In Vitro Culture and Drug Sensitivity Assay of Plasmodium falciparum with Nonserum Substitute and Acute-Phase Sera

Abstract

The short-term in vitro growth of Plasmodium falciparumparasites in the asexual erythrocytic stage and the in vitro activities of eight standard antimalarial drugs were assessed and compared by using RPMI 1640 medium supplemented with 10% nonimmune human serum, 10% autologous or homologous acute-phase serum, or 0.5% Albumax I (lipid-enriched bovine serum albumin). In general, parasite growth was maximal with autologous (or homologous) serum, followed by Albumax I and nonimmune serum. The 50% inhibitory concentrations (IC50s) varied widely, depending on the serum or serum substitute. The comparison of IC50s between assays with autologous and nonimmune sera showed that monodesethylamodiaquine, halofantrine, pyrimethamine, and cycloguanil had similar IC50s. Although the IC50s of chloroquine, monodesethylamodiaquine, and dihydroartemisinin were similar with Albumax I and autologous sera, the IC50s of all test compounds obtained with Albumax I differed considerably from the corresponding values obtained with nonimmune serum. Our results suggest that Albumax I and autologous and homologous sera from symptomatic, malaria-infected patients may be useful alternative sources of serum for in vitro culture of P. falciparum isolates in the field. However, autologous sera and Albumax I do not seem to be suitable for the standardization of isotopic in vitro assays for all antimalarial drugs.

Susceptibility of Plasmodium falciparum isolates to antimalarial drugs in a highly seasonal malaria endemic village in Mali

“…A cross-resistance between CQ-AQ and CQ-QN and between QN-AQ has already been reported in previous studies [27][28][29]. A negative correlation between the IC 50 values of DHA-QN, LUM-QN reflects higher activity of DHA and LUM against the isolates of P. falciparum QN-resistant.…”

A Histidine-Rich Protein 2–based Malaria Drug Sensitivity Assay for Field Use

“…Although results obtained with commercial albumin may not necessarily be identical with those obtained with human serum, results in the long run will be easier to compare due to consistent protein contents and quality in the culture medium. 12 The IC 50 s obtained from the HRP2 assay did not show any significant association with the parasite densities, suggesting that within the test range, the parasitemia does not have a major impact on the outcome of the tests. In well-equipped laboratories, however, the parasitemia may be adjusted by diluting the original blood sample with uninfected red blood cells (blood group O) as described previously to fully eliminate any influence from the inoculum effect.…”

Anti-plasmodial Effects of Zanthoxylum zanthoxyloides

“…This differences in an effective concentration between our study and earlier findings likely reflect the different culture conditions (e.g., Albumax vs. human serum), different drug treatment regimes (e.g., time of drug application, use of synchronous cells), and different assay methods (e.g., SYBRgreen based vs. manual counting). All of these differences have been linked to a significant variation in the assayed effective concentration depending on the drug and its mode of action [29,30]. By utilizing the current standard assay methodology, we provide drug efficacy data that is directly comparable to other compounds currently under development.…”