Effect of DODAB Nano-Sized Cationic Bilayer Fragments against Leishmania amazonensis

Abstract

The dioctadecyldimethylammonium bromide (DODAB) is a double-chained cationic lipid with potent bactericide and fungistatic activities; however, its toxicity on protozoan parasites is still unknown. Here, we show the antileishmanial activity of DODAB nano-sized cationic bilayer fragments on stationary-phase promastigotes and amastigotes of Leishmania amazonensis, the causative agent of cutaneous leishmaniasis. Upon treatment with DODAB, we analyzed the parasite surface zeta-potential, parasite viability, cellular structural modifications, and intracellular proliferation. The DODAB cytotoxic effect was dose-dependent, with a median effective concentration (EC50) of 25 µM for both life-cycle stages, comparable to the reported data for bacteria and fungi. The treatment with DODAB changed the membrane zeta-potential from negative to positive, compromised the parasite’s morphology, affected the cell size regulation, caused a loss of intracellular organelles, and probably dysregulated the plasma membrane permeability without membrane disruption. Moreover, the parasites that survived after treatment induced small parasitophorous vacuoles and failed to proliferate inside macrophages. In conclusion, DODAB displayed antileishmanial activity, and it remains to be elucidated how DODAB acts on the protozoan membrane. Understanding this mechanism can provide insights into the development of new parasite-control strategies.

The protein map of the protozoan parasiteLeishmania (Leishmania) amazonensis,Leishmania(Viannia) braziliensisandLeishmania (Leishmania) infantumduring growth phase transition and temperature stress

“…Although the information on host immune response against different Leishmania species has made great strides, the factors contributing to these differences are largely unknown [59, 60], despite several differences that have been reported among species. Indeed, amastigotes from Leishmania species belonging to the L. mexicana complex, such as L. amazonensis , are housed in large numbers within a large parasitophorous vacuole within the macrophages [61, 62]. In contrast, amastigotes from L. donovani and L. braziliensis complexes reside intracellularly within small parasitophorous vacuoles that typically contain a single parasite [63, 64].…”

“…For this, 30 μL of MTT [(3- [4,5-dimethyl-2-thiazolyl] -2,5-diphenyl-2H-tetrazolium bromide; 5 mg/mL; (Sigma-Aldrich)] was added in each well and the plate incubated for 3 hours at 25°C. Sodium dodecyl sulfate (50 μL of 10%) was used to solubilize the formazan crystals produced by the reaction, and the absorbance measured using a Microtiter plate reader (BioTek) at a reference wavelength of 690 nm and a test wavelength of 570 nm [41].…”

“…Parasite cell culture L. amazonensis (IFLA/BR/67/PH8), L. braziliensis (MHOM/BR/75/M2903), and L. infantum (syn L. chagasi) (MHOM/BR/1972/LD) promastigotes were cultured as described previously [40,41], with some modifications. Briefly, parasites were incubated in M199 medium (Vitrocell) supplemented with 20% inactivated fetal bovine serum (FBS) (Vitrocell), 40 mM HEPES, 2.5 µg/mL hemin, 10 mM adenine, 2 mM Lglutamine, 2 µg/mL D-biotin, 100 U/mL penicillin, 100 µg/mL streptomycin, 2% filter sterilized human urine, at pH 7.4.…”

Supramolecular Nanostructures for Vaccines

“…In a major, highly recommended review article, Irvine and coworkers considered that biotechnology combined with the nanomaterials science could bring about safer and more efficient vaccine formulations with major roles for the nanoparticles (NPs) [ 116 ]. In a fast moving field encompassing cancer nanotechnology [ 50 , 89 , 90 , 95 , 117 ], vaccinology against pathogenic viruses [ 61 , 62 , 96 , 97 , 98 , 99 , 100 , 106 , 118 ], and microbes such as bacteria [ 19 , 108 , 112 , 119 , 120 ], fungi [ 119 ], and parasites [ 22 , 120 , 121 , 122 , 123 , 124 ], elegant nanomaterials that are difficult to scale up for commercialization cannot become useful in clinics [ 116 , 125 ].…”

In Silico Characterization of Calcineurin from Pathogenic Obligate Intracellular Trypanosomatids: Potential New Biological Roles

“…People all over the world are affected by leishmaniasis and American trypanosomiasis, two neglected tropical diseases that infect over 6 and 12 million people, respectively [ 1 , 2 , 3 ]. Several issues, including a lack of safe/optional drugs, parasite resistance, and ineffective insect vector control, have caused researchers to race to develop more effective treatments for diseases [ 4 ], increasing the current alternative studies with promising results [ 5 , 6 , 7 ]. These vector-borne diseases are caused by protozoan parasites of the Trypanosomatidae family, Leishmania spp.…”