St Johns Wort, The Flower That Can Treat Depression

St Johns Wort, botanical name Hypericum perforatum , is considered a weed in temperate climates outside its native homelands of Europe, Asia and North Africa. The flowering tops and aerial parts of the plant are use medicinally in the form of tinctures and tablets to treat a number of conditions affecting the nervous and immune systems.

Records of the medicinal utilize of St Johns Wort date back to ancient Greece. It is believed Dioscorides and Hippocrates used it to cleanse the body of evil spirits. Since the times of the Swiss physician and botanist Paracelsus( 1493 -1 541 ), St Johns Wort has traditionally been used to treat nerve pain, anxiety, neurosis and depression and externally for bruises, meanders and shingles.

CC BY-SA

How is it used today ?

In modern times, St Johns Wort has been shown to be as effective as placebo and standard antidepressants in the treatment of mild to moderate depression.

In Australia, St Johns Wort is principally bought through pharmacies and health food stores with or without the guidance of a health-care professional.

The St Johns Wort products vary in the amount of key constituents they contain. Merely a few products actually match what was trialled in the studies with positive clinical outcomes. Variations in the active constituent content will affect the strength and effectiveness of the medicine and its possible safety.

It has become more common for complementary medicine manufacturers to include a standardised quantity of the herb constituents on the label. The daily dosage range for total hypericin content is 0.75 mg to 2.7 mg of hypericin daily. The published examines generally used standardised extracts to contain 0.3% hypericin and 2-5% hyperforin.

In 2000, St Johns Wort made up 25% of all antidepressant prescriptions in Europe. A more recent Australian analyze reported 4.3% or 17,780 patients who had visited a GP for depression had taken or were taking St Johns Wort .

How does it work ?

St Johns Wort has been reported as containing many constituents and demonstrating multiple and simultaneous mechanisms of action.

While individual key constituents have been identified as hypericin( a naturally occurring substance with a few different applications including antidepressive ), pseudohypericin and hyperforin( a phytochemical produced in some plants ), collectively they exert a number of pharmacological impacts including antidepressant activity.

The hypericin and flavonoids( namely hyperforin) and other flavonoid molecules that are may be in some fruits and vegetables are thought to play a role in exerting an antidepressant consequence by altering nerve chemical messengers known as neurotransmitters. It is considered important available products contain standardised quantities of these components.

St Johns Wort has been shown in non-human examines to assist in keeping the circulating levels of four key neurotransmitters( serotonin , noradrenaline, dopamine and gamma-aminobutyric acid) at levels that improve depressive symptoms.

This is a very distinctive feature of St Johns Wort . No other medication has been demonstrated to affect all four of these chemical messengers with similar potencies. Studies comparing the efficiency of St Johns Wort with different classes of other anti-depressants that target these neurotransmitters support the proposed multi-targeted mechanism of action of St Johns Wort .

Antidepressants Citalopram( Celexa) and Sertraline( Zoloft) belong to a class of antidepressants known as selective serotonin re-uptake inhibitors( SSRIs ). These block the reabsorption of the neurotransmitter serotonin in the brain, stimulating more serotonin available to assist the brain cells to send and receive chemical messages. This in turn boosts mood.

A high-standard systematic review conducted in 2009 concluded St Johns Wort extract was superior to placebo in patients with major depression and similarly effective to standard therapy with SSRIs. They also discovered fewer people taking St Johns Wort discontinued their therapy. This was due to them experiencing fewer side effects.

The same review also discovered no significant difference in the efficiency of St Johns Wort and the older class of antidepressants known as tri-cyclic. These work by blocking the absorption of serotonin to improve their accessibility for sending and receiving chemical messages that improve our mood.

St Johns Wort was reported as guys more efficient in German examines compared to those in non-European-based populations, but it is thought these results were over-optimistic.

Safety and side-effects

Like standard antidepressants, it may take up to four weeks to judge how effective St Johns Wort has been. It is generally well tolerated, but adverse effects may occur. These include mild gastrointestinal symptoms, skin reactions, increased sensitivity to sunlight, fatigue, sedation, restlessness, dizziness, headache and dry mouth.

St Johns Wort affects enzymes in the gastrointestinal tract and liver that participated in medication metabolism. It can reduce how much of a drug is available in the body by reducing how much is absorb and excreted. Therefore the potential effectiveness of many drugs can be limited.

This includes drugs used to treat serious conditions such as AIDs, cancer and epilepsy. St Johns Wort can also reduce the efficiency of the oral contraceptive pill. It should not be taken along with criterion antidepressant drugs.

Anyone suspecting they may have symptoms of depression should consult their doctor to ensure a correct diagnosis is stimulated. The utilize of St Johns Wort should be guided by a health-care professional who is knowledgeable about the quality of available products, effective dosing and safety considerations, including known medication interactions associated with its use.

Joanna Harnett, Associate Lecturer Faculty of Pharmacy – Complementary Medicine, University of Sydney

Read more: www.iflscience.com

About the Author

Leave a Comment: