Hypericum perforatum - St John's Wort In mild-to-moderate depression, Hypericum perforatum shows clinical efficacy not significantly different to conventional antidepressants [1]. Phytochemical actives include the naphthodianthrone hypericin, the phloroglucinol derivative hyperforin and several flavonoids. Hyperforin is said to impact monoamine reuptake transporters indirectly [2] It has a broad mechanism of action, putatively acting as a triple reuptake inhibitor of 5-HT, NE and DA, affecting GABAergic, beta-adrenergic and 5-HT2 receptors with chronic administration, with non-monoaminergic effects including cholinergic, GABAergic and glutamatergic effects [3,4] but inconsistent effects on neurotransmitter levels have been noted. Clinically significant interactions have been noted, St John's Wort being a potent inducer of CYP 3A4 and P-glycoprotein (PgP). Pharmacodynamic interactions, including with other serotonergics, have also been noted [5]. TLC Dried aerial (post-flowering) herb was macerated in acetone and concentrated to a small sample. Initial TLC eluting with acetone provided poor separation of the constituents so a mixed solvent (acetone:white spirits:1:1) was used. Good separation of visibly pigmented constituents were noted, the lowest Rf = 0.28 band having a pink fluorescence. 1 TLC (silica, 0.2mm, glass backed, acetone:white spirits:1:1 elution) Rf's obtained for visible/slightly visible bands were 0.28, 0.34, 0.44, 0.5, 0.53 References: [1] Ng QX, Venkatanarayanan N, Ho CY. Clinical use of Hypericum perforatum (St John's wort) in depression: A meta-analysis. J Affect Disord. 2017 Mar 1;210:211-221. . Epub 2017 Jan 3. PMID: 28064110. https://doi.org/10.1016/j.jad.2016.12.048 [2] Müller WE. Current St John's wort research from mode of action to clinical efficacy. Pharmacol Res. 2003 Feb;47(2):101-9. doi: 10.1016/s1043-6618(02)00266-9. PMID: 12543057. https://doi.org/10.1016/s1043-6618(02)00266-9 [3] Butterweck V. Mechanism of action of St John's wort in depression : what is known? CNS Drugs. 2003;17(8):539-62.. PMID: 12775192. https://doi.org/10.2165/00023210-200317080-00001 [4] Kholghi G, Arjmandi-Rad S, Zarrindast MR, Vaseghi S. St. John's wort (Hypericum perforatum) and depression: what happens to the neurotransmitter systems? Naunyn Schmiedebergs Arch Pharmacol. 2022 Jun;395(6):629-642. https://doi.org/10.1007/s00210-022-02229-z [5] Zhou S, Chan E, Pan SQ, Huang M, Lee EJ. Pharmacokinetic interactions of drugs with St John's wort. J Psychopharmacol. 2004 Jun;18(2):262-76. https://doi.org/10.1177/0269881104042632 2