Assessment of antioxidant activities and phenolic contents of some edible plants
Antioxidants have the ability to protect cells against the damaging effects of reactive oxygen species, such as singlet oxygen, superoxide, peroxyl radicals, hydroxyl radicals and peroxynitrite. An imbalance between antioxidants and reactive oxygen species results in oxidative stress that finally leads to cellular damage. On the other hand, oxidative stress has been linked to cancer, aging, atherosclerosis, ischemic injury, and inflammation along with neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Therefore, antioxidant compounds naturally occurring in plants may play a significant role for health protection.
In the current study, the ethanolic extracts prepared from the fruits of Turritis laxa (Sibth & Sm.) Hayek (Brassicaceae), Fritillaria pontica Wahlenb. (Liliaceae), Euonymus latifolius (L.) Mill. ssp. latifolius (Celastraceae), and Vicia sativa L. ssp. nigra (L.) Ehrh. var. nigra L. (Fabaceae), from the aerial parts of Vicia cracca L. (Fabaceae) and Oxyria digyna (L.) Hill. (Polygonaceae) were screened for their antioxidant activities by 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity test and ferric-reducing antioxidant power assay (FRAP) at 0.5, 1.0, and 2.0mg/ml concentrations using gallic acid and butylated hydroxyl anisol (BHA) as references. Total phenolic contents of the extracts were also determined using Folin-Ciocalteau reagent. T. laxa was also tested for its anti-acetylcholinesterase activity at 0.25, 0.5, 1.0, and 2.0mg/ml concentrations.
The extracts were analyzed by LC-DAD-MS for their flavonoid content and the ethanolic extract of T. laxa has been found to be remarkably rich in rutin (7.63%). It was also the most active in the antioxidant tests. To the best of our knowledge, this is the first study on antioxidant activity of the above-mentioned plants as well as existence of rutin in T. laxa.