顶空气相色谱法测定贯叶金丝桃提取物中大孔树脂有机溶剂残留物

目的 建立贯叶金丝桃大孔树脂提取物中正己烷、苯、甲苯、对二甲苯、邻二甲苯、苯乙烯、1,2-二乙基苯等7种有机溶剂的残留量的测定方法.方法 将提取物溶解于0.6％的十二烷基硫酸钠水溶液中,采用HP-INNOWAX毛细管柱和FID检测器,以高纯氮气为载气;应用顶空气相色谱法测定贯叶金丝桃大孔树脂提取物中7种有机溶剂的残留量.结果 该方法可将7种有机溶剂完全分离,且线性关系良好;精密度和重复性RSD均小于7％,平均同收率在82.6％ ～104.0％之间.结论 此法简便、快速、准确,可用于大孔树脂制备的贯叶金丝桃提取物中有机残留溶剂的质量控制.     

Does St. John’s Wort cause regression in gastrointestinal system adenocarcinomas?

St. John’s Wort (SJW) is an old herb which has long been consumed widely for its anti-inflammatory, antiviral, and anti-depressive properties. Here we present a detailed clinical evaluation of three cases (two colon and one duodenal adenocarcinoma) with remarkable and intensive lymphoplasmocytic host reaction, at the basal part of tumor, intensive fibrosis, giant cells, plasma cell increase in lymph nodes and few giant cells in germinal centers in resection specimens. The observation of similar host reaction in those tumors having otherwise usual appearance was interesting. None of the cases received neoadjuvant chemoradiotherapy or additional treatment before surgery but only SJW. These cases are presented to increase the awareness about such cases. Further research is needed to reveal the possible effect of SJW, which has long been consumed for different treatment purposes, on human tumors.     

St. John's Wort Reduces Beta‐Amyloid Accumulation in a Double Transgenic Alzheimer's Disease Mouse Model—Role of P‐Glycoprotein

The adenosine triphosphate‐binding cassette transport protein P‐glycoprotein (ABCB1) is involved in the export of beta‐amyloid from the brain into the blood, and there is evidence that age‐associated deficits in cerebral P‐glycoprotein content may be involved in Alzheimer''s disease pathogenesis. P‐glycoprotein function and expression can be pharmacologically induced by a variety of compounds including extracts of Hypericum perforatum (St. John''s Wort). To clarify the effect of St. John''s Wort on the accumulation of beta‐amyloid and P‐glycoprotein expression in the brain, St. John''s Wort extract (final hyperforin concentration 5%) was fed to 30‐day‐old male C57BL/6J‐APP/PS1 ^+/− mice over a period of 60 or 120 days, respectively. Age‐matched male C57BL/6J‐APP/PS1 ^+/− mice receiving a St. John''s Wort‐free diet served as controls. Mice receiving St. John''s Wort extract showed (i) significant reductions of parenchymal beta‐amyloid 1–40 and 1–42 accumulation; and (ii) moderate, but statistically significant increases in cerebrovascular P‐glycoprotein expression. Thus, the induction of cerebrovascular P‐glycoprotein may be a novel therapeutic strategy to protect the brain from beta‐amyloid accumulation, and thereby impede the progression of Alzheimer''s disease.     

In vitro receptor screening of pure constituents of St. John's wort reveals novel interactions with a number of GPCRs

RATIONALE: Hypericum perforatum L. (St. John's wort; SJW) is one of the leading psychotherapeutic phytomedicines and great effort has been devoted to clarifying its mechanism of action. OBJECTIVE: We have undertaken a comprehensive analysis of several pure compounds isolated from the crude extract to gain further insight into the molecular actions of various substituents of SJW. METHODS: We characterized the in vitro pharmacology of the naphthodianthrones hypericin and pseudohypericin, the phloroglucinol derivative hyperforin, and several flavonoids at 42 biogenic amine receptors and transporters using the resources of the National Institute of Mental Health Psychoactive Drug Screening Program. RESULTS: The biflavonoid amentoflavone significantly inhibited binding at serotonin (5-HT(1D), 5-HT(2C)), D(3)-dopamine, delta-opiate, and benzodiazepine receptors. The naphthodianthrone hypericin had significant activity at D(3)- and D(4)-dopamine receptors and beta-adrenergic receptors. With the exception of the D(1)-dopamine receptor, the phloroglucinol derivative hyperforin was less active than other SJW constituents tested on all screened receptors. CONCLUSION: Our present in vitro data clearly show that several pure substances in SJW are potential CNS psychoactive agents and may contribute to the antidepressant efficacy of the plant in a complex manner. Our data also reveal novel and heretofore unexpected interactions of pure compounds in SJW at a number of GPCRs, transporters, and ion channels. We hypothesize that additive or synergistic actions of different single compounds may be responsible for the antidepressant efficacy of SJW. These results and this general approach may impact our understanding of phytomedicines in general and H. perforatum specifically.     

Inhibition of Human Sperm Motility by Specific Herbs Used in Alternative Medicine

Purpose: Our purpose was to analyze sperm motility parameters in the presence of herbs. Methods: Washed sperm were incubated in either saw-palmetto (Serenoa repens, Permixon Sabal serrulatum), echinacea purpura, ginkgo biloba, St. John's wort (Hypericum perforatum), or control medium. Parameters were measured on a Hamilton-Thorn analyzer after 1, 4, 24, and 48 hr at 37°C. Results: Sperm motility was inhibited at the high concentration (0.6 mg/mL) of St. John's wort. Curvilinear velocities and beat cross frequencies also decreased, but not hyperactivation. High-concentration saw-palmetto, echinacea, or ginkgo inhibited motility at 24 and 48 hr. Conclusions: A potent inhibition of sperm motility was seen in St. John's wort unrelated to changes in pH. Furthermore, sperm viability was compromised in St. John's wort, suggesting a spermicidal effect. Metabolic changes were observed in saw-palmetto–treated sperm. High-concentration echinacea purpura interfered with sperm enzymes. Ginkgo did not have an antioxidant effect on sperm motility.     

Effect of St John's wort and ginseng on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects

M: The aim of this study was to investigate the effect of St John's wort and ginseng on the pharmacokinetics and pharmacodynamics of warfarin. METHODS: This was an open-label, three-way crossover randomized study in 12 healthy male subjects, who received a single 25-mg dose of warfarin alone or after 14 days' pretreatment with St John's wort, or 7 days' pretreatment with ginseng. Dosing with St John's wort or ginseng was continued for 7 days after administration of the warfarin dose. Platelet aggregation, international normalized ratio (INR) of prothrombin time, warfarin enantiomer protein binding, warfarin enantiomer concentrations in plasma and S-7-hydroxywarfarin concentration in urine were measured. Statistical comparisons were made using anova and 90% confidence intervals are reported. RESULTS: INR and platelet aggregation were not affected by treatment with St John's wort or ginseng. The apparent clearances of S-warfarin after warfarin alone or with St John's wort or ginseng were, respectively, 198 +/- 38 ml h(-1), 270 +/- 44 ml h(-1) and 220 +/- 29 ml h(-1). The respective apparent clearances of R-warfarin were 110 +/- 25 ml h(-1), 142 +/- 29 ml h(-1) and 119 +/- 20 ml h(-1) [corrected]. The mean ratio and 90% confidence interval (CI) of apparent clearance for S-warfarin was 1.29 (1.16, 1.46) and for R-warfarin it was 1.23 (1.11, 1.37) when St John's wort was coadministered. The mean ratio and 90% CI of AUC(0-168) of INR was 0.79 (0.70, 0.95) when St John's wort was coadministered. St John's wort and ginseng did not affect the apparent volumes of distribution or protein binding of warfarin enantiomers. CONCLUSIONS: St John's wort significantly induced the apparent clearance of both S-warfarin and R-warfarin, which in turn resulted in a significant reduction in the pharmacological effect of rac-warfarin. Coadministration of warfarin with ginseng did not affect the pharmacokinetics or pharmacodynamics of either S-warfarin or R-warfarin.     

Drug interaction between St John's Wort and quazepam

AIM: St John's Wort (SJW) enhances CYP3A4 activity and decreases blood concentrations of CYP3A4 substrates. In this study, the effects of SJW on a benzodiazepine hypnotic, quazepam, which is metabolized by CYP3A4, were examined. METHODS: Thirteen healthy subjects took a single dose of quazepam 15 mg after treatment with SJW (900 mg day(-1)) or placebo for 14 days. The study was performed in a randomized, placebo-controlled, cross-over design with an interval of 4 weeks between the two treatments. Blood samples were obtained during a 48 h period and urine was collected for 24 h after each dose of quazepam. Pharmacodynamic effects were determined using visual analogue scales (VAS) and the digit symbol substitution test (DSST) on days 13 and 14. RESULTS: SJW decreased the plasma quazepam concentration. The Cmax and AUC(0-48) of quazepam after SJW were significantly lower than those after placebo [Cmax; -8.7 ng ml(-1) (95% confidence interval (CI) -17.1 to -0.2), AUC0-48; -55 ng h ml(-1) (95% CI -96 to -15)]. The urinary ratio of 6beta-hydroxycortisol to cortisol, which reflects CYP3A4 activity, also increased after dosing with SJW (ratio; 2.1 (95%CI 0.85-3.4)). Quazepam, but not SJW, produced sedative-like effects in the VAS test (drowsiness; P < 0.01, mental slowness; P < 0.01, calmness; P < 0.05, discontentment; P < 0.01). On the other hand, SJW, but not quazepam impaired psychomotor performance in the DSST test. SJW did not influence the pharmacodynamic profile of quazepam. CONCLUSIONS: These results suggest that SJW decreases plasma quazepam concentrations, probably by enhancing CYP3A4 activity, but does not influence the pharmacodynamic effects of the drug.     

Antagonist effect of pseudohypericin at CRF1 receptors

St. John's wort (Hypericum perforatum L.) is widely used for the treatment of mild to moderately severe depression. However, the nature of its active principles and the exact mode of antidepressant action are still unknown. It has been suggested repeatedly in preclinical and clinical studies that the content of the acylphloroglucinol hyperforin decisively contributes to the antidepressant efficacy of St. John's wort extracts. Experimental studies in vivo also indicate that the naphthodianthrone hypericin may reduce the activity of the hypothalamic-pituitary-adrenal axis. Exacerbated hypothalamic-pituitary-adrenal activity has often been associated with depressive states in patients. Corticotropin-releasing factor (CRF) seems to be a major determinant in the regulation of the hypothalamic-pituitary-adrenal activity via activation of CRF(1) receptors. In the present study, we investigated the CRF(1) receptor antagonist activity of three main constituents of St. John's wort (hypericin, pseudohypericin and hyperforin) by measuring their effect on CRF-stimulated cAMP formation in recombinant Chinese hamster ovary (CHO) cells. As a selectivity test, the compounds were also tested against calcitonin in the same cells. Of the three compounds tested, only pseudohypericin selectively antagonised CRF (K(B) 0.76 microM). Hypericin and hyperforin affected both CRF and calcitonin with similar potencies and the same type of behaviour (competitive antagonism for hypericin, noncompetitive for hyperforin). It is concluded that pseudohypericin is the only real CRF(1) receptor antagonist of the three constituents tested. In addition, evidence is provided that beside hyperforin, both pseudohypericin and hypericin are implicated in the antidepressant efficacy of St. John's wort.     

中国近代教会大学早期的医学预科教育1901-1936

近代中国教会大学指19世纪末20世纪初开始西方基督教会在中国创办的13所和天主教会办的3所高等教育学校。医学教育的投入大，只有少数几个大学除提供医学预科课程外还开设完整的长学制的医学博士课程。多数教会大学则提供医学预科课程。从震旦大学，圣约翰大学和燕京大学等校的医学预科教育可看出当时医学院学生的入学基础很好。医学预科课程中，生物学、化学和物理为主要的学习科目，医学预科课程的学习为学生进入医学院打下了坚实的基础。     

Does St. John's wort interfere with the antiandrogenic effect of oral contraceptive pills?

BACKGROUND: St. John's wort (SJW), a commonly used herbal remedy, has been shown to compromise the efficacy of drugs, including oral contraceptive pills (OCPs), by inducing cytochrome P-450. We investigated whether the simultaneous use of SJW with OCPs resulted in elevated serum androgen levels with implications of impaired OCP treatment of hirsutism and acne. MATERIALS AND METHODS: Fifteen healthy women were treated with the low-dose OC Loestrin 1/20trade mark for 2 months and then additionally with SJW for 2 months. Androgen and sex hormone-binding globulin (SHBG) levels were measured in serum by immunoassay methods; free testosterone (fT) was calculated. Results were analyzed using the Wilcoxon signed-rank test. RESULTS: There were no statistically significant differences in androgen levels after the addition of SJW in women using Loestrin 1/20trade mark. However, there were decreases in total testosterone and fT levels (10.7% and 15.8%, respectively) along with a small increase in SHBG levels (7.0%). CONCLUSIONS: In women using OCPs and SJW simultaneously, it appears that SJW does not interfere with the antiandrogenic properties of OCPs.