Phenolic composition, antioxidant, antibacterial and anti-inflammatory activities of leaf and stem extracts from Cryptotaenia japonica Hassk

Cryptotaenia japonica Hassk. is a traditional medicinal plant in China to treat different diseases, as well as an edible leafy vegetable, but its biological functions is unknown. This study aimed to evaluate the antioxidant, antibacterial and anti-inflammatory activities of different phenolic extracts/fractions, which prepared with four kinds of methods and three kinds of polar solvent from Ctyptotaenia japonica Hassk. leaf and stem. DPPH, ABTS, and reducing power assays were used to evaluate their antioxidant activity; antibacterial activity assay was assessed by Escherichia coil, Staphylococcus aureus, Bacillus subtilis, and beta-hemolytic streptococcus; inflammatory cytokine secretions were detected by ELISA assay. UPLC-ESI-MS/MS was used to identify the phenolics compounds. Compared with other extracts/fractions, the ethyl acetate fraction (EAF) had the highest amount of total phenolic and total flavonoids. It also exhibited strong DPPH, ABTS radical scavenging activities, reducing power, and antibacterial activity. This fraction also exhibited greater inhibitory effects on secretion of inflammatory cytokines. Six kinds of phenolic acid compounds from Cryptotaenia japonica Hassk. were indentified and luteolin (106806.1 mu g/g dried weight, DW), apigenin (13780.8 mu g/g DW) and p-coumaric acid (8004.8 mu g/g DW) are main compounds. The results suggest that Cryptotaenia japonica Hassk. is a promising source of natural antioxidant, antibacterial and anti-inflammatory constituents for application in the food and pharmaceutical industries.