Artemisinin for people with cancer – the research gets interesting

Dr. Weeks’ Comment: Here is a brief sampling of the scientific rationale for asking your oncologist to add Artemisinin to your protocol

“In addition to their anti-malarial properties, artemisinins are cytotoxic for cancer cells.”

“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), instead of the previously used monotherapy with artemisinins.”

 

Expert Rev Mol Med. 2009 Oct 30;11:e32.

Anticancer activities of artemisinin and its bioactive derivatives.

Firestone GL, Sundar SN.

Source

Department of Molecular and Cell Biology and The Cancer Research Laboratory, The University of California at Berkeley, CA 94720-3200, USA. glfire@berkeley.edu

Abstract

Artemisinin, a sesquiterpene lactone derived from the sweet wormwood plant Artemisia annua, and its bioactive derivatives exhibit potent anticancer effects in a variety of human cancer cell model systems. The pleiotropic response in cancer cells includes growth inhibition by cell cycle arrest, apoptosis, inhibition of angiogenesis, disruption of cell migration, and modulation of nuclear receptor responsiveness. These effects of artemisinin and its derivatives result from perturbations of many cellular signalling pathways. This review provides a comprehensive discussion of these cellular responses, and considers the ramifications for the potential development of artemisinin-based compounds in anticancer therapeutic and preventative strategies.

 

Curr Drug Targets. 2006 Apr;7(4):407-21.

Molecular pharmacology and pharmacogenomics of artemisinin and its derivatives in cancer cells.

Efferth T.

Source

German Cancer Research Center, M070, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. t.efferth@dkfz.de

Abstract

Secondary metabolites from plants can serve as defense against herbivores, microbes, viruses or competing plants. Many compounds from medicinal plants have pharmacological activities and thus may be a source for novel anti-tumor agents. We have analyzed natural products from traditional Chinese medicine during the past decade and focused our interest on the compound artemisinin from Artemisia annua L. (qinghao, sweet wormwood) and its derivatives. In addition to their anti-malarial properties, artemisinins are cytotoxic for cancer cells. The present review focuses on the mechanisms of action of artemisinins in cancer cells relating to: 1. anti-proliferative and anti-angiogenic effects, 2. induction of apoptosis, 3. oxidative stress, 4. oncogenes and tumor suppressor genes, and 5. multidrug resistance. Data on putative target molecules of artemisinins are presented and discussed, e.g. the translationally controlled tumor protein (TCTP). Emphasis is given to pharmacogenomic approaches to analyze the pleiotropic nature of mechanisms of artemisinins in cancer cells.

 

Molecules. 2010 Apr 29;15(5):3135-70.

Flavonoids from Artemisia annua L. as antioxidants and their potential synergism with artemisinin against malaria and cancer.

Ferreira JF, Luthria DL, Sasaki T, Heyerick A.

Source

USDA-ARS, Appalachian Farming Systems Research Center, 1224 Airport Rd., Beaver, WV 25813, USA. Jorge.Ferreira@ars.usda.gov

Abstract

Artemisia annua is currently the only commercial source of the sesquiterpene lactone artemisinin.Since artemisinin was discovered as the active component of A. annua in early 1970s, hundreds of papers have focused on the anti-parasitic effects of artemisinin and its semi-synthetic analogs dihydroartemisinin, artemether, arteether, and artesunate. Artemisinin per se has not been used in mainstream clinical practice due to its poor bioavailability when compared to its analogs. In the past decade, the work with artemisinin-based compounds has expanded to their anti-cancer properties. Although artemisinin is a major bioactive component present in the traditional Chinese herbal preparations (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, only a few studies have focused on the potential synergistic effects between flavonoids 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), instead of the previously used 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 CYP450 enzymes 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.

 

 

Phytomedicine. 2011 Aug 15;18(11):959-69. Epub 2011 Aug 9.

Cytotoxic activity of secondary metabolites derived from Artemisia annua L. towards cancer cells in comparison to its designated active constituent artemisinin.

Efferth T, Herrmann F, Tahrani A, Wink M.

Source

Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, University of Mainz, Mainz, Germany. efferth@uni-mainz.de

Abstract

Artemisia annua L. (sweet wormwood, qinhao) has traditionally been used in Chinese medicine. The isolation of artemisinin from Artemisia annua and its worldwide accepted application in malaria therapy is one of the showcase success stories of phytomedicine during the past decades. Artemisinin-type compounds are also active towards other protozoal or viral diseases as well as cancer cells in vitro and in vivo. Nowadays, Artemisia annua tea is used as a self-reliant treatment in developing countries. The unsupervised use of Artemisia annua tea has been criticized to foster the development of artemisinin resistance in malaria and cancer due to insufficient artemisinin amounts in the plant as compared to standardized tablets with isolated artemisinin or semisynthetic artemisinin derivatives. However, artemisinin is not the only bioactive compound in Artemisia annua. In the present investigation, we analyzed different Artemisia annua extracts. Dichloromethane extracts were more cytotoxic (range of IC₅₀: 1.8-14.4 μg/ml) than methanol extracts towards Trypanosoma b. brucei (TC221 cells). The range of IC₅₀ values for HeLa cancer cells was 54.1-275.5 μg/ml for dichloromethane extracts and 276.3-1540.8 μg/ml for methanol extracts. Cancer and trypanosomal cells did not reveal cross-resistance among other compounds of Artemisia annua, namely the artemisinin-related artemisitene and arteanuine B as well as the unrelated compounds, scopoletin and 1,8-cineole. This indicates that cells resistant to one compound retained sensitivity to another one. These results were also supported by microarray-based mRNA expression profiling showing that molecular determinants of sensitivity and resistance were different between artemisinin and the other phytochemicals investigated.

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