Phytochemical screening, antioxidant, antityrosinase, and antigenotoxic potential of Amaranthus viridis extract.

Amaranthus viridis (Amaranthaceae) widely distributed all over the world, growing under a wide range of climatic conditions and has been utilized as a medicinal herb in traditional Ayurvedic medicine as antipyretic agents, also for the treatment of inflammation, ulcer, diabetic, asthma and hyperlipidemia. The aim of the study was designed to evaluate the chemical composition and antioxidant and biological properties of different fractions obtained from A. viridis.

Four different extracts of A. viridis were prepared using aqueous, methanol, chloroform, and hexane and investigated their antioxidant potential using free radical scavenging activities such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and nitric oxide (NO) radical scavenging activity, as well as metal chelating activity. In addition, antityrosinase and antigenotoxicity properties were also evaluated by the standard in vitro methods. Finally, the active methanolic extract (ME) was investigated for identifying the phenolic compounds using UPLC-MS/MS.

In the present study, chlorogenic acid, gulonic acid, and kaempferol were found to be the major components responsible for the antioxidant activity of A. viridis extract as evidenced from UPLC-MS/MS. Furthermore, the ME of A. viridis revealed excellent antioxidant activities such as DPPH radical scavenging activity (IC50= 47.23 ± 0.66 μg/mL), NO radical scavenging activity (IC50= 64.33 ± 2.01 μg/mL), hydrogen peroxide (H2O2) radical scavenging activity (IC50= 33.21 ± 3.3 μg/mL), ABTS radical scavenging activity (IC50= 47.61 ± 1.31 μg/mL), metal chelating activity (IC50= 32.1 ± 1.11 μg/mL), as well as lipid peroxidation inhibiting activity (IC50= 112 ± 1.21 μg/mL). Furthermore, ME revealed that the protective effects of extract were observed on H2O2-induced DNA damages with alkaline comet assay.

Taken together, the study concluded that the promising antioxidant capacities of A. viridis extract can further be utilized in various agricultural, pharmaceutical, and food applications.