DOI: 10.36347/sajb.2019.v07i03.003

Pages: 125-130

Context: Opuntia ficus- indica L. a médicinal plant traditionally used in the treatement of liver disorders, rheumatism, renal diseases, hypoglycemic and hypocholesterolemic in Algeria. Aims: The aim of this study is to determine the content of polyphénols and flavonoïds and to evaluate the antioxidant activity of the aqueous (AqE) and methanolic (ME) extracts of flowers of Opuntia ficus- indica L. Methods: the content of polyphénols was determined by Folin-ciocalteu and flavonoids by Aluminium trichloride, Antioxidant activity in vitro was evaluated using DPPH (2'2-diphenylpicrylhydrazyl), β-carotene /linoleic acid bleaching, chelation of ferrous iron and reducing power tests. Results: The ME was richer in polyphénols (167, 1± 1, 74 µg AGE\mg extract) than the AqE (120, 9 ± 4, 24µg AGE\mg extract). The ME contains (56.07 ± 0, 16 µg QE\mg extract) of flavonoïds and the AqE contains (22.50 ± 0, 06 µg QE\mg extract). AqE has higher antiradical activity (IC50=0,482 ± 0, 0228 mg/ml) than the ME (IC50=3,813 ± 0,075 mg/ml). AqE and ME have a strong capacity to inhibit the lipid peroxidation in the β-carotene /linoleic acid bleaching test with an antioxidant activity of 89.791±0.015% and 83.079±0.074% respectively. The two studies extracts have a chelation activity, compared with the EDTA, the AqE has higher chelation activity (inhibition of the formation of Fe2+-ferrosine complex) with IC50 = 4, 62 ± 0, 12 µg\ml than the ME with IC50 = 22, 64 ± 1, 53µg\ml. The ME has the higher reducing power (IC50=0, 39± 0,005mg/ml) than AqE (IC50=1, 22 ± 0,126 mg/ml). Conclusions: These results show the possibility of using the flowers of Opuntia ficus- indica L. as an antioxidant in folk medicine