In the present study were studied the antinociceptives properties of monoterpene R-(؉) (1 mg/kg, s.c.). It was also demonstrated that R-(؉)-limonene (25, 50 mg/kg) neither significantly enhanced the pentobarbital-sleeping time nor impaired the motor performance in rota-rod test, indicating that the observed antinociception is unlikely to be due to sedation or motor abnormality. In conclusion it may be suggested that the R-(؉)-limonene presented antinociceptive activity and that, probably, this action can be related with peripheral analgesia, but, not with the stimulation of opioids receptors.-

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The present study examined the antinociceptive effects of (O-methyl) N-benzoyl-tyramine (riparin I, ripI) isolated from the unripe fruit of Aniba riparia in chemical and thermal behavioral models of pain, such as acetic acid-induced abdominal writhing, formalin, and hot-plate tests in mice. Moreover, the involvement of the nitric oxide pathway as well as the opioid system in the antinociceptive action of ripI in the formalin test was investigated. RipI was administered both orally and intraperitoneally to male mice at single doses of 25 and 50 mg/kg. In the acetic acid-induced abdominal writhing, ripI decreased the number of writhings at both doses. In addition, in the formalin test, ripI reduced the paw licking time at both phases of the test. The effect of the highest dose of ripI in mice formalin test on the early phase was not reversed by naloxone (opioid receptor antagonist) but it was reversed by l-arginine (a nitric oxide precursor) in the late phase, suggesting that ripI may not act through opioid system and possibly acts through inhibition of nitric oxide pathway. In the hot-plate test, ripI increased the reaction time in the hot-plate test at the dose of 25 mg/kg, i.p., confirming the result found in the formalin test. Based on the obtained results, it is suggested that ripI presents antinociceptive activity that may be due to peripheral mechanisms (nitric oxide pathway) and central mechanisms, discarding the involvement of opioid system.

Abstract:Cissus verticillata (syn. C. sycioides, fam. Vitaceae) is a medicinal plant popularly used in Brazil, for the treatment of diabetes mellitus. The anti-diabetic activity of a fraction from leaves of Cissus verticilllata (MSF, methanol soluble fraction), as well as that of tyramine (TYR) were investigated, in the model of alloxan-induced diabetes, in male Wistar rats. The biochemical parameters studied were: serum glucose, triglycerides (TG), total cholesterol (TC) and very low density lipoprotein (VLDL), urea, creatinine, AST and ALT levels. Besides, glycated hemoglobin and liver glycogen concentrations were also determined. The MSF (50 and 100 mg kg , i.v.). Drugs were administered alone or associated. Alloxan-diabetic rats showed significant reductions in plasma glucose, triglycerides and total cholesterol, after the treatment with the MSF, tyramine and glibenclamide, as compared to diabetic controls. The MSF and TYR effects were not potentiated by their association with GLI. Besides, MSF or TYR did not reverse DZ-induced hyperglycemia. However, MSF and TYR effects were significantly potentiated by MET, suggesting that these drugs act by a mechanism similar to that of MET. The other biochemical parameters were unaltered. The treatment of diabetic animals with the MSF increased the number of pancreatic beta cells. TYR also decreased the concentration of glycated Hb. While a 61% decrease in glycogen concentration was observed in diabetic controls, a total and partial recoveries of alloxan effects were seen after treatment of diabetic animals with the MSF (100 mg kg −1 , p.o.) and measurements carried out 2 and 24 h after amyloglicosidase addition, respectively. In conclusion, our results showed that the MSF and TYR, when administered by gavage for 5 days, may reduce glucose, TG and TC levels by a mechanism at least in part similar to that of MET. These results point to the insulin-like effects of C. verticillata, probably due to the presence of tyramine in the plant.

Dehydrodieugenol, known as bis‐eugenol, is a eugenol ortho dimer, and both compounds were able to exhibit anti‐inflammatory and antioxidant activities in previous studies. Furthermore, eugenol showed antidepressant‐like effect; however, the biological actions of bis‐eugenol on experimental models for screening antidepressant activity are still unknown. The present study investigated a possible antidepressant‐like activity of bis‐eugenol in the forced swimming test (FST) and tail suspension test (TST) in mice and the involvement in the monoaminergic system in this effect. In addition, a neurochemical analysis on brain monoamines of mice acutely treated with bis‐eugenol was also conducted. Bis‐eugenol decreased the immobility time in the FST and TST without accompanying changes in ambulation in the open field test at 10 mg/kg, i.p.. Nevertheless, it induced ambulation at 25 and 50 mg/kg doses. The anti‐immobility effect of bis‐eugenol (10 and 50 mg/kg, i.p.) was prevented by pretreatment of mice with p‐chlorophenylalanine (PCPA, 100 mg/kg, i.p., an inhibitor of serotonin synthesis, for four consecutive days), yohimbine (1 mg/kg, i.p., an α2‐adrenoceptor antagonist), SCH23390 (15 μg/kg, s.c., a dopamine D1 receptor antagonist) and sulpiride (50 mg/kg, i.p., a dopamine D2 receptor antagonist). Monoamines analysis using high‐performance liquid chromatograph revealed significant increase in the 5‐HT, NE and DA levels in brain striatum. The present study indicates that bis‐eugenol possesses antidepressant‐like activity in FST and TST by altering dopaminergic, serotonergic and noradrenergic systems function.

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In the present study, the antioxidant activity of a methanol soluble fraction (MSF) from Cissus verticillata, used in Brazil and elsewhere as a hypoglycemic and antidiabetic medicinal plant, and tyramine (TYR), one of its main bioactive constituents, was assessed. For this, male Wistar rats were submitted to alloxan injection (40 mg/kg, i.v.) in order to induce a diabetic state and, 48 h later, glycemia was determined. Animals were distributed into groups: normal controls (NC); diabetic controls (DC); DC plus MSF; and DC plus TYR. Another group was treated with glibenclamide (GLI), used as a positive control. After 5-day treatments, animals were sacrificed for liver dissection, and determination of antioxidant markers such as thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), catalase and nitrite concentrations. The antioxidant effect was also evaluated on the pentobarbital-induced sleeping time, before and after CCl4 treatment. Under our experimental conditions, diabetic rats did not present any alteration in liver lipid peroxidation, before (DC) or after treatments with the MSF; TYR or GLI, as compared to normal controls (NC). Levels of GSH were significantly increased in 79% in DC, as related to NC, and the effects were partially reversed in diabetic rats, after MSF treatments at the higher dose. However, while similar effects were observed after TYR and GLI, both drugs brought values of GSH to normality. The DC group had increased liver catalase activity, as compared to NC, and these effects were partially reversed by MSF and almost completely by TYR and GLI. Significant increases were also detected in nitrite concentrations in livers of DC, as an index of free radical formation, and a large reduction was observed after MSF, TYR and GLI treatments of diabetic rats, as compared to NC. MSF and TYR also prevented prolongation of the pentobarbitalinduced sleeping time by CCl4, suggesting hepatoprotective and anti-oxidative effects. In conclusion, we showed that the antioxidant activity probably plays an important role in the antidiabetic effect of C. verticillata, and TYR is at least in part responsible for this property.

Objetivo: avaliar o perfil dos diferentes estágios da manifestação de estresse em discentes de uma Instituição Federal de Ensino Superior (IFES), no município de Redenção-CE, refletindo e discutindo o possível impacto disto no processo ensino-aprendizagem e na qualidade de vida dos mesmos. Métodos: estudo realizado com discentes de uma IFES, ambos os sexos, brasileiros e estrangeiros, matriculados em diferentes cursos de graduação da instituição. As descrições sobre as manifestações de estresse foram realizadas através do Inventário de Estresse de Lipp (ISS). Resultados: foram coletados dados de 120 alunos regularmente matriculados em diferentes cursos de graduação, modalidade presencial, nos Campi da IFES localizados no Estado do Ceará. Observou-se que cerca de 86 (72%) apresentaram sintomas da manifestação de estresse em algumas das fases apontadas no instrumento utilizado. Enquanto 34 (28%) não apresentaram quaisquer dos sintomas. Conclusão: evidenciou-se que as manifestações de estresse dos discentes participantes foram consideravelmente altas. Diante disto, denota-se a necessidade de se trabalhar melhor os pontos relacionados ao estresse no ambiente universitário, com vistas a diminuir os impactos biopsicossociais acarretados pela rotina da vida acadêmica.