Molluscicidal activity of Persea americana Mill. (Lauraceae) stem bark ethanolic extract against the snail Biomphalaria glabrata (Say, 1818): a novel plant-derived molluscicide?

Abstract

Plant-derived molluscicides have been indicated as biodegradable and lowcost strategies for control of Biomphalaria spp., intermediate host for the Schistosoma. This study evaluated whether the crude ethanolic extract of the Persea americana stem bark has molluscicidal activity against embryos, newly-hatched and adults of Biomphalaria glabrata. The extract was obtained, characterized and its toxicity analyzed by snail embryotoxicity test (144 h) and acute toxicity test with newly-hatching and adult snails (96 h). Results showed the presence of fl avonoids, anthraquinone heterosides, coumarins and tannins in the crude ethanolic extract, which showed molluscicidal activity against all life cycle stages of B. glabrata. The LC 50 for embryos, newly-hatched and adults were 27.06, 30.60 and 55.55 ppm, respectively. Embryos exposed to the extract at 50 ppm showed hatching inhibition and at 6.2 and 25 ppm had the highest rates of morphological alterations, such as shell malformations and coagulation of the perivitelline substance. Adult snails exposed to the extract at 75 ppm showed a peak of behavioral changes, such as lethargy and shell reclusion, in addition to answers like hemolymph release in most concentrations. Further studies are required, prioritizing toxicity testing on non-target organisms and further elucidation of the active molecules.

Insecticidal activity of Ageratina adenophora (Asteraceae) extract against Limax maximus (Mollusca, Limacidae) at different developmental stages and its chemical constituent analysis

“…Results show the presence of flavonoids, anthraquinone heterosides, coumarins, and tannins in the crude ethanolic extract, which exhibited molluscicidal activity against all life cycle stages of B . glabrata [ 32 ]. We did not determine the existence of other secondary metabolites in the study, and cannot deny that the activity of substances with low content is low, and more substances can be determined in future studies.Under stress conditions, insects accumulate superoxide anion radicals, hydroxyl radicals, hydrogen peroxide, and other reactive oxygen species, resulting in organismal damage.…”

Molluscicidal activity of plant alkaloids

“…Due to the role of intermediate hosts, species from the Lymnaeidae family, together with Oncomelania hupensis (Bekkouche et al, 2000; Ke et al, 2017; Ming et al, 2011), were often used. The most studied species, however, turned out to be a representative of the Planorbidae family— Biomphalaria glabrata (Silva et al, 2020). We suggest that this species is worth considering as a potential model species in future research.…”

“…Juveniles of snails may also experience morphological disorders (Silva et al, 2020). This can lead to significant changes in the size of the population.…”

“…One of the most serious problems with the spread of gastropods is the simultaneous spread of parasitic diseases. This problem mainly affects the inhabitants of Asia, Africa, and Latin America (Silva et al, 2020). In these areas, a frequently registered disease is schistosomiasis—a parasitosis caused by trematodes of the genus Schistosoma (Esch et al, 2001; Ke et al, 2017).…”

“…Capsaicin, on the other hand, like other vanilloids, has the ability to stimulate the TRV1 receptor, responsible for aversive reactions (Kalil‐Gaspar et al, 2007). Juveniles of snails may also experience morphological disorders (Silva et al, 2020). This can lead to significant changes in the size of the population.…”