Time- and dose-dependent effects of curcumin on gene expression in human colon cancer cells

BACKGROUND: Curcumin is a spice and a coloring food compound with a promising role in colon cancer prevention. Curcumin protects against development of colon tumors in rats treated with a colon carcinogen, in colon cancer cells curcumin can inhibit cell proliferation and induce apoptosis, it is an anti-oxidant and it can act as an anti-inflammatory agent. The aim of this study was to elucidate mechanisms and effect of curcumin in colon cancer cells using gene expression profiling. METHODS: Gene expression changes in response to curcumin exposure were studied in two human colon cancer cell lines, using cDNA microarrays with four thousand human genes. HT29 cells were exposed to two different concentrations of curcumin and gene expression changes were followed in time (3, 6, 12, 24 and 48 hours). Gene expression changes after short-term exposure (3 or 6 hours) to curcumin were also studied in a second cell type, Caco-2 cells. RESULTS: Gene expression changes (>1.5-fold) were found at all time points. HT29 cells were more sensitive to curcumin than Caco-2 cells. Early response genes were involved in cell cycle, signal transduction, DNA repair, gene transcription, cell adhesion and xenobiotic metabolism. In HT29 cells curcumin modulated a number of cell cycle genes of which several have a role in transition through the G2/M phase. This corresponded to a cell cycle arrest in the G2/M phase as was observed by flow cytometry. Functional groups with a similar expression profile included genes involved in phase-II metabolism that were induced by curcumin after 12 and 24 hours. Expression of some cytochrome P450 genes was downregulated by curcumin in HT29 and Caco-2 cells. In addition, curcumin affected expression of metallothionein genes, tubulin genes, p53 and other genes involved in colon carcinogenesis. CONCLUSIONS: This study has extended knowledge on pathways or processes already reported to be affected by curcumin (cell cycle arrest, phase-II genes). Moreover, potential new leads to genes and pathways that could play a role in colon cancer prevention by curcumin were identified

Cross-Sectional Study to Map Nutritional Quality of Meat, Fish, and Dairy Alternatives in Dutch Supermarkets According to the Dutch Food-Based Dietary Guidelines and Nutri-Score

Due to a growing challenge to feed the world’s population and an increased awareness to minimize the impact of our food choices on climate change, a more plant-based diet has gained popularity with a growing number of plant-based products on the market. To stimulate a plant-based diet that also improves long-term health, data are needed to monitor whether these products are healthy alternatives to animal-based foods. Therefore, this study inventoried 916 plant-based meat, fish, and dairy alternatives from eight Dutch supermarkets. The nutritional quality of each product was assessed by (1) the Dutch food-based dietary guidelines and (2) the Nutri-Score. The results show that over 70% of meat, fish, and dairy alternatives have an A/B Nutri-Score (indicating high nutritional quality), but do not comply with the Dutch dietary guidelines. This is mainly due to high salt and low vitamin B12 and iron content (meat and fish alternatives) or low protein and calcium levels (dairy alternatives). In conclusion, the majority of plant-based products are nutritionally not full alternatives of the animal-based equivalents; however, there are still opportunities for reformulation. To aid the consumer in making healthy plant-based food choices, a better alignment between the Nutri-Score and the recommended dietary guidelines is needed

Age-dependent alterations in Ca2+ homeostasis: Role of TRPV5 and TRPV6

Aging is associated with alterations in Ca2+ homeostasis, which predisposes elder people to hyperparathyroidism and osteoporosis. Intestinal Ca2+ absorption decreases with aging and, in particular, active transport of Ca2+ by the duodenum. In addition, there are age-related changes in renal Ca2+ handling. To examine age-related changes in expression of the renal and intestinal epithelial Ca2+ channels, control (TRPV5+/+) and TRPV5 knockout (TRPV5-/-) mice aged 10, 30, and 52 wk were studied. Aging of TRPV5+/+ mice resulted in a tendency toward increased renal Ca2+ excretion and significantly decreased intestinal Ca2+ absorption, which was accompanied by reduced expression of TRPV5 and TRPV6, respectively, despite increased serum 1,25(OH)2D3 levels. Similarly, in TRPV5-/- mice the existing renal Ca2+ loss was more pronounced in elder animals, whereas the compensatory intestinal Ca2+ absorption and TRPV6 expression declined with aging. In both mice strains, aging resulted in a resistance to 1,25(OH)2D3 and diminished renal vitamin D receptor mRNA levels, whereas serum Ca2+ levels remained constant. Furthermore, 52-wk-old TRPV5-/- mice showed severe hyperparathyroidism, whereas PTH levels in elder TRPV5+/+ mice remained normal. In 52-wk-old TRPV5-/- mice, serum osteocalcin levels were increased in accordance with the elevated PTH levels, suggesting an increased bone turnover in these mice. In conclusion, downregulation of TRPV5 and TRPV6 is likely involved in the impaired Ca2+ (re)absorption during aging. Moreover, TRPV5-/- mice likely develop age-related hyperparathyroidism and osteoporotic characteristics before TRPV5+/+ mice, demonstrating the importance of the epithelial Ca2+ channels in Ca2+ homeostasis. Copyrigh