Multi-level assessment of Myristica fragrans-induced reproductive toxicity using reciprocal mating crosses in Drosophila melanogaster

Abstract Myristica fragrans (nutmeg), a common culinary spice with diverse biological activities, has received little attention regarding its reproductive toxicity following dietary exposure. Therefore, this study investigated the sublethal reproductive toxicity of nutmeg crude extract using Drosophila melanogaster as a model organism. Adult flies were exposed to graded concentrations of the extract through their diet to determine the median lethal concentration (LC 50 ). Following LC 50 determination, sublethal effects were evaluated using reciprocal mating assays, transmission electron microscopy (TEM) of reproductive tissues, gas chromatography–mass spectrometry (GC-MS) analysis, and molecular docking of the major identified constituent with selected reproductive-related and antioxidant receptors. The extract produced concentration- and time-dependent mortality, with LC₅₀ values decreasing from 0.041 mg/mL fly diet after 24 h to 0.017 mg/ mL fly diet after 72 h. More importantly, sublethal exposure significantly reduced fecundity, delayed offspring development, and decreased adult emergence. TEM analysis revealed pronounced ultrastructural alterations in both ovaries and testes, with male reproductive tissues exhibiting greater susceptibility. GC–MS analysis identified several bioactive constituents previously implicated in reproductive toxicity, while molecular docking predicted favorable binding affinities of the major identified compound toward selected reproductive and antioxidant-related receptors. These findings demonstrate that dietary exposure to M. fragrans extract can adversely affect reproductive function in D. melanogaster with sex-dependent effects.