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Seasonal variation of the chemical composition and antioxidant activity of leaf extracts of "Maytenus ilicifolia" Mart. ex Reiss, "Maytenus aquifolium" Mart. (Celastraceae) and their hybrid

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Author(s):
Elisa Ribeiro Miranda Antunes
Total Authors: 1
Document type: Master's Dissertation
Institution: Universidade Estadual de Campinas, Instituto de Biologia
Defense date:
Advisor: Alexandra Christine Helena Frankland Sawaya
Abstract

The species "Maytenus ilicifolia" and "Maytenus aquifolium", commonly known as "Espinheira Santa" are widely used in Brazilian traditional medicine for treatment of gastritis and dyspepsia. Several studies have confirmed that both species have gastroprotective and antiulcerogenic activities, whose action may be related to their antioxidant properties. According to some studies, the high production of reactive oxygen and nitrogen species, cause severe cellular alterations, characterizing a state of oxidative stress. Therefore, the impairment of the antioxidant defense system has been associated with the pathogenesis of stress-related lesion of the gastric mucosa. However, to obtain a high quality phytotherapic and to propose a standardization criteria, it is essential to know the chemical variability of the species used as raw material. Regarding the seasonal variations in the chemical composition of the Maytenus genus, there is only one study in the literature in which it was observed that during the spring the plants presented higher levels of flavonoids and total phenols, while in winter, they presented higher levels of triterpenes. The present work aimed to identify possible seasonal variations on the chemical composition of the leaf extracts of these species and their hybrid. For this, leaf samples were collected from 5 individual of of "M. ilicifolia", "M. aquifolium" and their hybrid, monthly over a year. The leaf extracts were analyzed by ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) and submitted to antioxidant tests of DPPH and ORACFL. Through the results obtained it was possible to conclude that the chemical difference between the species were more pronounced that possible seasonal variations. The hybrid, however, presented more chemical, biological and morphological similarities with the species "M. aquifolium". Furthermore, differences in 4 features were observed, which demonstrated higher intensities in the months of October and May. Such variations may be the result of climate variations in the months in question or the response to damage and the signaling between plants, capable of altering the chemical composition of the individuals not pruned. All the samples demonstrated accentuated antioxidant activity, with "M. ilicifolia" as the most efficient on the DPPH assays and "M. aquifolium"on the ORACFL assays, showing that differences in composition interfere on the antioxidant efficiency, depending on the assay's mechanism (AU)

FAPESP's process: 17/00155-5 - Seasonal variation of the chemical composition and antioxidant activity extracts of leaves of Maytenus ilicifolia Mart. ex Reiss, Maytenus aquifolium Mart (Celastraceae) and their hybrids
Grantee:Elisa Ribeiro Miranda Antunes
Support type: Scholarships in Brazil - Master