[Effects of flavonoids from Pyrrosiae folium on pathological changes and inflammatory response of diabetic nephropathy].

Diabetic nephropathy (DN) is closely related to immune-mediated inflammatory damage. Pyrrosiae folium is used commonly for the urinary system diseases with a good efficacy, which contains abundant flavonoids (SWHT). This study was performed to investigate the therapeutic effect of SWHT on DN and its effect on inflammatory response. In this study, the main active components of SWHT were identified by high performance liquid chromatography (HPLC). The results showed that SWHT mainly contained mangiferin and isomucoside. Rat model of diabetic nephropathy (DN) was established by feeding high glucose & high fat diet and injecting streptozocin (STZ). Then the rats were randomly divided into control group, DN model group, positive control group, and SWHT groups (50, 100, 200 mg·kg⁻¹, ig). The levels of AGEs and RAGE in serum were measured by ELISA after 12 weeks of drug administration. The serum creatinine, blood urea nitrogen and total protein levels were detected by using test kit. HE staining and transmission electron microscopy were applied to observe the pathological changes and structure of renal tissue. Western blot and ELISA were used to detect the protein expression and content levels of interleukin 6 (IL-6), tumor necrosis factor (TNF-α) and IL-1ß in renal tissue. Results showed that SWHT significantly decreased serum AGEs and RAGE levels in DN rats; decreased serum creatinine, blood urea nitrogen and total urinary protein levels, improved renal pathological damages and reduced basement membrane thickening in DN rats. In addition, SWHT down-regulated the protein expression levels of inflammatory mediators IL-6, TNF-α and IL-1ß. The research studies indicated that SWHT component had a potential anti-diabetic nephropathy activity, and its improvement effect on pathological damages may be related to reducing inflammation. This provides the basis for the scientific and rational application of P. folium, and also provides active components for further development of Chinese medicine for diabetic nephropathy.

Quantitative relationship between visibility and mass concentration of PM2.5 in Beijing.

The pollution of particulate matter less than 2.5 microm (PM2.5) is a serious environmental problem in Beijing. The annual average concentration of PM2.5 in 2001 from seasonal monitor results was more than 6 times that of the U.S. national ambient air quality standards proposed by U.S. EPA. The major contributors to mass of PM2.5 were organics, crustal elements and sulfate. The chemical composition of PM2.5 varied largely with season, but was similar at different monitor stations in the same season. The fine particles (PM2.5) cause atmospheric visibility deterioration through light extinction. The mass concentrations of PM2.5 were anti-correlated to the visibility, the best fits between atmospheric visibility and the mass concentrations of PM2.5 were somehow different: power in spring, exponential in summer, logarithmic in autumn, power or exponential in winter. As in each season the meteorological parameters such as air temperature and relative humidity change from day to day, probably the reason of above correlations between PM2.5 and visibility obtained at different seasons come from the differences in chemical compositions of PM2.5.

Chemical composition and quantitative relationship between meteorological condition and fine particles in Beijing.

The recent year's monitor results of Beijing indicated that the pollution level of fine particles PM2.5 showed an increasing trend. To understand pollution characteristics of PM2.5 and its relationship with the meteorological conditions in Beijing, a one-year monitoring of PM2.5 mass concentration and correspondent meteorological parameters was performed in Beijing in 2001. The PM2.5 levels in Beijing were very high, the annual average PM2.5 concentration in 2001 was 7 times of the National Ambient Air Quality Standards proposed by US EPA. The major chemical compositions were organics, sulfate, crustals and nitrate. It was found that the mass concentrations of PM2.5 were influenced by meteorological conditions. The correlation between the mass concentrations of PM2.5 and the relative humidity was found. And the correlation became closer at higher relative humidity. And the mass concentrations of PM2.5 were negtive-correlated to wind speeds, but the correlation between the mass concentration of PM2.5 and wind speed was not good at stronger wind.