Hormetic Effects of Bioactive Compounds from Foods, Beverages, and Food Dressing: The Potential Role in Spinal Cord Injury

Abstract

Spinal cord injury (SCI) is a damage or trauma to the spinal cord resulting in a total or partial loss of motor and sensory function. SCI is characterized by a disequilibrium between the production of reactive oxygen species and the levels of antioxidant defences, causing oxidative stress and neuroinflammation. This review is aimed at highlighting the hormetic effects of some compounds from foods, beverages, and food dressing that are able to reduce oxidative stress in patients with SCI. Although curcumin, ginseng, and green tea have been proposed for SCI management, low levels of antioxidant vitamins have been reported in individuals with SCI. Mediterranean diet includes food rich in vitamins and antioxidants. Moreover, food dressing, including spices, herbs, and extra virgin olive oil (EVOO), contains multiple components with hormetic effects. The latter involves the activation of the nuclear factor erythroid-derived 2, consequently increasing the antioxidant enzymes and decreasing inflammation. Furthermore, EVOO improves the bioavailability of carotenoids and could be a delivery system for bioactive compounds. In conclusion, Mediterranean dressing in addition to plant foods can have an important effect on redox balance in individuals with SCI.

Figure 1

Representation of molecules involved in oxidative stress and inflammation after spinal cord injury (SCI). On the left are depicted as the antioxidants that are present in low concentrations, while on the right are molecules that are present at higher levels causing oxidative stress. SOD: superoxide dismutase; CAT: catalase; GPX: glutathione peroxidase; GSH: glutathione; UA: uric acid; Nrf2: nuclear factor erythroid-derived 2; O2^•−: superoxide; H₂O₂: hydrogen peroxide; HO^•: hydroxyl radical; NO^•: nitric oxide; ONOO⁻: peroxynitrite; p38MAPK: p38 mitogen-activated protein kinase; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; TNF: tumor necrosis factor; IL: interleukin.

Figure 2

Bioactive compounds that act on the Nrf2/NF-κB pathway. DOPET: 3,4-dihydroxyphenylethanol; EGCG: epigallocatechin-3-gallate; GR: ginsenoside R; IκB: inhibitor κB; Keap1: Kelch-like ECH-associating protein 1; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; Nrf2: nuclear factor erythroid-derived 2; SCI: spinal cord injury.