St. John’s wort (Hypericum perforatum) is an invasive weed in Australia, growing to about a metre high with small oval-shaped leaves and yellow flowers. The plant’s Latin name refers to the many transparent oil glands in the leaves which look like perforations when held up to the light. When you gather it for drying, the flowers stain your fingers a tell-tail red.

It is a well-known herb, available in healthfood shops and even supermarkets, where it is known mostly as an antidepressant. Apart from enhancing mood, St. John’s wort has a long history of use in Europe as an astringent for treating the gastro-intestinal system, an anticatarrhal for the lungs, a fever herb, a liver herb, a diuretic, and as an external wound healer for inflammations, burns, mastitis and tumours.¹

St. John’s wort has been extensively trialled in modern research and found to be effective in treating mild to major depression. In fact, the accumulated evidence from many trials shows that when compared to placebo, or treatment with standard antidepressants, there is a similar reduction in severity, remission and relapse rate, but with significantly less side-effects.^2,3 The mechanism appears to follow several pathways resulting in the favourable alteration of neurotransmitters: the reuptake inhibition of serotonin, dopamine, noradrenaline, GABA and L-glutamate; also the inhibition of monoamine oxidase.⁴

These kind of studies of the effect of bioactive substance in herbs on neurotransmitter levels, in this instance hypericin and hyperforin, are in line with the old model of the aetiology of mood disorders called the ‘monoamine hypothesis’. This hypothesis proposed that a deficit in key neurotransmitters of the brain, such as dopamine and serotonin, was responsible for depression. The crude effectiveness of this approach is testified to by the success of a particular class of medicines called selective serotonin re-uptake inhibitors (SSRIs).

It should be obvious that prescribing for any condition in this manner leads to mere symptoms management, with a drug regime that can last for decades. Unfortunately, the physiology of the brain is not static, and anyone associated with this kind of conventional treatment knows that the new mental equilibrium is often unstable due to the development of tolerance, and also fraught with side-effects.

Furthermore, additional drugs are often gradually added to what eventually becomes a cocktail, and any straightforward underlying conditions are often neglected. For instance, there may be an incompatible diet, nutrient deficiencies (zinc, B-vitamins, omega-3), allergies, lack of exercise, low thyroid function, adrenal exhaustion, blood sugar dysregulation, the oral contraceptive pill,⁵ as well as chronic inflammation or infection. Indeed chronic inflammation, measurable by elevated CRP, is the cornerstone of the latest theory of mood disorders such as generalised anxiety and depression.⁶

By contrast, the traditional approach to treating these conditions is to support the whole nervous system with something modern herbalists call a nervine. In this manner, the herb not only elevates mood and calms the nervous system, but is restorative to nerves and tissues. Modern research in fact demonstrates that St. John’s wort is neuroprotective, that is, it can protect the nervous system from toxic injury either directly, or indirectly, through antioxidant, anti-inflammatory, anti-apoptotic activity. It can therefore play an important role in protection from the development of central nervous system diseases, as well as in their treatment.⁴ It is also considered a modulator of brain-derived neurotrophic factor (BDNF), an important growth factor present in the brain. BNDF stimulates the growth and differentiation of new nerve tissues, so the use of St. John’s wort encourages neuroplasticity and therefore adaptation to change and new challenges.⁷

To be fair, Dioscorides pointed out this herb’s powerful effect on the physical nervous system two thousand years ago when he stated that a decoction of the seeds can cure sciatica. He also says that it heals burns, something that we still use it for today because it is anodyne, antimicrobial, anti-inflammatory in activity, and speeds up the healing process.^8–10

Despite the surge of recent evidence-based research, the homeopathic texts already provide a complete picture of its therapeutics. From almost a century ago, William Boericke states that excessive tenderness and pain is a guide to the use of St. John’s wort in injuries to tissues rich in nerves. Lacerated wounds, crushed fingers, stubbed toes, post-operative pain, puncture wounds, animal bites, haemorrhoids, an injured coccyx, concussion, neuralgia, toothache, shingles and neuritis all profit from its use. Early administration will even protect against tetanus. He recommends internal administration as a tincture or low homeopathic potency.¹¹

St. John’s wort can be drunk in the form of an infusion made from the dried flowers, or used as an eyewash when cool. The tincture can be made into a cream for external applications, or a poultice comprising other herbs such as comfrey and calendula. The oil is prepared by steeping the flowers in olive oil and leaving it in a warm place for a few weeks.

A word of warning, the plant can make you photosensitive as demonstrated by farm animals that get sunburned ears after feeding on it. It also readily interacts with some supplements, foods, and other pharmaceutical drugs thereby decreasing their effectiveness (anticonvulsants, digoxin, finasteride, omeprazole, oral contraceptives, statins, oxycodone).

A version of this Article appears in the 2021 eBook edition of Wholefoods And Common medicinal Herbs.

Disclaimer: this article is intended for the purpose of general education only, and is not a substitute for a diagnosis, treatment advice, or a prescription given in a consultation with a qualified physician.

References:

1.         Grieve M. A Modern Herbal. London: Tiger Books International; 1994.

2.         Haller H, Anheyer D, Cramer H, Dobos G. Complementary therapies for clinical depression: an overview of systematic reviews. BMJ Open 2019;9:e028527.

3.         Linde K, Berner MM, Kriston L. St John’s wort for major depression. Cochrane Database Syst Rev 2008;CD000448.

4.         Oliveira AI, Pinho C, Sarmento B, Dias ACP. Neuroprotective Activity of Hypericum perforatum and Its Major Components. Front Plant Sci 2016;7:1004.

5.         Skovlund CW, Mørch LS, Kessing LV, Lidegaard Ø. Association of Hormonal Contraception With Depression. JAMA Psychiatry 2016;73:1154–62.

6.         Osimo EF, Baxter LJ, Lewis G, Jones PB, Khandaker GM. Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels. Psychol Med 2019;49:1958–70.

7.         Sangiovanni E, Brivio P, Dell’Agli M, Calabrese F. Botanicals as Modulators of Neuroplasticity: Focus on BDNF. Neural Plast 2017;2017:5965371.

8.         Dioscorides P. De Materia Medica. South Africa: Ibidis; 2000.

9.         Wölfle U, Seelinger G, Schempp CM. Topical application of St. John’s wort (Hypericum perforatum). Planta Med 2014;80:109–20.

10.       Saddiqe Z, Naeem I, Maimoona A. A review of the antibacterial activity of Hypericum perforatum L. J Ethnopharmacol 2010;131:511–21.

11.       Boericke W. Pocket Manual Of Homoeopathic Materia Medica, c. 1927. Delhi: Indian Books & Periodical Publishers; 2007.