Antibiofilm, Antioxidant, Antimutagenic Activities and Phenolic Compounds of Allium orientale BOISS.

This is the first study to investigate the antibiofilm, antioxidant and antimutagenic activities and phenolic compounds of Allium orientale. Antimicrobial activity of ethanolic extracts of A. orientale was determined by a broth microdilution method. Antibiofilm activity was evaluated by microplate biofilm assay. The antioxidant activity was determined using three complementary assays; namely, DPPH scavenging, beta-carotene-linoleic acid, and total phenolic compounds assays. Phenolic compounds were evaluated by reverse-phase high-performance liquid chromatography. The antimutagenic effect of extracts was analyzed by the Ames test. In RP-HPLC analysis, (+)-catechin, apigenin and caffeic acid were identified as major phenolic compounds in the aerial parts of A. orientale. The aerial parts extract possessed the highest total phenolic content (120.979 +/- 1.05 mg gallic acid equivalent/g), which were in good correlation with its significant DPPH (IC50 42.18 +/- 1.68 mg/mL) and lipid peroxidation (89.98 +/- 0.69% at 10 mg/mL concentration) capacities. A. orientale exhibited potent antimicrobial activity against the organisms tested with MICs ranging from 3.125 to 25 mg/mL. Escherichia coli biofilm formation was inhibited maximum by the aerial parts extract to an extent of 68.51%. The strongest antimutagenic activity was observed at 2.5 mg/plate concentration of aerial parts extract against Salmonella typhimurium TA98. These results suggested that the ethanolic extract of the aerial parts of A. orientale could become useful supplement for pharmaceutical products as a new antioxidant, antibiofilm and antimutagenic agent.