Matrigel

To assess Matrigel tube formation, 400 μL/well Matrigel (Solarbio, Beijing, China) was added to 24-well plates and incubated for 30 min. Next, 1 mL of HUVECs (5 × 10⁴/mL) mixed with each coated SAL decoction in medium for 5 days was added to the Matrigel. The cells were incubated for another 6 h. The tube formation was analyzed visually using photographs at 0 h and 6 h, and the tube areas were calculated using ImageJ.

Transwell assays were used to measure the invasion of NPC cells based on the prior reports [61 , 62 ]. Transfected cells were resuspended into RPMI-1640 media at a density of 5 × 10⁴ cells/well without FBS, and Matrigel (356,234, Solarbio) was then added to the upper chamber of 24-well transwell plates (3422, Corning Company, New York, NY, USA). Media containing 10% FBS was distributed in the bottom chamber. A cotton swab was used to scratch the Matrigel after 24 h, and cells were subsequently fixed with 4% paraformaldehyde (P1110, Solarbio) and stained for 30 min with 0.1% crystal violet (G1062, Solarbio). An inverted microscope (Olympus) was used to capture images of the cells, and 10 randomly selected fields were used to tally the numbers of invaded cells.

Matrigel (Solarbio)was added to a 96‐well plate at a volume of 50 µL per well and incubated at 37°C for 1 h. Then, HUVEC and RA‐FLS were added to each well at a density of 1 × 105/mL in 200 µL of medium containing Matrigel. After incubation at 37°C for 8 h, the formed tubes were counted under a microscope (OLYMPUS) and analyzed using the Angiogenesis Analyzer plugin in the Image J software.