Submitted to: Molecules
Publication Type: Review Article
Publication Acceptance Date: March 15, 2010
Publication Date: April 29, 2010
Citation: Ferreira, J.F., Luthria, D.L., Sazaki, T., Heyerick, A. 2010. Flavonoids from Artemisia annua L. as antioxidants and their potential synergism with Artemisinin. Molecules. 15:3135-3170.
Since artemisinin was discovered as the active antimalarial component in a diethyl ether extract of Artemisia annua in early 1970’s, hundreds of papers have focused on the antimalarial effects of the artemisinin semi-synthetic analogs dihydroartemisinin, artemether, arteether, and artesunate. Artemisinin itself has not been widely used as an antimalarial due to its poor stability, solubility, and short half-life. In the past decade, the work with these artemisinin-based compounds has expanded to their anti-cancer properties. Although artemisinin is a major bioactive component present in the traditional tea, leaf flavonoids, also present in the tea, have shown a variety of biological activities and may synergize the effects of artemisinin against malaria and cancer. However, there are few studies that show the potential synergistic effects between flavonoids and other antioxidant polyphenols and artemisinin. The resurgent idea that multi-component drug therapy might be better than monotherapy is illustrated by the recent resolution of the World Health Organization to support artemisinin-based combination therapies (ACT), while phasing out monotherapy with artemisinins. In this critical review we will discuss the possibility that artemisinin and its semi-synthetic analogs might become more effective to treat parasitic diseases (such as malaria) and cancer if simultaneously delivered with flavonoids. The flavonoids present in A. annua leaves have been linked to suppression of Cyt P450 enzymes and p-glycoproteins, responsible for altering the absorption and metabolism of artemisinin in the body, but also have been linked to a beneficial immunomodulatory activity in subjects afflicted with parasitic and chronic diseases.