Biochemical and histopathological evidence of hepatoprotection by Nigella sativa and Syzygium cumini seed extracts in a deltamethrin-induced toxicity model in Swiss albino mice

Pyrethroid insecticides like deltamethrin pose significant risks to non-target organisms due to widespread use in agriculture and vector control. Researchers explore synthetic and plant-derived compounds to counteract pesticide toxicity. This study shows that seed extracts from Nigella sativa (NSSE) and Syzygium cumini (SCSE) possess strong antioxidant properties, effectively mitigating deltamethrin-induced oxidative damage. Deltamethrin generates reactive oxygen species (ROS), causing cytotoxicity, mitochondrial dysfunction, hepatic injury, and potential apoptosis. In vitro studies on HepG2 cells revealed that deltamethrin (10–50 µM) reduced viability (45–70%), increased ROS (2.5-fold), and impaired mitochondrial membrane potential. Pretreatment with NSSE or SCSE (50–200 µg/mL) restored viability (60–85% recovery), reduced ROS (50–70%), and maintained mitochondrial function. Key bioactives were thymoquinone (NSSE) and ellagic acid (SCSE). In vivo experiments in Swiss albino mice ( n = 30; deltamethrin 18 mg/kg b.w., oral, 10 days) showed elevated serum ALT (3.2-fold), AST (2.8-fold), and ALP (2.5-fold), with depleted antioxidants (GSH: 55% reduction; SOD/CAT: 40–50% inhibition). Co-administration of NSSE or SCSE (200 mg/kg) reversed these changes (enzyme reductions: 55–70%; GSH recovery: 80–90%) and decreased lipid peroxidation (MDA: ~65%). Histopathological examination confirmed deltamethrin-induced necrosis, sinusoidal dilatation, and inflammation, largely ameliorated (80–95% recovery) by extracts; NSSE showed superior antifibrotic effects. The findings indicate that seed extracts from Nigella sativa and Syzygium cumini display strong antioxidant, anti-inflammatory, and tissue-repairing properties that counteract liver damage caused by deltamethrin, both in laboratory settings and animal models. This evidence highlights their promise as naturally derived agents for protecting the liver.