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Updated: May 17, 2026
High Yield Purification of Plasmodium falciparum Merozoites For Use in Opsonizing Antibody Assays
Published on: July 17, 2014
In vitro activity of Pheroid vesicles containing antibiotics against Plasmodium falciparum
Lissinda H Du Plessis1, Anel C van Niekerk, Marlene M Maritz
1Unit for Drug Research and Development, North-West University, Potchefstroom, South Africa. Lissinda.DuPlessis@nwu.ac.za
Abstract:
The macrolide antibiotics, erythromycin and azithromycin, have been studied for their potential antimalarial activity, but only modest activity has been demonstrated. In this study, we investigated the enhancement of the efficacy of these antibiotics in combination with a patented lipid-based drug delivery system, Pheroid technology. A chloroquine resistant strain of Plasmodium falciparum (RSA11) was incubated with the formulations for a prolonged incubation time (144 h). Drug efficacy assays were conducted by analyzing the histidine-rich protein II levels of the parasites. The effects of azithromycin and erythromycin were compared with other antibiotics and standard antimalarial drugs. The poor water soluble nature of the drugs led to the formation of micro scale Pheroid vesicles with average particle sizes of 72.76±10.73 μm for azithromycin and 100.62±29.27 μm for erythromycin. The IC(50) values of erythromycin and azithromycin alone and entrapped in Pheroid vesicles decreased statistically significant (P0.05). Prolonged exposure was also statistically meaningful (P0.05), although it seems that exposure need not exceed 96 h. Pheroid vesicles also proved successful in decreasing the IC(50) values of doxycycline, tetracycline and triclosan. Pheroid vesicles containing antibiotics could prove successful as a malaria treatment option.
Insights
Macrolide antibiotics like azithromycin and erythromycin show enhanced antimalarial efficacy when formulated with Pheroid vesicles. This novel drug delivery system significantly reduces the half-maximal inhibitory concentration (IC50) against malaria parasites.
Area of Science:
- Pharmacology
- Infectious Diseases
- Drug Delivery Systems
Background:
- Macrolide antibiotics (erythromycin, azithromycin) exhibit limited antimalarial activity.
- Chloroquine-resistant Plasmodium falciparum poses a significant challenge in malaria treatment.
- Poor water solubility of antibiotics hinders their therapeutic efficacy.
Purpose of the Study:
- To investigate the enhancement of macrolide antibiotic efficacy using Pheroid technology.
- To evaluate the antimalarial activity of azithromycin and erythromycin in Pheroid vesicles against Plasmodium falciparum.
- To compare the efficacy of Pheroid-encapsulated antibiotics with standard antimalarial drugs.
Main Methods:
- Plasmodium falciparum (RSA11, chloroquine-resistant strain) was incubated with antibiotic formulations.
- Pheroid vesicles were formulated with azithromycin and erythromycin, characterizing particle size.
- Drug efficacy was assessed by measuring histidine-rich protein II levels and determining IC50 values.
Main Results:
- Pheroid vesicles successfully encapsulated poorly water-soluble antibiotics, forming microscale vesicles.
- Encapsulation in Pheroid vesicles significantly decreased the IC50 values of azithromycin and erythromycin (P<0.05).
- Pheroid vesicles also enhanced the efficacy of doxycycline, tetracycline, and triclosan.
Conclusions:
- Pheroid technology significantly improves the antimalarial efficacy of macrolide antibiotics.
- This lipid-based drug delivery system offers a promising strategy for malaria treatment.
- Further investigation into Pheroid-antibiotic formulations could lead to novel malaria therapies.
