This article was written by Year 13 biology students, Shi Min and Grace, about their recent visit to the Royal College of Physicians' Garden of Medicinal Plants.

Introduction

Of the many plants that exist around the world, thousands can be used medicinally. Plants often evolved chemicals to protect them from being eaten by animals. Our trip to the Royal College of Physicians taught us how we have manipulated plant chemicals by looking at an array of their chemical pathways in order to make life saving treatments.

Chinese lantern

One of the interesting plants that we learnt about were Chinese lanterns (Physalis alkekengi), which come from the same family of potatoes (Solanaceae). What we found fascinating was that it had the ability to turn from an opaque orange to translucent so birds could see when the berry inside of it had fully developed. As a result, the seed inside of the berry can be eaten and then excreted with bird waste, which acts as a fertiliser, and grow in other locations (animal mediated seed dispersal). Whilst the unripe fruits are toxic, the orange berries were traditionally used in ancient China to treat kidney stones. Now, a chemical compound produced by the plant called calystegines is being investigated as a treatment for Gaucher’s disease.

Tobacco plants

We also learnt how tobacco plants can be genetically modified to produce antibodies against Ebola. Because of how fast the plant can grow, a whole field of antibodies can potentially be made within weeks, saving many lives around the world. The nicotine in tobacco is arguably one of the world’s most poisonous plants not only because the tar can alter cells, causing cancer, but also due to its addictive nature. Nevertheless, through the use of genetic engineering, a plant that is considered toxic could be modified to save many lives around the world!

Anti-cancer medication

In addition to this, we learnt that there are only a few plants regularly used to make anti-cancer medications. These were discovered due to mass screening of thousands of plants by the US National Cancer Institute (NCI). For instance, the bark of the Pacific yew tree (Taxus brevifolia) can be used to make Taxol, which can stop cell proliferation.

Elephants' use of medicinal plants

In our further research, we learnt that scientists recently observed elephants using medicinal plants to treat themselves when sick in Kenya. The findings suggest elephants can recognise and select plants with healing properties, highlighting both animal intelligence and the importance of conserving natural habitats so we do not lose possible life saving treatments before we find them.

Conclusion

This trip has made us reconsider how plants can be used holistically. While plants such as cannabis and opioids are usually associated with recreational use, we also saw how they can be used to treat conditions. For example, cannabis for epilepsy and opioids as painkillers. By having a black-and-white perspective on plants, we miss out opportunities to discover more revolutionary treatments for tomorrow’s healthcare.