چکیده (انگلیسی):

Objective: To study antiplasmodial and antioxidant activities of the isolation of alkaloids
from the active dichloromethane extract of Alseodaphne corneri.
Methods: Phytochemical studies of the crude extract led to the isolation of six alkaloids
using recycle high performance liquid chromatography and preparative thin layer chromatography.
The antiplasmodial activity of the isolated compounds was evaluated using
the histidine-rich protein II assay. The isolated alkaloids were also tested for their antioxidant
activity using three different assays; DPPH, ferric reducing ability of plasma and
metal chelating assays.
Results: Malaria infection caused the formation of free radicals which subsequently led
to oxidative stress and apoptosis. The antioxidant properties of the alkaloids under
investigation revealed that in addition to the antiplasmodial activity, the alkaloids could
also prevent oxidative stress. (+)-laurotetanine and (+)-norstephasubine exhibited strong
antiplasmodial activities with IC50 values of 0.189 and 0.116 mM, respectively.
Conclusions: Interestingly, the two most potent compounds that exhibit antiplasmodial
activity also exhibit good antioxidant activities. The crude dichloromethane extract and
the isolated compounds exert substantial antiplasmodial and antioxidative activities which
in turn suppress oxidative stress and cause less damage to the host.