Estudo fitoquímico e biológico do óleo essencial e extrato bruto etanólico das folhas de Pogostemon cablin (Blanco) Benth

Abstract

Introduction: Pogostemon cablin (Blanco) Benth, popularly known as Oriza and Patchouli is a plant of the family Lamiaceae, which has several biological activities including antimicrobial, antioxidant, analgesic, anti-inflammatory, antithrombotic, antidepressant, cytotoxic and recognized entomotoxic potential that serve as alternative strategy for the chemical control of A. aegypti. Objective: To carry out the chemical study and evaluation of the antioxidant, cytotoxic, antimicrobial and larvicidal activity of the essential oil and crude ethanolic extract of P. cablin. Methodology: The identification of metabolites was performed by phytochemical tests, quantification of total phenolics for extracts, and GC-MS for essential oil. The larvicidal activity was performed against the larvae of A. aegypti. The antioxidant activity was evaluated by the sequestering ability of 2,2-diphenyl-1-picryl-hydrazyl (DPPH). As for the microbiological evaluation, the technique of dilution in microplates against three bacteria was used. The cytotoxic activity was evaluated against larvae of Artemia salina. Results and discussion: The species P. cablin presented the following major compounds in the essential oil: patchouli alcohol (33.25%), Seyshellene (6.12%), α-bulnesene (4.11%), Pogostol 33%) and Norpatchouleno (5.72%), in the extract the classes of compounds: steroids and triterpenoids, depsides and depsidones, which in synergy with the other substances potentiated the significant larvicidal action of the species with LC50 of 28.43 μg.mL-1 for oil, and LC50 of 63.91 μg.mL-1 for the extract, in 24 h. There was no antioxidant activity, however, the essential oil presented antimicrobial activity against all bacteria tested with MIC and CBM of 62.5 μg.mL-1 and the extract showed inhibition of bacterial growth against E. coli with MIC of 31.25 μg.mL -1 . The essential oil showed a significant LC50 toxicity of 24.25 μg.mL-1 and the moderate extract LC50 toxicity of 257.93 μg.mL-1. Conclusions: The P. cablin species showed a significant larvicidal potential with antimicrobial action, absence of antioxidant action and high toxicity