Lee KP, et al. Nutr Res Pract. 2014 Jun;8(3):267-271. https://doi.org/10.4162/nrp.2014.8.3.267

Tumor cell motility exhibits a crucial role in tumor development. Therefore, the present study aimed to investigate whether thymol could reduce C6 glioma cell migration. Cell viability was determined using the EZ-Cytox Cell Viability kit. The scratch wound healing and Boyden chamber assays were performed to test C6 glioma cell migration in the presence of fetal bovine serum (FBS). Additionally, the study investigated whether signaling proteins relevant to C6 glioma cell migration, i.e., extracellular signal-regulated kinases (ERK)1/2, protein kinase Cα (PKCα), matrix metallopeptidase (MMP)9 and MMP2, were affected by thymol treatment. Up to 30 µM, thymol did not alter cell viability, whereas 100 µM thymol induced the death of ~20% of the cells. Furthermore, thymol (30 µM) significantly reduced FBS-induced migration. In the FBS-stimulated C6 glioma cells, thymol (30 µM) suppressed PKCα and ERK1/2 phosphorylation. MMP9 and MMP2 production was also significantly reduced by treatment with 30 µM thymol in the C6 glioma cells. Taken together, these results indicate that thymol attenuates C6 glioma cell migration. Additionally, the study suggests that the effect of thymol on the FBS-induced migration of C6 glioma cells affects PKCα and ERK1/2 signaling, and suppresses MMP9 and MMP2 production.

Endocrine-disrupting chemicals (EDCs) have been reported to interfere with estrogen signaling. Exposure to these chemicals decreases the immune response and causes a wide range of diseases in animals and humans. Recently, many studies showed that licorice (Glycyrrhiza glabra) root extract (LRE) commonly called "gamcho" in Korea exhibits antioxidative, chemoprotective, and detoxifying properties. This study aimed to investigate the mechanism of action of LRE and to determine if and how LRE can alleviate the toxicity of EDCs. LRE was prepared by vacuum evaporation and freeze-drying after homogenization of licorice root powder that was soaked in 80% ethanol for 72 h. We used 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a representative EDC, which is known to induce tumors or cancers; MCF-7 breast cancer cells, used as a tumor model, were treated with TCDD and various concentrations of LRE (0, 50, 100, 200, 400 μg/mL) for 24, 48, and 72 h. As a result, TCDD stimulated MCF-7 cell proliferation, but LRE significantly inhibited TCDD-induced MCF-7 cell proliferation in a dose- and time-dependent manner. The expression of TCDD toxicity-related genes, i.e., aryl hydrocarbon receptor (AhR), AhR nuclear translocator, and cytochrome P450 1A1, was also down-regulated by LRE in a dose-dependent manner. Analysis of cell cycle distribution after treatment of MCF-7 cells with TCDD showed that LRE inhibited the proliferation of MCF-7 cells via G2/M phase arrest. Reverse transcription-polymerase chain reaction and Western blot analysis also revealed that LRE dose-dependently increased the expression of the tumor suppressor genes p53 and p27 and down-regulated the expression of cell cycle-related genes. These data suggest that LRE can mitigate the tumorigenic effects of TCDD in breast cancer cells by suppression of AhR expression and cell cycle arrest. Thus, LRE can be used as a potential toxicity-alleviating agent against EDC-mediated diseases.

Lee KP, et al. Nutr Res Pract. 2014 Oct;8(5):521-525. https://doi.org/10.4162/nrp.2014.8.5.521

Gastric ulcer is a common digestive disorder that results in considerable suffering. Hence, this digestive pathology has been the focus of a number of recent studies. Although numerous drugs have been developed to treat gastric ulcers, therapeutic approaches for many of the complications associated with these drugs remain to be identified. For this reason, many natural compounds have been explored as alternatives for these drugs. In this study, we have investigated the effectiveness of Areca catechu leaf ethanol extract (ACE) for treating ethanol-induced gastric ulcers in mice. We performed histological as well as immunohistochemical examinations to explore the therapeutic properties of ACE. We also examined the levels of inflammatory signaling molecules to confirm the anti-inflammatory effects of ACE. The histochemical data demonstrate that ACE can protect the mucosal epithelium as well as the vascular supply in the gastric tract. Furthermore, ACE significantly reduced the expression levels of tumor necrosis factor-alpha (TNF- α ), interleukin-6 receptor (IL-6R), inducible NO synthase (iNOS), cyclooxygenase 2 (COX2), and nuclear factor-kappa B (NF- κ B). Taken together, these data suggest that ACE administration may have the potential as an alternative treatment for gastric ulcer because of its cytoprotective and anti-inflammatory effects and ability to promote the rejuvenation and revascularization of the damaged gastric epithelium.