Background: Andrographis paniculata has been exploited for its ethnomedicinal properties as an antimicrobial agent across decades. The antiplasmodial efficacy of Andrographis paniculata methanol leaf extract was established in this study.
Methods: Forty-two mice were divided into 7 treatment groups. Groups 1 and 7 served as negative and positive control respectively, while groups 2 – 6 were treated with different concentrations of the extract. The parasites were also cultured in Roswell Park Memorial Institute (RPMI) 1640 medium, and treated with different concentrations of the extract.
Results: This study showed a significant reduction in the parasitaemia level in the blood of mice treated with the extract. The different concentrations of the extract also had a positive effect on some haematological parameters. The white blood cell counts changed significantly with concentration of 10, 50, 100 and 500mg/ml. Also, there was significant increase in the packed cell volume (31.00±0.00, 36.33±0.58, 38.33±0.58 and 46.67±0.58%) at concentration of 10, 50, 100 and 500mg/ml respectively, while the untreated group remained low. The extract displayed a significant antiplasmodial activity against P. berghei in vitro at different concentrations of 5, 10, 20, 30, 40 and 50mg/ml with plasmodial load of 1.8%, 1.21%, 0.68%, 0.51%, 0.44% and 0.26% respectively compared with chloroquine and untreated samples that had 0.21% and 4.0% parasitized erythrocytes.
Conclusion: This study has demonstrated the in vivo antiplasmodial efficacy of A. paniculata methanol leaf extract. Hence, the study recommends that the leaf extract of A. paniculata should be considered for production of novel antimalarial drugs.