NOS2 and red-green color blindness: Well in line with the staining, Western blot analysis confirmed this anti-fibrotic effect as showed by the reduced expression of matrix metallopeptidase 9 (MMP-9) (Figure 3D), inducible nitric oxide synthase (iNOS) (Figure 3E) and transforming growth factor-β (TGF-β) (Figure 3F) in CBD tissues, as compared to the vehicle treated rats.