St. John’s Wort

St. John’s Wort, a perennial herb, is a well-recognized remedy for mental health conditions since the Greco-Roman times. Nowadays, the main indication is for mild to moderate depression. Botanists recommend SJW also as a mild sedative and nerve tonic for excitability, anxiety and nervous irritability.

To note, its mechanism of action is not completely understood. Among the hypothesis, one of them describes a possible significant binding of hyperforin (the main active principle) to GABA A and GABA B, adenosine, MAO and benzodiazepine receptors.

In addition, there could be also some effects that inhibit synaptosomal uptake of serotonin (5-HT), dopamine and noradrenaline with some increase in dopamine and noradrenaline. Instead, other studies underline the possible decrease in tryptophan degradation (a 5-HT precursor).

Finally, there could be an explanation for the antidepressant effect that considers the inhibition of interleukin-6 (IL-6) by hyperforin and through the inhibition of substance P mediated effects on depression.
If literature showed great evidence of efficacy of SJW in treating depression and other mental disorders, some caution could be taken into consideration for possible drug interactions.