Evaluation of the Effectiveness and Mechanism of Action of Hypericum Perforatum in the Treatment of Depressive Disorders

Abstract

Introduction: Hypericum perforatum (HP), also commonly rеfеred as St John`s wort, is a medical plant traditionally used for its antidepressant-like properties. The purpose of the study was to assess the effectiveness of St. John`s wort in the treatment of depressive disorders in comparison to some commonly used antidepressants. Materials and Methods: Our research was based on literature found in the scientific databases Biomed, Pubmed and Oxford Academic with keywords: Hypericum and depression. Results: Naphtodianthrone hypericin and the phloroglucinol derivate hyperforin are shown to be the main phytochemicals responsible for the antidepressive properties of HP, though flavonoids are also proven to play a role. Some clinical studies testify that certain HP preparations are equal to or even exceed the effect of certain conventional antidepressants such as fluoxetine, paroxetine etc. in the treatment of depressive disorders. HP extracts have a very good tolerability with their adverse reactions being closer to those of placebo. However, hypericin has a unique cutaneous phototoxic effect in higher doses. Studies on the mechanism of action of HP extracts reveal GABA A , GABA B , glutamate and adenosine receptors agonistic properties; serotonin, dopamine and noradrenaline reuptake inhibitory activity and monoaminooxidase (MAO) A and B inhibition in vitro. In addition, it is shown that HP extracts cause downregulation of beta-adrenergic and upregulation of the 5-HT receptors in the frontal cortex, which changes neurotransmitter concentrations in the brain areas related to depression. Conclusion: Although HP shows promise in the treatment of depressive disorders, clinical trials with a larger sample size are needed to examine further its effectiveness and mechanism of action.