Figure 9.

Mechanisms of antioxidant and anti-inflammatory effects of T. algeriensis extracts. Oxidative stress is associated with increased lipid peroxidation product (MDA) and decreased antioxidant enzyme activities such as SOD, GST, and CAT and nonenzymatic antioxidants such as GSH. Increased oxidative stress is a trigger for release of inflammatory cytokines such as TNF-α and IL-1β which increase p38 and subsequent phosphorylation and translocation of NF-κB to the nucleus and subsequent transcription of genes responsible for formation of inflammatory cytokines creating a vicious cycle of inflammation. Furthermore, oxidative stress activates inflammatory enzymes such as LOX and COX with subsequent increase in both leukotriene and PG syntheses, respectively. T. algeriensis through its potent antioxidant effects can suppress all these inflammatory pathways and thus protect susceptible tissues against oxidative and inflammatory reactions. Abbreviations: LOX: lipoxygenase; COX: cyclooxygenase; LT: leukotrienes; PGE2: prostaglandin E2; GSH: reduced glutathione; GST: glutathione transferase; CAT: catalase; SOD: superoxide dismutase; MDA: malondialdehyde; IL-1β: interleukin-1β; IL-6: interleukin-6; NF-κB: nuclear factor kappa B; Nrf–2: nuclear factor erythroid 2; p38: mitogen-activated protein kinase; TNF-α: tumor necrosis factor.