From the article...
Approved by the US Food and Drug Administration as a first-line oral treatment for MS earlier this year, BG12 has been used for decades as a treatment for psoriasis. It likely acts as an immunomodulating agent, inhibiting proinflammatory cytokines and chemokines and promoting anti-inflammatory activity. It also acts as an antioxidant and may also have a neuroprotective effect.
This statement couldn't further from the truth. Dimethylfumarate is not an antioxidant. Not in the sense that vitamin C, vitamin E, r-lipoic acid and others are antioxidants. Indeed, it is a strong oxidant that's highly reactive against thiol groups such as those in glutathione through a chemical reaction known as Michael Addition. Dimethylfumarate depletes intracellular glutathione making cells think that they're under oxidative stress which induces the Nrf2 transcription factor. This enters the nucleus and induces the production of several antioxidant defense enzymes. Unlike chemical antioxidants, the antioxidant enzymes can quench many more free radicals. While this might lead to an overall antioxidant effect, calling dimethylfumarate an antioxidant is simply incorrect. Even in spite of the induction of antioxidant cellular defense enzymes, chronic glutathione depletion has been reported.
Here is one post from a thread discussing dimethylfumarate. There are many others. general-discussion-f1/topic17487.html#p173757