Research Paper Volume 11, Issue 23 pp 11391—11415

Melatonin protects blood-brain barrier integrity and permeability by inhibiting matrix metalloproteinase-9 via the NOTCH3/NF-κB pathway

Figure 3. Melatonin inhibited MMP-9 but not MMP-2 activity and protein levels and increased TIMP-1 but not TIMP-2 protein levels. (A) MMP-9 and MMP-2 activities were measured using gelatin zymography analysis in different groups. (BC) MMP-2 and MMP-9 activities were quantified by densitometry analysis. (D) MMP-9, MMP-2, TIMP-1, and TIMP-2 protein levels were measured using western blot analysis. (EH) MMP-9, MMP-2, TIMP-1, and TIMP-2 protein levels were quantified by densitometry analysis. Results are presented as the mean ± SD, n = 3. *p < 0.01 compared with the control; #p < 0.01 compared with the IL-1β-treated group; ##p < 0.01 compared with the IL-1β + DAPT group; $p < 0.01 compared with the IL-1β + PDTC group; &p < 0.01 compared with the IL-1β + SB-3CT group.