[In vitro and in vivo evaluation of total flavones of Hippophae rhamnoides self-microemulsifying drug delivery system].

The goal of the study is to evaluate the self-microemulsifying drug delivery system (SMEDDS) which enhances the oral bioavailability of the poorly water-soluble drug, total flavones of Hippophae rhamnoides (TFH). It is orally administered for the protection of human cardiovascular system. Self-microemulsifying time, particle size, polydispersity index (PDI), morphological characterization, in vitro dispersity, stability, in situ intestinal absorption and relative bioavailability were investigated in detail. The TFH-SMEDDS rapidly formed fine oil-in-water microemulsions with 0.1 mol x L(-1) hydrochloride solution, with average size of which was less than 40 nm, PDI was below 0.2, and the particles of which were observed round-shaped under transmission electron microscope. Almost 90% of TFH (expressed with quercetin) was released from SMEDDS within 20 min, which was remarkably higher than that from common capsules. The stability test showed the TFH-SMEDDS maintained stable in 6 months under accelerated condition. In situ absorption study demonstrated the absorption rate constant of TFH-SMEDDS (expressed with quercetin) was significantly higher than that of TFH in ethanolic solution (P < 0.05). The absorption of TFH from SMEDDS showed a 4.18-fold increase in relative bioavailability (expressed with quercetin) compared with that of the suspension. The results suggest that SMEDDS is a promising drug delivery system to increase the oral bioavailability of TFH.

Fungichromin Production by Streptomyces padanus PMS-702 for Controlling Cucumber Downy Mildew.

Streptomyces padanus PMS-702 strain produces a polyene macrolide antibiotic fungichromin and displays antagonistic activities against many phytopathogenic fungi. In the present study, experimental formulations were assessed to improve the production of fungichromin, the efficacy of PMS-702 on the suppression of sporangial germination, and the reduction of cucumber downy mildew caused by Pseudoperonospora cubensis. PMS-702 strain cultured in a soybean meal-glucose (SMG) medium led to low levels of fungichromin accumulation and sporangial germination suppression. Increasing medium compositions and adding plant oils (noticeably coconut oil) in SMG significantly increased fungichromin production from 68 to 1,999.6 µg/ml. Microscopic examination reveals that the resultant suspensions significantly reduced sporangial germination and caused cytoplasmic aggregation. Greenhouse trials reveal that the application of PMS-702 cultural suspensions reduced downy mildew severity considerably. The addition of Tween 80 into the synthetic medium while culturing PMS-702 further increased the suppressive efficacy of downy mildew severity, particularly when applied at 24 h before inoculation or co-applied with inoculum. Fungichromin at 50 µg/ml induced phytotoxicity showing minor necrosis surrounded with light yellowish halos on cucumber leaves. The concentration that leads to 90% inhibition (IC90) of sporangial germination was estimated to be around 10 µg/ml. The results provide a strong possibility of using the S. padanus PMS-702 strain as a biocontrol agent to control other plant pathogens.

Seroprevalence of Toxoplasma gondii in horses and donkeys in Yunnan Province, Southwestern China.

BACKGROUND: Toxoplasma gondii is an intracellular protozoan parasite that infects almost all warm-blooded animals, including humans, with a worldwide distribution. There have been limited reports about the seroprevalence of T. gondii infection in equids around the world and little is known about the seroprevalence of T. gondii in equids in southwestern China, in particular in Yunnan Province. The objective of the present investigation was to estimate the seroprevalence of T. gondii infection in equids in this area. METHODS: A total of 399 serum samples (266 from horses and 133 from donkeys) were collected in 2012, and assayed for T. gondii antibodies by Indirect Haemagglutination (IHA) test using a commercially available kit. RESULTS: A total of 108 (27.1%) equids, including 81 (30.5%) horses and 27 (20.3%) donkeys were positive for T. gondii antibodies, and the seroprevalence ranged from 18.8% to 37.5% among different sampling areas. The seroprevalence was 27.4% and 26.8% for male and female equids, respectively, and the difference was not statistically significant (P > 0.05). The seroprevalence ranged from 21% to 32.9% among different age groups, and the difference was not statistically significant (P > 0.05). CONCLUSIONS: The results of the present survey indicated the existence of high T. gondii seroprevalence in Yunnan Province, southwestern China, which has significant public health concern. Therefore, it is imperative that improved integrated measures be carried out to prevent and control T. gondii infection in equids in the studied region.