Changes in herbaceous plants in an urban habitat garden in Kyoto city, Japan, 9 years after construction

To understand the characteristics and problems of artificial urban ecological environments, we investigated the changes in herbaceous plants in an urban habitat garden for 9 years after construction and compared the results with 15 remnant semi-natural green spaces in Kyoto city, Japan. The area of the habitat garden is 0.6 ha and it was constructed approximately 3 km from the nearest mountains in 1996. From 1996 to 2004, 301 unplanted species, including 218 native species and 83 alien species, were recorded. Most newly recorded species were recorded in 1998 and the timing of colonization was different from ferns. The species turnover rate per year decreased from 30.8% in 1998 to 18.5% in 2004. This indicates that established species in the habitat garden have been gradually determined. In the species recorded in the habitat garden in 2004, the percentage of high-temperature species, which were relatively departed from the nested pattern of species composition for the 15 green spaces, was significantly high. It was considered that herbaceous plant succession in the habitat garden was at an early stage, even though it was 9 years ago since construction. Buried seeds and various environments are likely to contribute to higher species richness in the habitat garden as compared to remnant green spaces of approximately the same area. On the other hand, the high percentage of alien species and the low percentages of forest and forest edge species in the habitat garden indicate the problems of a habitat garden constructed in the center of a city.     

Alachlor and carbaryl suppress lipopolysaccharide-induced iNOS expression by differentially inhibiting NF-kappaB activation

Nitric oxide (NO) produced by macrophages plays an important role in host defense and inflammation. We found that two agrochemicals, alachlor and carbaryl, inhibit lipopolysaccharide (LPS)-induced NO production by macrophages. In the present study, we investigated this inhibitory mechanism in RAW 264 cells. Both chemicals inhibited LPS-induced iNOS protein and mRNA expression as well as murine iNOS promoter activity. When treating these chemicals with reducing agents, the inhibition by carbaryl was reversed, but not the inhibition by alachlor. These chemicals also inhibited LPS-induced interferon-beta (IFN-beta) expression, an indispensable factor for LPS-induced iNOS expression. The inhibited iNOS expression, however, was not restored by exogenous IFN-beta supplementation. LPS-induced nuclear translocation of NF-kappaB, which is necessary for the expression of IFN-beta and iNOS, was inhibited by these chemicals: however, the LPS-induced degradation of IkappaB-alpha and IkappaB-beta was inhibited only by alachlor. These results indicate that alachlor and carbaryl differentially impair the LPS-induced NF-kappaB activation, leading to the inhibition of NO production.