Antioxidant and growth inhibitory activities of Mesembryanthemum crystallinum L. in HCT116 human colon cancer cells / 한국영양학회지

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.

Effect of Yoga on Heart Rate Variability in Women with Metabolic Syndrome

BACKGROUND: The purpose of this study was to investigate the correlation between yoga and autonomic nervous system in women with metabolic syndrome. METHODS: A randomized controlled study was performed in participants recruited from a public center for managing chronic diseases located in Gyeong-gi Province. The 39 women participants diagnosed with metabolic syndrome were randomly assigned to the 12-week yoga exercise group (n=22) or the wait-listed control group (n=17). Biochemical laboratory tests and heart rate variability were measured before and after the 12-week program. RESULTS: In post-menopausal women, the low frequency power of frequency domain significantly decreased in the yoga exercise group compared to the control group (P=0.07). On the time domain of heart rate variability and metabolic syndrome components, there were no significant differences between the groups. CONCLUSIONS: Sympathetic activity was decreased in post-menopausal women with metabolic syndrome who practiced yoga. Our results suggest that yoga might be beneficial in improving the autonomic nervous system in post-menopausal women with metabolic syndrome.