In 2001 WHO posted a statement on their home page, without signatures, without references: « Due to the instability of artemisinin in raw materials of Artemisia annua L, the leaves need to be stored in cool conditions — preferably below 20°C. Most malaria endemic countries have warm climates and people generally lack access to refrigeration, so it is difficult for patients to keep artemisinin-containing tea bags under 20°C in their homes” A statement not substantiated by scientific papers. Cui bono?
Our associations immediately gathered available data which prove the contrary
- The analysis done by Rosine Chougouo at the LNS at Luxembourg on 3 year old samples
- The data from Fr VanderKooy
- The data from the VUB for samples stored > 3 years
- The thesis of Ivanescu in Romania.
- The data from Pamela Weathers, Worcester Polytech Institute.
Scattered data of course, but which gave us good confidence. We than discovered an important paper from South Africa which shows that Artemisia afra improves with age in 16 years of dry storage.
Stephen O Amoo, Adeyemi O Aremu. Antioxidant and acetylcholinesterase-inhibitory properties of long-term storedmedicinal plants. BMC Complementary and Alternative Medicine 2012, 12:87 doi:10.1186/1472-6882-12-87
The instability is rather a problem of ACTs, artesunate and other antimalarials as demonstrated in the scientif literrature.
S Houzé, A Munier. Shelflife of Predosed Plates containing Mefloquine, Artemisinine, Artesunate. J. Clin. Microb 2007, 4, 8. 2734-36