TABLE 1.

Mechanism and research progress of EGCG

Mode of action	Effect	Research phase	System for experiment	Reference
EGCG target virus/host cells protein	1. Inhibits GRP78 receptor and makes it accumulate in ER rather than on cell membrane	Preclinical study (in vivo & in vitro)	Nervous system diseases (MME cells, Ren cells)	(Martinotti, Ranzato, & Burlando, 2018)
	2. Inhibits GRP78 expression by enhancing mir‐155‐5p level	Preclinical study	Colon cancer (HCT116)	(La, Zhang, Li, Li, & Yang, 2019)
	3. Inhibits the binding of S‐spike protein to ACE2 receptor and effectively blocks the infection of SARS‐COV‐2 and new variants	Preclinical study	SARS‐CoV‐2 and its variants with D614G, K417N, E484K, and N501Y mutation)	(Liu et al., 2021)
	4. Targets to inhibit 3CLpro	Preclinical study (in vitro)	SARS‐CoV‐2	(Zhu & Xie, 2020)
Regulate immune level	Via TLR4/MyD88/NF‐κB signaling pathway, EGCG maintains Th1/Th2 balance and reduces inflammatory factors	Preclinical study (animal level)	Ulcerative colitis rat model	(Xue, Liu, Dong, Liang, & Chen, 2017)
	2. Increases lymphocytosis and shows a reduction in the absolute number of circulating Treg, and serum IL‐10 and TGF‐β d	Clinical study	12 CLL patients and 12 healthy person as control	(Most et al., 2018)
	2Mixed flavonoids and EGCG induces immune enhancement and antiinflammatory transcriptional changes in overweight women	Clinical study	Overweight women	(Cialdella‐Kam et al., 2016)
Inhibits cytokine storm	Reduces the lung severity and TNF‐α, elevation of MIP‐2 and neutrophils in mice induced by LPS	Preclinical study (animal level)	Lipopolysaccharide‐induced acute lung injury model in mice	(Bae et al., 2010 )
	2Reduces the concentration of inflammatory factors in plasma and the severity of ARDS	Preclinical study (animal level)	Lung injury in thermal injury rat model	(Liu et al., 2017)
	3Significantly inhibits radiation‐induced pulmonary fibrosis, activates Nrf‐2, and regulates serum level of TGF‐β1, IL‐6, IL‐10, and TNF‐α	Preclinical study (animal level)	Pulmonary fibrosis (radiation‐induced pulmonary fibrosis rat model)	(You et al., 2014)
Broad‐spectrum antivirus function	EGCG has a broad spectrum of antiviral activities against RNA viruses such as HIV, HCV, human immunodeficiency virus, Ebola virus, influenza virus, and respiratory virus	Clinical study (animal level)	HIV and HCV	(Halegoua‐De Marzio et al., 2012; Shiha, Soliman, Elbasiony, Darwish, & Mousa, 2019)