Pharmacokinetics of acteoside following single dose intragastric and intravenous administrations in dogs / 中国天然药物

Acteoside (verbascoside), a phenylethanoid glycoside widely distributed in various plants, has been shown to have potential activity against Alzheimer's disease, attracting great attentions recently. The present study was designed to develop a selective and sensitive LC-MS/MS method for the determination of acteoside in biological samples and carry our a pharmacokinetic (PK) study in beagle dogs. The PK parameters were calculated using non-compartmental models. Following a single-dose oral administration, acteoside was rapidly absorbed and eliminated, with Tmax being between 30 to 45 min and terminal half-life being about 90 min. The areas under the time-concentration curve (AUC) were 47.28 ± 8.74, 87.86 ± 13.33, and 183.14 ± 28.69 mg · min · L(-1) for oral administration of 10, 20, and 40 mg · kg(-1), respectively, demonstrating that the exposure of acteoside proportionally increased with the dose level. The absolute bioavailability of acteoside was around 4%. For all the PK parameters, there were large variations between individual dogs. In conclusion, the pharmacokinetic characteristics observed in the present study can be of great value to help better understand the pharmacological properties of acteoside and to improve the outcome of its clinical use.

Effect of decoction of Radix glycyrrhizae on the growth and acid-production of Streptococcus mutans in vitro / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the antibacterial activity of decoction of Radix glycyrrhizae against Streptococcus mutans (S. mutans) in vitro.</p><p><b>METHODS</b>The decoction of Radix glycyrrhizae was prepared by boiling particles of Radix glycyrrhizae, the diameter was 0.2-3.2 mm. In distilled water and filtered, the filtrate was collected for study. The minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) of the decoction against S. mutans were detected using double dilution. The effect of decoction on growth and acidogenic profile of S. mutans were investigated by detecting the Abs of bacteria suspension and the pH value of medium at definite time intervals(0, 3, 7, 12, 23, 40 h) during cultured.</p><p><b>RESULTS</b>The MIC determined for decoction was 50 mg x mL(-1) and there was no bactericidal effect when concentration of decoction lower than 100 mg x mL(-1). The decoction inhibitted multiplication of bacteria significantly and the effects became stronger with concentration increasing. The decoction also inhibitted S. mutans producing acid and the effect became stronger with concentration increasing. The most efficient inhibition were observed when incubated 12 hours.</p><p><b>CONCLUSION</b>The decoction of Radix glycyrrhizae can inhibite the growth and acid-production of S. mutans in vitro.</p>

Study on protein extraction methods for Streptococcus mutans / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish an efficient and stable method for protein extraction of Streptococcus mutans.</p><p><b>METHODS</b>The collected bacteria were treated by freeze-thaw and ultrasonic (method 1), ultrasonic (method 2), boiling (method 3), boiling and ultrasonic (method 4), respectively. The index such as state of bacteria broken, concentration of extracted protein and SDS-PAGE of protein were employed to evaluate the effects of above four methods.</p><p><b>RESULTS</b>Beside the method 3, the other three methods could break the bacteria effectively, of which ultrasonic was the key factor. The pattern of SDS-PAGE which treated by method 1, method 2 and method 4 was almost same, but method 1 resulted in the best abundance. There was significantly difference among the four protein concentration extracted by four methods (P < 0.05). All methods exhibited good stability and reproducibility.</p><p><b>CONCLUSION</b>Method of freeze-thaw and ultrasonic resulted in an efficient proteins extraction of Streptococcus mutans which demonstrated good stability and reproducibility and easy to handle.</p>