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

Abstract

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 μM and 3.6 μM, 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.