Salivary gland homogenates from wild‐caught sand flies Lutzomyia flaviscutellata and Lutzomyia (Psychodopygus) complexus showed inhibitory effects on Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis infection in BALB/c mice

Abstract

During the natural transmission of Leishmania parasites, the infected sand fly female regurgitates promastigotes into the host's skin together with its saliva. It has been reported that vector saliva contains immunomodulatory molecules that facilitate the establishment of infection. Thus, the main objective of this study was to evaluate the specificity of Lutzomyia (Lu.) flaviscutellata and Lu. (Psychodopygus) complexus salivas on the infectivity of Leishmania (L.) (Leishmania) amazonensis and L. (Viannia) braziliensis, respectively. BALB/c mice were inoculated into the skin of hind footpad with L. (L.) amazonensis and L. (V.) braziliensis promastigotes in the absence or presence of Lu. flaviscutellata and Lu. (P.) complexus salivary gland homogenates (SGHs). The evolution of the infection was evaluated by lesion size, histopathological analysis and determination of the parasite load in the skin biopsies collected from the site of infection at 4 and 8 weeks PI. The lesion size and the parasite load of both groups of mice infected in the presence of SGHs were smaller than the control groups. The histopathological features showed that the inflammatory reaction was less prominent in the groups of mice infected in the presence of both SGHs when compared to the control group. The results showed that the presence of SGHs of Lu. flaviscutellata and Lu. (P.) complexus led to induction of processes that were disadvantageous to parasite establishment during infection by L. (L.) amazonensis and L. (V.) braziliensis. An inhibitory effect on Leishmania infection could be observed in both groups inoculated with SGHs, especially when the SGH from Lu. (P.) complexus was used.

Maxadilan-simile expression in Nyssomyia neivai, a sandfly vector in an endemic region of Brazil, and its immunogenicity in patients with American tegumentary leishmaniasis

“…flaviscutellata ) and Psychodopygus complexus (Mangabeira, 1941) (= Lu. complexa ), vectors of Leishmania ( L. ) amazonensis and Leishmania ( V. ) braziliensis in the Brazilian Amazonian Region, respectively, exerts an inhibitory effect on parasite infection, resulting in small lesions and low levels of skin parasitism ( Francesquini et al 2014) .…”

The Potential of Traditional Knowledge to Develop Effective Medicines for the Treatment of Leishmaniasis

“…Considering that ethnopharmacological studies have guided the characterization of biologically active molecules and drugs for different diseases, it is evident that this science can contribute to the search for active substances to treat neglected diseases, such as leishmaniasis, an infectious disease caused by parasitic protozoa of the genus Leishmania , endemic in tropical and subtropical countries. This neglected infectious disease is transmitted during the blood meal of sandflies of the genera Lutzomyia and Phlebotomus ( Francesquini et al, 2014 ; Courtenay et al, 2017 ).…”