Effect of Bauhinia monandra Kurz Leaf Preparations on Embryonic Stages and Adult Snails of Biomphalaria glabrata (Say, 1818), Schistosoma mansoni Cercariae and Toxicity in Artemia salina.

Biomphalaria glabrata snails constitute the main vector of schistosomiasis in Brazil, and Bauhinia monandra Kurz, the leaves of which contain BmoLL lectin with biocidal action, is a plant widely found on continents in which the disease is endemic. This work describes the composition of B. monandra preparations and the effect on embryos and adult snails, their reproduction parameters and hemocytes. We also describe the results of a comet assay after B. glabrata exposure to sublethal concentrations of the preparations. Additionally, the effects of the preparations on S. mansoni cercariae and environmental monitoring with Artemia salina are described. In the chemical evaluation, cinnamic, flavonoid and saponin derivatives were detected in the two preparations assessed, namely the saline extract and the fraction. Both preparations were toxic to embryos in the blastula, gastrula, trochophore, veliger and hippo stages (LC50 of 0.042 and 0.0478; 0.0417 and 0.0419; 0.0897 and 0.1582; 0.3734 and 0.0974; 0.397 and 0.0970 mg/mL, respectively) and to adult snails (LC50 of 6.6 and 0.87 mg/mL, respectively), which were reproductively affected with decreased egg deposition. In blood cell analysis, characteristic cells for apoptosis, micronucleus and binucleation were detected, while for comet analysis, different degrees of nuclear damage were detected. The fraction was able to cause total mortality of the cercariae and did not present environmental toxicity. Therefore, B. monandra preparations are promising in combating schistosomiasis since they can control both the intermediate host and eliminate the infectious agent, besides being safe to the environment.

Toxic, cytotoxic and genotoxic effect of saline extract and fraction of Parkia pendula seeds in the developmental stages of Biomphalaria glabrata (Say 1818 - intermediate host) and cercaricide activity against the infectious agent of schistosomiasis.

This study describes for the first time the effect of saline extract and Parkia pendula seed fraction on Biomphalaria glabrata adult embryos and molluscs well as the reproductive parameters (fecundity and fertility) and survival, in addition to cytotoxicity and genotoxicity through the profile of blood cells after exposure to sublethal concentrations. Furthermore, we analyzed the action of both preparations against the cercariae of Schistosoma mansoni and their environmental safety using the bioindicator Artemia salina. The saline extract and fraction showed toxic effects for embryos (CL90 of 464.25, 479.62, 731.28, 643.28, 408.43 and 250.94, 318.03, 406.12, 635.64, 1.145 mg/mL, for blastula, gastrula, trocophore, veliger and hippo stage respectively), adult snails after 24 h of exposure (CL90 of 9.50 and 10.92 mg/mL, respectively) with increased mortality after 7 days of observation and significant decrease (p <0.05; p < 0.01 and p < 0.001) in egg mass deposition. At sublethal concentrations, an increase in quantitative and morphological changes in hemocytes was observed, and in the genotoxicity/comet assay analysis, varying degrees of nuclear damage were detected. In addition, the saline extract showed changes in the motility of the cercariae, while the fraction howed toxicity from a concentration of 1.0 mg/mL. The saline extract showed toxicity to A. salina at the highest concentrations (3.0, 4.0 and 5.0 mg/mL), while the fraction did not show ecotoxicity. Thus, the saline extract and fraction was promising in combating schistosomiasis by eliminating the intermediate host and causing alterations and/or mortality to the infectious agent.

An arabinogalactan-glycoconjugate from Genipa americana leaves present anticoagulant, antiplatelet and antithrombotic effects.

Glycoconjugates extracted from Genipa americana leaves (PE-Ga) were separated into two fractions, denominated as PFI and PFII (total carbohydrate: 23-36%/uronic acid: 9-30%; protein:4-5%; polyphenols:0.776-0.812 mg/g), mainly composed by arabinose, galactose and uronic acid and presenting high (PFI) and low (PFII) molecular weight (based on polyacrylamide electrophoresis gel and gel permeation chromatography). Uronic acid was also detected by FT-IR (wavenumbers: 1410 and 1333 cm-1) and NMR (α-GalpA). Deproteinization of glycoconjugates showed reduced protein and polyphenol levels with loss of its biological effects. PE-Ga and PFII prolonged clotting time-aPTT (3.6 and 1.8x), while PE-Ga and PFI inhibited by 48% (100 µg/µL) the ADP-induced platelet aggregation. In vivo, these glycoconjugates at 1 mg/kg inhibited (37-53%) venous thrombus formation (4.7 ± 0.1 mg) and increased bleeding time (PE-Ga and PFI:3.0x; PFII:1.7x vs. PBS:906 ± 16.7 s). In conclusion, the arabinogalactan-rich glycoconjugate of G. americana leaves, containing uronic acid, present antiplatelet, anticoagulant (intrinsic/common pathway) and antithrombotic effects, with low hemorrhagic risk.