Table 2.

Summary of the biological activities conducted with triterpene saponins in glycyrrhiza ¹.

No.	Compound	Activity			References
		Property	Method	Major Findings
1	glycyrrhizin (glycyrrhizic acid, uralsaponin A or 18β-glycyrrhizic acid)	Hepatoprotective activities	In vitro—primary rat hepatocytes injured by d-galactosamine (d-GalN)	Lower alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST) levels	[20]
			PLA2 inhibitory potency	IC50 = 9.3 μM	[20]
			In vitro—primary cultured rat hepatocytes induced by CCl4	Prevent soluble enzyme release	[39]
			In vitro—PLC/PRF/5 cells	Modify the expression of hepatitis B virus (HBV)-related antigens on the hepatocytes and suppress sialylation of HBsAg	[40]
			In vivo—BALB/c mice	Suppress increases in AST and ALT, inhibit inducible nitric oxide synthase (iNOS) mRNA expression, and reduce protein and cell infiltration and the degeneration of hepatocytes	[41]
			In vivo—ICR mice	Alleviate CCl4-induced liver injury	[42]
			In vivo—Sprague Dawley rats	Exhibit protective effect on retrorsine-induced liver damage	[43]
			In vivo—Wistar rats	Provide partial protection of the liver against ischemia-reperfusion damage	[44]
			In vivo—Wistar rats	Protect against NTiO2-induced hepatotoxicity	[45]
		Anti-inflammatory activities	In vitro—lipopolysaccharide (LPS)-stimulated mouse endometrial epithelial cells (MEEC)	Inhibit LPS-induced inflammatory response by inhibiting TLR4 signaling pathway	[47]
			In vitro—neutrophil	Inhibit reactive oxygen species (ROS) generation by neutrophils	[48]
			In vivo—Sprague Dawley rats	Inhibit HMGB1 expression and subsequent production of inflammatory cytokines to prevent cerebral vasospasm (CVS) following subarachnoid hemorrhage (SAH)	[49]
			In vivo—SD rats	Alleviate brain injury after diffuse axonal injury (DAI) via its anti-inflammatory effects	[50]
		Antimicrobial and antiviral activities	In vitro	Inhibit varicella zoster virus (VZV)	[53]
			In vitro	Inhibit severe acute respiratory syndrome coronavirus (SARS-CoV) replication	[54]
			In vitro	Inhibited influenza A virus (IAV) uptake into the cell	[55]
			In vitro	Reduce the severity of an infection with COVID-19 at the two stages of the COVID-19 induced disease process, 1. To block the number of entry points and 2. provide an ACE2 independent anti-inflammatory mechanism.	[57]
			The commercial NA inhibitory screening kit	Possess moderate influenza NA inhibitory activity	[31]
		Cytotoxic and antitumor activities	In vivo—tumor-bearing mice	Reduce expression of TxAS, as well as proliferating cell nuclear antigen (PCNA), and rescue liver and kidney damage	[58]
			In vitro—HepG2	Display protective effects against Aflatoxin B1 (AFB1)-induced cytotoxicity	[59]
		Other activities	-	1. Possess immunomodulatory, neuroprotective effects, and antioxidant activities; 2. Bronchitis, peptic ulcers, skin diseases, and oral diseases; 3. Allergic rhinitis	[56,61,62,63,64,65,66]
3	licorice-saponin A3	Antimicrobial and antiviral activities	The commercial NA inhibitory screening kit	Possess moderate influenza NA inhibitory activity	[31]
9	licorice-saponin G2	Hepatoprotective activities	In vitro—primary rat hepatocytes injured by d-GalN	Lower ALT and AST levels	[20]
			PLA2 inhibitory potency	IC50 = 16.9 μM	[20]
		Antimicrobial and antiviral activities	The commercial NA inhibitory screening kit	Possess moderate influenza NA inhibitory activity	[31]
17	22β-acetoxylglycyrrhizin	Hepatoprotective activities	In vitro—primary rat hepatocytes injured by d-GalN	Lower ALT and AST levels	[20]
			PLA2 inhibitory potency	IC50 = 27.1 μM	[20]
		Antimicrobial and antiviral activities	In vitro—Madin–Darby canine kidney (MDCK) cells	Inhibit influenza virus A/WSN/33 (H1N1)	[27]
			The commercial NA inhibitory screening kit	Possess moderate influenza NA inhibitory activity	[31]
21	uralsaponin D	Hepatoprotective activities	PLA2 inhibitory potency	IC50 = 32.2 μM	[20]
25	licorice-saponin M3(uralsaponin T)	Antimicrobial and antiviral activities	In vitro—MDCK cells	Inhibit influenza virus A/WSN/33 (H1N1)	[27]
			The commercial NA inhibitory screening kit	Possess moderate influenza NA inhibitory activity	[31]
28–39	uralsaponins M–Y	Antimicrobial and antiviral activities	In vitro—MDCK cells	Uralsaponin M (28) and uralsaponin S (34) exhibited inhibitory activities against influenza virus A/WSN/33 (H1N1)	[27]
44–45	licorice-saponin Q2 (44) macedonoside A (45)	Hepatoprotective activities	In vitro—primary rat hepatocytes injured by d-GalN	Lower ALT and AST levels	[20]
			PLA2 inhibitory potency	IC50 = 3.6 μM (44) and 6.9 μM (45)	[20]
63–70	glyuralsaponins A–H	Hepatoprotective activities	MDA colorimetric assay	Glyuralsaponin B (64) and glyuralsaponin H (70) exhibited moderate antioxidant activities against Fe2+/cysteine-induced liver microsomal lipid peroxidation	[32]

¹, Columns 1 and 2 is the same in Table 1. It should be noted that the empty rows with triterpene saponins are grouped together or not listed in Table 2.