• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.800-805
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• 2012

Licochalcone E was firstly isolated from licorice root in 2005, which belongs to the retrochalcone family. Studies on the biological activities of licochalcone E were in the initial stage. In the study, we demonstrated that licochalcone E has potent antimicrobial property against Staphylococcus aureus. Furthermore, via hemolysis, Western blot, and real-time RT-PCR assays, we have shown that subinhibitory concentrations of licochalcone E dose-dependently reduces the production of ${\alpha}$-toxin in both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The data suggest that licochalcone E may deserve further investigation as a potential therapeutic against S. aureus infections, or the structure of licochalcone E may be used as a basis for chemical synthesis of novel anti-S. aureus compounds.

• Journal of Life Science
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• v.21 no.5
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• pp.656-663
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• 2011

Licochalcone, a major phenolic constituent of the licorice species Glycyrrhiza inflata, a constituent of licorice, exhibits various biological properties, including chemopreventive-, antibacterial-, and anti-spasmodic activities. Recently, Licochalcone E (LicE) was isolated from the roots of Glycyrrhiza inflate, however its biological functions have not been fully examined. In the present study, we investigated the ability of LicE to regulate inflammation reactions in macrophages. Our in vitro experiments using murine macrophages, RAW264.7 cells, showed that LicE suppressed not only nitric oxide (NO) and prostaglandin $E_2$ generation, but also the expression of inducible NO synthase and cyclooxygenase-2 induced by lipopolysaccharide (LPS). Similarly, LicE inhibited the release of proinflammatory cytokines induced by LPS in RAW264.7 cells, including tumor necrosis factor-${\alpha}$ and interleukin-6. The underlying mechanism of LicE on anti-inflammatory action correlated with down-regulation of the nuclear factor-${\kappa}$B. Our data collectively indicate that LicE inhibited the production of several inflammatory mediators and might be used in the treatment of various inflammatory diseases.

• YAKHAK HOEJI
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• v.53 no.6
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• pp.321-327
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• 2009

Licochalcone A is a chalcone isolated from the roots of Glycyrrhiza inflate. In this study, we examined the effects of licochalonce A on the production of cytokines in LPS-activated macrophages. Licochalcone A inhibited the secretion of proinflammatory cytokines such as IL-1$\beta$, IL-6, and TNF-$\alpha$. The reduced secretion of proinflammatory cytokines is related to the differences in the mRNA expression of IL-1$\beta$, IL-6, and TNF-$\alpha$. Moreover, licochalcone A inhibited the mRNA expression of IL-12p40, IL-18, and IL-23p19. To investigate its mechanism, we performed gel shift assay. Licochalcone A reduced nuclear NF-${\kappa}B$ binding activity in LPS-activated RAW264.7 cells. Taken together, these results suggest that licochalcone A has anti-inflammatory effects in LPS-activated macrophages and its mechanism could be through the down-regulation of binding to the ${\kappa}B$ site.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.1085-1087
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• 2010

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.54-58
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• 2013

Licochalcones, derived from the dried roots of Glycyrrhiza inflata, have been reported to show various biological activities including antitumor, antiparasitic, antileishmanial, antioxidative, superoxide scavenging, antibacterial, and PTP1B activity. Licochalcone D has an allyl group on ring A instead of ring B, however, most other natural licochalcones possess the group on ring B. Total synthesis of licochalcone D has not been reported even possessing the strongest anti-inflammatory activity. Therefore, the first total synthesis of licochalcone D has been developed by using water-accelerated [3,3]-sigmatropic rearrangement method.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1917-1920
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• 2013

• Toxicological Research
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• v.30 no.1
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• pp.19-25
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• 2014

Licochalcone (LC), a major phenolic retrochalcone from licorice, has anti-inflammatory activity. This study investigated the effects of licochalcone A (LCA) and licochalcone E (LCE) on Liver X receptor-${\alpha}$ ($LXR{\alpha}$)-mediated lipogenic gene expression and the molecular mechanisms underlying those effects. LCA and LCE antagonized the ability of $LXR{\alpha}$ agonists (T0901317 or GW3965) to increase sterol regulatory element binding protein-1c (SREBP-1c) expression and thereby inhibited target gene expression (e.g., FAS and ACC) in HepG2 cells. Moreover, treatment with LCA and LCE impaired $LXR{\alpha}/RXR{\alpha}$-induced CYP7A1-LXRE-luciferase (CYP7A1) transactivation. The AMPK-Sirt1 signaling pathway is an important regulator of energy metabolism and, therefore, a potential therapeutic target for metabolic diseases, including hepatic steatosis. We found here that LCE increased AMPK phosphorylation and Sirt1 expression. We conclude that LC inhibits SREBP-1c-mediated hepatic lipogenesis via activation of the AMPK/Sirt1 signaling pathway.

• Biomedical Science Letters
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• v.17 no.1
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• pp.85-88
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• 2011

Tumor angiogenesis, which is essential for tumor growth and tumor metastasis, depends on angiogenic factors produced by tumor cells and/or infiltrating cells such as endothelial cells and immune cells in tumor tissue. Previously, we reported that licochalcone A (LicA), an important bioactive compound of Glycyrrhiza inflate, suppresses angiogenesis, tumor growth and metastasis. In this study, we evaluated the effect of LicA on angiogenin production in colon cancer cells because angiogenin is an essential factor to regulate angiogenesis and tumor progression. When we examined the angiogenin levels in three human colon cancer cells, HT-29, SW480 and Caco-2, LicA treatment significantly reduced the amounts of angiogenin among three cancer cell lines. In an in vivo study in which mice were implanted with HT-29 cells, oral administration of LicA reduced angiogenin in tumor tissues when compared with vehicle-administered mice. These results suggest that reduced angiogenin in response to LicA treatment may play essential role to inhibit tumor growth, angiogenesis as well as metastasis.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2959-2961
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• 2009

Total synthesis of (${\pm}$)-licochalcone E (1), an allyl retrochalcone isolated from roots of Glycyrrhiza inflata, has been achieved from 4-tetrahydropyranyloxyacetophenone (7) with (E)-2-methoxy-4-(2-methyl-2-butenyloxy)benzaldehyde (6) or (Z)-2-methoxy-4-(2-methyl-2-butenyloxy)-benzaldehyde (11) through a convergent strategy involving aldol condensation and Claisen rearrangement as key steps.

• Nutritional Sciences
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• v.8 no.3
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• pp.153-158
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• 2005

Numerous natural herbal compounds have been reported to inhibit adhesion and migration of leukocytes to the site of inflammation Licorice extracts, which have been widely used in traditional Chinese medicinal preparation, possess various pharmacological effects. Isoliquiritigenin, a biogenetic precursor of flavonoids with various pharmacological effects, is a natural pigment present in licorice. We attempted to explore whether licorice extracts and isoliquiritigenin mitigate monocyte adhesion to tumor necrosis factor-$\alpha$ (TNF-$\alpha$)-activated human umbilical vein endothelial cells (HUVEC). In addition, it was tested whether the inhibition of monocyte adhesion to the activated HUVEC accompanied a reduction in vascular cell adhesion molecule-l expression(VCAM-l). Dry-roasted licorice extracts in methylene chloride but not in ethanol markedly interfered with THP-l monocyte adhesion to INF-$\alpha$-activated endothelial cells. licochalcone A compound isolated from licorice extract in methylene chloride appeared to modestly inhibit the interaction of THP-l monocytes and activated endothelium. In addition, isoliquiritigenin abolished the monocyte adhesion with attenuating VCAM-l protein expression on HUVEC induced by INF-$\alpha$. These results demonstrated that non-polar components from dry-roasted licorice extracts containing licochalcone A as well as isoliquiritigenin were active in blocking monocyte adhesion to cytokine-activated endothelimn, which appeared to be mediated most likely through the inhibition of VCAM-l expression on HUVEC. Therefore, licorice may hamper initial inflammatory events on the vascular endothelium involving induction of endothelial cell adhesion molecules.