Vitamin C kills tuberculosis

Robbie Burns the wonderful Scots poet wrote that the best laid plans of both mice and men go astray and leave us with grief where we expected joy. Burns wrote it in a much more evocative brogue but that was his message. It’s true enough that when plans go wrong it can be painful and that the best way to make God laugh is to tell him your plans. It is also true, though, that out of plans gone astray can come some of the true magic of life and this was borne out in the activities of some researchers who recently found a surprising use for vitamin C.

The research journey began with the researchers from Albert Einstein College of Medicine, Yeshiva University, trying to establish how tuberculosis (TB) bacteria become resistant to the drug isoniazid, a frontline TB drug.

First the researchers observed that isoniazid resistant TB bacteria lack a molecule called mycothiol. They thought that maybe these resistant TB strains that don’t make mycothiol might contain more of an amino acid called cysteine. To test this theory, they got some TB bacteria that were not resistant to isoniazid and added cysteine and isoniazid to the cell culture. If they were right then the cysteine should help the TB bacteria become resistant to isoniazid.

The surprise result was that instead of developing resistance, the TB bacteria were killed off. Since cysteine is a “reducing” agent, they then tried another reducing agent, vitamin C. They found that again a combination of isoniazid and vitamin C killed off the bacteria. Then when they tried vitamin C on its own not only did it kill off drug-sensitive TB bacteria, it was also found to kill off multi-drug resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB).

The World Health Organization estimates that around 8.7 million people worldwide are infected with TB and that in 2011 around 1.4 million people died from it. These are laboratory tests at this stage but if they pan out in people then the promise is immense.

Sometimes the best things are those that you would never expect.