10 Aug 2013

Artemisia annua tea stronger than chloroquine !

Recent results obtained at the AlQuds University in partnership with IFBV-BELHERB from Luxembourg show that freshly prepared infusion of Artemisia annua is stronger than chloroquine in the inhibition of beta-hematin (hemozoin) formation. In the infected erythrocyte the malaria parasite generates large quantities of toxic heme which it has to render innocuous by polymerizing it into hemozoin. The mechanism of quinine and all its deriva-tes, chloroquine, amodiaquine operates by inhibiting this hemozoin crystallization.

Pr Mutaz Akkawi in previous work (Malaria Journal 2012, 11-suppl.p3) has shown that extracts from Salvia officinalis also inhibit hemozoin formation. Extracts from Artemisia sieberi growing in Palestine were shown to have similar properties. More recently the strongest inhibitory effect was displayed by Artemisia annua infu-sions as used by thousands of people in China, Africa, South America. In this research work it could also be demonstrated that it is essential to prepare fresh infusions rather than working with extracts. It was a surprising discovery by AlQuds University that lyophilized extracts even when kept in hermetic glassware lose their power over weeks. This is the case also for other isolated molecules like artesunate ( S Houzé et al., J Clin Microbiol. Aug 2007, 2734-2736) and may have an impact not only on treatment results but also on in vitro results obtai-ned with aged extracts.

Surprising was also the fact that the beta-hematin inhibitory power of fresh infusions seems to increase with dilution of the infusion. This is eventually in line with recent in vivo results obtained on malaria patients in RDCongo where capsules containing powdered leaves of Artemisia annua from Luxembourg with 0.1 % artemisininin appear to have a higher curing rate than capsules with high artemisinin leaves from A3 hybrid. It is not excluded that for Artemisia annua tea a hormetic effect has to be considered and that a high content in artemisinin is not necessarily the optimum. Or that even Artemisia apiacea and Artemisia afra which contain no or very little artemisinin are strong antimalarials.

The scientific literature is poor in research work dealing with beta-hematin inhibition, except for the papers dealing with quinine and its derivatives chloroquine and amodiaquine. Some extensive work however was done at the University of Baroda, India in 2012 (PhD thesis, Soni Sanketkumar Chandrakant). This research confirms the link between antimalarial properties and beta-hematin inhibition. Quercetin, a flavonoid found in many herbal medicines, has a much lower IC50 than chloroquine for beta-hematin inhibition. The synergy between different flavonoids was extensively studied in this thesis. In all cases did the combination of several flavonoids enhance the antimalarial properties. It is in line with the results of AlQuds where we will concentrate our efforts now on the individual constituents of Artemisia annua and their combinations.And all this confirms the important work published in December 2012 by Pamela Weathers from the Worcester Polytechnic Institute ( MA Elfawal et al., PLoS One, 2012, 7-12, e52746) : the dried whole plant Artemisia annua as an antimalarial therapy has superior properties when compared with pure artemisinin. The synergistic benefits may derive from the presence of other antimalarial compounds in Artemisia annua.

Pierre Lutgen                                     Mutaz Akkawi
IFBV-BELHERB                                             AlQuds University

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