantification of the total flavonoids (aluminum chloride method) and total polyphenols (Folin-Ciocalteu method) was also performed since the relation of those components with gastric protection has been previously highlighted. The tests showed a significant reduction of the ulcer formation in the mice treated with the plant extract (10, 100 and 300 mg/kg). This effect may be related to the presence of polyphenols whose content was found to be 74.3 ± 7.5 μg/mg of vegetal material and 82.7 ± 7.1 μg/mg of crude extract and flavonoids, which in turn showed a content of 17.1 ± 1.4 μg/mg dry extract.

Sex hormones modulate the action of both cytokines and the renin-angiotensin system. However, the effects of angiotensin I-converting enzyme (ACE) on the proinflammatory and anti-inflammatory cytokine levels in male and female spontaneously hypertensive rats (SHR) are unclear. We determined the relationship between ACE activity, cytokine levels and sex differences in SHR. Female (F) and male (M) SHR were divided into 4 experimental groups each (n = 7): sham + vehicle (SV), sham + enalapril (10 mg/kg body weight by gavage), castrated + vehicle, and castrated + enalapril. Treatment began 21 days after castration and continued for 30 days. Serum cytokine levels (ELISA) and ACE activity (fluorimetry) were measured. Male rats exhibited a higher serum ACE activity than female rats. Castration reduced serum ACE in males but did not affect it in females. Enalapril reduced serum ACE in all groups. IL-10 (FSV = 16.4 ± 1.1 pg/mL; MSV = 12.8 ± 1.2 pg/mL), TNF-α (FSV = 16.6 ± 1.2 pg/mL; MSV = 12.8 ± 1 pg/mL) and IL-6 (FSV = 10.3 ± 0.2 pg/mL; MSV = 7.2 ± 0.2 pg/mL) levels were higher in females than in males. Ovariectomy reduced all cytokine levels and orchiectomy reduced IL-6 but increased IL-10 concentrations in males. Castration eliminated the differences in all inflammatory cytokine levels (IL-6 and TNF-α) between males and females. Enalapril increased IL-10 in all groups and reduced IL-6 in SV rats. In conclusion, serum ACE inhibition by enalapril eliminated the sexual dimorphisms of cytokine levels in SV animals, which suggests that enalapril exerts systemic anti-inflammatory and anti-hypertensive effects.

A espécie vegetal Alpinia zerumbet (Pers.) B.L.Burtt & R.M. Sm. é popularmente empregada para o tratamento de diversas enfermidades, entre elas a hipertensão. Avaliar a composição química, a atividade antihipertensiva e ação na hipertrofia cardíaca do óleo essencial das folhas de Alpinia zerumbet (OEAZ) em ratos foram os objetivos deste estudo. O OEAZ, obtido por hidrodestilação em aparelho Clevenger, teve sua composição química analisada em cromatografia gasosa acoplada à espectrometria de massas (CG-EM). Foram identificados 14 constituintes, sendo terpinen-4-ol (37,45%) o majoritário, seguido pelos óxido de cariofileno (7,56%), trans-hidrato de sabineno (6,61%) e 1,8-cineol (4,02%). A avaliação cardiovascular foi feita após o tratamento crônico de ratos espontaneamente hipertensos (SHR) e seus respectivos controles, ratos Wistar-Kyoto (WKY). Os dados hemodinâmicos revelaram redução da pressão arterial média (PAM) no grupo tratado (SHRP: 160 ± 7 mm Hg; p<0,01) em relação ao não tratado (SHR: 180 ± 5 mm Hg). A relação entre peso do ventrículo esquerdo e peso corporal (VE/PC) do SHRP (2,50 ± 0,03 mg g-1; p<0,01) mostrou-se inferior ao SHR (2,61 ± 0,01 mg g-1), confirmando a redução da hipertrofia cardíaca (HC). Os dados de PAM e VE/PC dos animais SHRP foram estatisticamente diferentes quando comparados com os ratos controle (WKY: 116 ± 2 mm Hg e WKYP: 119 ± 4 mm Hg; p<0,05; WKY: 2,15 ± 0,04 mg g-1 e WKYP: 2,17 ± 0,04 mg g-1 ; p<0,01), indicando não ter havido normalização dos mesmos. Conclui-se que o tratamento crônico com OEAZ foi capaz de determinar redução, mas não a normalização, da PAM e da HC de ratos SHR, provavelmente pela presença dos componentes terpinen-4-ol e 1,8-cineol. Estudos com doses maiores ou período de tratamento superior são necessários para avaliar a possibilidade de o OEAZ normalizar os parâmetros analisados (PAM e HC).

Alpinia zerumbet (Pers.) B.L. Burtt & R.M.Sm. is traditionally employed to treat several diseases such as hypertension. The aim of this study was to evaluate the chemical composition, the anti-hypertensive activity and the capacity to reduce cardiac hypertrophy of the essential oil of A. zerumbet leaves (EOAZ) in rats. EOAZ was obtained through hydrodistillation in Clevenger apparatus and its chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Several constituents (14) were identified, terpen-4-ol (37.45%) being the major component, followed by caryophyllene oxide (7.56%), trans-sabinene hydrate (6.61%) and 1,8-cineol (4.02%). The cardiovascular effect was investigated after chronic treatment with spontaneously hypertensive rats (SHR) and their respective controls, Wistar-Kyoto rats (WKY). The treated group showed a lower mean arterial pressure (MAP) (SHRP: 160 ± 7 mm Hg; p<0.01) than the untreated group (SHR: 180 ± 5 mm Hg). The ratio of left ventricle-to-body weight (LV/BW) for SHRP was lower (2.504 ± 0.03 mg g-1; p<0.01) than that for SHR (2.162 ± 0.01 mg g-1), confirming the cardiac hypertrophy (CH) reduction. There were significant differences in MAP and CH between SHRP animals and control rats (WKY: 116 ± 2 mm Hg and WKYP: 119 ± 4 mm Hg; p<0.05. WKY: 2.152 ± 0.04 mg g-1 and WKYP: 2.168 ± 0.04 mg g-1; p<0.01), indicating that these values were not normalized. Those data showed that the chronic treatment with EOAZ reduces MAP and CH in SHR probably due to the presence of the compounds terpinen-4-ol and 1,8-cineol. Studies with higher doses or longer treatment periods are necessary to evaluate whether EOAZ can reduce the analyzed parameters (MAP and CH) to normal values.

Obstructive apnea (OA) can exert significant effects on renal sympathetic nerve activity (RSNA) and hemodynamic parameters. The present study focuses on the modulatory actions of RSNA on OA-induced sodium and water retention. The experiments were performed in renal-denervated rats (D; N = 9), which were compared to sham (S; N = 9) rats. Mean arterial pressure (MAP) and heart rate (HR) were assessed via an intrafemoral catheter. A catheter was inserted into the bladder for urinary measurements. OA episodes were induced via occlusion of the catheter inserted into the trachea. After an equilibration period, OA was induced for 20 s every 2 min and the changes in urine, MAP, HR and RSNA were recorded. Renal denervation did not alter resting MAP (S: 113 ± 4 vs D: 115 ± 4 mmHg) or HR (S: 340 ± 12 vs D: 368 ± 11 bpm). An OA episode resulted in decreased HR and MAP in both groups, but D rats showed exacerbated hypotension and attenuated bradycardia (S: -12 ± 1 mmHg and -16 ± 2 bpm vs D: -16 ± 1 mmHg and 9 ± 2 bpm; P < 0.01). The basal urinary parameters did not change during or after OA in S rats. However, D rats showed significant increases both during and after OA. Renal sympathetic nerve activity in S rats increased (34 ± 9%) during apnea episodes. These results indicate that renal denervation induces elevations of sodium content and urine volume and alters bradycardia and hypotension patterns during total OA in unconscious rats.