Protective effect of taurine on cardiotoxicity of the bufadienolides derived from toad (Bufo bufo gargarizans Canto) venom in guinea-pigs in vivo and in vitro.

In China, toad venom is an anti-inflammatory agent used in small doses for the treatment of various types of inflammation. Bufadienolides are cardioactive steroids responsible for the anti-inflammatory actions of toad venom. We studied the protective effect of taurine on the cardiotoxicity of bufadienolides in guinea-pigs. Bufadienolides (8 mg/kg) caused arrhythmias, cardiac dysfunction and death in guinea-pigs. Pretreatment with taurine (150, 300 mg/kg) significantly prevented bufadienolide-induced cardiotoxicity and reduced the mortality in vivo. Taurine markedly increased the cumulative doses of bufadienolides and resibufogenin required for lethal arrhythmia in ex vivo isolated guinea-pig heart. Taurine did not compromise the anti-inflammatory activity of the bufadienolides on concanavalin-A-stimulated proliferation of guinea-pig splenocytes in vitro. These data indicate that taurine can prevent bufadienolide-induced cardiotoxicity and could be a novel antidote in combination with bufadienolide therapy.

[Effect of anti-arrhythmia drugs on mouse arrhythmia induced by Bufonis Venenum].

This study is to investigate the effects of phenytoin sodium, lidocaine (sodium channel blockers), propranolol (beta-adrenergic receptor antagonist), amiodarone (drugs prolonging the action potential duration) and verapamil (calcium channel blockers) on arrhythmia of mice induced by Bufonis Venenum (Chansu) and isolated mouse hearts lethal dose of Chansu. Arrhythmia of mice were induced by Chansu and then electrocardiograms (ECGs) were recorded. The changes of P-R interval, QRS complex, Q-T interval, T wave amplitude, heart rate (HR) were observed. Moreover, arrhythmia rate, survival rate and arrhythmia score were counted. Isolated mouse hearts were prefused, and the lethal dose of Chansu was recorded. Compared with control group, after pretreatment with phenytoin sodium, broadening of QRS complex and HR were inhibited, and the incidence of ventricular arrhythmia was reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with lidocaine, the prolongation of P-R interval and broadening of QRS complex were inhibited, and the incidences of ventricular arrhythmia were reduced dramatically, while survival rate was improved; the isolated mouse hearts lethal dose of Chansu was increased significantly. After pretreatment with propranolol, prolongation of P-R interval, broadening of QRS complex, prolongation of Q-T interval and HR were inhibited, and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically, while survival rate was improved. After pretreatment with amiodarone, HR was inhibited, the incidences of ventricular tachycardia were reduced dramatically. Lastly, after pretreatment with verapamil, the prolongation of P-R interval and Q-T interval were inhibited and the incidences of both supraventricular and ventricular arrhythmias were reduced dramatically; the isolated mouse hearts lethal dose of Chansu was reduced significantly. In in vivo experiments, phenytoin sodium was most effective against the mice arrhythmias induced by Chansu while cautious use of verapamil for Chansu inducing arrhythmia should be noted. It is also concluded that mice ventricular arrhythmias induced by Chansu might be most closely related to sodium channel, supraventricular arrhythmias might be related to beta-adrenergic receptor, and calcium channel plays an important role in conduction block. In in vitro experiments, phenytoin sodium was most effective, followed by lidocaine and propranolol, and amiodarone had no obvious effect and verapamil reduced the lethal dose of Chansu.

[Cell continuous extraction-HPLC determination biological affinity of 8 bufadienolides on MGC-803 cells and their correlation with anti-tumor activities].

OBJECTIVE: To study the bioaffinity between 8 bufadienolides(Bu) and tumor cells and analyze the correlation between the bioaffinity and the anti-tumor activities of Bu. METHOD: Mix and cultivate the chloroform extract of Chansu and MGC-803. Measure the content of 8 Bu in supernatant and cells using HPLC and calculate their affinity rate. RESULT: The coefficient correlation between the decrease of Bu in cell supernatant after affinity and its MGC-803 restrictive activities, and between the cotent percentage of the free Bu in free cells with its MGC-803 restrictive activities, and between the difference between the decrease and the percentage and its MGC-803 restrictive activities is r = 0.82 (P < 0.05), r = -0.04 and r = 0.83 (P < 0.05) respectively. CONCLUSION: Eight Bu have different levels of affinity with MGC-803 which correlate with their anti-tumor activities.

13C-NMR data of three important diterpenes isolated from Euphorbia species.

Euphorbia species are widely distributed plants, many of which are used in folk medicine. Over the past twenty years, they have received considerable phytochemical and biological attention. Their diterpenoid constituents, especially those with abietane, tigliane, ingenane skeletons, are thought to be the main toxicant and bioactive factors. In this work, the utility of (13)C-NMR spectroscopy for the structural elucidation of these compounds is briefly discussed.

Comparative characteristic of the inflammatory diterpenes in the roots of Euphorbia fischeriana with different preparation method using HPLC-ELSD.

A rapid and simple method was established for the simultaneous determination of ten diterpenes by reversed phase HPLC coupled with evaporative light scattering detection. Chromatographic separation was carried out in gradient mode by using a WondaSil™ C(18) column (250mm×4.6mm, 5µm) with mobile phases of methanol and water at 1mL/min. The drift tube temperature of evaporative light scattering detector was set to 65°C and nitrogen flow-rate was 2.7L/min. The method validated was shown to be specific, precise, accurate and linear. Moreover, it was applied to investigate four samples of E. fischeriana with different extracting methods. Contrast to the dried roots, the fresh roots had much higher content of prostratin which represented much higher inflammatory effects than other diterpenes. The results demonstrated that the dried roots were suitable for the ordinary therapy to avoid intense stimulatory, while the fresh roots could be used in the anticancer treatment. All of the results suggested that comparative analysis of chemical components as biomarker and connecting toxic effects of an herb was helpful for revealing the mechanism of its toxicity, and for guiding safer and better application of the herb in TCM clinic.