Stability of Artemisia tea infusions. Part 1

As part of our Artemisia crowdfunding campaign we decided to create this website so that we can report on our progress. The main idea here is to give a short overview of the tests that we are conducting, the reason why we are conducting these tests, and also to give the public an opportunity to make comments or suggestions (this site will be updated as we go along).

The first test that we are currently conducting is to check if the Artemisia annua and Artemisia afra tea infusions, prepared in a similar way than in the clinical trials, will be stable over a 12-16 hour period. We need to get our head around the chemistry and stability of these infusions for quality control purposes. In the clinical trials, 5g of plant material was added to 1L of boiling water, it was left to infuse for 10min, after which it was filtered and administered over a 1 day period to the participants in the trials (a 12 hour period). We used the same ratio (100mg/20mL of boiling water), used a 0.45 micron syringe filter to filter the infusion into HPLC vials for HPLC analysis (equipment depicted above). The detector that we use is a PDA detector which detects UV-absorbing compounds. The figure below illustrates the chemical profile of a fresh A. annua tea infusion. The x-axis is time in minutes, and the y-axis the intensity of UV absorbance by the different compounds.

Figure 1. Chemical profile measured at 254nm of a fresh A. annua tea infusion. x-axis is time and y-axis the intensity. Each peak corresponds to an unique molecule.
Figure 2. The same chemical profile as in figure 1, but with the baseline highlighted to illustrate the hundreds of minor compounds present in the tea infusion.

The current plan is to compare the chemical profiles of the fresh tea with the profile of a 16 hour old tea. If any of the molecules disappear then we have stability issues. There is now obviously a number of problems.

  1. We do not know which of these compounds are the ‘actives’, and therefore even if a number of compounds degrade, we will still not know if it will have an impact on the activity.
  2. The analytical instrument only detects UV absorbing compounds. There are many compounds that will not be detected. The well known antimalarial compound, artemisinin, does not absorb UV and will not be detected with this technique.
  3. Based on the clinical trial publications, we do not know how the tea infusions where stored eg. fridge, at room temp, exposed to light or not etc. and what the influence of this will be on the chemistry.
  4. etc.

In order to get a better idea about the chemistry and the stability of the tea infusions we therefore need to conduct a number of tests. HPLC with UV detection is one method, this will be followed mass spectroscopy specifically to look at artemisinin and related compounds. And finally we will conduct Nuclear Magnetic Resonance spectroscopy in order to get a more ‘complete’ picture of the chemistry of the Artemisia tea infusions.

 

3 thoughts on “Stability of Artemisia tea infusions. Part 1”

  1. Welldone. In my opinion, In which country and land did the Artemisia plant grow for the tests is also important. Which recipient is it boiled and served before drinking. Thank for your work it’s very interesting. Nadia

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    1. The A annua used came from Germany (harvested in 2018). The chemical variation can indeed be quite significant depending on the where, how and when it was harvested and of course how it was stored and prepared. We will be looking into this.

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  2. Welldone. In my opinion, In which country and land did the Artemisia plant grow for the tests is also important. Which recipient is it boiled and served before drinking. Thank for your work it’s very interesting. Nadia

    Like

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