Espécies vegetais no tratamento das disfunções sexuais: revisão sistemática, estudo etnofarmacológico, análise química e atividade biológica de Cinnamomum verum J. Presl

Abstract

The therapeutic use of plants and their derived preparations must be based on parameters of efficacy, safety and quality, certified by validation studies, which must be based on criteria for the selection of target material for the investigation. In this sense, ethnopharmacological studies represent an essential tool for the selection of plant species, in the perspective of obtaining new drugs from material traditionally used popularly, especially in diseases of great impact on public health such as sexual dysfunctions, especially erectile dysfunction. Thus, the objective of this work was to carry out a systematic review of the plant species used in sexual disorders, to develop an ethnopharmacological study of plant species used in popular practices for the treatment and / or prevention of such disorders in São Luis, Maranhão, Brazil and to develop a bioprospecting study ( chemical and biological analysis of the action on the corpora cavernosa) of Cinnamomum verum J. Presl (cinnamon), a plant species selected by the ethnopharmacological study, aiming to contribute to the research and development of new alternatives and / or therapeutic complements. The systematic review was performed in electronic databases covering articles from 2008 to 2019, showing an indication of 66 species, belonging to 42 families, predominating: Tribulus terrestre L. (Zygophyllaceae), Lepidium meyenii Walp. (Brassicaceae), Crocus sativus L. (Iridaceae) and Anthocleista djalonensis A. Chev. (Gentianaceae). In the ethnopharmacological survey, interviews were used with adult users of health facilities in the municipality of São Luís, with a prevalence of 28.60% for knowledge of aphrodisiac plant species (62.80% female) and 8.07% refer to use plants with this medicinal purpose (56.52% male); evidencing that 89.79% of the interviewees who mention knowledge and / or use of plants in sexual dysfunctions do not recognize dangers in the use, confirming Trichilia catigua Adr. Juss. (catuaba) and Cinnamomum verum J. Presl (cinnamon) as the most commonly used species in the study sample. Based on the ethnopharmacological survey, Cinnamomum verum was selected for chemical (phytochemical screening, polyphenols and flavonoid content) and biological (evaluation of the effect on reactivity in mouse cavernous bodies) characterization tests. The species was subjected to maceration extraction of bark powder, using ethanol / water (70:30 v/v), in the drug/solvent ratio of 1: 6 (v/v) (EHCV), with a yield of 27.16 %; proving the presence of alkaloids, phenols, flavonoids, saponins, condensed tannins and triterpenes, with a concentration of 370.05 ± 21.67 mgGA/g and flavonoid content of 14.52 ± 0.46 mgQ / g, of flavonoids. The effect of EHCV (50 µg/mL) on the cavernous bodies (CC) of C57BL / 6 mice, aged between 10 and 12 weeks (25 g), showed a statistical difference only when assessing relaxation against acetylcholine concentration-response curves (ACh), with difference between the groups incubated with EHCV for 30 min when compared to the vehicle, promoting a decrease in the maximum effect produced by the agonist (Emáx), and between EHCV incubated for 120 min versus vehicle, with an increase in the negative logarithm of the molar concentration which produces 50% of the maximum response (pD2). Thus, a 120 min time was selected for tests with different concentrations (15 µg / mL, 50 µg / mL and 150 µg / mL) of EHCV. In this step, the statistical difference occurred only in the ACh concentration-response curve, with a decrease in Emáx in the group incubated with 150 µg/mL EHCV compared to the vehicle; and again, in the pD2 values between the EHCV groups 50 µg / mL versus vehicle, with an increase in the group incubated with the extract. These results, taken together, signal the potential action of the EHCV in improving the relaxation of the CC, with verification of chemical constituents that justify such potential, which, together, should stimulate the continuity of studies in the perspective of seeking new options in therapy erectile dysfunction, as well as the need for actions to maintain and enhance traditional knowledge, but with guarantee of safety, efficacy and quality of plant species used for therapeutic purposes.