Estudo de padronização de extratos de folhas da caramboleira (Averrhoa carambola L.) na pesquisa e desenvolvimento de medicamentos antimicrobianos

Abstract

The pharmaceutical industry invests millions of dollars on research of new pharmacs with antimicrobial activity, that can be used to develop new medicines, highlighting the ones from natural sources. To produce any kind of medicine is important to assure the quality, efectiveness and safe and in this process the raw material should be analyzed. The genus Averrhoa (Oxalidaceae) has two species of economic interest: A. bilimbi (cucumber tree) and A. carambola (starfruit). They are plants that grown in Brazil and probable natives from Asia, both have usages in the food industry, pharmaceutical potential and have many traditional uses against various pathologies. This dissertation was divided in two parts. The first part consists of a literature review covering botanical, economic, chemical, pharmacological and toxicity aspects of A. carambola and A. bilimbi, where it was observed that the majority of the studies is about A. carambola, which has over 170 compounds identified, mainly phenolic glycosides. Both plants have pharmacological studies with antimicrobial, antioxidant, cytotoxic, hypoglycemic, antitumor actions. Most studies were performed with hydroalcoholic and methanolic extracts, with some activity relating to isolated compounds. Further studies on chemical composition and biological activities of these species are needed, especially A. bilimbi, and of their biological properties. The data can support the future studies with these species. In the second part we aimed to provide data for the standardization of extracts from A. carambola L., from chemical and biological assays of antimicrobial activity, to contribute to produce safe medicines. The antimicrobial activity was performed with bacteria, using microdilution methods and difusion in agar well technique. Sample leaves of A. carambola was collected in the region of Matões in Maranhão state. The dried and powdered leaves were used to obtain hydroalcoholic extracts from factorial design, with variables as different extractive methods (maceration, percolation and Soxhlet apparatus) and hydromodules (1: 8, 1:12 and 1:16). The extracts were evaluated, qualitatively and semi-quantitatively chemical constituents, total polyphenol content, flavonoid content and antimicrobial activity against S. aureus, E. coli, P. aeruginosa and K. pneumoniae. The extracts presented differences in color, quantitative variations in the chemical constituents and content of flavonoids and phenolic compounds. It was also observed differences in antimicrobial activity of the extracts tested in the two methods. The extract obtained, by percolation and using hydromodule ratio of 1: 8 showed the more expressive results for chemical composition and biological activity, thereby confirming that the examined variables influenced the composition of the extracts and consequently in the results. We have showed the best methods for this species to get an extract with antimicrobial activity.