Brassica nigra L. Seed Extracts as a Promising Source of Antioxidant and Anti-Inflammatory Agents

Black mustard (Brassica nigra L.) seeds are a rich source of bioactive phytochemicals; however, their antioxidant, antibacterial, and anti-inflammatory potential has not been comprehensively explored. Therefore, this study aimed to assess antioxidant, antibacterial, and anti-inflammatory effects of black mustard seed extracts obtained from Soxhlet extraction with hexane (HE) and ethanol (EE), and ultrasonic-assisted ethanolic (UE) extraction. HPLC analysis confirmed the presence of sinapic acid in all extracts. Phytochemical profiling revealed that the EE was enriched in phenolic compounds, while the UE exhibited a higher flavonoid content. Accordingly, both EE and UE demonstrated strong antioxidant activities, including radical scavenging capacity, reducing power, and inhibition of lipid peroxidation. All extracts demonstrated antibacterial activity against Staphylococcus epidermidis. The anti-inflammatory potential of extracts was supported by the inhibition of lipoxygenase and protease. The UE showed the strongest lipoxygenase inhibition, while the EE and UE exhibited comparable protease inhibitory effect. Regarding RAW264.7 cells, the extracts were non-cytotoxic and reduced the expression of IL-6 and IL-31. Molecular docking analysis suggested that sinapic acid contributes to the anti-inflammatory activity through interactions with key inflammatory targets. Overall, the EE and UE demonstrated multitarget antioxidant, antibacterial, and anti-inflammatory activities, supporting their potential application in functional and dermatological formulations for inflammation management.