Comparative pharmacokinetics of three phenylpropanoids in rat plasma after oral administration of Ramulus Cinnamomi and Ramulus Cinnamomi-Ephedrae Herba herb-couple extract.

OBJECTIVE: To investigate the pharmacokinetic characteristics of three phenylpropanoids (cinnamic acid, cinnamic alcohol and coumarin) in Ramulus Cinnamomi (GZ) and Ramulus Cinnamomi-Ephedrae Herba (MH) herb-couple (GZMH). METHODS: Twelve male Sprague-Dawley rats were randomly and equally divided into the GZ and GZMH herb-couple groups. Blood samples were collected at 0, 0.08, 0.25, 0.5, 0.75, 1.5, 3, 4, 6, 8, 12, 24, 36 and 48 h after oral administration. The three phenylpropanoids in rat plasma were quantified using an ultra-performance liquid-chromatography with tandem mass spectrometry (UPLC-MS/MS) method for pharmacokinetic study. RESULTS: In GZMH group, the area under the curve (AUC), mean retention time (MRT) of cinnamic acid and coumarin were increased significantly (P<0.01, respectively), and biological half-life (t1/2z) was obviously shorter (P<0.05) compared with the GZ group. There were no significant differences in the mean retention time from 0 to ∞ (MRT0-∞), the peak concentration (Cmax), the time to peak (Tmax) and t1/2z, except for AUC and MRT0-t (the mean retention time from 0 to t) of cinnamic alcohol in the GZMH group by comparison to the GZ group (P<0.01, respectively). The AUC, MRT (both P<0.01) and t1/2z (P<0.05) of coumarin were increased significantly, while Cmax, and Tmax were decreased slightly by comparison to the GZ group (P>0.05). CONCLUSIONS: There were statistically significant differences in some pharmacokinetic parameters of the three compounds between GZ and GZMH groups, which meant that MH could affect the absorption and elimination of the three compounds.

[Changes in plasma pharmacokinetics and urinary excretion characteristics before and after combined administration of Ephedrae Herba-Gypsum Fibrosum].

In this study, UPLC-MS/MS was adopted to determine the contents of five ephedrine alkaloids (Norephedrine, Norpseudoephedrine, Ephedrine, Pseudoephedrine, Methylephedrine) in plasma and urine in rats after the combined administration of Ephedrae Herba-Gypsum Fibrosum and calculate relevant pharmacokinetic parameters, in order to discuss the effect of the combined administration of Ephedrae Herba-Gypsum Fibrosum on plasma pharmacokinetics and urinary excretion characteristics. According to the results, after being combined with Gypsum, the five ephedrine alkaloids showed similar pharmacokinetic changes, such as shortened t(max), accelerated absorption rate, but reduced AUC(0-t) and V(z)/F, which may be related to the increase in urine excretion. Besides, Gypsum was added to enhance C(max) of Pseudoephedrine and prolong MRT(0-t) of Methylephedrine, so as to enhance the anti-asthmatic effect of Ephedrae Herba and resist the toxic effect of Norephedrine and Ephedrine. This study proved the scientific compatibility of Ephedrae Herba-Gypsum Fibrosum and provided a reference for studies on the prescription compatibility regularity and relevant practices.

Neuroprotective effect of gui zhi (ramulus cinnamomi) on ma huang- (herb ephedra-) induced toxicity in rats treated with a ma huang-gui zhi herb pair.

Herb Ephedra (Ma Huang in Chinese) and Ramulus Cinnamomi (Gui Zhi in Chinese) are traditional Chinese herbs, often used together to treat asthma, nose and lung congestion, and fever with anhidrosis. Due to the adverse effects of ephedrine, clinical use of Ma Huang is restricted. However, Gui Zhi extract has been reported to decrease spontaneous activity in rats and exert anti-inflammatory and neuroprotective effects. The present study explored the possible inhibitory effect of Gui Zhi on Ma Huang-induced neurotoxicity in rats when the two herbs were used in combination. All Ma Huang and Ma Huang-Gui Zhi herb pair extracts were prepared using methods of traditional Chinese medicine and were normalized based on the ephedrine content. Two-month-old male Sprague-Dawley rats (n = 6 rats/group) were administered Ma Huang or the Ma Huang-Gui Zhi herb pair extracts for 7 days (ephedrine = 48 mg/kg), and locomotor activity was measured. After 7 days, oxidative damage in the prefrontal cortex was measured. Gui Zhi decreased hyperactivity and sensitization produced by repeated Ma Huang administration and attenuated oxidative stress induced by Ma Huang. The results of this study demonstrate the neuroprotective potential of Gui Zhi in Ma Huang-induced hyperactivity and oxidative damage in the prefrontal cortex of rats when used in combination.

Pharmacokinetic comparisons of five ephedrine alkaloids following oral administration of four different Mahuang-Guizhi herb-pair aqueous extracts ratios in rats.

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.