Abstract
DNA microarray technology was used to evaluate the effect of dietary intake of nigana (Crepidiastrum lanceolatum), an edible plant in Okinawa, on gene-expression pattern in the liver. The expression levels of several genes were changed in the liver of mice that consumed nigana or spinach. Whereas dietary intake of spinach and water did not affect the mRNA level of erythropoietin (EPO), intake of nigana induced gene expression of EPO in the mouse liver. To produce high-quality vegetables, we changed the growth conditions for nigana. Three irrigation rates (potential free energy; pF 1.5, 1.8, and 3.0) were used for nigana hydro culture. The irrigation conditions affected the contents of nutritional factors in nigana as well as the level of expression of the EPO gene in the liver of mice that ingested the plant. The pF 1.5 condition did not afford the highest levels of nutrients. However, the low levels of potassium and nitric acid found under this condition were a positive aspect, as these chemicals are known to be unfavorable factors in vegetables. The greatest induction of EPO mRNA at pF 1.5 was also beneficial. These findings indicate that the application of DNA microarray technology to experimental animals ingesting a specific dietary component is useful for producing high-quality food.
