In vitro antiprotozoal, antimicrobial and antitumor activity of Pavetta crassipes K. Schum leaf extracts

Pavetta crassipes K. Schum (Rubiaceae) leaves traditionally used in Guinea against hypertension and malaria were evaluated for antiproliferative activity in vitro in protozoan and bacterial microorganisms, and cancer and normal cell lines. The alkaloid fractions showed promising antiprotozoal (IC 50 < 2 μg/ml) and anticancerous activities (IC 50 < 3 μg/ml). IC 50 values are given below for the most active extract. To study the potential benefit of the traditional medicinal plant Pavetta crassipes K. Schum (Rubiaceae), which is widely distributed throughout West Africa, the methanol and dichloromethane extracts were isolated from the plant leaves to determine if they exhibited antiprotozoal, antibacterial, antifungal or antitumor activity in vitro. The methanol and dichloromethane extracts and their specific fractions were obtained using bioassay-guided fractionation and investigated for antiproliferative activity in vitro in microorganisms ( Staphylococcus aureus, Escherichia coli and Candida albicans), protozoans ( Trypanosoma cruzi, Trypanosoma brucei, Leishmania infantum and Plasmodium falciparum), and cancer (U373, PC3, MXT and A549) and normal cell lines (NHDF and MRC-5). Most of the alkaloid fractions investigated exhibited antiproliferative activity in all the cancer cell lines, microorganisms and protozoans studied. The benefit of Pavetta crassipes as a traditional medicinal remedy was confirmed using antiprotozoal and cytotoxicity assays in vitro. These analyses revealed that the components present in the alkaloid extract of Pavetta crassipes are responsible for its antiprotozoal and cytotoxic efficacy.