[Identification, biological characteristics, and screening of effective fungicides of Phoma rhei causing leaf spot on Polygonum cuspidatum].

Severe leaf spot on Polygonum cuspidatum was found in the planting base of P. cuspidatum in Fangxian county, Shiyan of Hubei province. To clarify the types of pathogens and their pathogenesis, the present study isolated and purified the pathogen of leaf spot disease of P. cuspidatum according to Koch's postulates, determined the pathogenicity of the pathogen, and investigated its biological characteristics. Meanwhile, the inhibitory effects of 11 types of fungicides on the bacteria were determined according to the mycelium growth rate, and suitable prevention and control drugs were selected. The results showed that the pathogen isolated from the diseased leaves of P. cuspidatum was Phoma rhei by morphological and molecular identification. The colony morphology and microscopic characteristics were the same as those of Ph. rhei. The homology of rDNA-ITS and TEF gene sequences with Ph. rhei reached 99.96% and 99.43%, respectively. The optimal growth temperature of Ph. rhei was 25 ℃, and the optimal pH was 7-10. Furthermore, Ph. rhei grew faster under dark or light conditions. In fungicides, 0.3% eugenol, 250 g·L~(-1) propiconazole, and 33.5% quinoline copper had significant inhibitory effects on the pathogen with EC_(50) values of 57.54, 59.58, 88.69 µg·mL~(-1), respectively. Eugenol is a botanical fungicide, which can be used as a green and environmentally friendly fungicide in the prevention and control of P. cuspidatum. This study reported for the first time that the pathogen of P. cuspidatum leaf spot was Ph. rhei. investigated the biological characteristics of the pathogen, and screened the indoor chemicals, which provided a theoretical basis for the prevention and control of P. cuspidatum leaf spot in production.

[Effect of Gegen Qinlian decoction on hepatic cytochrome CYP450 isozymes in rats by HPLC-MS/MS].

To study the effect of Gegen Qinlian decoction and its major effective components on five hepatic microsomal CYP450 isozymes in rats. The in vitro hepatic microsomal incubation technique was used to co-culture Gegen Qinlian decoction and its major effective components together with each probe substrate. HPLC-MS/MS was used to establish the analytical method for metabolites of the five isoform probe substrates of CYP450 isozymes, detect the linearity among micoromal protein concentration, incubation time and metabolite formation amount. And HPLC-MS/MS was applied to determine the formation rate (V) of corresponding metabolites (acetaminophen, 4-OH-chlorzoxazone, dextrophan, 6-OH-chlorzoxazone and 6ß-hydroxytestosterone) specific probe substrates of the five isoform probe substrates of CYP450 isozymes (phenacetin, polbutamide, dextromethorphan, chlorzoxazone, testosterone), in order to determine the activity of each isozyme. The result showed good linearity among acetaminophen, 4-OH-tolbutamide, dextrophan, 6-OH-chlorzoxazone and 6ß-hydroxytestosterone, satisfactory precision, stability and average recovery, suggesting the method was feasible. The optimized in vitro microsomal incubation conditions conformed to the requirements in the guideline of drug-drug interaction. Gegen Qinlian decoction showed different degrees of inhibitor effect on 5 CYP450 isoforms (CYP1A2, CYP2C11, CYP2D2, CYP2E1, CYP3A1/2). Its major effective component berberine could inhibit each CYP450 isoform at high concentrations (except for CYP1A2, CYP3A1/2).

Spatial memory impairment is associated with hippocampal insulin signals in ovariectomized rats.

Estrogen influences memory formation and insulin sensitivity. Meanwhile, glucose utilization directly affects learning and memory, which are modulated by insulin signals. Therefore, this study investigated whether or not the effect of estrogen on memory is associated with the regulatory effect of this hormone on glucose metabolism. The relative expression of estrogen receptor ß (ERß) and glucose transporter type 4 (GLUT4) in the hippocampus of rats were evaluated by western blot. Insulin level was assessed by ELISA and quantitative RT-PCR, and spatial memory was tested by the Morris water maze. Glucose utilization in the hippocampus was measured by 2-NBDG uptake analysis. Results showed that ovariectomy impaired the spatial memory of rats. These impairments are similar as the female rats treated with the ERß antagonist tamoxifen (TAM). Estrogen blockade by ovariectomy or TAM treatment obviously decreased glucose utilization. This phenomenon was accompanied by decreased insulin level and GLUT4 expression in the hippocampus. The female rats were neutralized with hippocampal insulin with insulin antibody, which also impaired memory and local glucose consumption. These results indicated that estrogen blockade impaired the spatial memory of the female rats. The mechanisms by which estrogen blockade impaired memory partially contributed to the decline in hippocampal insulin signals, which diminished glucose consumption.