Simultaneous determination of five alkaloids from Rauvolfia vomitoria in rat plasma by LC-MS/MS: Application to a comparative pharmacokinetic study in normal and type 2 diabetic rats.

Rauvolfia vomitoria is widely distributed in the tropical regions of Africa and Asia, and has been used in traditional folk medicine in China. Indole alkaloids were found to be major bioactive components, while the effects of diabetes mellitus on the pharmacokinetic parameters of the components have not been reflected in vivo. In this study, an efficient and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of five ingredients of R. vomitoria in rats. Detection was implemented in multiple-reaction-monitoring mode with an electrospray positive-ionization source. Validation parameters were all in accordance with the current criterion. The established method was effectively employed to compare the pharmacokinetic behaviors of five alkaloids (reserpine, yohimbine, ajmaline, ajmalicine, and serpentine) between normal and type 2 diabetic rats. The single-dose pharmacokinetic parameters of the five alkaloids were determined in normal and diabetic rats after oral administration of 100 and 200 mg/kg body weight. The results indicated that diabetes mellitus significantly altered the pharmacokinetic characteristics of yohimbine, ajmaline, and ajmalicine after oral administration in rats. This is an attempt to provide some evidence for clinicians that may serve as a guide for the use of antidiabetic medicine in clinical practice.

[Research progress on chemical composition and pharmacological effects of Periplocae Cortex and predictive analysis on Q-marker].

Periplocae Cortex is a traditional Chinese medicine in China, which is mainly produced in northeast China, north China, northwest China, southwest China. In recent years, the increasing in-depth research resulted in the discovery of anti-tumor and cardiac pharmacological activities of Periplocae Cortex, which has broad application prospects. On the basis of summarizing chemical components and pharmacological effects, combined with the theoretical system of Q-marker, the quality control components of Periplocae Cortex were predicted from the aspects of the correlation between chemical composition and traditional medicinal properties, traditional efficacy, and new clinical use, plasma composition, measurable composition, storage time by analyzing literature. Among the components, periplocoside, periplocin, periplogenin, 4-methoxy salicylaldehyde showed significant activity, which provides a scientific basis for quality evaluation of Periplocae Cortex.

[Effects of moxibustion on the structure and function of blood brain barrier in Alzheimer's disease model rats].

OBJECTIVE: To investigate the effects of moxibustion on the structure and function of blood-brain barrier in Alzheimer's disease (AD) model rats. METHODS: Forty-eight SD rats were randomly divided into 4 groups: normal control group, sham operation group, model group, moxibustion group. Model group and moxibustion group rats were injected with aggregated Aß25-35 by bilateral hippocampus. In the rat model, the sham-operated group was injected with the same amount of normal saline in the bilateral hippocampus, and the normal group was not treated. After successful modeling, the moxibustion treatment was given at 2～3 cm above the Baihui, Shenshu and Yintang points of the moxibustion group rats, each time for 10 min, once a day, continuous treatment for 21 d. The Morris water maze test was used to evaluate the learning and memory ability of rats in each group. The Evans blue method was used to detect the permeability of blood-brain barrier. The ultrastructure of blood-brain barrier was observed under electron microscope. The matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) positive cells in hippocampus were detected by immunohistochemistry. RESULTS: Compared with the sham operation group, the escape latency was significantly increased (P＜0.01), and the space exploration time was decreased (P＜0.01), the learning and memory function in model group was impaired seriously, the Evans blue content in the brain was increased significantly (P＜0.01), the perivascular edema became larger, and the blood-brain barrier structure function was impaired. At the same time, the positive expressions of MMP-2 and MMP-9 in hippocampus were increased significantly (P＜0.01). Compared with model group, the learning and memory ability in moxibustion group rats was enhanced (P＜ 0.05), the content of Evans blue in the brain was decreased (P＜0.05), the degree of perivascular edema was reduced, and the damage of blood-brain barrier was improved. Positive expressions of MMP-2 and MMP-9 in hippocampus were decreased (P＜0.05 or P＜ 0.01). CONCLUSION: Moxibustion can decrease the expressions of MMP-2 and MMP-9, and reduce the damage of the structure and function of blood-brain barrier, thereby improving the learning and memory ability of AD model rats, and exerting therapeutic effects.