Pharmacokinetic Study of Artemisinin After Oral Intake of a Traditional Preparation of Artemisia Annua L. (Annual Wormwood)

Abstract

Artemisia annua L. (annual wormwood) contains the antimalarial artemisinin. Aqueous preparations of the dried herb are included in the pharmacopoeia of the People's Republic of China for treatment of fever and malaria. Fourteen healthy male volunteers received one liter of tea prepared from nine grams of Artemisia annua leaves. Blood samples were taken and artemisinin was detected by reversed phase high-performance liquid chromatography. The mean +/- SD maximum plasma concentration of artemisinin was 240 +/- 75 ng/mL and the mean +/- SD area under the plasma concentration-time curve was 336 +/- 71 ng/mL x hr. Artemisinin was absorbed faster from herbal tea preparations than from oral solid dosage forms, but bioavailability was similar. One liter of an aqueous preparation of nine grams of Artemisia annua contained 94.5 milligrams of artemisinin (approximately 19% of the usually recommended daily dose). Artemisinin plasma concentrations after intake of this herbal tea are sufficient for clinical effects, but insufficient to recommend such preparations as equivalent substitutes for modern artemisinin drugs in malaria therapy.

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

“…Pure artemisinin has poor solubility in water and, as was shown above, infusions of the dry leaves of A. annua prepared as recommended in the Chinese Pharmacopeia contain a substantial quantity of artemisinin (Table I). These findings are similar to those found by Räth et al (2004), who performed a pharmacokinetic study utilising an infusion of A. annua to determine the plasma concentration of artemisinin after the oral administration of the infusion. In the study by Räth et al (2004), the leaf infusion was prepared in a way that was analogous to that used in the present study starting from dry leaves with 1.39% artemisinin and yielding infusions with 57.5 mg artemisinin/L.…”

“…These findings are similar to those found by Räth et al (2004), who performed a pharmacokinetic study utilising an infusion of A. annua to determine the plasma concentration of artemisinin after the oral administration of the infusion. In the study by Räth et al (2004), the leaf infusion was prepared in a way that was analogous to that used in the present study starting from dry leaves with 1.39% artemisinin and yielding infusions with 57.5 mg artemisinin/L. Atemnkeng et al (2009) used this procedure to prepare infusions containing 34 mg artemisinin/L from dry leaves that contained 1.12% artemisinin.…”

“…The quality of the infusions prepared from the leaves of the Amazonian hybrids was also monitored and compared with the standardised plant from Paulínia through the levels of artemisinin in the infusions and by testing these infusions for antimalarial activity against P. falciparum in vitro. There are reports in the literature on the in vivo antimalarial activity, pharmacology, efficacy and safety of A. annua infusions in human clinical trials (Mueller et al 2000, Räth et al 2004) and in vivo in animals using rodent malaria parasite-based models (Atemnkeng et al 2009). However, we could find no previous report on the in vitro antiplasmodial activity of A. annua infusions.…”

“…In the most important clinical studies reported in the literature involving infusions of A. annua, 5-9 g of dry plant per litre of boiling water per day for five-seven days has been the usual course of treatment. In clinical studies, the therapeutic efficiency of A. annua infusions was up to 70%, but high recrudescence rates were reported, which led the authors of these clinical studies to not recommend the use of A. annua infusions as a monotherapy (Mueller et al 2000, Räth et al 2004.…”

Antiulcer Activity after Oral Administration of the Wormwood Ethanol Extract on Lesions due to <I>Leishmania major</I> Parasites in BALB/C Mice

“…Novel approaches including the oral administration of natural pharmaceutical products from medicinal herbs such as wormwood, Artemisia, have been proposed 33 . The currently well-known anti-malaria compound, artemisinin (a sesquiterpene with an endoperoxide bridge), is derived from this plant 24,36 .…”