MPO and ulcerative colitis: Elmaksoud et al. [46] previously demonstrated, besides the anti-inflammatory and antioxidant effects, with downregulation of pro-inflammatory cytokines, a reduction in colon malondialdehyde, myeloperoxidase and nitric oxide levels, and an increase in superoxide dismutase, catalase, and glutathione peroxidase levels, also the anti-apoptotic activity of an olive leaf extract standardized with 25% hydroxytyrosol in an experimental model of ulcerative colitis, reporting BAX downregulation and Bcl-2 upregulation.