RESUMO
Abstract Hedyosmum brasiliense Miq., Chloranthaceae, has been used in Southern Brazil as a sedative, anti-inflammatory, and aphrodisiac. In this study, endothelium-intact and endothelium-denuded rat aortic rings and strips of corpus cavernosum were used to investigate the relaxant effects of an hexane fraction of leaves of H. brasiliense and its sesquiterpene lactones 13-hydroxy-8,9-dehydroshizukanolide, podoandin, and elemanolide 15-acetoxy-isogermafurenolide. The incubation of hexane fraction of leaves of H. brasiliense resulted in significant relaxation of endothelium-intact aortic rings previously contracted by phenylephrine. In addition, 13-hydroxy-8,9-dehydroshizukanolide and podoandin displayed a clear concentration-dependent ability to relax endothelium-intact (∼85 to 90%) and endothelium-denuded (∼45 to 55%) rat aortic rings. A less pronounced vascular relaxation was recorded when 15-hydroxy-isogermafurenolide was tested. Interestingly, in tissues previously incubated with the nitric oxide synthase inhibitor L-NAME (100 µM), both 13-hydroxy-8,9-dehydroshizukanolide and podoandin had their effects in endothelium-intact vessels reduced to the same degree of relaxation observed in endothelium-denuded aortic rings. Podoandin, 13-hydroxy-8,9-dehydroshizukanolide, and 15-acetoxy-isogermafurenolide (100 µM) were also able to relax precontracted corpus cavernosum strips by 49.5 ± 3.9%, 65.9 ± 7.3% and 57.9 ± 5.5%, respectively. Our results demonstrated that 13-hydroxy-8,9-dehydroshizukanolide, podoandin and 15-acetoxy-isogermafurenolide, isolated from H. brasiliense, generate both endothelium-dependent and -independent relaxation of rat aortic rings, as well as being able to induce in vitro relaxation of rat corpus cavernosum. Importantly, the endothelium-dependent effect is fully dependent on nitric oxide production. Considering that penile erection depends on both relaxation of cavernosal smooth muscle and inflow of blood for the cavernous bodies, this is the first study reporting experimental evidence supporting the aphrodisiac properties of H. brasiliense.
RESUMO
This paper is the result of a visit by Brazilian researchers to Ghana, with the aim of improving understanding of the relationship between traditional healers and conventional health practices, specifically in relation to tuberculosis. Through this exploratory visit, this group of researchers promoted by the Edital Pro Africa (CNPq) had an opportunity to learn about, reflect on, and discuss the different social, economic and cultural realities and contexts that have led to the different health conditions and forms of healthcare in Ghana. Besides the direct relationship between the social and economic conditions of the country and the health of its population, it was also concluded that there is a clear distancing, in the Ghanaian reality, between the traditional healers and the conventional system, in terms of culture and modes of operation, each constituting isolated systems with little or no collaboration between them.The visit enabled us to see the difficulties involved in managing TB, including diagnosis, treatment, monitoring and co-infection with HIV. The majority of patients with TB only go to hospital after several attempts at self-medication, due to the non-specificity of the principal symptoms, and also to the trust in the traditional medicine. Initiatives to encourage research into medicinal plants in Ghana are seeking partnerships with developed countries, but not always with clear or secure national interests. For the traditional healers, there are high hopes that the information gathered by researchers from the local universities, on the plants and traditional methods they use, will result in affirmation and recognition of their practices, but they complain strongly that they receive no feedback on the research carried out.