Effects of Aphidius gifuensis on the feeding behavior and potato virus Y transmission ability of Myzus persicae.

The stylet penetration behavior of aphids when feeding on plants is associated with virus acquisition and inoculation. Aphidius gifuensis (Ashmead) is a primary endoparasitoid of Myzus persicae (Sulzer) which is the most efficient vector of plant viruses. Information about the effects of parasitoid on aphid and virus transmission can provide an essential foundation for designing effective biological control strategies. This study aimed to investigate the effects of A. gifuensis on the feeding behavior and potato virus Y (PVY) transmission ability of M. persicae. The results showed that after M. persicae was parasitized by A. gifuensis, the duration of the first probe significantly decreased. Additionally, A. gifuensis exerted remarkable effects on aphid feeding in phloem ingestion. The contribution of the E1 waveform to the phloem phase was significantly higher in all parasitized aphids than in the control group. Although the time of infestation increased for parasitized aphids, the total duration of phloem sap ingestion decreased. Interestingly, the percentage of time M. persicae spent in the xylem and phloem phases only changed significantly on day 5. The percent transmission of PVY by the aphids parasitized on day 5 was lower than that in the control, but no significant differences were detected. The significance of this work is the demonstration that A. gifuensis can impede the feeding behavior of M. persicae, which sheds light on the biological basis of A. gifuensis as a natural enemy, but unfortunately does not provide an immediate solution for disrupting the transmission of PVY.

Suppression of hepatic stellate cell activation through downregulation of gremlin1 expression by the miR-23b/27b cluster.

The imbalance between transforming growth factor ß and bone morphogenetic protein 7 signaling pathways is a critical step in promoting hepatic stellate cell activation during hepatic fibrogenesis. Gremlin1 may impair the balance. Something remains unclear about the regulatory mechanisms of gremlin1 action on hepatic stellate cell activation and hepatic fibrosis. In the current study, gremlin1 overexpression promotes activation of hepatic stellate cells. Knockdown of gremlin1 with siRNAs suppresses hepatic stellate cell activation and attenuates hepatic fibrosis in rat model. Our results also show that miR-23b/27b cluster members bind to 3'-untranslated region of gremlin1 resulting in reduction of transforming growth factor ß, α-smooth muscle actin and collagenI α1/2 gene expression. Our findings suggest that gremlin1 promotes hepatic stellate cell activation and hepatic fibrogenesis through impairment of the balance between transforming growth factor ß and bone morphogenetic protein 7 signaling pathways. The miR-23b/27b cluster suppresses activation of hepatic stellate cells through binding gremlin1 to rectify the imbalance.

[Study on chemical constituents of triterpenoids from Potentilla discolor].

OBJECTIVE: To study the triterpenoids constituents in Potentilla discolor. METHODS: The compounds were isolated by silica gel chromatography, macroporous resins and polyamide column chromatography from the 70% ethanol extract, and their structures were identified by spectral analysis. RESULTS: Six compounds were obtained and their structures were identified as 3-O-beta-D-glucopyranosyl-(1 --> 2) -beta-D-xylopyranosyl-19a-hydroxyurs-12-en-28-acid (1), 2alpha, 3/beta, 19alpha-trihydroxyurs-12-en-28-acid (2), 3beta, 19alpha-trihydroxyurs-12-en-24, 28-acid (3), 2alpha, 3beta-dihydroxyolean-12-en-28-acid (4), 2alpha, 3alpha, 19alpha-trihydroxyurs-12-en-28-acid (5), beta-sitosterol (6). CONCLUSION: Compounds 1 and 3 are obtained from this plant for the fisrt time.

[Preparation technology of Zhangyanming dispersible tablet and determination of puerarin by HPLC].

OBJECTIVE: To study the extraction and pharmceutics technology of Zhangyanming dispersible tablet and establish the method for determining the content of puerarin by HPLC. METHODS: Using total extracted puerarin and disintegrating time as evaluation indexes and the conditions for determination were as follows: Hypersil BDS C18 column (5 microm, 4.6 mm x 200 mm), Methanol-H2O (25:75) as the mobile phase, the detection wavelength at 250 nm, the column temperature at 30 degrees C, and 1.0 mL/min as the mobile phase speed. RESULTS: The calibration curve was linear at the range of 0.1699 to 1.3594 microg for the puerarin content and the linear equation was y = 3.054 x 10(6)x - 24019 (r = 0.9998). The average recovery ratio was 100.03%, and the relative standard deviation was 1.79%. CONCLUSIONS: The new preparation technology is reasonable and HPLC can be used to determine the content of puerarin in Zhangyanming dispersible tablet because the operation was convenient, fast, easy to repeat, and the analysis results were accurate and especial.