ABSTRACT
Syringa oblata Lindl. (S. oblata) is a medicinal plant with effective broad-spectrum antibacterial activity, which can also inhibit Streptococcus suis biofilm formation. The processing of herbal medicine can purify medicinal materials, provide acceptable taste, reduce toxicity, enhance efficacy, influence performance and facilitate preparation. Thus, the aim of this study was to enhance the biofilm inhibition activity of S. oblata toward Staphylococcus xylosus (S. xylosus) using the best processing method. The content of rutin and flavonoids and the ability to inhibit the biofilm formation by S. oblata were examined using four processing methods. One of the best methods, the process of stir-frying S. oblata with vinegar, was optimized based on the best rutin content by response surface methodology. The histidine content and hisB gene expression of S. xylosus biofilm in vitro, resulting from stir-frying S. oblata with vinegar, were evaluated and were found to be significantly decreased and down-regulated, respectively. The results show that S. oblata stir-fried with vinegar can be used to effectively treat diseases resulting from S. xylosus infection. This is because it significantly inhibited S. xylosus biofilm formation by interfering with the biosynthesis of histidine; thus, its mechanism of action is decreasing histidine synthesis.
ABSTRACT
Cows infected with Escherichia (E.) coli usually experience severe clinical symptoms, including damage to mammary tissues, reduced milk yield, and altered milk composition. In order to investigate the host response to E. coli infection and discover novel markers for mastitis treatment, mammary tissue samples were collected from healthy cows and bovines with naturally occurring severe E. coli mastitis. Changes of mammary tissue proteins were examined using two-dimensional gel electrophoresis and label-free proteomic approaches. A total of 95 differentially expressed proteins were identified. Of these, 56 proteins were categorized according to molecular function, cellular component, and biological processes. The most frequent biological processes influenced by the proteins were response to stress, transport, and establishment of localization. Furthermore, a network analysis of the proteins with altered expression in mammary tissues demonstrated that these factors are predominantly involved with binding and structural molecule activities. Vimentin and a-enolase were central "functional hubs" in the network. Based on results from the present study, disease-induced alterations of protein expression in mammary glands and potential markers for the effective treatment of E. coli mastitis were identified. These data have also helped elucidate defense mechanisms that protect the mammary glands and promote the pathogenesis of E. coli mastitis.
