Artemisia, edited by C.W. Wright. Taylor & Francis. New York, NY. 2002., 344 pp., hardcover. $110.00 ISBN 0-415-27212-2.
I was pleased to receive this book for review, hoping to find support for my long-held contention that whole sweet wormwood (Artemisia annua L., Asteraceae) should be sent to Africa to treat malaria, rather than such pure silver bullets derived from this plant as artemisinin and artesunate, which cost at least three orders of magnitude more and are more likely to lead to multi-drug resistance. But this book favors the silver bullet in synergistic drug cocktails with synthetic antimalarials, to the whole herbal shotgun (i.e., the chemically complex herbal extract), with its naturally occurring synergistic antimalarial phytochemicals.
This book is timely. The New York Times reported in 2002 that many American scientists are reluctant to send artemisinin or artesunate to Africa, where malaria kills "1ï¿½2 million people each year, mostly children." (Chap. 13)
One reason not to send artemisinin to Africa appears in Chapter 15, "Since artemisinin and its derivatives are among the most effective antimalarials known and resistance to them has not yet been observed outside models, use in each country must be regulated."
I attribute this reluctance to the selfish fear of resistance, a consequence of monochemical approaches. Will whole sweet wormwood with cinchona bark (Cinchona spp., Rubiaceae) and/or barberry (Berberis vulgaris L., Berberidaceae) and/or epazote (Chenopodium ambrosioides L., Chenopodiaceae) prevent or treat malaria without leading to resistance? The answer can only be found through clinical trials. Such trials will not happen in the United States, I predict, for monetary reasons. It's hard to patent and control a whole herb, and harder to make money therefrom. Africa, if I were you, I'd start my own clinical trials.
More than half the pages on this monograph on Artemisia, a genus of some 400 species, are dedicated to the one major antimalarial species, A. annua, which is also commonly called sweet Annie and qing hao in Chinese, and its derivatives. Single chapters are devoted to A. absinthium, A. dracunculuis, A. herba-alba, A. ludoviciana, A. pallens and A. vulgaris.
Artemisia annua is clearly a weed, but it contains several compounds that are synergistic with artemisinin. This is alluded to once: "[C]asticin, chrysosplenitin and cirsineol were found to enhance the antimalarial activity of artemisinin. In particular, casticin was found to be active in inhibiting some cytophysiological activities of the parasite." The authors do not mention that another endoperoxide, ascaridole, reported herein for several Artemisia species, including A. annua, is itself antimalarial. They make no mention of the multidrug resistant inhibitory activity of chrysosplenol D and chrysosplenitin.
According to this book, qing hao (as it is called in pinyin) is not recommended for the prevention of malaria or as a deterrent to mosquitos. I disagree. History indicates that the leaves were burned as a fumigant insecticide to kill mosquitoes in ancient China. In 340 C.E., the renowned Daoist, Ge Hong, recommended that to reduce fevers one should soak a handful of qing hao in approximately 1 liter of water, strain, and drink. The classic Chinese herbal text, Ben Cao Gang Mu, states that malaria with chills and fever could be treated with qing hao.
Occasionally one finds contradictions in the book. "... To date there have been no published reports of clinical trials in which A. annua herb has been used alone for the treatment of malaria." "... A crude ethanolic extract of A. annua was formulated with oil in a soft gel capsule and administered to mice and tried clinically in man." "The soft gel capsule was administered to 103 patients with malaria (P. falciparum or P. vivax) and compared with the tablet formulation which was given to 41 malaria patients." "Both formulations were effective in reducing fever and clearing parasites at doses equivalent to 73.6 g raw herb (for the capsule), and 80.8 g (for the tablet) given over three days but recrudescent [recurrance] rates were high with both dosage forms although they were reduced by increasing the duration of treatment." "... Crude extracts alone may not give an acceptable cure rate."
This book added many quantitative data and new entries to my phytochemical database at the U.S. Department of Agriculture, almost doubling the number of quantified chemical entries. I'll send an e-copy of the updated A. annua phytochemical listing to those readers who request it (email <email@example.com>).
I have looked at several books in this series devoted to a single economic genus. I find this the best among the four in the series (Medicinal and Aromatic Plants ï¿½ Industrial Profiles) I have been invited to review. It is a good source book for anyone interested in malaria, A. annua, and artemisinin. But I disagree with one major conclusion of this excellent book. I personally believe that whole A. annua extracts, with all their synergens, could be better and cheaper than the isolated silver bullet, or derivatives thereof, at preventing as well as treating malaria, could have fewer side effects, and would less likely lead to multidrug resistance.
ï¿½ James A. Duke, Ph.D. Botanist Fulton, Maryland