RESUMO
Damaged tissue with an open wound is one of the daily injuries and can have different levels of severity. Inspired by the textile dyeing, coloration and skin care effect of pyrogallol-rich red wine, tannic acid-KH561 (TA561) copolymer was fabricated by phenol-silanol reaction and polycondensation of silane in an aqueous medium under mild conditions. This copolymer could undergo sol-gel transition via continuous heating or when simply placed at room temperature, during which liquid TA561 oligomers connected with each other to form solid TA561 as a bulk resin or thin film. Combining the advantages of the polyphenols and polysiloxane, TA561 can be used as an adhesive for multiple surfaces, including wood, polytetrafluoroethylene, poly(vinyl chloride), aluminum chips and silicon rubber. Furthermore, TA561 also possessed reducing activity towards Ag+ or Au3+ ions to form the corresponding nanoparticles. An in vivo antimicrobial ability test indicated that TA561 could promote wound healing and showed resistance to methicillin-resistant Staphylococcus aureus (MRSA) infection in comparison with KH561. Indeed, TA561 has the potential to be utilized as a low-cost, green bioadhesive material for skin preparations.
RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Herba Ephedra (Mahuang in Chinese), is derived from dried Ephedra sinica Stapf stems and has been widely used to treat the common cold, coughs, asthma, and edema for thousands of years. The Mahuang-Guizhi herb-pair is a famous formula composed of Mahuang and Ramulus Cinnamomi (Guizhi in Chinese, the dried twig of Cinnamomum cassia Presl.), used to improve pharmacological effects and reduce toxicity. In order to investigate the influence of Mahuang-Guizhi herb-pair ratios on bioavailability, the plasma pharmacokinetics profiles of five ephedrine alkaloids were compared following oral administration of four different ratios to rats. MATERIALS AND METHODS: Sprague-Dawley rats were randomly assigned to four groups and orally administered Mahuang-Guizhi (ratios 3:0; 3:1; 3:2; 3:4, w/w). Assays for five ephedrine alkaloids (ephedrine, pseudoephedrine, methylephedrine, norephedrine, and norpseudoephedrine) were developed and validated using ultra-high-performance liquid chromatography tandem mass spectrometry coupled with liquid-liquid extraction. RESULTS: Key pharmacokinetic parameters of the five ephedrine alkaloids (maximal plasma concentration, mean residence time, and half-life) were significantly different (p<0.05) after oral administration of Mahuang-Guizhi herb-pair ratios, as compared to those of Mahuang. CONCLUSION: Ephedrine alkaloid pharmacokinetic differences in rat plasma could help explain previous findings of pharmacological and toxicity differences between Mahuang and Mahuang-Guizhi herb-pair preparations. These results could facilitate future studies to increase the efficacy and decrease the toxicity of Mahuang and Guizhi.