Question: can you realy treat cancer using rainforest plants?

Jessica Chu answered on 10 Jun 2011:

Heya,

That is a good question! There is quite a lot of up and down side in this area of drug discovery.

The use of plants, animals and minerals in treating diseases have been discovered by humans over 4 thousand years ago (through trial and error). Some of the earlier, more well-known drugs (you probably heard of these examples) from nature are: Aspirin, which is from the barks of Willow trees and Morphine can be found in red poppy.

More specifically to your question – not too long ago (1960’s), the National Cancer Institute in the US have started a programme where they wanted to find chemicals that will treat cancer. People went out to the forests to collect hundreds and thousands of plants for testing to see if they can work against cancer cell lines (cancer cells that have been removed from the body and grown in the lab for research use so it still have some of the cancer cell characteristics).

Dr Wall and Dr Wani noticed when they give the cancer cell lines the extracts of a particular plant, Pacific Yew tree (Taxus brevifolia Nutt), the cancer cell lines stopped growing. (let me know if you want to know how it works :))
So Dr Wall and Dr Wani did some more studies on this tree and have found the active ingredient in it, which is paclitaxel. Paclitaxel is currently used to treat breast, ovarian and a certain type of lung cancer. It is very successful and is still being given to cancer patients today.
However, people still die from this horrible disease because cancer cells (cells from our body that have gone bad/mutated) are very good to adapting so whatever you try to do to it it will resist. So for example, if you want to starve cancer cell from oxygen (without oxygen, cells cannot fuction because acid will build up) then the cancer cells in our body might send signals to grow some new blood vessels to get more oxygen being delievered to them.

Other successful chemicals found in plants in the rainforest (such as the rainforest in Madagascar!) that are used to treat cancer today includes:
Podophyllotoxin, Vinca alkaloids and Camptothecin.

Two researchers (Newman and Cragg) reported that between 1981-2006, there were 1,184 new chemicals approved for drug use and 52% were based on the chemical shape of a natural product. In 2005, another researcher, Sneader suggested that less than 1% of the 320, 000 plant species on earth have been used in traditional medicine. So, I guess we still have the other ~99% of plants to look at! Lots of work to be done 🙂

Some extra bits if you are interested (sorry about the long plant names!):
Here are some other plants that are useful to treat very dreadful diseases currently being sold in the US:

Chemicals from another tree is used to treat malaria, the tree is called Artemisia annua L.
Galantamine is found in Galanthus woronowii and this is used to treat Alzheimer’s disease
Calanolide A from Calophyllum lanigerum var. austrocoriaceum to treat HIV/AIDS.

Hope this answers your question 🙂

Let me know if there’s anything else you want to know!

Jess