Comparative Evaluation of Antiplasmodial and Cytotoxic Activities of Alkaloid Extracts from Coffea arabica and Coffea canephora

The growing resistance of Plasmodium parasites to current antimalarial drugs emphasizes the urgent need to discover alternative therapies. Medicinal plants historically used in the treatment of malaria are promising sources for new bioactive compounds, though their effectiveness requires scientific validation. This study aimed to evaluate the antiplasmodial and cytotoxic properties of alkaloid extracts from Coffea arabica and Coffea canephora. Alkaloids were extracted from powdered dry leaves of both plants using an acidic medium. The alkaloids were identified by Mayer and Wagner reagents. The antiplasmodial activity was assessed using SYBR green fluorescence assays on two Plasmodium falciparum isolates and analyzed by flow cytometry. Toxicological evaluations were performed by hemolysis, erythrocyte sensitivity, and cytotoxicity tests on Vero and Raw cells, with measurements taken by spectrophotometry. The results showed that C. arabica demonstrated significant activity against both Pf3D7 and PfDd2 strains, with resistance indices of 0.78 and IC50 values of 9.53 ± 1.51 µg/mL and 7.48 ± 0.93 µg/mL, respectively. In contrast, C. canephora showed limited activity against Pf3D7 (IC50 > 100 µg/mL) but moderate activity against PfDd2 (IC50 = 85.55 ± 1.17 µg/mL). The toxicity profile for both extracts was promising, as demonstrated by hemolysis results (HC50 > 1000 µg/mL) and cytotoxicity assays (CC50 > 30 µg/mL). This study highlights the potential of these plant extracts as suitable alternatives for malaria treatment.