Phytochemical screening and evaluation of the antioxidant and antibacterial activity of ‎Atriplex halimus from two regions Algeria (El Oued and Tlemcen)

Abstract

The purpose of this work is to study the antioxidant and antibacterial activity of two plants of the same species « Atriplex halimus » from two different regions El Oued and Tlemcen. The plant leaves were subjected to a one-hour reflux extraction in methanol/acetone (70/30: v/v). Qualitative phytochemical examination of the leaf extract showed the presence of alkaloids, tannins and flavonoids of varying intensity. Coumarins, terpenoids and saponins are absent in both plants. Qualitative analysis of total polyphenols, flavonoids and condensed tannins of extracts shows that Atriplex halimus from the El Oued region has a high content of total polyphenols (10.25 ± 1.17 mg GAE/g DW) and tannins (9.23 ±1.09 mg EC/g DW) compared to Tlemcen. However, the high flavonoid content presented by Atriplex halimus from the Tlemcen region (3.09 ± 0.13 mg EC/g DW). The evaluation of the antioxidant activity of the extracts was carried out by three methods: total antioxidant capacity, trapping of the free radical DPPH and iron reducing power, the results obtained show that the extract of Atriplex halimus from Tlemcen reveals an interesting activity compared to that of El Oued with a CI50 = 193.47 ± 1.79µg/mL. Evaluation of antibacterial activity showing that El Oued extract has activity against Salmonella typhimirium ATCC 13311, Enterobacter cloacae ATCC 13047, Staphylococcus aureus ATCC 6538 and Listeria monocytogenes ATCC 15313 with a CMI value of 5 mg/mL, 10 mg/mL and 2.5 mg/mL respectively. However, Atriplex halimus from Tlemcen does not reveal any antibacterial activity against the strains tested.