This post has stemmed directly from my undergraduate research, where I tested extracts from the plant Espeletia pycnophylla against microbial pathogens to determine if this plant had potential as an antimicrobial.
Herbal medicines are a type of dietary supplement sold as tablets, capsules, teas and extracts that derive from plants but can also extend to honey and fungal products.The use of plants for medicinal purposes is known as herbalism. When people hear the terms traditional, herbal or alternative medicines many people scoff and picture thoughts of a shaman dancing around a fire blowing smoke in your face shaking maraca’s while calling on the gods for healing, however before the advent of modern medicine plants and natural compounds were used as medicines for thousands of years to treat almost every type of infection. In some developing countries plants are still the only source of medicinal compounds with up to 80% of the population depending upon traditional medicines.
The antibiotic era of the 20th century has dramatically reduced the threat of infectious disease caused by microorganisms however in recent years microbial sensitivity to these antibiotics has reduced to a dangerous level, resulting in the risk of serious infections in hospitals such as methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Natural bacterial resistance mechanisms (which have been described in a previous post) are rendering many of our antimicrobials useless. Recent attention has therefore been directed at plants as a source of new and reliable antimicrobial drugs (Tagboto and Townson 2001). The world health organisation (WHO) estimates that up to 80% of the world’s population still uses traditional medicines and during the period of 1981-2001 of 109 new antimicrobials 69% were derived from natural products or mimicked natural products (Newman 2008). Many studies have shown that the essential oils of plants are active against a wide range of microbial pathogens. However of the estimated 250,000-500,000 plant species only a small fraction is currently being investigated for the presence of antimicrobial activity. It is also important to look at plants for sources of antimicrobials as it has been suggested that up to 50% of all plant species are at risk of extinction (IUCN 2014) which could result in the loss of potential from a number of plants that have not yet been investigated. Basic home herbal medicines such as ginger, honey and lemon, aloe Vera and chamomile have been used throughout the generations in the form of teas and oils to cure everyday ailments such as the common cold, coughs, sore throats and even eczema and psoriasis. Studies have also suggested that herbal medicines can even treat things such as hepatitis C or have potential in managing snake bite envenomation. It therefore seems clear that in an age of ever-increasing bacterial resistance we should look to alternative sources of antimicrobial drugs and treatments, with plants being the obvious starting point.
Of course just because these medicines are natural, doesn’t mean they are always good for you and you should only consume plants that you can guarantee are safe or buy herbal medicines from recognised and safe vendors. I could write a long list of plants that are poisonous to eat and many plants contain arsenic, mercury and lead which can cause a number of illnesses’ including kidney failure, paralysis and severe nausea.
Image credit: http://bhma.info/
IUCN (2014) The IUCN Red List of Threatened Species, Version 2014.3, http://www.iucnredlist.org Downloaded on 17 November 2014
Newman D (2008) Natural products as leads to potential drugs: an old process or the new hope for drug discovery? Journal of medicinal chemistry, Vol. 51, p2589-2599
Tagboto S and townson S (2001) Antiparasitic properties of medicinal plants and other naturally occurring products, Advances in parasitology, Vol. 50 p199–295