Phytochemical Composition and Evaluation of Acute Toxicity, Antioxidant, and Antibacterial Activities of Spondias mombin L. and Myracrodruon urundeuva Allemão Ethanolic Extracts Against Vibrio parahaemolyticus.

Plant-derived natural products are emerging as promising sources of bioactive compounds against parasites and microorganisms. This study investigated the phytochemical composition, antibacterial and antioxidant activities, and acute toxicity of ethanolic extracts from Spondias mombin L. and Myracrodruon urundeuva Allemão. Extracts were analyzed by ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). Antibacterial activity was tested against Vibrio parahaemolyticus strains, whereas antioxidant activity was assessed using the DPPH assay. Acute toxicity was evaluated with Artemia salina nauplii. The M. urundeuva extract contained hydrolyzable tannins, gallic acid derivatives, anacardic acids, and agathisflavone, along with phenolic acids and dimeric chalcones, including urundeuvine B, in the stem bark. Only procyanidins were detected in S. mombin extracts. Both extracts exhibited moderate antibacterial activity and promising antioxidant potential, relevant for neutralizing oxidative bacterial defenses through scavenging of reactive oxygen species (ROS) and reactive nitrogen species (RNS), thereby supporting cellular redox homeostasis. The M. urundeuva extract showed the lowest minimum inhibitory concentration (MIC, 0.625-1.25 mg/mL) and, together with S. mombin, demonstrated bactericidal activity surpassing ampicillin. Low acute toxicity was observed for both extracts (LC50 > 1000 µg/mL), reinforcing their potential safety. These findings suggest that these plant extracts are promising natural alternatives for controlling V. parahaemolyticus in aquaculture systems.