CHEMOSENSITIVITY OF A CHLOROQUINE-RESISTANT PLASMODIUM-FALCIPARUM ISOLATE TO QUININE - TYPE COMPOUNDS INVITRO

In vitro relative chemosensitivity of erythrocytic stages of a chloroq uine and antifol resistant P. falciparum isolate to quinine-type compo unds was evaluated. Apart from natural cinchona alkaloids, quinine and quinidine, their hydrogen derivatives proved to be more potent erythr ocytic schizontocidal compounds. Some drug combinations also show extr emely good antimalarial property in vitro. Going by the IC50 values of the eight preparations tested the compounds can be arranged in the fo llowing order with respect to their schizontocidal activity: Quinidine /Hydroquinidine greater-than-or-equal-to Hydroquinidine > Quinine/Hydr oquinine greater-than-or-equal-to Quinidine > Hydroquinine > Quinine > Apoquinine > Epiquinine. Clearly in depth investigations are required for exploiting the antimalarial potentials of these cinchona derivati ves or mixtures and other combinations.