In vitro and in vivo antiplasmodial activity and cytotoxicity of extracts of Phyllanthus niruri L. herbs traditionally used to treat malaria in Indonesia.

In endemic areas where malaria is prevalent, medicinal plants are often used to treat malaria. This study was conducted to evaluate the in vitro and in vivo antiplasmodial activity and cytotoxicity of extracts of meniran (Phyllanthus niruri L.) herb traditionally used to treat malaria in Indonesia. Three extracts viz aqueous, methanolic and chloroformic extracts were obtained by maceration of the herbs. A radioactive method was used to evaluate the in vitro antiplasmodial activity of the extracts on chloroquine-resistant (FCR-3) and chloroquine-sensitive (D-10) strains of Plasmodium falciparum. In vitro antiplasmodial activity was expressed by the concentration inhibiting 50% of parasite growth (IC50). Cytotoxicity was estimated on Hela cells and the Cytotoxicity Index (CI = IC50 on HeLa cells/IC50 on FCR-3 strain) was calculated to evaluate the safety of tested extracts. A standard 4-day test on P berghei infected mice was used to evaluate the in vivo antiplasmodial activity of the extracts showing strong in vitro antiplasmodial activity, for both the methanolic and aqueous extracts. The in vivo antiplasmodial activity was expressed by the dose inhibiting 50% of parasite growth (ED50). The IC50 values obtained for these extracts against P. falciparum ranged from 2.3 to 202.4 microg/ml. The methanolic extract was the most active in vitro extract with an IC50 that ranged from 2.3 to 3.9 microg/ml and a CI that ranged from 41.3 to 57.5. This was also the most in vivo active extract with an ED50 of 9.1 mg/kg/d. Further study will be conducted to isolate and purify active compounds presented in the methanolic extract.

In vitro antiplasmodial activity and cytotoxicity of newly synthesized N-alkyl and N-benzyl-1,10-phenanthroline derivatives.

A previous study showed that the 1,10-phenanthroline skeleton was active in vitro against chloroquine-resistant and sensitive strains of Plasmodium falciparum. Based on this skeleton, 8 derivatives of N-alkyl and N-benzyl-1,10-phenanthrolines have been synthesized. This study was conducted to evaluate the in vitro antiplasmodial activity and cytotoxicity of these compounds. The in vitro antiplasmodial activity was tested on two strains of P. falciparum, FCR-3 chloroquine-resistant and D10 chloroquine-sensitive strains, while their cytotoxicity was tested on the Vero cell line. The parasite and cell growth were estimated by hypoxantine-[2,8-3H] uptake after 24- and 72-hour incubation with each compound tested. The control parasite or cell free from any compounds was referred to as having 100% growth. For this radioactive method, the IC50 value showing concentration inhibiting 50% of the parasite growth was determined by probit analysis. The results showed that the highest antiplasmodial activity was observed with (1)-N-benzyl-1,10-phenanthrolinium iodide with the IC50 0.18-0.45 microM, and the IC50 of the compound on Vero cells ranged from 2,582.30 to 7,057.71 microM. The cytotoxic/ antiplasmodial ratio indicates that this compound has high selectivity (10,993 +/- 330.79-38,965 +/- 6,888.27).