| dc.description.abstract | Malaria is a major cause of deaths in the world. It is a vector-borne disease caused by
protozoan plasmodia parasites. The parasites are currently becoming resistant to current
antimalarial drugs thus there is need to find alternative drugs. Plants have been used
traditionally to treat malaria and they could be a source of alternative antimalarial drugs.
This study was conducted to investigate antimalarial activity, acute toxicity and
phytochemical composition of selected antimalarial plants. The plants studied were
Flacourtia indica (Burm.f.) Merr. (Flacourtiaceae), Hoslundia opposita Vahl. (Lamiaceae),
Ocimum gratissimum L. (Lamiaceae) and Solanum incanum L. (Solanaceae). Either whole or
parts of the plant depending on the part traditionally used to treat malaria were collected from
Msambweni district, Kenya. Aqueous and organic extracts from each plant part were
evaluated for their in vivo antimalarial activity and acute toxicity using mice model.
Antimalarial activity was evaluated using Swiss albino mice infected with Plasmodium
berghei (ANKA). Thin Layer Chromatography (TLC) was used to screen the extracts for
possible active compounds.
The aqueous and organic extracts of the plants under study exhibited a range of
chemosuppression. Aqueous extracts of S. incanum, F. indica, 0. gratissimum and H
opposita had percentage chemosuppression of 14.77, 0.21, 17.95 and 90.62% respectively.
The organic extracts on the other hand exhibited percentage chemosuppression of 31.22,
87.84, 88.07 and 41.97% respectively. Chloroquine, which was the positive control, had a
chemosuppression of 95.97%. There was no significant difference between the
chemosuppression of the aqueous extracts of H opposita and the organic extracts of F. indica
and 0. gratissimum and that of Chloroquine (p < 0.05).
Aqueous extracts of 0. gratissimum and organic extracts of S. incanum had LD50 above
1000ug/ml and were hence considered to be non-toxic to brine shrimp. On the other hand,
aqueous extracts of S. incanum, F. indica and H opposita and organic extracts of F. indica,
0. gratissimum and H opposita with LD50 < 500~Lg/ml were found to be toxic. Acute toxicity
studies showed that the aqueous and organic extracts of the four plants under study were not
toxic to mice at a concentration of2000 mg/kg body weight.
The current project was carried out to validate the medicinal use of the plants in traditional
healthcare and allow for the sustainable use and commercialization of these plants. The
findings indicate good antimalarial activity of the aqueous extract of H opposita roots, and
organic extracts of the leaves of F. indica and 0. gratissimum. This suggests these plants may
have active principles against P. Jalciparum parasites and are thus a potential source of
antimalarial drugs.
Key words: Antimalarial; acute toxicity; phytochemical analysis; medicinal plants, aqueous,
organic, Flacourtia indica, Hoslundia opposita, Ocimum gratissimum, Solanum incanum | en_US |
