Ethnobotanical data can be an important tool in the search for new drugs. The Brazilian Health Surveillance Agency accepts the registration of herbal medicines based on ethnopharmacological and ethnobotanical studies. With the purpose of increasing the knowledge of potentially useful plants for the treatment of painful conditions, we analyzed the ethnobotanical studies carried out in Rio Grande do Sul state (RS-Southern Brazil); we had access to nineteen studies.To our knowledge, this is the first compilation of ethnobotanical studies that focus on pain relief carried out in RS. The species native to RS cited in at least nine (about 50%) of these studies were selected. The search retrieved 28 native species cited as used to alleviate painful conditions, which are distributed in eighteen botanical families, being Asteraceae the most mentioned. The species more frequently cited for pain relief were Achyrocline satureioides, Baccharis articulata, Baccharis crispa, Lepidium didymum, Eugenia uniflora and Maytenus ilicifolia. The only species not reported in any pre-clinical study associated with pain relief was B. articulata. Among the six species cited, no studies on clinical efficacy were found. In conclusion, the folk use of native plants with therapeutic purposes is widespread in RS State (Brazil), being pain relief an important property.

Os terpenóides constituem um vasto grupo de metabólitos secundários com ações sobre o SNC, destacando-se suas atividades sedativa, ansiolítica, antinociceptiva, anticonvulsivante, pró-convulsivante e alucinógena. Neste trabalho foi realizada uma revisão bibliográfica sobre terpenóides com ações descritas no SNC, enfocando moléculas e sistemas neurotransmissores relacionados com sua atividade. As substâncias abordadas encontram-se divididas em mono, sesqui, di, tri e meroterpenóides e incluem compostos isolados e plantas que apresentam ação principalmente sobre os sistemas neurotransmissores GABAérgico, glutamatérgico, dopaminérgico e opióide.

The terpenoids are a large group of secondary metabolites which display many activities in the CNS, such as sedative, ansiolytic, antinociceptive, anticonvulsant, pro-convulsant and hallucinogenic. In this work we performed a research on terpenoids that exert effects on the CNS, focusing molecules and neurotransmitter systems related to their actions. The substances approached were classified as mono, sesqui, di, tri and meroterpenoids and include isolated compounds and plants which exert activities mainly on GABAergic, glutamatergic, dopaminergic and opioid neurotransmitter systems.

Neste trabalho foi avaliado, em roedores, o efeito depressor das frações clorofórmio (CHCl3), acetato de etila (EtOAc) e n-butanol, obtidas das partes subterrâneas de Pfaffia glomerata, empregando-se o teste de tempo de sono barbitúrico como referência. Somente a fração lipofílica (CHCl3:EtOAc, 1:1, m/m) (i.p. 500 mg/kg; v.o. 1000 mg/kg) potenciou o tempo de sono induzido por pentobarbital. A ecdisterona foi isolada e identificada como constituinte majoritário (1,4% m/m) desta fração, através de cromatografia líquida de alta eficiência e métodos espectroscópicos, respectivamente. Este composto potenciou o tempo de sono barbitúrico (100 mg/kg, i.p.; 400 mg/kg, v.o), sem causar hipotermia. Nestas mesmas doses, a ecdisterona não alterou a performance dos animais no rota-rod, esquiva inibitória e labirinto em cruz-elevado, além de não alterar o padrão de convulsões induzidas por pentilenotetrazol. Este perfil indica que esta substância, nestas doses, não apresenta perfil ansiolítico ou neurotóxico. Estes resultados indicam que a ecdisterona é o componente responsável pela ação hipnótica apresentada pela fração lipofílica obtida das partes subterrâneas de P. glomerata.

In this study the depressant effect of fractions from P. glomerata was initially evaluated using the mice barbiturate sleeping time test as reference. The fractions tested were the CHCl3, the EtOAc, the n-BuOH and the aqueous fraction obtained from P. glomerata subterraneous parts. Only the pretreatment with the lipophilic fraction (CHCl3: EtOAc, 1:1, w/w) increased the barbiturate sleeping time (i.p 500 mg/kg; v.o. 1000 mg/kg). Ecdysterone, the main substance isolated from this lipophilic fraction, was identified by spectroscopic methods and its content in the ethanol extract was determined as 1.4% (w/w) by HPLC. In order to investigate the hypothesis of ecdysterone displaying a depressant effect on nervous central system, an evaluation toward the hypnotic-sedative and anxiolytic effects of this drug was carried out. Ecdysterone 100 mg/kg, i.p, increased the barbiturate sleeping time without provoking hypothermia; when administered by oral route its minimal effective dose was 400 mg/kg. On the other hand, ecdysterone (100 mg/kg, i.p; 400 mg/kg, p.o) did not impair motor coordination and was ineffective on pentylenetetrazole-induced convulsion, elevated plus-maze and step-down inhibitory avoidance tests, indicating that at these doses the drug does not present an anxiolytic profile and does not cause manifest neurotoxic effects as well. In conclusion, the lipophilic fraction from P. glomerata presents a hypnotic effect being ecdysterone one of the compounds responsible for this CNS activity.

Na última década, o gênero Hypericum ganhou repercussão mundial devido à utilização de Hypericum perforatum para obtenção de medicamentos antidepressivos. Por esta razão, a maioria dos estudos com outras espécies do gênero centra-se nesta atividade. Porém, um dos usos populares de espécies de Hypericum nativas do sul do Brasil é no tratamento de problemas gastrintestinais, inclusive como antiespasmódico. Neste trabalho, foi avaliado o efeito de uma das espécies de Hypericum nativas do Rio Grande do Sul, H. caprifoliatum, sobre as contrações induzidas por agonistas em íleo isolado de cobaio. Foi investigado o efeito de um extrato ciclo-hexano purificado (isento de clorofila e ceras), nas concentrações de 1, 3, 10 e 30 mg/mL, sobre curvas cumulativas de acetilcolina, histamina, potássio e serotonina (10-7 a 10-4 M). Na concentração de 30 mg/mL o extrato inibiu totalmente as contrações induzidas por todos os agonistas. Na concentração de 10 mg/mL, o extrato apresentou efeito antagonista não-competitivo de serotonina, reduzindo a contração máxima induzida por serotonina em cerca de 50 %. A resposta contrátil aos outros mediadores não foi alterada. Estes resultados indicam que espécies de Hypericum do sul do Brasil podem ser uma perspectiva interessante na busca de moléculas com atividade sobre a motilidade gastrintestinal.

In the last decade the genus Hypericum has achieved worldwide recognition due to the therapeutic value of H. perforatum as an antidepressant drug. Consequently this activity is the most investigated one. However, species native to Brazil have other folk uses such as for the treatment of digestive disorders, including cramps. In this study we evaluated the effect of a purified cyclohexane extract (chlorophyll and waxes free) (1,3,10 and 30 mg/mL) of H. caprifoliatum, a specie native to South Brazil, on isolated guinea pig ileum contractions induced by different mediators: serotonin, histamine, acetylcholine and potassium chloride (10-7 - 10-4 M). At 30 mg/mL all contractile responses were abolished. At 10 mg/mL only serotonin responses were altered: the extract reduced the maximal effect in 50%, which represents a non-competitive antagonism. At 1 and 3 mg/mL the extract was unable to modify all mediators response. These results point to native species of Hypericum as an interesting perspective in searching new molecules active on gastrointestinal motility.

The understanding of the scientific basis of the erectile function expanded rapidly the range of therapies for treating erectile dysfunction in recent years. This article reviews the role of dopamine on the erection mechanisms and its importance for new pro-erectile drug design. The ability of dopaminergic agents to elicit penile erection has been described since 1975 and successively confirmed by numerous studies. The development of apomorphine SL (dopaminergic non selective agonist) to enhance erectile function represents a new pharmacological approach to the management of erectile dysfunction using CNS drugs. The search for selective D4 dopaminergic agents is being explored by some research groups and pharmaceutical companies.