Metabolomic quality control of claimed anti-malarial Artemisia afra herbal remedy and A. afra and A. annua plant extracts

Malaria remains a serious health problem world wide, especially in developing countries. Recent advances in the treatment of malaria have taken place and today combination therapies containing artemisinin (isolated in 1971 from Artemisia annua) and its derivatives have become the main weapon in the fight against this disease. Many herbal companies are now trying to make use of the success of artemisinin by selling Artemisia plant material in various formulations. We have therefore decided to test the product of one such company which claims that its capsules contain artemisinin. We have used a rapid NMR targeted metabolomics approach combined with principle component analysis (PCA) to verify that the capsules are indeed A. afra and not A. annua. In addition the concentration of artemisinin in the plant material was determined with a sensitive LC–MS method. This analysis indicated that even if the company has used A. annua in their capsules the dosage of artemisinin will be far to low to be effective. Our analysis shows that NMR with PCA can be a rapid and valuable tool in the quality control of herbal supplements.