Planta Med 2003; 69(8): 720-724
DOI: 10.1055/s-2003-42778
Original Paper
© Georg Thieme Verlag Stuttgart · New York

In Vitro Antiplasmodial Activity of Abietane and Totarane Diterpenes Isolated from Harpagophytum procumbens (Devil’s Claw)

Cailean Clarkson1 , William E. Campbell1 , Peter Smith1
  • 1Pharmacology Division, Department of Medicine, University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa
Further Information

Publication History

Received: December 6, 2002

Accepted: March 11, 2003

Publication Date:
06 October 2003 (online)


The development of drug resistance and resurgence of malaria has highlighted the need for new chemically diverse antimalarial drugs. This study investigates Harpagophytum procumbens DC. as a source of antiplasmodial hit compounds. The roots of wild harvested plants as well as the aerial sections, seeds and roots of cultivated H. procumbens were evaluated for in vitro antiplasmodial activity. Bioassay-guided fractionation of the petroleum ether root extract yielded two diterpenes, (+)-8,11,13-totaratriene-12,13-diol (1) and (+)-8,11,13-abietatrien-12-ol (2). Compounds 1 and 2 displayed significant (IC50 < 1 μg/mL) in vitro antiplasmodial activity against a chloroquine-resistant (K1) and -sensitive (D10) strain of Plasmodium falciparum, and low cytotoxicity (SI > 65) against two mammalian cell lines (CHO and HepG2). It was found that 1 and 2 did not modify the erythrocyte shape, which in conjunction with the cytotoxicity results, indicates selective antiplasmodial activity.


Dr. William E. Campbell

Pharmacology Division

Department of Medicine

University of Cape Town

K-45 OMB

Groote Schuur Hospital

Observatory 7925

Cape Town

South Africa

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