Format

Send to

Choose Destination
Parasit Vectors. 2019 Jan 8;12(1):14. doi: 10.1186/s13071-018-3282-x.

Effect of flubendazole on developing stages of Loa loa in vitro and in vivo: a new approach for screening filaricidal agents.

Author information

1
Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon.
2
Department of Zoology and Animal Physiology, Faculty of Science, University of Buea, Buea, Cameroon.
3
Department of Biomedical Science, Faculty of Health Science, University of Buea, Buea, Cameroon.
4
Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany.
5
Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde, Cameroon.
6
German Centre for Infection Research (DZIF), Bonn-Cologne partner site, Bonn, Germany.
7
Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, 48824, USA.
8
Filariasis Programmes Support Unit, Liverpool School of Tropical Medicine, Pembroke Place, L3 5QA, Liverpool, UK.
9
Parasites and Vectors Biology Research Unit (PAVBRU), Department of Microbiology and Parasitology, Faculty of Science, University of Buea, Buea, Cameroon. samwandji@gmail.com.

Abstract

BACKGROUND:

Loiasis, an often-neglected tropical disease, is a threat to the success of lymphatic filariasis and onchocerciasis elimination programmes in rainforest areas of the central and western Africa. Its control and even its elimination might be possible through the use of a safe macrofilaricide, a prophylactic drug, or perhaps a vaccine. This present study evaluated the effect of flubendazole (FLBZ) on the development of Loa loa L3 in vitro and in vivo.

METHODS:

Infective stages of L. loa were isolated and co-cultured in Dulbecco's Modified Eagle's Medium in the presence of monkey kidney epithelial cells (LLC-MK2) feeder cells. FLBZ and its principal metabolites, reduced flubendazole (RFLBZ) and hydrolyzed flubendazole (HFLBZ), were screened in vitro at concentrations 0.05, 0.1, 0.5, 1 and 10 μg/ml. The viability of the parasites was assessed microscopically daily for 15 days. For in vivo study, a total of 48 CcR3 KO mice were infected subcutaneously with 200 L. loa L3 and treated with 10 mg/kg FLBZ once daily for 5 consecutive days. Twenty-four animals were used as control and received L3 and vehicle. They were dissected at 5, 10, 15 and 20 days post-treatment for worm recovery.

RESULTS:

The motility of L3 larvae in vitro was reduced from the second day of incubation with drugs at in vivo plasma concentration levels, with a strong correlation found between reduced motility and increased drug concentration (Spearman's rho = -0.9, P < 0.0001). Except for HFLBZ (0.05 μg/ml and 0.01 μg/ml), all concentrations of FLBZ, HFLBZ and RFLBZ interrupted the moulting of L. loa infective larvae to L4. In vivo, regardless of the experimental group, there was a decrease in parasite recovery with time. However, at each time point this reduction was more pronounced in the group of animals treated with FLBZ compared to equivalent control. Parasites were recovered from the flubendazole-treated groups only on day 5 post-inoculation at an average rate of 2.1%, a value significantly lower (Mann-Whitney U-test, U = 28, P = 0.0156) than the average of 31.1% recovered from the control group.

CONCLUSIONS:

This study reveals the ability of flubendazole to inhibit the development of L. loa L3 both in vitro and in vivo, and in addition validates the importance of in vitro and animal models of L. loa as tools for the development of drugs against loiasis.

KEYWORDS:

Flubendazole; In vitro; In vivo; Loa loa L3; Motility; Moulting

Supplemental Content

Full text links

Icon for BioMed Central Icon for PubMed Central
Loading ...
Support Center