Wolffia globosa Ethanolic Extract Protects Against Bisphenol A-Induced Osteoblast Dysfunction via Antioxidant Defense, Apoptosis Inhibition, and β-Catenin Modulation

The prevalent endocrine disruptor bisphenol A (BPA) is associated with aging-related conditions, including metabolic disorders. It has been shown that BPA promotes bone fragility through oxidative stress-induced apoptosis and impaired osteoblast differentiation. The identification of sustainable bioactive substances that alleviate BPA-induced bone toxicity is thus of biomedical and environmental significance. Wolffia globosa (WG), the world’s smallest flowering aquatic plant, has recently gained attention as a high-protein, antioxidant-rich nutraceutical, yet its impact on BPA-induced osteoblast dysfunction has not been systematically investigated. This study presents a comprehensive assessment of WG ethanolic extract (WGE) in MC3T3-E1 pre-osteoblasts, incorporating thorough phytochemical characterization, acute high-dose and chronic low-dose BPA exposure models, and multi-faceted mechanistic analysis. LC-MS/MS profiling identified luteolin (116.17 ± 0.69 µg/g), rosmarinic acid (54.80 ± 2.12 µg/g), and apigenin (48.77 ± 0.61 µg/g) as the predominant bioactive compounds. WGE exhibited potent antioxidant capacity across DPPH and ABTS radical scavenging assays, complemented by high ORAC and FRAP values, reflecting broad-spectrum antioxidant mechanisms. Treatment with WGE (25 and 50 µg/mL) resulted in significant alleviation of BPA-induced cytotoxicity, decreased intracellular ROS levels, and inhibited apoptosis. WGE (12.5 µg/mL) also modulated autophagy-related markers (LC3-II, Beclin-1, and p62), suggesting potential autophagic participation, although flux verification was not conducted. Treatment with WGE (12.5 µg/mL) also restored BPA-suppressed osteogenesis under chronic exposure, as evidenced by enhanced alkaline phosphatase activity, and increased both mineralization and upregulation of osteogenic genes including runt-related transcription factor2 (Runx2), collagen type I alpha 1 (Colla1), alkaline phosphatase (ALP), and osteocalcin (OCN). These effects were accompanied by partial reactivation of Wnt/β-catenin signaling. This study is the first to demonstrate that WGE protects osteoblasts from BPA toxicity by concurrently strengthening antioxidant defenses, limiting apoptosis, modulating autophagy-related markers, and supporting β-catenin-mediated osteogenesis, highlighting WG as a promising sustainable nutraceutical candidate for the prevention of environmental toxin-related bone fragility.