Anti-inflammatory and antiviral activities of flavone C-glycosides of Lophatherum gracile for COVID-19

• DOI: 10.1016/j.jff.2023.105407
• Publication Date: 2023-01-05T08:57:29Z
• Authors: Yu-Li Chen; Chun-Yu Chen; Kuei-Hung Lai; Yu-Chia Chang; Tsong-Long Hwang
• Keywords: 0301 basic medicine; 03 medical and health sciences; Neutrophils; SARS-CoV-2; Nutrition. Foods and food supply; Lophatherum gracile; COVID-19; Flavone C-glycosides; TX341-641; Article

Lophatherum gracile (L. gracile) has long been used as a functional food and herbal medicine. Previous studies have demonstrated that extracts of L. gracile attenuate inflammatory response and inhibit SARS-CoV-2 replication; however, the underlying active constituents have yet to be identified. This study investigated the bioactive components of L. gracile. Flavone C-glycosides of L. gracile were found to dominate both anti-inflammatory and antiviral effects. A simple chromatography-based method was developed to obtain flavone C-glycoside-enriched extract (FlavoLG) from L. gracile. FlavoLG and its major flavone C-glycoside isoorientin were shown to restrict respiratory bursts and the formation of neutrophil extracellular traps in activated human neutrophils. FlavoLG and isoorientin were also shown to inhibit SARS-CoV-2 pseudovirus infection by interfering with the binding of the SARS-CoV-2 spike on ACE2. These results provide scientific evidence indicating the efficacy of L. gracile as a potential supplement for treating neutrophil-associated COVID-19.