The Prospective Use of Brazilian Marine Macroalgae in Schistosomiasis Control

Abstract

Schistosomiasis is a parasitic disease that affects more than 250 million people. The treatment is limited to praziquantel and the control of the intermediate host with the highly toxic molluscicidal niclosamide. Marine algae are a poorly explored and promising alternative that can provide lead compounds, and the use of multivariate analysis could contribute to quicker discovery. As part of our search for new natural compounds with which to control schistosomiasis, we screened 45 crude extracts obtained from 37 Brazilian seaweed species for their molluscicidal activity against Biomphalaria glabrata embryos and schistosomicidal activities against Schistosoma mansoni. Two sets of extracts were taxonomically grouped for metabolomic analysis. The extracts were analyzed by GC–MS, and the data were subjected to Pattern Hunter and Pearson correlation tests. Overall, 22 species (60%) showed activity in at least one of the two models. Multivariate analysis pointed towards 3 hits against B. glabrata veliger embryos in the Laurencia/Laurenciella set, 5 hits against B. glabrata blastula embryos, and 31 against S. mansoni in the Ochrophyta set. Preliminary annotations suggested some compounds such as triquinane alcohols, prenylated guaianes, dichotomanes, and xenianes. Despite the putative identification, this work presents potential candidates and can guide future isolation and identification.

Algal-Derived Halogenated Sesquiterpenes from Laurencia dendroidea as Lead Compounds in Schistosomiasis Environmental Control

“…L. dendroidea extracts were previously selected for bioguided fractionation together with other algal species in our trial studies [9,10]. In the present study, extracts of L. dendroidea, as shown in the GC-MS chromatograms in the 20-60 min range (Figure 2), revealed samples to be complex mixtures that contained a wide variety of volatile compounds from different chemical classes according to searches of various GC-MS libraries.…”

“…13 C NMR (CDCl 3 , 125 MHz) δ = 19.4 (CH 3 -C15), 20.7 (CH 3 -C12), 24.2 (CH 3 -C13), 25.6 (CH 2 -C5), 29.3 (CH 2 -C4), 38.0 (CH 2 -C8), 38.1 (CH 2 -C1), 43.1 (C-C11), 49.1 (C-C6), 70.9 (CH-C10), 72.1 (CH-C9), 115.9 (CH 2 -C14), 124.1 (C-C3), 128.1 (C-C2), 140.7 (C-C7). EI-MS m/z (rel int %) 334 (0.1), 319 (2), 317 (1), 299 (3), 297 (3), 281 (2), 253 (8), 237 (32), 235 (76), 207 (24), 200 (10), 199 (41), 91 (59), 85 (100), 69 (50), 41 (51). [α] 20 D = −89.5 • (c 0.1, MeOH).…”

“…Five coupled male and female worms were exposed to the test compounds; praziquantel was used as the positive control and DMSO as the negative control. Worms were maintained in 24-well culture plates at 37 • C and 5% CO 2 , and monitored after 2 h and then every 24 h thereafter for 96 h for motility, morphological alterations, and reproduction [10]. Experimental procedures were employed according to accepted principles of animal welfare in experimental science (CEUA N 5042140818).…”

“…Three out of the thirteen tested extracts induced lethal effects in the exposed worms [9]. In a more comprehensive screening, in addition to the effects on S. mansoni, the molluscicidal activity was evaluated, indicating the activity of 22 out of 37 species in at least one of the models [10]. In the present study, the halogenated sesquiterpenes (−)-elatol, obtusol, and rogiolol isolated from the extract of one of the 22 species, Laurencia dendroidea, were assayed for their antischistosomal and molluscicidal activities.…”

Aquatic Contamination in Lugano Lake (Lugano Lake Ecological Reserve, Buenos Aires, Argentina) Cause Negative Effects on the Reproduction and Juvenile Survival of the Native Gastropod Biomphalaria straminea

“…Freshwater gastropods have been suggested as useful model organisms to evaluate the toxicity of chemicals compounds and environmental biomonitoring ( Tripathi and Singh, 2004 ; Rivadeneira et al, 2013 ; Tallarico et al, 2014 ; Otero and Kristoff, 2016 ; Agrelo et al, 2019 ; Herbert et al, 2021 ; Siqueira et al, 2021 ; Stein et al, 2021 ). Their slow mobility and difficulty to detoxify pollutants make them sensitive species for water contamination ( Gao et al, 2017 ).…”