Inhibition of Pancreatic Lipase Activity and Adipocyte Differentiation in 3T3-L1 Cells Treated with Purple Corn Husk and Cob Extracts

Accumulation of nitrate in edible crops is undesirable due to potential risks to human health. Since nitrate has a role in the osmotic regulation of plants, salt accumulation in soil is expected to stimulate nitrate accumulation in plants. Lettuce (Lactuca sativa L.) was grown in soils of different salinities, 9.69 and , in a greenhouse, and the effect of soil salinity on nitrate accumulation in lettuce was investigated. Content of nitrate in the lettuce increased significantly as soil salinity increased under low light intensity and ample supply of nitrate in root media. Soluble sugar and oxalate contents in lettuce were also significantly higher in the soil of higher salinity. Phosphate, Cl, and contents in lettuce were not significantly different in soils of different salinities. Among the cations, K content in lettuce was significantly higher in the soil of higher salinity, but Na, Ca, and Mg comtents were not much influenced. Comparing to the lettuce grown in low salinity soil, although the growth of lettuce was decreased by 9% in the soil of higher salinity, nitrate accumulation in the lettuce was increased by 18.6%. These results indicate that higher nitrate content in lettuce of higher salinity soil is a positive accumulation to adapt to the water stress condition. The nitrate accumulation of vegetables grown in plastic film houses is known to be due to the heavy fertilization and low light intensity, but salt accumulation in the soil, which can lower soil water potential, is expected to stimulate the nitrate accumulation further.