Artemisia annua (Sweet Wormwood)

Professional info

- The main constituent of the plant Artemisia annua, artemisinin, and its derivatives such as artesunate, are used in the treatment of malaria. The anti-cancer properties of artemisinin have also been demonstrated in cells and laboratory animals.
- The aim of this project was to explore the potential of the total ethanolic extract of Artemisia annua as an anticancer therapy.
- In three mice experiments, the ethanolic extract and artesunate orally did not show a significant effect on tumor growth in mice despite good in vitro results.
- This research shows that there are several components influencing the efficacy of herbal extracts and that results obtained on cells (in vitro), do not necessarily translate to results in animal models (in vivo).
 
 
Why did we choose this project?

Artemisia annua or Sweet Wormwood is a common type of wormwood native to Asia, but naturalized throughout the world. The main constituent artemisinin, and its derivatives such as artesunate, are used in the treatment of malaria. The anticancer properties of artemisinin have also been demonstrated in cells and laboratory animals. The plant extract is also used in traditional medicine in China as an anticancer agents amongst other uses (fever, inflammation,…). A review on Artemisia annua was funded by Reliable Cancer Therapies and is available on request (Heyerick 2009 Artemisia annua and artemisin-related endoperoxides).

A plant extract is a complex mixture of different yet often closely related compounds that can act on various targets, so it is an interesting cocktail of natural origin. Due to the generally low concentration of the individual constituents, low toxicity can be expected, whereas with regards to biological activity synergism is often observed. This makes plant extracts a promising combination in cancer treatment.

Artemisia annua tea is also popular amongst cancer patients in the Western world but except for some case reports, to date there is no evidence in humans that an extract of Artemisia annua could benefit cancer patients.

 

The aim

The aim of this project is to explore the potential of the total ethanolic extract of Artemisia annua as an anticancer therapy. 

 

How did we approach the project?

The ethanolic extract of Artemisia annua was tested in vitro in cancer cell lines from 3 different cancers (breast, colon, and pancreas). The study experiments compared this extract with 1) artemisinin, the main active constituent of Artemisia annua, 2) artesunate, a semi-synthetic derivative of Artemisinin, and 3) a water extract. From these in vitro results, the ethanolic extract and artesunate were selected to be tested in vivo.
The ethanolic extract and artesunate were tested for its safety and efficacy in three xenograft mouse models in three different settings: a colon model at Oncodesign, France, a pancreatic model at Precos, UK, and an endometrium model at University of Leuven, Belgium.

 

What did we find?

In all three animal experiments, the ethanolic extract and artesunate orally did not show a significant effect on tumor growth in mice despite good in vitro results. The absence of clear antitumor effect is likely due to the overall low bioavailability of artemisinin from the ethanolic extract and artesunate. The reports are available upon request.

 
Based on what we learnt, what’s the message we want to give to the public?

This research again shows that there are several components influencing the efficacy of herbal extracts. The dose, the type of extraction solvent, the formulation, the standardization,… are all key for optimal activity. It is important that patients are aware that results obtained with one herbal extract cannot account for all extracts from the same plant. These results also clearly demonstrate that results obtained on cells (in vitro), do not necessarily translate to results in animal models (in vivo). This is very often the case in cancer research therefore efficacy on tumor cells should not be considered as evidence for use in humans.