Análise microscópica, química e atividades antioxidante e anti-inflamatória do óleo essencial e extrato aquoso de folhas de Tetrapanax papyrifer (Hook.) K.Koch

Abstract

Tetrapanax papyrifer (Hook.) K.Koch (Araliaceae) is popularly known as rice paper tree, tung-tsao, bok-shunge, kamiyatsude and embaúba. It originates from China, growing mainly on the edges of forests in Taiwan. Considered an exotic plant, its leaves and stem are the most used organs in folk medicine with anti-inflammatory, antitussive, antithrombotic, antihepatotoxic, anticancer, analgesic, antioxidant, diuretic and antimicrobial action. The morpho-anatomical study, chemical characterization and determination of biological activities is extremely important, as plant species are commonly confused, especially when they are known by the same popular name. The main objective of the present study was to determine the microscopic and microchemical characteristics of T. papyrifer leaves, in addition to evaluating the

chemical profile of the essential oil and the aqueous extract, as well as testing the anti- inflammatory and antioxidant activity of the extract. To analyze the microscopic

characteristics, light microscopy and field effect scanning electron microscopy methods were used. The essential oil was extracted by hydrodistillation and characterized by gas chromatography coupled to mass spectrometry. The constituents of the aqueous extract were chemically characterized. The main anatomical markers were amphi-hypostomatic leaf, multicellular non-glandular trichomes uniseriate at the base with branched apical portion, dorsiventral mesophyll, collateral vascular bundles, midrib with biconvex shape, uniseriate epidermis, calcium oxalate drusen and secretory ducts. Microchemical analysis revealed the presence of starch grains, pectins, oleoresin and phenolic, lipophilic and lignified compounds. The main special

metabolites found in the essential oil were β-pinene (27,73%), α-pinene (12,23%), β- selinene (11,74%) and nerolidol (7,13%). In the analysis of the aqueous extract, signs

of phenolic compounds, flavonoids, flavonol and condensed tannins were observed. The analysis of antioxidant activity (DPPH, ABTS + and β-carotene/linoleic acid) was carried out for both the essential oil and the extract, which obtained a superior result

(IC50 29,33 ug/mL) when compared to the essential oil. In tests to verify the anti- inflammatory activity of aqueous extract Tetrapanax papyrifer (EATP), it showed anti- hyperalgesic action. The results obtained in the morphoanatomical characterization

and the special metabolites found in both the extract and the essential oil, contribute to the identification of T. papyrifer and confirm its use as an anti-inflammatory agent.