The
pyrrolizidine alkaloid content of Solanecio gigas (Vatke) C. Jeffrey (Asteraceae), an Ethiopian medicinal plant widely used for the treatment of
colic,
diarrhea,
gout,
otitis media,
typhoid fever, and noted for its
wound dressing and antiabortifacient activities was studied. The flower and leaf extracts contained 0.19% and 0.14%
alkaloids (dry weight), respectively. GLC-MS analysis indicated that all the
alkaloids in the flowers are
pyrrolizidine alkaloids (PAs), whereas the leaves contain other type of
alkaloids with PAs occurring in low concentrations. Roughly, 80% and 90% of the total PAs in the flowers and the leaves, respectively, were shown to occur as N-
oxides. Eighteen
alkaloids were detected in the flower extract with the
retronecine type twelve-membered macrocyclic diesters
integerrimine,
senecionine and
usaramine comprising 82% of the total PA content. Analysis of the PA profile of the leaves indicated that it has a simpler pattern than the one observed for the flowers. Only five PAs were detected in the leaves with
integerrimine making up about 50% of the total PAs. Quantification of the PA content by GLC showed that the flowers and leaves contain 3321.21 and 84.84 microg per 10 g of dried plant material, respectively. These results indicate that users of this herb are at high risk of
poisoning since the most toxic twelve membered macrocyclics of the
retronecine type are the dominant PAs in the plant.