RESUMO
The production of reactive oxygen species (ROS) increases considerably in situations of cellular stress, inducing lipid peroxidation and multiple alterations in proteins and nucleic acids. However, sensitivity to oxidative damage varies between organs and tissues depending on the triggering process. Certain drugs used in the treatment of diverse diseases such as malaria have side effects similar to those produced by oxidative damage, although no specific study has been conducted. For this purpose, cell membrane microarrays were developed and the superoxide production evoked by the mitochondrial activity was assayed in the presence of specific inhibitors: rotenone, antimycin A and azide. Once the protocol was set up on cell membrane isolated from rat brain areas, the effect of six antimalarial drugs (atovaquone, quinidine, doxycycline, mefloquine, artemisinin, and tafenoquine) and two essential oils (Rosmarinus officinalis and Origanum majoricum) were evaluated in multiple human samples. The basal activity was different depending on the type of tissue, the liver, jejunum and adrenal gland being the ones with the highest amount of superoxide. The antimalarial drugs studied showed specific behavior according to the type of human tissue analyzed, with atovaquone and quinidine producing the highest percentage of superoxide formation, and doxycycline the lowest. In conclusion, the analysis of superoxide production evaluated in cell membranes of a collection of human tissues allowed for the characterization of the safety profile of these antimalarial drugs against toxicity mediated by oxidative stress.
RESUMO
Rhipicephalus microplus (Canestrini, 1888) is one of the species with medical and economic relevance that has been reported in the list of Cuban tick species. Some morphological characterizations about the R. microplus species in Cuba have been published; however, molecular studies are lacking. Molecular phylogenetic analyses have grouped R. annulatus, R. australis and three clades of R. microplus in a complex named R. microplus. The present study aimed to characterize two R. microplus tick isolates, established as colonies at the Cuban National Laboratory of Parasitology. Morphological characterization of adult specimens was carried out by using Scanning Electron Microscopy. The sequences of mitochondrial genes: 12S rRNA, 16S rRNA and the subunit I of cytochrome c oxidase (coxI) and one nuclear sequence: internal transcribed spacer 2 (its2) were used for phylogenetic analyses. The life cycle under laboratory conditions for both isolates was also characterized. Tick specimens of both colonies showed morphological characteristics comparable with those distinctive for the R. microplus species. Phylogenies based on mitochondrial gene sequences identified congruently the Cuban tick colonies within the clade A of R. microplus. The life cycle of both isolates under laboratory conditions lasted 65 ± 5 days and the reproductive performance of female ticks of each colony also were similar with approximately 2500 larvae obtained from fully engorged female ticks. This study constitutes the first molecular characterization of ticks from the R. microplus species in Cuba.
