J Soc Integr Oncol. 2006 Winter;4(1):52-5.
Derived from the aerial parts of the plant, St. John's wort generally is used for depression, seasonal affective disorder, and anxiety. Products currently are standardized based on hypericin content, although the hyperforin and bioflavonoid contents are also believed responsible for activity. St. John's wort is metabolized primarily by the liver. Some studies comparing St. John's wort to standard antidepressants suggest that it may be as effective as imipramine or selective serotonin reuptake inhibitors (SSRIs) to treat mild to moderate depression. Results from another clinical trial indicate that the effectiveness of St. John's wort is comparable to paroxetine, an SSRI, in the treatment of moderate to severe depression and is well tolerated. But a meta-analysis shows that data are inconsistent. Studies also show possible efficacy in the management of anxiety and premenstrual syndrome, although additional research is necessary. St. John's wort can interact with many medications owing to induction of cytochrome P-450 3A4 and other mechanisms. Significant interactions include decreased efficacy of antiretrovirals, cyclosporine, tacrolimus, antiepileptics, irinotecan, and other chemotherapeutic agents. Serotonin syndrome may occur when St. John's wort is combined with sympathomimetics, antidepressants, or triptans. Frequently reported adverse events include nausea, headache, constipation, dizziness, confusion, fatigue, and dry mouth. St. John's wort should be used under medical supervision.
圣约翰草提取物源自植物的地上部分，一般用于治疗抑郁症、季节性情感障碍和焦虑症。目前产品是根据金丝桃素含量进行标准化的，不过人们也认为贯叶连翘素和生物类黄酮含量与药物活性有关。圣约翰草提取物主要在肝脏进行代谢。一些将圣约翰草提取物与标准抗抑郁药进行比较的研究表明，在治疗轻至中度抑郁症方面，它可能与丙咪嗪或选择性5-羟色胺再摄取抑制剂（SSRI）的效果相当。另一项临床试验结果表明，圣约翰草提取物在治疗中至重度抑郁症方面与SSRI类药物帕罗西汀效果相当，且耐受性良好。但一项荟萃分析显示，数据并不一致。研究还表明，在治疗焦虑症和经前综合征方面可能有疗效，不过还需要更多研究。由于细胞色素P - 450 3A4的诱导作用及其他机制，圣约翰草提取物可与多种药物发生相互作用。显著的相互作用包括抗逆转录病毒药物、环孢素、他克莫司、抗癫痫药物、伊立替康和其他化疗药物的疗效降低。当圣约翰草提取物与拟交感神经药、抗抑郁药或曲坦类药物合用时，可能会发生5-羟色胺综合征。常见的不良事件包括恶心、头痛、便秘、头晕、意识模糊、疲劳和口干。圣约翰草提取物应在医疗监督下使用。
