An experiment that was being conducted to check for Isoniazid resistance to Mycobacterium tuberculosis in fact turned turtle and an accidental discovery of Vitamin C killing the bacteria was made.
A reducing agent cysteine along with isoniazid was added to a culture medium growing mycobacteria expecting the bacteria to develop drug resistance. Instead the culture was killed. The cysteine was then replaced with another reducing agent, Vitamin C. Lo and behold!! The result was the same.
More drama was to unfold. Isoniazid was left out and Vitamin C was left alone. When the result was same yet again, it was concluded that Vitamin C kills mycobacteria.
Drug resistant strains also tested with this vitamin yielded the same outcome.
There has been a long-standing observation that vitamin C is toxic to M tuberculosis, a Gram-positive bacterium. Experiments in the 1930s showed that only 6% of guinea pigs exposed to the bacteria and given tomato juice became infected compared with 70% of guinea pigs not given the vitamin C–rich juice.
In vitro experiments conducted in 1950 confirmed the effect of the vitamin on bacterial cultures, and a study in 2011 correlated vitamin C content of various medicinal plants with antibacterial effects.
TB was declared a global health emergency by the World Health Organisation (WHO) 20 years ago, but remains a leading cause of death by an infectious disease despite a 41% drop in the death rate from 1990 to 2011.
Further research into the potential uses of Vitamin C in TB treatment is definitely the need of the hour since it is "inexpensive, widely available and very safe to use."