Universidade Federal Rural Do Rio De Janeiro

The Cosmetocleithrum represents the most diverse group of monogenoids parasitizing Neotropical doradid catfishes. In this study, based on morphological and molecular data, we describe two new species, Cosmetocleithrum guamaensis n. sp. and Cosmetocleithrum taeniophallum n. sp., and assess their phylogenetic relationships within the Dactylogyridae using partial 28S rDNA sequences. Our analyses support the validity of these new taxa and suggest their phylogenetic affinity with Cosmetocleithrum species parasitizing auchenipterid catfishes. Additionally, we confirm the presence of Cosmetocleithrum falsunilatum and Cosmetocleithrum bulbocirrus in Megalodoras uranoscopus and Pterodoras granulosus, respectively, with C. falsunilatum exhibiting notable morphological variation across river basins, possibly influenced by environmental factors. Our phylogenetic results corroborate previous studies indicating two distinct Cosmetocleithrum lineages, one exclusively associated with doradids and another with both doradids and auchenipterids, with weak support for the genus' monophyly. Furthermore, we discuss morphological diversity within Cosmetocleithrum, highlighting significant variation in key diagnostic features, including haptoral structures, copulatory complex morphology, and vaginal opening orientation. These findings reinforce previous hypotheses suggesting that Cosmetocleithrum may not constitute a natural group and that taxonomic revisions are needed. The limited molecular data available for Cosmetocleithrum species (with only 13 out of 31 described species studied) and the disparity between the number of known doradid hosts and those surveyed for monogenoids highlight the urgent need for further integrative taxonomic and phylogenetic studies. This approach will be crucial for providing valuable insights and advancing our understanding of the complex evolutionary puzzle of one of the largest genera of monogenoids parasitizing Neotropical Siluriformes.

Schinus genus plants have a long history of use in traditional medicine, particularly in South America. The ethnopharmacological applications of Schinus species include antiseptic, antiplasmodial, antimalarial and antileishmanial properties.

In the present work, we investigated the action of essential oil (EO) against cutaneous leishmaniasis causing agent Leishmania amazonensis in promastigote and amastigote forms as well as cytotoxicity against host cells.

After hydrodistillation, drying and concentration of S. molle leaves, obtained EO chemical analysis was performed by gas chromatography-mass spectrometry. L. amazonensis promastigotes were treated or not (control) with different concentrations of the EO, being daily counted on Neubauer chamber up to 96 h after treatment. The effect of the EO on parasite promastigote forms was also analyzed by ultrastructural and mitochondrial membrane potential (ΔΨm) alterations. The cytotoxicity of S. molle essential EO on Balb/c mice peritoneal macrophages was evaluated by XTT cell viability assay. The anti-amastigote effect was quantified either by counting the fixed and Giemsa-stained intracellular parasites inside macrophages treated or not (control) with different concentrations of the EO or by amastigote-promastigote conversion rate. For the latter, infected macrophages were treated with SDS at 0.01 % and released amastigotes were grown at conditions that favored their transformation into promastigotes and those were then collected from the Schneider's Insect medium supernatant and counted.

S. molle EO had 33 identified compounds with sabinene (26.2 %) and epi-α-cadinol (15.2 %) as the major constituents. The EO significantly inhibited L amazonensis promastigotes growth even in very low concentrations with IC₅₀/96 h of 0.0196 ± 0.0036 μg/mL. The volatile oil induced autophagosome formation and cell shrinkage in promastigotes and disruption of parasite mitochondria membrane potential (ΔΨm). Moreover, the compound was able to inhibit more than 90 % of macrophage-released amastigote differentiation into promastigote forms with IC₅₀ of 0.069 ± 0.04 μg/mL. Conversely, the essential oil did not induce relevant cytotoxicity, presenting no harmful effects to the host cell after 48h (CC₅₀ > 0.1 μg/mL).

Overall, the results presented herein show the initial and promising use of S. molle essential oil as chemotherapy against the L. (L.) amazonensis parasite, and consequently against cutaneous and diffuse cutaneous leishmaniasis.

This study investigated pregnancy loss (PL) in embryo recipients based on pregnancy-associated glycoproteins (PAGs) and impact of P4 supplementation on pregnancy per embryo transfer (P/ET) and PL. In experiment 1, 1003 fresh IVF embryos were transferred into Holstein heifers. Overall P/ET was 42.3 % at 28d (424/1003), 39.1 % at 33d (392/1003), 37.0 % at 47d (371/1003), and 35.5 % at 63d (356/1003). Overall PL was 16.5 % from 28 to 63d, 7.5 % 28-33d, 5.4 % 33-47d, and 4.0 % 47-63d. Using an observational retrospective cohort experimental design, each PL heifer was matched to a non-pregnant and pregnant heifer. Embryonic attachment (Eatt) at 21d (PAGs>0.6 ng/mL) was similar for Pregnant (80 %), PL 33-47d (76.2 %), and PL 47-63d (80 %), but lower for PL 28-33d (50 %). The PAGs at 28d were lower for PL 28-33d vs. Pregnant (10.1 vs. 15.3) and tended lower for PL 33-47d vs. Preg (12.4 vs. 15.9). In experiment 2, Holstein heifers received ET (n = 540) and were randomized to P4 supplementation (PlusP4) from 14 to 19d or untreated (Control). PlusP4 was greater than Control for Eatt at 21d (64 vs. 55 %) and for P/ET at 28d (52 vs. 39 %). Heifers were divided into terciles for PAGs at 21d. Upper PAGs tercile had greatest P/ET (81 %), medium PAGs tercile was intermediate with PlusP4 greater than control (58.5 % vs. 38.6 %), and lowest PAGs tercile was lowest P/ET with PlusP4 greater than Control (12.2 % vs. 2.3 %). Thus, embryo recipients with suboptimal placentation, indicated by PAGs (at d21 or d28) had greater PL d28-33 and d33-47. Also, early P4 supplementation (d14-19) increased P/ET in these heifers.