Sublethal concentrations of usnic acid potassium salt impairs physiological parameters of Biomphalaria glabrata (Say, 1818) (Pulmonata: Planorbidae) infected and not infected with Schistosoma mansoni

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

“…Apoptosis is a self-induced mechanism of death and an important physiological process for homeostasis and immune response [ 54 ]. Similar results are presented with potassium usnate [ 36 ] and extract and fraction of P. pendula [ 35 ], demonstrating the importance of the study with AP and BN cells to evaluate the toxic effects on B. glabrata hemocytes. Thus, the preparations showed significant cytotoxic effects in the highest concentrations evaluated.…”

“…According to the study using saline extract and fraction enriched with lectin from Parkia pendula seeds [ 35 ], the different alterations presented after exposure may be associated with the capacity of protein/lectin to bind to different carbohydrates, causing damage, inhibition of hatching and death of these embryos. Embryos with teratogenic effects rarely hatch [ 36 ], thus, the presence of morphological alterations in embryos exposed to B. monandra preparations demonstrate the capacity to inhibit development and hatching, consequently causing population control of this host.…”

“…The preparations tested in the present study induced a decrease in egg oviposition, both in the case of the saline extract (reduction from 10.55% to 52.65% at 0.5 and 4.0 mg/mL, respectively) ( Figure 4 E) and the fraction (reduction from 9.62% to 88.52% at 0.5–1.0 mg/mL, respectively) ( Figure 4 F). Effects such as reduced egg hatching and decreased fecundity rates were also seen when evaluating the toxic capacity of Ramalina aspera [ 16 ], potassium usnate [ 36 ] and curcumin [ 46 ] on B. glabrata . Studies have suggested that the reduction in egg deposition of snails when exposed to Haplophyllum tuberculatum [ 47 ] and organotin [ 48 ] is associated with the decreased biosynthesis of hormones such as progesterone and testosterone, which they associated with decreased fertility.…”

“…The egg position of the embryos was recorded for seven consecutive days, started after 24 h of exposure, being analyzed until complete hatching in the negative control group (dechlorinated filtered water). Then, after hatching, the embryos were counted and classified as viable (normal) and unfeasible (malformed and dead) [ 36 ].…”

Toxic, cytotoxic and genotoxic effect of plumbagin in the developmental stages of Biomphalaria glabrata (Say, 1818‐intermediate host) and cercaricidal activity against the infectious agent of schistosomiasis mansoni

“…In our study, after 6 h of exposure to plumbagin, these same behavioral changes were visualized, in addition to the release of hemolymph, suggesting rupture of the external membranes 21 . These tissue damages can alter the reproductive capacity and homeostasis of snails, in addition to affecting the maintenance of intramolluscan stages of S. mansoni and, therefore, interrupting the continuity of the biological cycle 43 . Furthermore, the fecundity and fertility of snails exposed to molluscicides are important, as a single snail that survives the exposure is able to repopulate the region in a few days, due to the hermaphroditic character of the species 44 .…”