Table 1.
Therapeutic effects of antioxidants on degenerative disc cells and intervertebral disc degeneration.
| Antioxidant | Therapeutic effects | |
|---|---|---|
| Polyphenols | Resveratrol (RSV) | Inhibition of NP cell death and senescence [123, 124] Promoted NP cell proliferation [120, 123] Downregulates matrix protease and cytokine expression [125–128] Enhanced the synthesis of PG in NP cells ([125], [128], [126], [127]) |
| Polyphenol epigallocatechin 3-gallate | Inhibited NP cell senescence and apoptosis [52, 129] Inhibited the expression of cytokines and MMPs in NP cells ([52], [129]) |
|
| Ferulic acid (FA) | Inhibited the accumulation of ROS in NP cells [130, 131] Upregulated the expression of aggrecan and type II collagen [130, 131] Downregulated the expression of MMP-3 ([130], [131]) |
|
| Cordyceps militaris | Inhibition of ROS production [132, 133] Inhibition of NF-κB pathway activation [134] |
|
| ROS scavengers | Pyrroloquinoline quinone (PQQ) | An important cofactor for mitochondrial dehydrogenase redox ROS scavenger [135, 136] Inhibited NP cell apoptosis [137] Inhibited downregulation of type II collagen and aggrecan in NP cells [138] |
| Fullerenes | Powerful ROS scavenger ([139], [140]) | |
| Fullerol | Reduction of ROS production in NP cells [141] Attenuated upregulation of matrix proteases and downregulation of type II collagen [142] Promoted matrix synthesis [141] Inhibited ectopic ossification [142] |
|
| Nonenzymatic antioxidants | Glutathione (GSH) | Inhibited NP cell apoptosis and stromal breakdown [141, 143] Reduced OS production ([49], [94]) |
| N-Acetylcysteine (NAC) | Reduced ROS levels [49, 94] Inhibited the activation of inflammatory signalling pathways [49, 94] Inhibited catabolism of intervertebral disc cells [49, 94] Inhibited autophagy and apoptosis of intervertebral disc cells [49, 94] Improved premature aging ([49], [94]) |
|
| Oestrogen | Oestrogen | Enhanced antioxidant capacity [144] Upregulation of aggrecan and type II collagen expression [145–147] Downregulates the expression of MMP-3 and MMP-13 [148] Reduces oxidative damage and promotes autophagy ([149], [137]) |