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Macrophages can initiate innate immune responses against microbes and cancer. The aim of this study was to elucidate the effects of Brassica rapaL. on macrophages. The production of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and interferon-γ induced by the insoluble fraction of B. rapaL. was decreased in macrophage-depleted spleen cells compared with controls. The insoluble fraction of B. rapaL. induced expression of H-2Kb, I-Ab, CD40, and CD86, production of cytokines and nitric oxide, and phagocytic activity in RAW264 cells. After treatment with the insoluble fraction, IL-6 and TNF-α production was significantly decreased by anti-Toll-like receptor (TLR)2 mAb or polymyxin B compared with the control. Furthermore, insoluble fraction-mediated cytokine production was significantly lower in peritoneal macrophages from TLR2−/−and TLR4−/−mice compared with wild-type mice. These results suggest that B. rapaL. is a potentially effective immunomodulator for activating macrophages to prevent infections.Graphical AbstractThe insoluble fraction of B. rapaL. activates macrophages to produce cytokines and NO. The macrophage activation by the insoluble fraction were mediated by TLR2 and TLR4.

AbstractDynamic states of water in the leaves and roots of perennial ryegrass (Lolium perenneL.) exposed to cold and heat stresses were studied by using 1H-NMR. NMR spin-lattice relaxation times (T1) of leaves in Arrhenius plots linearly decreased but increased as temperature decreased below 0°C. However, spin-spin relaxation times (T2) of the leaves increased as temperature decreased from 20 to –20°C. The T2value of the long fraction (associated with vacuole) in leaves decreased to about 600 µs at –25°C, but that of the short fraction was about 10 µs, and the relative value of signal intensity of the long fraction decreased to about 0.2 at –25°C. The T2values of the two fractions in roots decreased to about 1ms at –10°C. Judging from T2and electrolyte leakage, both vacuolar and cytoplasmic compartments of leaves and roots froze at these temperatures. T1of the leaves decreased slightly as temperatureincreased from 20 to 40°C but greatly decreased as temperature increased further. On the other hand, T1of the roots decreased linearly as temperature increased from 20 to 50°C. The levels of electrolyte leakage from leaves exposed to the above heat stress was low suggesting that membrane was not severely injured. In conclusion, analysis of Arrhenius plots of T1and T2is a sensitive and non-invasive method to evaluate primary responses of perennial ryegrass organs to the temperature stresses.