Banca de DEFESA: KARINA ALCÂNTARA DE SOUSA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : KARINA ALCÂNTARA DE SOUSA
DATE: 27/05/2022
TIME: 08:30
LOCAL: https://meet.google.com/qyy-bdjv-krf
TITLE:

Volatile constituents and anticholinesterase activity of the essential oil of three chemotypes of Lippia alba (Mill.) N.E.Br. ex Britton & P.Wilson Verbenaceae

KEY WORDS:

Lippia alba; essential oil; GC-MS; acetylcholinesterase inhibition.

PAGES: 78
BIG AREA: Ciências da Saúde
AREA: Saúde Coletiva
SUMMARY:

Ethnopharmacological relevance: Lippia alba (Mill.) N. E. Brown (Verbenaceae), is a plant that is frequently utilized due to the wide chemical variation of its essential oils. The diversification of the components of essential oils is responsible for its diverse uses in traditional medicine applications. However, the wide chemical variation of chemotypes of Lippia alba is not without concern with respect to its use as a phytotherapeutic medicine since the user could be using material that is not adequate to the achieve the desired effect.Aim of the study: Evaluate if the essential oil of three specimens of Lippia alba have an inhibitory effect on the acetylcholinesterase enzyme.Methods: The volatile constituents of the essential oils obtained through hydrodistillation (L.alba1 and L.alba2) and by steam distillation (L.alba3) were determined by gas chromatography–mass spectrometry and were then submitted to acetylcholinesterase enzyme inhibition trials using the direct bioautography methods of Marston et al., (2001) and Ellman et al., (1961) with modifications.Results:The chromatographic profiles of the principle volatile constituents of the essential oil samples showed three distinct chemotypes:  L.alba1 with a high content of citral (neral 23.84% and geranial 32.31%); L.alba2 with carvone (30.72%), 1,8-cineol (14.37%) and limonene (10.3%), and L.alba3 principally constituted of linalool (68.31%).  All essential oil samples displayed inhibitory activity to the acetylcholinesterase enzyme, with L.alba1 showing the highest inhibition (I%: 97.9 ± 0.8), followed by L.alba2 (I%: 54.3 ± 5.6) and L.alba3-(I%: 46.9 ± 5.6). The percentage of inhibition of acetylcholinesterase shown by the isolated citral constituent (synthetic) was lower (49.3%±12.2) than for the L.alba1 chemotype, suggesting a synergism between the constituents present in the essential oils than can enhance  anticholinesterase activity.Conclusions:  The essential oil of L. alba is a potent inhibitor of the acetylcholinesterase enzyme, and this activity varies between moderate and high depending on the chemotype. In this way, as an aid in the tracking of phytotherapeutic raw materials, programs of plant seedling production and distribution should include botanical and chemical identification of accessions of L. alba.

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Externo à Instituição - PABLO LUÍS BAIA FIGUEIREDO - UEPA