UHPLC/TOFHRMS analysis and anti-inflammatory effect of leaf extracts from Zizyphus jujuba in LPS-stimulated RAW264.7 cells

Zizyphus jujube is a plant in the buckthorn family (Rhamnaceae) that has been the subject of research into antibacterial, antifungal and anti-inflammatory properties of its fruit and seed. However, few studies have investigated its leaves. In this study, the anti-inflammatory activity of ZJL (an extract of Z. jujube leaf) was evaluated to verify its potential as an anti-inflammatory agent and SARS-CoV-2 medicine, using nitric oxide (NO) assay, RT-PCR, SDS-PAGE, Western blotting, and UHPLC/TOFHRMS analysis. We found that ZJL suppresed pro-inflammatory mediators such as NO, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumor necrosis factor α (TNF-α) in lipopolysaccharide (LPS)-induced RAW264.7 cells. ZJL acted by inhibiting NF-KB and MAPK signaling pathway activity. We also confirmed that ZJL contains a phenol compound and flavonoids with anti-inflammatory activity such as trehalose, maleate, epigallocatechin, hyperoside, catechin, 3-O-coumaroylquinic acid, rhoifolin, gossypin, kaempferol 3-neohesperidoside, rutin, myricitrin, guaiaverin, quercitrin, quercetin, ursolic acid, and pheophorbide a. These findings suggest that ZJL may have great potential for the development of anti-inflammatory drugs and vaccines via inhibition of NF‐ĸB and MAPK signaling in LPS-induced RAW264.7 cells. © Korean Society for Plant Biotechnology.