Flower Power

Harnessing nature’s healing properties
It has been recognised for thousands of years that some plants have healing properties and can be used to treat a wide variety of illnesses, […]

Art by Maria Demidova

It has been recognised for thousands of years that some plants have healing properties and can be used to treat a wide variety of illnesses, ranging from minor ailments to life threatening diseases. Many plants are still used by herbalists in traditional medicine, and while it is easy to shrug off herbal remedies in favour of pharmaceuticals, one must remember that many important drugs, including aspirin, tamiflu and taxotere come from compounds found in plants which originated as traditional medicines. In fact, over 70% of the world’s poorest inhabitants still depend on medicinal plants for primary healthcare.

In recent years, scientists have continued to identify new medicinal plants by collecting plant species and screening their compounds for anti-fungal, antibacterial or antiviral properties. Such surveys are central to finding novel compounds with medicinal properties. Ethnobotanists, who study the relationships between different cultures and their uses of plants, aim to document knowledge on species used for traditional herbal remedies in remote regions where mainstream therapies are unavailable. Following a recent survey of plant remedies used in rural Namibia, ethnobotanists identified two tree species (Pergularia daemia and Tragia okanyua) used to treat weakness, dizziness and cardiovascular disorders that could have useful applications in modern medicine. Their next step would be to identify the active compounds and assess their effectiveness and suitability for use as drug treatments.

Once active compounds which have the desired disease-fighting properties are extracted from a plant, they are tested in the lab on isolated pathogens of interest to determine which ones are most effective. After a potential new drug is identified, the process of drug development, which can take many years, proceeds. This involves extensive testing on laboratory animals, such as mice, to ensure the compounds have the desired effect against the disease within an infected host. During subsequent clinical trials the new drug is first tested on healthy volunteers, and then on patients affected with the target illness. Methods of synthesising the drug from scratch, which is much more cost effective than harvesting the compounds from their natural sources, also have to be developed.

Plants can help to provide breakthrough treatments for some of the world’s most widespread and unmanageable diseases. For example, several chemotherapy drugs are derived from plant compounds. Moreover, a recent screening of compounds taken from marine plants and animals collected in Fiji revealed that the red alga Callophycus serratus, produces antifungal compounds called bromophycolides that can kill malarial parasites, even those resistant to the existing anti-malarial drug chloroquine. The most effective of these compounds are currently being tested on mouse models, and ways of synthesising and mass producing them are also being investigated. This exciting discovery could provide a valuable weapon in the fight against the global malaria pandemic (see ‘The War on Malaria’, Bang! Issue 8).

Plant remedy enthusiasts even argue that it is sometimes preferable to use plant compounds rather than mainstream treatments to treat ailments. A research group at the University of London’s Centre for Pharmacognosy and Phytotherapy is investigating the benefits of using phytoestrogens, plant compounds which have similar effects to the hormone oestrogen when consumed, to treat the symptoms of menopause. This would be an alternative to widely-used Hormone Replacement Therapy (HRT) drugs, which have several undesirable side effects including an increased risk of breast cancer. Studies have shown that phytoestrogens may have beneficial effects on bone density and cholesterol levels, and some even suggest that a high consumption of phytoestrogens actually lowers the risk of breast cancer. However, it is still unclear whether their use is more effective or lower risk than HRT, and there needs to be more research in order to address these questions.

While the effectiveness of many plants used for traditional remedies lack solid scientific evidence, it is clear that the plant kingdom has equipped us with a range of novel compounds. These provide us with some of the tools needed to fight various diseases. Plant-derived treatments continue to play an important role in modern medicine, and past success stories have taught us never to underestimate the power of plants.

 

About Emma Stoye

Emma Stoye is a 3rd year undergraduate studying Biological Sciences at Somerville College.