• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.151-161
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• 2022

This study elucidates the anti-cancer potential of gallic acid (GA) as a promising therapeutic agent that exerts its effect by regulating the PI3K/Akt pathway. To prove our research rationale, we used diverse experimental methods such as cell viability assay, colony formation assay, tumor spheroid formation assay, cell cycle analysis, TUNEL assay, Western blot analysis, xenograft mouse model and histological analysis. Treatment with GA inhibited cell proliferation in dose-dependent manner as measured by cell viability assay at 48 h. GA and cisplatin (CDDP) also inhibited colony formation and tumor spheroid formation. In addition, GA and CDDP induced apoptosis, as determined by the distribution of early and late apoptotic cells and DNA fragmentation. Western blot analysis revealed that inhibition of the PI3K/Akt pathway induced upregulation of p53 (tumor suppressor protein), which in turn regulated cell cycle related proteins such as p21, p27, Cyclin D1 and E1, and intrinsic apoptotic proteins such as Bax, Bcl-2 and cleaved caspase-3. The anti-cancer effect of GA was further confirmed in an in vivo mouse model. Intraperitoneal injection with GA for 4 weeks in an A549-derived tumor xenograft model reduced the size of tumor mass. Injection of them downregulated the expression of proliferating cell nuclear antigen and p-Akt, but upregulated the expression of cleaved caspase-3 in tumor tissues. Taken together, these results indicated that GA hindered lung cancer progression by inducing cell cycle arrest and apoptosis, suggesting that GA would be a potential therapeutic agent against non-small cell lung cancer.

• The Korean Journal of Physiology and Pharmacology
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• v.27 no.4
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• pp.345-356
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• 2023

This study aimed to assess the effects of exogenous hydrogen sulfide (H₂S) on abdominal aorta coarctation (AAC) induced myocardial fibrosis (MF) and autophagy in rats. Forty-four Sprague-Dawley rats were randomly divided into control group, AAC group, AAC + H₂S group, and H₂S control group. After a model of rats with AAC was built surgically, AAC + H₂S group and H₂S group were injected intraperitoneally with H₂S (100 µmol/kg) daily. The rats in the control group and the AAC group were injected with the same amount of PBS. We observed that H₂S can improve left ventricular function and the deposition of myocardial collagen fibers, inhibit pyroptosis, down-regulate the expression of P-eif2α in myocardial tissue, and inhibit cell autophagy by activating the phosphatidylinositol 3-kinase (PI3K)/AKT1 signaling pathway (p < 0.05). In addition, angiotensin II (1 µM) H9c2 cardiomyocytes were injured in vitro experiments, and it was also observed that pyroptosis was inhibited after H₂S (400 µmol/kg) intervention, the expression of P-eif2α in cardiomyocytes was significantly down-regulated, and the PI3K/AKT1 signaling pathway was activated at the same time. Therefore, increasing the expression of P-eif2α reverses the activation of the PI3K/AKT1 signaling pathway by H₂S. In conclusion, these findings suggest that exogenous H₂S can ameliorate MF in rats with AAC by inhibiting pyroptosis, and the mechanism may be associated with inhibiting the phosphorylation of eif2α and activating the PI3K/AKT1 signaling pathway to inhibit excessive cell autophagy.

• Biomolecules & Therapeutics
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• v.31 no.6
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• pp.682-691
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• 2023

Cell transformation induced by epidermal growth factor (EGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA) is a critical event in cancer initiation and progression, and understanding the underlying mechanisms is essential for the development of new therapeutic strategies. Licorice extract contains various bioactive compounds, which have been reported to have anticancer and anti-inflammatory effects. This study investigated the cancer preventive efficacy of licochalcone D (LicoD), a chalcone derivative in licorice extract, in EGF and TPA-induced transformed skin keratinocyte cells. LicoD effectively suppressed EGF-induced cell proliferation and anchorage-independent colony growth. EGF and TPA promoted the S phase of cell cycle, while LicoD treatment caused G1 phase arrest and down-regulated cyclin D1 and up-regulated p21 expression associated with the G1 phase. LicoD also induced apoptosis and increased apoptosis-related proteins such as cleaved-caspase-3, cleaved-caspase-7, and Bax (Bcl2-associated X protein). We further investigated the effect of LicoD on the AKT signaling pathway involved in various cellular processes and found decreased p-AKT, p-GSK3β, and p-NFκB expression. Treatment with MK-2206, an AKT pharmacological inhibitor, suppressed EGF-induced cell proliferation and transformed colony growth. In conclusion, this study demonstrated the potential of LicoD as a preventive agent for skin carcinogenesis.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.452-459
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• 2012

This study was conducted in order to investigate the effect of resveratrol on the induction of apoptosis in MDA-MB-231 breast cancer cells. The result of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl terazolium bromide (MTT) assay shows that cell viability significantly decreased in a dose and time-dependent manner. 4',6-diamidino-2-phenylindole (DAPI) staining shows significantly increased chromatin condensation in a dose and time-dependent manner. Resveratrol increased the expression of p53, cleaved-caspase-3, and cleaved-caspase-9, whereas the expression of PI3K/Akt decreased in a time-dependent manner. We investigated the in vivo tumor growth inhibitory effect of resveratrol. Tumor volume was significantly decreased in the 50 mg/kg resveratrol-administration group compared to the control group. In the 50 mg/kg treated group. Apoptosis cells were frequently observed by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay. Immunohistochemistry staining shows increased the expression of p53, cytochrome-C, and cleaved-caspase-3 in the 50 mg/kg treated group. These results indicate that resveratrol induced apoptosis through PI3K/Akt and p53 signal pathway in MDA-MB-231 cell.

• Nutrition Research and Practice
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• v.3 no.4
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• pp.265-271
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• 2009

The role that antioxidants play in the process of carcinogenesis has recently gained considerable attention. $\alpha$-Lipoic acid, a naturally occurring disulfide molecule, is a powerful antioxidant that reportedly exerts beneficial effects in patients with advanced cancer by reducing the level of reactive oxygen species and increasing glutathione peroxidase activity. In this study, we examined changes in the protein and mRNA expression associated with cell proliferation and apoptosis in MDA-MB-231 breast cancer cultured in the presence of various concentrations (0, 250, 500, and 1000 ${\mu}mol/L$) of $\alpha$-lipoic acid. The results revealed that $\alpha$-lipoic acid inhibited the growth of breast cancer cells in a dose-independent manner (P < 0.05). Additionally, $ErbB_2$ and $ErbB_3$ protein and mRNA expressions were significantly decreased in a dose-dependent manner in response to $\alpha$-lipoic acid (P < 0.05). Furthermore, the protein expression of phosphorylated Akt (p-Akt) levels and total Akt, and the mRNA expression of Akt were decreased dose-dependently in cells that were treated with $\alpha$-lipoic acid (P < 0.05). Bcl-2 protein and mRNA expressions were also decreased in cells that were treated with $\alpha$-lipoic acid (P < 0.05). However, Bax protein and mRNA expressions were increased in cells treated with $\alpha$-lipoic acid (P < 0.05). Finally, caspase-3 activity was significantly increased in a dose-dependent manner in cells treated with $\alpha$-lipoic acid (P < 0.05). In conclusion, we demonstrated that $\alpha$-lipoic acid inhibits cell proliferation and induces apoptosis in MDA-MB-231 breast cancer cell lines.

• Preventive Nutrition and Food Science
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• v.20 no.4
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• pp.221-229
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• 2015

Hesperidin has been shown to possess a potential inhibitory effect on vascular formation in endothelial cells. However, the fundamental mechanism for the anti-angiogenic activity of hesperidin is not fully understood. In the present study, we evaluated whether hesperidin has anti-angiogenic effects in mouse embryonic stem cell (mES)-derived endothelial-like cells, and human umbilical vascular endothelial cells (HUVECs), and evaluated their mechanism via the AKT/mammalian target of rapamycin (mTOR) signaling pathway. The endothelial cells were treated with several doses of hesperidin (12.5, 25, 50, and $100{\mu}M$) for 24 h. Cell viability and vascular formation were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and tube formation assay, respectively. Alteration of the AKT/mTOR signaling in vascular formation was analyzed by western blot. In addition, a mouse aortic ring assay was used to determine the effect of hesperidin on vascular formation. There were no differences between the viability of mES-derived endothelial-like cells and HUVECs after hesperidin treatment. However, hesperidin significantly inhibited cell migration and tube formation of HUVECs (P<0.05) and suppressed sprouting of microvessels in the mouse aortic ring assay. Moreover, hesperidin suppressed the expression of AKT and mTOR in HUVECs. Taken together, these findings suggest that hesperidin inhibits vascular formation by blocking the AKT/mTOR signaling pathways.

• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.21-26
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• 2011

Ceramide is an important lipid mediator of extracellular signals that control various cellular functions, including apoptosis. In this study, we showed that ceramide induced apoptosis in U373MG human glioblastoma cells associated with G1 cell cycle arrest. Treatment of cells with ceramide increased proapoptotic Bax expression and inhibited the expression of antiapoptotic Bcl-2 and Bcl-xL Ceramide also downregulated cyclin E, cyclin D1, cdk 2, and cdk4 which are involved in regulating cell cycle. In addition, ceramide suppressed phosphorylation of Akt, Bad, p70 S6 kinase, and 4E-BP1, suggesting the involvement of Akt/mTOR signaling pathway. Additionally, okadaic acid, an inhibitor of protein phosphatase 2A, partially blocked the ceramide mediated inhibition of phosphorylation of Akt and 4E-BP1. These results suggest that ceramide induces apoptosis in U373MG glioblastoma cells by regulating multiple signaling pathways that involve cell cycle arrest associated with Akt signaling pathway.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.3
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• pp.184-194
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• 2023

In this study, we investigated whether p-anisaldehyde (PAA), the main component of essential oils derived from anise seeds, influences the differentiation of mouse C2C12 myoblasts. Cells were induced to differentiate over 5 days using a differentiation medium with or without PAA (50 or 200 mg/mL). Myotube length and diameter were measured, and the expressions of myogenic markers (myoblast determination protein 1, myogenin, myocyte enhancer factor 2, muscle creatine kinase, and myosin heavy chain) and atrophy-related genes (atrogin-1 and muscle ring finger-1 [MuRF-1]) were assessed by quantitative real-time polymerase chain reaction. Additionally, protein kinase B (Akt) phosphorylation was monitored by western blotting. PAA significantly induced the formation of smaller and thinner myotubes and reduced myogenic marker expression. Furthermore, PAA increased the expressions of atrogin-1 and MuRF-1 and simultaneously reduced Akt phosphorylation. Our findings indicate that PAA inhibits the myogenic differentiation of C2C12 cells by reducing the phosphorylation and activation of Akt.

• Journal of Life Science
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• v.29 no.1
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• pp.18-28
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• 2019

Recent studies reported that obesity upregulated the expression of neuronal nitric oxide synthase (nNOS) and regulated particular behavior patterns in animal models. They also reported that ameliorated the increase in nNOS expression and decreased depression and anxiolytic effects. Thus, exercise seems to be an effective strategy for improving brain function by downregulating nNOS. However, the immune response differs greatly, depending on the exercise intensity. The aim of the present study was to investigate differences in brain nNOS expression in obese C57BL/6 mice that performed exercise of different intensities. Obesity was induced in 6-wks-old mice (n=35) by feeding a 60%-fat diet for 6-wks. A control (CON) group (n=14) was fed a normal diet. At the end of the induction 6-wks period of obesity, seven animals in the CON group and obesity-induced group were sacrificed to confirm obesity induction (preliminary experiments and confirmation of visceral fat accumulation). The remaining animals were then used in an 8-wks exercise intervention. Other than the CON (n=7), the obesity-induced animals were divided into the following groups: high-fat diet (HFD, n=7), HFD-low intensity (HFD-LI, n=7, 12 m/min for 75 min), HFD-moderate intensity (HFD-MI, n=7, 15 m/min for 60 min), and HFD-high intensity (HFD-HI, n=7, 18 m/min for 50 min). The exercise was performed on an animal treadmill. The expression of the nNOS protein in the hippocampus was significantly higher in the HFD group as compared with that in the CON group (p<0.01). However, there was no difference in the hippocampal expression of the nNOS protein in the other exercise groups as compared with that in the CON group. In contrast, nNOS expression in the HFD-HI group was significantly lower than that in the HFD-LI group (p<0.05). The expression of phosphorylated Akt (pAkt) was significantly higher in all the exercise groups as compared with that in the CON and HFD groups. There was no difference in the expression of pAkt in the cerebral cortex among groups, and the expression of pAkt in the cerebellum was significantly higher in the HFD-HI group as compared with that in the CON group (p<0.05). There were also no between-group differences in pAkt expression in the cerebellum among the various exercise groups. In conclusion, nNOS seems to be overexpressed in response to obesity, and it appears to be downregulated by exercise. Relatively high-intensity exercise may be effective in improving brain function by downregulating nNOS.

• Korean Journal of Acupuncture
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• v.28 no.3
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• pp.43-51
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• 2011

Objectives : In this study, we investigated the effect of Fructus Ligustri Lucidi $H_2O$ fraction (FLLW) on cell proliferation, and the phosphorylation of ERKs and Akt in human dermal fibroblast neonatal (HDFn). Methods : After treatment of HDFn with FLLW, MTT assay was performed to quantitatively determine cellular viability. The ERK and Akt pathways were analyzed in vitro by Western blot in a HDFn. HDFn proliferation after FLLW and minoxidil treatment in the absence or presence of PD98059, a MEK inhibitor, LY294002, and a PI3K inhibitor, was examined by Western blot or MTT assay. Results : FLLW increased cell proliferation in a dose-dependent manner and minoxidil used as positive control also induced cell proliferation in HDFn. FLLW increased the phosphorylation of ERK and Akt. In addition, minoxidil, too, induced the phosphorylation of ERK and Akt in HDFn. PD98059 and LY294002 significantly attenuated FLLW-inducible p-ERK and p-Akt expression and proliferation in cultured HDFn. Conclusions : Our results suggest that FLLW stimulates the growth of fibroblast cells through ERK and Akt pathways. Therefore, FLLW is a potential agent for the inducer of fibroblast growth.