2.4. Cell Viability and Nitric Oxide (NO) Release Assay in RAW 264.7 Macrophage

The mice macrophage RAW 264.7 cell line was purchased from the American Type Culture Collection (ATCC) and cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% FBS and 1% penicillin/streptomycin at 37°C in a humidified atmosphere of 5% CO₂ in air. RAW 264.7 cells were seeded in a 96-well plate with a density of 2 × 10⁴ cells/well and further cultured for 24 h. RAW 264.7 cells were treated LPS (0.3 µg/ml) with various concentrations (3, 10, and 30 μg/ml) of BJL for 24 h. The cell viability was measured by MTT assay. The supernatant medium was used for NO release assay by total NO detection kit (Griess reagent, Beyotime Biotechnology). The results were presented as the percentage or folds of the control group.