For centuries, four Rosaceae species—Malus sieboldii, Sorbus commixta, Duchesnea indica, and Prunus sargentii—have been prized for their pharmacological properties. In this study, solvent extracts from the seeds of these species were prepared, and their total polyphenol and flavonoid contents were measured. Antioxidant capacity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, as well as ferric reducing antioxidant power (FRAP) and Fe²⁺ chelation tests. Compounds in the extracts were identified through molecular networking with the Global Natural Products Social Molecular Networking (GNPS) platform. Among all samples, D. indica extract contained the highest polyphenol and flavonoid concentrations (335.63 ± 0.03 mg gallic acid equivalents (GAE) per gram of extract and 230.14 ± 2.90 mg rutin equivalents (RE) per gram of extract, respectively). It also exhibited the strongest antioxidant activity in DPPH, ABTS, and FRAP assays, with statistically significant outcomes. Liquid chromatography/mass spectrometry analysis and molecular networking revealed a diverse metabolite profile corresponding to seven biosynthetic pathways in the extracts. Notably, D. indica extract was rich in shikimates, phenylpropanoids, and ellagic acid derivatives, which have potent antioxidant effects. These results suggest a strong relationship between the extract’s chemical profile and its biological activity, offering promising opportunities to use D. indica seeds as functional ingredients across various fields.

Natural products have contributed significantly to anti-inflammatory drug development, but the therapeutic potential of fish visceral extracts has yet to be fully investigated. In this study, we investigated the anti-inflammatory properties of a crude spleen extract from rainbow trout (Oncorhynchus mykiss). The extract significantly reduced nitric oxide (NO) production and downregulated iNOS and COX-2 expression at both mRNA and protein levels. Among four fractions derived from the extract, the OSB fraction showed the strongest and most consistent activity. OSB suppressed LPS-induced expression of iNOS, COX-2, and pro-inflammatory cytokines, while enhancing anti-inflammatory cytokine expression. Mechanistic studies revealed that OSB inhibited NF-κB activation by blocking nuclear translocation of the p65 subunit. Additionally, OSB reduced M1 macrophage markers and LPS-induced ROS generation, indicating inhibition of M1 polarization. These findings suggest that OSB exerts anti-inflammatory effects by modulating the NF-κB pathway and highlight its potential as a natural therapeutic agent for inflammatory diseases.

Background: Natural products are key sources of anti-inflammatory agents, yet the potential of fish visceral extracts remains largely unexplored. This study evaluated the anti-inflammatory activity of a spleen extract from rainbow trout (Oncorhynchus mykiss). Methods: A crude spleen extract and its four solvent fractions were tested in LPS-stimulated RAW264.7 macrophages. Nitric oxide production and expression of iNOS, COX-2, and cytokines were assessed by qRT-PCR and Western blotting. The most active fraction, OSB (n-butanol layer), was further analyzed for its effects on NF-κB signaling, macrophage polarization, and ROS generation. Results: The crude spleen extract significantly reduced NO production and downregulated iNOS and COX-2 expression at both the transcriptional and translational levels. Among the four fractions, the OSB fraction exhibited the most potent and consistent anti-inflammatory effects. OSB markedly suppressed LPS-induced expression of iNOS, COX-2, and pro-inflammatory cytokines, while enhancing anti-inflammatory cytokines. Mechanistic analyses demonstrated that OSB inhibited NF-κB activation by preventing the nuclear translocation of the p65 subunit. Additionally, OSB attenuated LPS-induced ROS production and reduced the expression of M1 macrophage markers, indicating inhibition of M1 polarization. Conclusions: The OSB fraction from rainbow trout spleen exhibits potent anti-inflammatory activity by modulating the NF-κB pathway and suppressing M1 macrophage polarization, suggesting its potential as a natural therapeutic agent.