Mankind’s relationship with plants is continually evolving and since the dawn of time, humans
have sought food, shelter, and medicine from natural sources using only instinct and intuition to guide them. Over the centuries and with the advent of science we have begun to understand plants and their constituents concerning the human organism more fully.
Our increasing understanding of plant chemistry (pharmacognosy) has led to the development of medicines many of which are still in use today.1 In the last three decades 50% of approved drugs have been developed from natural products.2 Research is ongoing into medicinal plants and their potential for new therapeutic agents, but according to the World Health Organization, 80% of the world’s population currently rely on plants for some of their primary healthcare.3
What are medicinal herbs?
Unlike humans and animals, plants under threat cannot run away and have had to develop unique survival mechanisms to ensure they succeed. Secondary metabolites are compounds that protect plants from predators, disease, and environmental threats. Some plants have a very unpleasant taste that makes them unpalatable to predators, this ‘bitter’ element would be used in herbal medicine to stimulate the digestive process. The active constituents found in plants are known as phytochemicals (plant chemicals).
Phytochemicals and their actions
The list below covers the main categories of secondary metabolites found in plants considered to be of therapeutic value to humans.4
- Alkaloids - potent nerve action, toxic effects
- Bioflavonoids - antioxidants
- Essential oils - volatile and aromatic
- Glycosides - Cardiac glycosides are in this category including the heart drug Digitoxin
- Phenylpropanoids - in this class are antiviral and antitumor agents
- Resins - a wound-healing mechanism for plants
- Saponins - soap-like, anti-inflammatory, and expectorant (helps to expel mucus)
- Sterols - precursors of steroids
- Tannins - astringent effects (e.g. drying action as in leather tanning)
- Terpenes - antioxidants and vitamins.
Are medicinal herbs effective?
Anecdotal evidence gathered over thousands of years would suggest that medicinal herbs have helped many people with their health. Herbal medicine today remains largely unregulated and quality scientific studies are lacking to support efficacy.
Many more studies are required to prove the effectiveness of medicinal herbs to a satisfactory standard. Larger studies have been undertaken on certain popular herbs such as St John’s Wort, and these have found the herbs in question to be therapeutically beneficial.5
What health conditions do medicinal herbs treat?
Herbs can be used for many health conditions but it is very important to take advice from your conventional health professional when treating very serious conditions such as diabetes or cancer.
Common health conditions medicinal herbs are used for:
- Skin Conditions
- Mood disorders
- Sleep issues
- Hormonal imbalances and menopausal symptoms
- Digestive issues
- Musculoskeletal problems
Generally, herbs can help to enhance health and well-being through their various actions.
Are medicinal herbs safe?
Medicinal herbs are generally safe and well tolerated when taken correctly. It is important to consider dosage, any underlying health conditions, and other medicines that are being taken. Some medicinal plants are potentially toxic even in small doses and can only be used according to the directions by professional herbalists. As with all medicines, extra caution should be taken during pregnancy and breastfeeding.
Do medicinal herbs have side effects?
All drugs, including natural ones, have the potential to cause side effects but thankfully in most cases, these will be mild and short lasting. Medicinal herbs are generally associated with very few side effects but more common ones may include minor stomach upsets and skin irritations.
Can medicinal herbs be taken with other medications?
In most cases, you can but it is very important to either consult with a professional herbalist who will be aware of all potential interactions or take advice when purchasing supplements and always read labels with care. One very popular and well-studied medicinal herb, St John’s Wort, has been found to act upon the liver and may accelerate the metabolism of other drugs therefore reducing their therapeutic effect.
How can I start using medicinal herbs?
Eating a wide variety of fruits, legumes, and vegetables as possible will increase your intake of beneficial phytochemicals. Try replacing regular tea and coffee with herbal teas and dandelion coffee.
Many herbal supplements can be purchased easily from health shops and chemists but always read labels carefully and do your research. Some excellent books and courses will help you learn more about medicinal herbs.
To gain the maximum benefit from medicinal herbs make an appointment with a professional Medical Herbalist. To find your nearest herbalist visit the National Institute of Medical Herbalists (NIMH). This article is an introduction to herbal medicine and discusses how herbs work, how safe and effective they are, the conditions they may help, and how to start using medicinal herbs.
- Petrovska B. Historical review of medicinal plants′ usage. Phcog Rev. 2012;6(11):1. Available from: http://www.phcogrev.com/article/2012/6/11/1041030973-784795849
- Veeresham C. Natural products derived from plants as a source of drugs. J Adv Pharm Tech Res. 2012;3(4):200. Available from: http://www.japtr.org/text.asp?2012/3/4/200/104709
- Ahmad Khan MS, Ahmad I. Herbal medicine. In: New Look to Phytomedicine. Elsevier; 2019. p. 3–13. Available from: https://linkinghub.elsevier.com/retrieve/pii/B978012814619400001X
- Rotblatt, Michael, and Irwin Ziment. Evidence-Based Herbal Medicine. Hanley & Belfus, 2002.
- Ernst E. The efficacy of herbal medicine - an overview. Fundam Clin Pharmacol. 2005 Aug;19(4):405–9. Available from: https://onlinelibrary.wiley.com/doi/10.1111/j.1472-8206.2005.00335.x