科学美国人60秒:Vitamin C Kills TB Cells

“We’ve discovered that vitamin C kills Mycobacterium tuberculosis cells.” TB researcher William Jacobs, with the Albert Einstein College of Medicine in the Bronx. “And in fact it works not only on the multidrug-resistant strains, but the totally drug-resistant strains as well.”

Jacobs was studying whether the TB drug isoniazid was being inactivated by the presence of a particular amino acid, cysteine, which in chemical terms acts as a reducing agent, by donating electrons.

“So we added this with the isoniazid expecting that we’d get resistance. And to our surprise it actually led to sterilization. This reducing agent actually induced free radicals.”

Free radicals are highly reactive chemical entities that can damage cells.

“And it was the free radicals that were killing the TB. We decided to try another reducing agent, vitamin C. We saw that just like the other reducing agent, it in combination with isoniazid sterilized the culture. Even more surprisingly, was when we just had vitamin C alone, we discovered that vitamin C kills tuberculosis. [Catherine Vilchèze et al., Mycobacterium tuberculosis is extraordinarily sensitive to killing by a vitamin C-induced Fenton reaction, in Nature Communications]

“We’ve only been able to demonstrate this in a test tube, and we don’t know if it will work in humans. But before this study, you wouldn’t have even thought about trying in humans.”

—Steve Mirsky

[Scientific American is part of Nature Publishing Group.]