Pesquisa de atividade biológica de extratos de seis espécies de Plectranthus : P. cylindraceus, P. petiolaris, P. spicatus, P. swynnertonii, P. Welwitschii e P. woodii
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2019
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O género Plectranthus, tem sido usado na medicina tradicional, sendo os diterpenos o grupo de compostos bioativos mais proeminentes.
Esta dissertação tem como objetivo avaliar a atividade biológica (atividades antimicrobiana e antioxidante, inibição da acetilcolinesterase -AchE- e toxicidade geral) de extratos acetónicos de seis espécies: Plectranthus swynnertonii, P. welwitschii, P. woodii, P. cylindraceus, P. spicatus e P. petiolaris.
Os extratos em estudo foram obtidos usando o método de extração por ultrassons (10% m/v), onde o P. petiolaris obteve o maior rendimento de extração (11,07 % m/m). No ensaio de inibição da AChE, o extrato de P. cylindraceus foi o mais ativo (30,16 ± 3,78%). A atividade antimicrobiana foi avaliada pelo método de difusão em poços, contra bactérias Gram positivas, negativas e leveduras, porém, nenhum extrato demostrou atividade antimicrobiana relevante.
A atividade antioxidante foi avaliada usando o método de DPPH, onde o extrato de P. swynnertonii demonstrou ser o mais ativo (20,24 %). No ensaio da toxicidade geral em Artemia salina, o extrato de P. swynnertonii foi o mais tóxico (CL50 de 0,036 mg / L).
Em conclusão, os extratos de P. cylindraceus e de P. swynnertonii demonstraram um maior potencial para futuros trabalhos, nomeadamente, isolamento, caracterização estrutural e posterior citotoxicidade.
The genus Plectranthus, has been used in traditional medicine, with diterpenes being the most prominent group of bioactive compounds. This dissertation aims to evaluate the biological activity (antimicrobial and antioxidant activities, acetylcholinesterase -AchE- inhibition and general toxicity) of acetone extracts from six species: Plectranthus swynnertonii, P. welwitschii, P. woodii, P. cylindraceus, P. spicatus and P. petiolaris. The extracts under study were obtained using the ultrasonic extraction method (10% m/v), where P. petiolaris obtained the highest extraction yield (11.07% m / m). In the AChE inhibition assay, P. cylindraceus was the most active (30.16 ± 3.78%). The antimicrobial activity was evaluated by the diffusion method in wells, against Gram-positive, negative and yeast bacteria, however, no extract showed relevant activity. The antioxidant activity was evaluated using the DPPH method, where the extract of P. swynnertonii showed to be the most active (20.24%). In the general toxicity assay in Artemia salina, the extract of P. swynnertonii was the most toxic (LC50 of 0.036 mg / L). In conclusion, the extracts of P. cylindraceus and P. swynnertonii demonstrated a greater potential for future works, namely, isolation, structural characterization and subsequent cytotoxicity.
The genus Plectranthus, has been used in traditional medicine, with diterpenes being the most prominent group of bioactive compounds. This dissertation aims to evaluate the biological activity (antimicrobial and antioxidant activities, acetylcholinesterase -AchE- inhibition and general toxicity) of acetone extracts from six species: Plectranthus swynnertonii, P. welwitschii, P. woodii, P. cylindraceus, P. spicatus and P. petiolaris. The extracts under study were obtained using the ultrasonic extraction method (10% m/v), where P. petiolaris obtained the highest extraction yield (11.07% m / m). In the AChE inhibition assay, P. cylindraceus was the most active (30.16 ± 3.78%). The antimicrobial activity was evaluated by the diffusion method in wells, against Gram-positive, negative and yeast bacteria, however, no extract showed relevant activity. The antioxidant activity was evaluated using the DPPH method, where the extract of P. swynnertonii showed to be the most active (20.24%). In the general toxicity assay in Artemia salina, the extract of P. swynnertonii was the most toxic (LC50 of 0.036 mg / L). In conclusion, the extracts of P. cylindraceus and P. swynnertonii demonstrated a greater potential for future works, namely, isolation, structural characterization and subsequent cytotoxicity.
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Orientação: Patrícia Dias Mendonça Rijo
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MESTRADO INTEGRADO EM CIÊNCIAS FARMACÊUTICAS, CIÊNCIAS FARMACÊUTICAS, PHARMACEUTICAL SCIENCES, PLANTAS MEDICINAIS, MEDICINAL PLANTS, DITERPENOS, DITERPENES, ACETILCOLINESTERASE, ACETYLCHOLINESTERASE, ANTIOXIDANTES, ANTIOXIDANTS, ANTIMICROBIANOS, ANTIMICROBIAL, TOXICIDADE, TOXICITY