ABSTRACT
PURPOSE: This study examined the antioxidant and cancer cell growth inhibitory activities of an ethanol extract and different solvent fractions of Mesembryanthemum crystallinum L. (ice plant). METHODS: The ice plant was freeze-dried, extracted with 99.9% ethanol, and then fractionated with hexane, ethyl acetate, butanol, and water. The total polyphenol content (TPC), total carotenoid content (TCC), 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity (RSA), and ferric reducing antioxidant power (FRAP) were measured. Assays using 2′,7′-dichlorofluorescin-diacetate and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide were performed to measure the intracellular reactive oxygen species (ROS) and cell growth, respectively. Annexin V/propidium iodide staining and cell cycle analysis were performed for the detection of apoptosis and cell cycle arrest. RESULTS: TPC, TCC, RSA, and FRAP of the ethanol extract (EE) were 3.7 mg gallic acid equivalent/g, 13.2 µg/g, 21.0% (at a concentration of 5 mg/mL), and 21.0% (at a concentration of 5 mg/mL), respectively. Among the different solvent fractions, the butanol fraction (BF) showed the highest TPC (5.4 mg gallic acid equivalent/g), TCC (86.6 µg/g), RSA (34.9% at 5 mg/mL), and FRAP (80.8% at 5 mg/mL). Treatment of HCT116 human colon cancer cells with EE and BF at concentrations of 250 and 500 µg/mL reduced the levels of intracellular ROS. Concomitantly, EE and BF resulted in the dose-dependent inhibition of cell growth (at the concentrations of 125, 250, and 500 µg/mL for 24 ~ 48 h) and the induction of apoptosis (at the concentrations of 250 and 500 µg/mL for 48 h) in HCT116 cells. An increased G2/M cell population was also found in the BF-treated cells. CONCLUSION: These results suggest that ice plant possesses antioxidant and growth inhibitory activities in colon cancer cells.
Subject(s)
Humans , Apoptosis , Cell Cycle , Cell Cycle Checkpoints , Colon , Colonic Neoplasms , Ethanol , Gallic Acid , HCT116 Cells , Mesembryanthemum , Reactive Oxygen Species , WaterABSTRACT
BACKGROUND/OBJECTIVES: Perilla frutescens Britton leaves are a commonly consumed vegetable in different Asian countries including Korea. Cancer is a major cause of human death worldwide. The aim of the current study was to investigate the inhibitory effects of ethanol extract of perilla leaf (PLE) against important characteristics of cancer cells, including unrestricted growth, resisted apoptosis, and activated metastasis, using human cancer cells. MATERIALS/METHODS: Two human cancer cell lines were used in this study, HCT116 colorectal carcinoma cells and H1299 non-small cell lung carcinoma cells. Assays using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide were performed for measurement of cell growth. Soft agar and wound healing assays were performed to determine colony formation and cell migration, respectively. Nuclear staining and cell cycle analysis were performed for assessment of apoptosis. Fibronectin-coated plates were used to determine cell adhesion. RESULTS: Treatment of HCT116 and H1299 cells with PLE resulted in dose-dependent inhibition of growth by 52-92% (at the concentrations of 87.5, 175, and 350 microg/ml) and completely abolished the colony formation in soft agar (at the concentration of 350 microg/ml). Treatment with PLE at the 350 microg/ml concentration resulted in change of the nucleus morphology and significantly increased sub-G1 cell population in both cells, indicating its apoptosis-inducing activity. PLE at the concentration range of 87.5 to 350 microg/ml was also effective in inhibiting the migration of H1299 cells (by 52-58%) and adhesion of both HCT116 and H1299 cells (by 25-46%). CONCLUSIONS: These results indicate that PLE exerts anti-cancer activities against colon and lung cancers in vitro. Further studies are needed in order to determine whether similar effects are reproduced in vivo.
Subject(s)
Humans , Agar , Apoptosis , Asian People , Cell Adhesion , Cell Cycle , Cell Line , Cell Movement , Colon , Colorectal Neoplasms , Ethanol , Korea , Lung , Lung Neoplasms , Neoplasm Metastasis , Perilla , Perilla frutescens , Vegetables , Wound HealingABSTRACT
The aim of the study was to investigate the inhibitory effects of calcium against intestinal cancer in vitro and in vivo. We first investigated the effects of calcium treatment in HCT116 and HT29 human colon cancer cells. At the concentration range of 0.8-2.4 mM, calcium significantly inhibited cell growth (by 9-29%), attachment (by 12-26%), invasion (by 15-31%), and migration (by 19-61%). An immunofluorescence microscope analysis showed that the treatment with calcium (1.6 mM) for 24 h increased plasma membrane beta-catenin but decreased nuclear beta-catenin levels in HT29 cells. We then investigated the effect of dietary calcium on intestinal tumorigenesis in ApcMin/+ mice. Mice received dietary treatment starting at 6 weeks of age for the consecutive 8 weeks. The basal control diet contained high-fat (20% mixed lipids by weight) and low-calcium (1.4 mg/g diet) to mimic the average Western diet, while the treatment diet contained an enriched level of calcium (5.2 mg calcium/g diet). The dietary calcium treatment decreased the total number of small intestinal tumors (by 31.4%; P or = 2 mm in diameter, showing a 75.6% inhibition in the small intestinal tumor multiplicity (P < 0.001). Immunohistochemical analysis showed significantly reduced nuclear staining of beta-catenin (expressed as nuclear positivity), but increased plasma membrane staining of beta-catenin, in the adenomas from the calcium-treated groups in comparison to those from the control group (P < 0.001). These results demonstrate intestinal cancer inhibitory effects of calcium both in human colon cancer cells and Apc Min/+ mice. The decreased beta-catenin nuclear localization caused by the calcium treatment may contribute to the inhibitory action.