Activités biologiques des extraits aqueux de Cotula cinerea (Astéraceae) de la région de Ghardaïa

Abstract

This Works focuses on the valorization of spontaneous species of the northern Sahara Cotula cinerea (Asteraceae) in characterizing the determination of certain phenolic compounds (polyphenols, flavonoids, phenolic acids and condensed tannins) and evaluation of biological activities (anti -oxydante and antibacterial) its various aqueous extracts. These extracts are obtained by conventional preparation methods which are: decoction, infusion and maceration. The results obtained showed that the extract obtained by decoction has the highest values of yield (22.71 ± 1.05%) and polyphenols which is (2853.30, 256.78 ±). Regarding the contents of flavonoids, phenolic acids and condensed tannins, the extract is obtained by macerating the richest in these compounds with rate of (690.92 ± 72.08), (333.33 ± 28.87) ( 1069.79114 ± 91.83, respectively. The antioxidant activity of these extracts was determined by three tests that are ABTS, DPPH and FRAP. Different Cotula cinerea aqueous extracts were reacts differently with these tests. In fact, better activity for ABTS test is achieved with the decoction (6389,85μM AND / g), whereas for the test of DPPH and the larger FRAP activities were obtained with the maceration and are (2002.27 ± 17 , 39) AND .mu.M / g and (7576.19 ± 67.51) AND .mu.M / g respectively. The IC50 for ABTS and DPPH test and EC50 for FRAP were determined the results are determined maceration IC50 = 21.19 g / ml , the infusion IC50 = 11.51 mg / ml and the infusion and maceration is equal to 0.14 mcg / ml , respectively. The various extracts were also subjected to screened for their potential antibacterial activity. The results obtained showed that aqueous extracts of different Cotula cinerea have no antibacterial activity.