The Effect of Ultrafine Process on the Dissolution, Antibacterial Activity, and Cytotoxicity of Coptidis rhizoma

BACKGROUND: The dosage of herb ultrafine particle (UFP) depended on the increased level of its dissolution, toxicity, and efficacy. OBJECTIVE: The dissolution, antibacterial activity, and cytotoxicity of Coptidis rhizoma (CR) UFP were compared with those of traditional decoction (TD). MATERIALS AND METHODS: The dissolution of berberine (BBR) of CR TD and UFP was determined by high-performance liquid chromatography. The antibacterial activity of CR extract was assayed by plate-hole diffusion and broth dilution method; the inhibitory effect of rat serums against bacteria growth was evaluated after orally given CR UFP or TD extract. The cytotoxicity of CR extract was evaluated by 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide assay. RESULTS: The dissolution amount of BBR from CR UFP increased 6–8-folds in comparison to TD at 2 min, the accumulative amount of BBR in both UFP and TD group increased in a time-dependent manner. The minimal inhibitory concentrations and minimal bactericidal concentrations of CR UFP extract decreased to 1/2~1/4 of those of TD extract. The inhibitory effect of rat serums against bacteria growth decreased time-dependently, and no statistical difference was observed between two groups at each time point. The 50% cytotoxic concentrations of UFP extract increased 1.66~1.97 fold than those of TD. CONCLUSIONS: The antibacterial activity and cytotoxicity of CR UFP increased in a dissolution-effect manner in vitro, the increased level of cytotoxicity was lower than that of antibacterial activity, and the inhibitory effect of rat serums containing drugs of UFP group did not improve. SUMMARY: Ultrafine grinding process caused a rapid increase of BBR dissolution from CR. The antibacterial activity and cytotoxicity of UFP extract in vitro increased in a dissolution-effect manner, but the cytotoxicity increased lower than the antibacterial activity. The antibacterial activity of rat serums of UFP group did not improve in comparison to that of TD group. [Image: see text]