Bioactive Fractions of the Ethanolic Extract of Abelmoschus esculentus Seeds with Molluskicidal Potential

Schistosomiasis remains a critically neglected tropical disease, and its control relies on the suppression of vector snails of the genus Biomphalaria. The extensive use of niclosamide is limited by its high cost, poor water solubility, and ecotoxicity. In this study, the molluskicidal, ovicidal, ecotoxicological, and biosafety properties of fractions obtained from the ethanolic seed extract of Abelmoschus esculentus were evaluated. Soxhlet extraction and liquid–liquid partitioning yielded five fractions of increasing polarity. LC–QTOF–MS analysis of the active fractions: crude ethanolic extract in ethyl acetate, crude ethanolic extract in acetone, and crude ethanolic extract in ethanol revealed bioactive polyphenols, including glycosylated flavonols, astilbin, catechin/epicatechin, procyanidin dimers, and protocatechuic acid. The ethyl acetate fraction showed the highest molluskicidal activity against adult Biomphalaria glabrata (48 h LC50 = 41.76 mg/L; LC90 = 61.25 mg/L), while crude ethanolic extract in acetone and crude ethanolic extract in ethanol also met the World Health Organization (WHO) efficacy threshold (LC90 < 100 mg/L). Strong ovicidal activity was observed, particularly for the crude ethanolic extract in ethanol (LC50 = 37.82 mg/L) and crude ethanolic extract in ethyl acetate (LC50 = 40.56 mg/L) fractions. The crude ethanolic extract in ethanol and crude ethanolic extract in dichloromethane fractions caused no mortality in Physella acuta or Biomphalaria tenagophila. Biosafety assays demonstrated low cytotoxicity, minimal hemolysis, and no acute toxicity in mice. These findings highlight A. esculentus seed fractions, especially crude ethanolic extract in ethyl acetate, as promising, biodegradable botanical molluskicides for schistosomiasis control.