Licochalcone A induces T24 bladder cancer cell apoptosis by increasing intracellular calcium levels.

Licochalcone A (LCA) has been reported to significantly inhibit cell proliferation, increase reactive oxygen species (ROS) levels, and induce apoptosis of T24 human bladder cancer cells via mitochondria and endoplasmic reticulum (ER) stress-triggered signaling pathways. Based on these findings, the present study aimed to investigate the mechanisms by which LCA induces apoptosis of T24 cells. Cultured T24 cells were treated with LCA, and cell viability was measured using the sulforhodamine B assay. Apoptosis was detected by flow cytometry with Annexin V/propidium iodide staining, and by fluorescent microscopy with Hoechst 33258 staining. The levels of intracellular free calcium ions were determined using Fluo-3 AM dye marker. Intracellular ROS levels were assessed using the 2',7'-dichlorodihydrofluorescein diacetate probe assay. The mitochondrial membrane potential was measured using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl benzimidazole carbocyanine iodide. Furthermore, the mRNA expression levels of B­cell lymphoma (Bcl)­extra large, Bcl­2­associated X protein, Bcl­2­interacting mediator of cell death, apoptotic protease activating factor­1 (Apaf­1), calpain 2, cysteinyl aspartate specific proteinase (caspase)­3, caspase­4 and caspase­9 were determined using reverse transcription semiquantitative and quantitative polymerase chain reaction analyses. Treatment with LCA inhibited proliferation and induced apoptosis of T24 cells, and increased intracellular Ca2+ levels and ROS production. Furthermore, LCA induced mitochondrial dysfunction, decreased mitochondrial membrane potential, and increased the mRNA expression levels of Apaf­1, caspase­9 and caspase­3. Exposure of T24 cells to LCA also triggered calpain 2 and caspase­4 activation, resulting in apoptosis. These findings indicated that LCA increased intracellular Ca2+ levels, which may be associated with mitochondrial dysfunction. In addition, the ER stress pathway may be considered an important mechanism by which LCA induces apoptosis of T24 bladder cancer cells.

Antimetastatic effects of licochalcone B on human bladder carcinoma T24 by inhibition of matrix metalloproteinases-9 and NF-кB activity.

This study investigated the mechanisms by which licochalcone B (LCB) inhibits the adhesion,invasion and metastasis of human malignant bladder cancer T24 cells. Cell viability was evaluated using a sulforhodamine B (SRB) assay. Cell migration and invasion ability were conducted using wound-healing assay and matrigel transwell invasion assay. The activities of matrix metalloproteinases (MMP)-2 and MMP-9 were measured by gelatin zymography protease assays. The expression in protein level of NF-κBP65 and AP-1 was determined using the ELISA method; the protein levels of MMP-9, NF-κBP65, IκBα and P-IκBα were detected by Western blot. The expression in mRNA level of MMP-9 was assessed using quantitative real-time polymerase chain reaction (PCR) and reverse transcription PCR. The results indicated that LCB attenuated T24 cell migration, adhesion and invasion in a concentration-dependent manner. LCB treatment down-regulated the mRNA expression, protein expression and activity of MMP-9 but had no effect on MMP-2. In addition, LCB treatment decreased the protein level of NF-кBP65 and nuclear translocation of NF-кB. These findings suggested that LCB attenuated migration of bladder cancer T24 cells and adhesion and invasion accompanied with down-regulated protein expression of MMP-9 and the nuclear translocation of NF-кB. Our results provide support that LCB may be a potent adjuvant therapeutic agent in the prevention and therapy of bladder cancer.

Antioxidative and cardioprotective effects of total flavonoids extracted from Dracocephalum moldavica L. against acute ischemia/reperfusion-induced myocardial injury in isolated rat heart.

This study evaluates antioxidative and cardioprotective effects of total flavonoids extracted from Dracocephalum moldavica L. (DML). The total flavonoids showed remarkable scavenging effects against 1,1-diphenyl-2-picrylhydrazyl, hydroxyl and superoxide anion radicals in vitro. Compared with the ischemia/reperfusion (I/R) group as demonstrated by the use of improved Langendorff retrograde perfusion technology, the total flavonoids (5 µg/mL) pretreatment improved the heart rate and coronary flow, rised left ventricular developed pressure and decreased creatine kinase, lactate dehydrogenase levels in coronary flow. The infarct size/ischemic area at risk of DML-treated hearts was smaller than that of I/R group; the superoxide dismutase activity and glutathione/glutathione disulfide ratio increased and malondialdehyde content reduced obviously (P < 0.01) in total flavonoids treatment groups. In conclusion, the total flavonoids possess obvious protective effects on myocardial I/R injury, which may be related to the improvement of myocardial oxidative stress states.

Licochalcone A inhibiting proliferation of bladder cancer T24 cells by inducing reactive oxygen species production.

The aim of this study was to determine the relationship between proliferation inhibition and the production of reactive oxygen species (ROS) induced by Licochalcone A (LCA). Cell viability was evaluated using sulforhodamine B (SRB) assay. Intracellular ROS level was assessed using the 2, 7-dichlorofluorescein diacetate (H2DCFDA) probe and dihydroethidium (DHE) probe assay. The results indicate that LCA inhibits human bladder cancer T24 proliferation in a concentration-dependent manner, with an IC50 value of approximately 55 µM. The LCA-induced ROS production is inhibited by the co-treatment of LCA and free radical scavenger N-acetyl-cysteine (NAC), on the contrary, the proliferation rate and ROS production increase when treated by the combination of LCA and L-buthionine-(S,R)-sulfoximine (BSO). The ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) decreases in a concentration-dependent manner. The results suggest that LCA inhibits proliferation by increasing intracellular ROS levels resulted in an oxidative stress status in T24 cells.

Licochalcone A-induced human bladder cancer T24 cells apoptosis triggered by mitochondria dysfunction and endoplasmic reticulum stress.

Licochalcone A (LCA), a licorice chalconoid, is considered to be a bioactive agent with chemopreventive potential. This study investigated the mechanisms involved in LCA-induced apoptosis in human bladder cancer T24 cells. LCA significantly inhibited cells proliferation, increased reactive oxygen species (ROS) levels, and caused T24 cells apoptosis. Moreover, LCA induced mitochondrial dysfunction, caspase-3 activation, and poly-ADP-ribose polymerase (PARP) cleavage, which displayed features of mitochondria-dependent apoptotic signals. Besides, exposure of T24 cells to LCA triggered endoplasmic reticulum (ER) stress; as indicated by the enhancement in 78 kDa glucose-regulated protein (GRP 78), growth arrest and DNA damage-inducible gene 153/C/EBP homology protein (GADD153/CHOP) expression, ER stress-dependent apoptosis is caused by the activation of ER-specific caspase-12. All the findings from our study suggest that LCA initiates mitochondrial ROS generation and induces oxidative stress that consequently causes T24 cell apoptosis via the mitochondria-dependent and the ER stress-triggered signaling pathways.

Isoliquiritigen enhances the antitumour activity and decreases the genotoxic effect of cyclophosphamide.

The aim of this study was to evaluate the antitumour activities and genotoxic effects of isoliquiritigenin (ISL) combined with cyclophosphamide (CP) in vitro and in vivo. U14 cells were treated with either of ISL (5-25 µg/mL) or CP (0.25-1.25 mg/mL) alone or with combination of ISL (5-25 µg/mL) and CP (1.0 mg/mL) for 48 h. The proliferation inhibitory effect in vitro was evaluated by MTT and colony formation assays. KM mice bearing U14 mouse cervical cancer cells were used to estimate the antitumour activity in vivo. The genotoxic activity in bone marrow polychromatic erythrocytes was assayed by frequency of micronuclei. The DNA damage in peripheral white blood cells was assayed by single cell gel electrophoresis. The results showed that ISL enhanced antitumour activity of CP in vitro and in vivo, and decreased the micronucleus formation in polychromatic erythrocytes and DNA strand breaks in white blood cells in a dose-dependent way.

Involvement of endoplasmic reticulum stress in isoliquiritigenin-induced SKOV-3 cell apoptosis.

Isoliquiritigenin (ISL), a licorice chalconoid, is a bioactive agent with chemopreventive potential that has been patented for tumor treatment in China. This study investigated the mechanisms of ISL-induced apoptosis in ovarian carcinoma SKOV-3 cells. Cell viability was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. The apoptotic rate was determined via flow cytometry using an annexin V-FITC apoptosis detection kit. The intracellular reactive oxygen species (ROS) levels were assessed using a 2,7-dichlorofluorescein probe assay. Malondialdehyde (MDA) formation was determined via thiobarbituric acid reactive substance test. The expressions of growth arrest and DNA damage-inducible gene (GADD153/CHOP), 78 kDa glucose-regulated protein (GRP 78), α-subunit of eukaryotic initiation factor 2 (eIF2α) phosphorylation, activating transcription factor 6α (ATF6α), and unspliced form of X-box binding protein1 (XBP1U) were analyzed via Western blot. Caspase-3 and caspase-12 activities were assessed using a fluorometric kit. Findings indicate that ISL significantly inhibits SKOV-3 cell proliferation, increases intracellular ROS levels, and causes SKOV-3 cell apoptosis. Moreover, ISL-exposed SKOV-3 cells trigger endoplasmic reticulum (ER) stress, as indicated by the enhancement of ER stress-related molecules p-eIF2α, GADD153/CHOP, GRP78, XBP1 expression, and cleavage of ATF6α. However, caspase-12 inhibitor (Z-ATAD) effectively and partially prevents ROS and MDA formation and inhibits ISL-induced SKOV-3 cell apoptosis. ISL induces apoptosis via ER stress-triggered signaling pathways in SKOV-3 cells. ER stress-induced cancer cell apoptosis has been discussed in some patents.

[Advance in studies on pharmacological effects of licochalcone A].

Licochalcone A (LCA), as a major flavonoid in Glycyrrhiza inflate, has attracted wide attention in recent years. Studies showed that LCA has multiple pharmacological effects such as anti-tumour, anti-inflammation, anti-bacteria and anti-parasite. We made a summary for domestic and foreign study literatures for various pharmacological effects of LCA.