POLYPHENOLS CONTENT AND EVALUATION OF ANTIOXIDANT ACTIVITY OF ANACYCLUSPYRETHRUM(L.) LAG. FROM TIMAHDITE A MOROCCAN MIDDLE ATLAS REGION.

Abstract

As part of valorisation of medicinal and aromatic plants from Timahdite, a region located in Moroccan Middle Atlas, we focused our study on an endemic species which belongstoAsteraceae family: Anacyclus pyrethrum L. This species, widely used by local people in traditional pharmacopeia, was chosen to conduct phytochemical studies and to assess the antioxidant activity of its roots, leaves and flowers extracts. Thus, the plant was harvested in May 2014. The selected organs (roots, leaves and flowers) of Anacyclus pyrethrum were sorted, cleaned and dried separately. Then, they were reduced into powder and stored away from light in a cool and dry place until use. Each organ was subjected to a phytochemical screening in order to qualitatively highlight its secondary metabolites. This qualitative analysis shows that roots are rich in alkaloids while the aerial parts (leaves and flowers) are rich in tannins and flavonoids. Extraction of total polyphenols was performed by maceration using methanol / water (70/30) as solvent. Yields were 2.30% for roots, 3.3% for leaves and 3.8% for flowers. Then, fractionation of hydro-methanol crude extract was carried out using successively three organic solvents of increasing polarity: chloroform, ethyl acetate and butanol. Quantitative analysis of total polyphenols conducted with Folin-Ciocalteu reagent showed that hydro-methanol crude extracts are richer in phenolic compounds than other fractions. Antioxidant activity of crude extracts determined through DPPH test was spectrophotometrically quantified and values of the half-maximal inhibitory concentrations (IC50) were graphically determined. These values are 77.62μggallic acid equivalent (GAE) / ml for flowers, 94.18μg / ml for leaves and 145.81μg / ml for roots, while 46.79μg / ml was found for ascorbic acid which was used as standard. Finally, a correlation was observed between total polyphenols content and antioxidant capacity determined by DPPH method: Aerial parts