Mechanism of Anti-Inflammatory Action of Glycyrrhizin: Effect on Neutrophil Functions Including Reactive Oxygen Species Generation

Abstract

The effect of glycyrrhizin on inflammatory mediators such as neutrophil functions including reactive oxygen species (ROS) generation was examined. Glycyrrhizin significantly decreased neutrophil-generated O2-, H2O2 and OH in a dose-dependent manner. However, the drug did not reduce any of the ROS generated in a cell-free, xanthine-xanthine oxidase system. The drug did not affect neutrophil chemotaxis or phagocytosis, either. The present study indicates that glycyrrhizin is not an ROS scavenger but exerts an anti-inflammatory action by inhibiting the generation of ROS by neutrophils, the most potent inflammatory mediator at the site of inflammation.

18β-Glycyrrhetinic Acid Inhibits Methicillin-Resistant Staphylococcus aureus Survival and Attenuates Virulence Gene Expression

“…3C). The decrease in KC and G-CSF in infected and GRA-treated mice suggests an anti-inflammatory effect of GRA during MRSA skin and soft tissue infection, supporting previously published data that show the anti-inflammatory effects of licorice root compounds, including reducing the expression of inflammatory cytokines such as IL-6 and IL-1, inhibition of complement, and reducing reactive oxygen species levels in neutrophils (9,13,26,28).…”

“…contributes to anti-inflammatory responses by inhibition of signaling pathways such as the PI3K/Akt pathway and by inhibiting the induction of IL-12 and IFN-␥ (13,26,27). GRA has been shown to inhibit the classical complement pathway, reduce IL-6 expression, and inhibit inflammation also via the PI3K/Akt pathway (9,28).…”

“…GA inhibits growth of herpes simplex type 1 in human cells, prevents the hepatitis A virus from penetrating cells, and inhibits HIV replication (11,12). Glycyrrhizin was shown to have anti-inflammatory properties as demonstrated by decreased production of reactive oxygen species (ROS) in human neutrophils (13). GRA can induce cell death in some tumor cells, such as primary effusion lymphoma cells transformed by Kaposi sarcoma-associated herpesvirus, possibly through the release of mitochondrial apoptotic factors (14)(15)(16).…”

Anti-Inflammatory Actions of Pentacyclic Triterpenes

“…However, in immature thymocytes GL accelerated IL-2 production on the one hand and inhibited growth response on the other hand. These actions in immature cells were accompanied by an inhibition of tyrosine phosphorylation of p40 and c-los expression (15).…”

Glycyrrhizic acid nanoparticles inhibit LPS-induced inflammatory mediators in 264.7 mouse macrophages compared with unprocessed glycyrrhizic acid

“…1 Its main components are considered to be the triterpene saponins glycyrrhizin and GA. [18][19][20] Nanomaterials are important materials due to their unique physical and chemical properties. 21 Due to accumulation of nanoparticles in the cell by enhanced permeability and retention effect, nanoparticles achieve new biological properties.…”