Contents of total alkaloid in three formulations of Sini Decoction.

[Objective]To study the bacteriostasis in vitro of different solvent extracts from the fruits of Rosa laxa Ratz.and to find the antibacterial components.[Method]Effects of R.laxa fruit extracts by different polar solvents on the growth and biofilm formation of Streptococcus mutans and Escherichia coli were determined by microporosity plate method and dilution method.[Result]The ethyl acetate extracts from R.laxa fruits had certain inhibitory effects on the growth of Streptococcus mutans.Extracts from R.laxa fruits by five polar solvents could obviously inhibit the formation of biofilm of Streptococcus mutans Extracts from R.laxa fruits by five polar solvents had inhibitory effects on the biofilm formation of Escherichia coli,among which,chloroform and ethyl acetate extracts showed the strongest antibacterial effects.[Conclusion]Extracts from R.laxa fruits had relatively good inhibitory effects on Streptococcus mutans and Escherichia coli;and further research was needed.