Establishment of Plasmodium Falciparum Culture for the First Time in Bangladesh and in Vitro Antimalarial Activity Assessment of Methanolic Extract of Clerodendrum Infortunatum Linn

Abstract

Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an urgent need for new, more affordable and accessible antimalarial agents possessing original modes of action. Developing countries, where malaria is endemic, depend strongly on traditional medicine as a source for inexpensive treatment of this disease. Consequently, it is important that antimalarial medicinal plants are investigated, in order to establish their efficacy and to determine their potential roles of new antimalarial drugs. Thus the objectives of the present study are to establish Plasmodium falciparum culture for the first time in Bangladesh and to assess In-vitro antimalarial activity of methanolic extract of Clerodendrum infortunatum Linn. In this study, we established culture of P. falciparum 3D7 strain (MRA-102 and MRA-1240) for the first time in Bangladesh. Strains were cultured in human RBC at 5% hematocrit in complete medium composed of RPMI 1640 medium supplemented with 25 ml HEPES buffer (pH 7.4) and 10% AB human serum. Culture jars were incubated at 37°C under a gaseous mixture of 5% CO2, 5% O2, and 90% N2. Parasites were synchronized by using 5% sorbitol. Then the antimalarial properties of crude extract Clerodendrum infortunatum Linn. Was evaluated. The whole parts of the plant contain different medicinally active substances which were variously used in Ayurveda, Unani and Homeopathy system of medicines. Its root, leaf and stem extract are used in microbial infection as well as traditionally used against malaria and fever, mainly from Asia regions including Bangladesh. The air-dried powdered plant parts (roots, leaves,) or whole plant was extracted with solvents (Methanol). Schizontocidal activity was measured using a standard In vitro assay, with 3D7 Plasmodium falciparum wild type (MRA-1240) and chloroquine resistance (MRA-102) strain. The methanolic extract of Clerodendrum infortunatum Linn. (0.35, 0.116, 0.038, 0.012, 0.004, 1.43×10-3, 4.79×10-4, 1.59×10-4 and 5.3×10-5 µg/ml) showed antimalarial activity against 3D7 (Chloroquine resistance) strain of P. falciparum. In addition, other concentrations (0.2, 0.04, 0.008, 1.6×10-3, 3.2×10-4 and 6.4×10-5 µg/ml) of extract of Clerodendrum infortunatum Linn. showed antimalarial activity against 3D7 (chloroquine resistance) strain of P. falciparum. The methanolic extract of Clerodendrum infortunatum Linn. (0.35, 0.116, 0.038, 0.012, 0.004, 1.43×10-3, 4.79×10-4, 1.59×10-4 and 5.3×10-5 µg/ml) showed antimalarial activity against 3D7 (Wild type) strain of P. falciparum. We conclude that methanolic extract of Clerodendrum infortunatum Linn. showed antimalarial activity. Further study is needed to find out the efficacy and safety of the Clerodendrum infortunatum Linn. extract.