Antiplasmodial activity of atisinium chloride from the Bhutanese medicinal plant, Aconitum orochryseum

Ethnopharmacological relevance: The plant Aconitum orochryseum Stapf. (Ranunculaceae) is employed together with other Plants in Bhutanese traditional medicine and is indicated for malaria-associated fever.

Aim of the study: To study the in vitro antiplasmodial activity of atisinium chloride, the major alkaloid from Aconitum orochryseum.

Materials and methods: Atisinium chloride was extracted and purified from aerial parts of Aconitum orochryseum and its structure and absolute configuration confirmed by single crystal X-ray crystallography. The crude methanol extract, crude alkaloid fraction, and atisinium chloride were tested for in vitro antiplasmodial activity against the malarial Plasmodium falciparum strains TM4/8.2 (TM4; wild type) and K1CB1 (K1; chloroquine and Antifolate resistant).

Results: The diterpenoid alkaloid atisinium chloride was shown to have moderate antiplasmodial activities with IC(50) values of 4 microM and 3.6 microM, respectively against the TM4 strain and the K1 strain of Plasmodium falciparum.

Conclusions: Our studies provide the first evidence in support of one of the indicated treatments with Aconitum orochryseum in Bhutanese traditional medicine. This alkaloid also represents a potential new antimalarial structural lead.