Vitamin C could help cut TB treatment time

Every year, over 130,000 Kenyans contract tuberculosis, but only 82,000 are diagnosed and treated.

For those diagnosed and put on treatment, the regimen can last up to six months, raising challenges of adherence, and the resultant possibility of developing drug-resistant TB.

Treatment of multidrug resistant TB takes up to two years, and requires use of toxic second-line drugs with severe side effects.

Now researchers have discovered that taking vitamin C alongside tuberculosis drugs could reduce the amount of time needed for the drugs to work.

The researchers treated mice infected with Mycobacterium tuberculosis (Mtb) with anti-tuberculosis drugs alone, vitamin C alone and vitamin C combined with TB medication.

They then measured levels of Mtb at four and six weeks after treatment. They found that vitamin C alone had no effect, but when combined with first-line tuberculosis drugs isoniazid and rifampicin, the drugs worked faster to reduce Mtb levels, than when used without the vitamin.

Further experiments in infected tissue cultures returned similar results, shortening treatment time by seven days.

DRUG RESISTANT

Lead researcher William R Jacobs Jr said that the results were important because the prolonged treatment of tuberculosis results in “some treatment mismanagement, potentially leading to the emergence and spread of drug-resistant TB.”

Long-term TB treatment is prescribed because a subpopulation of Mtb cells can form Mtb persister cells, which are dormant cells that are virtually impervious to antimicrobials.

Previous studies had shown that low concentrations of vitamin C stimulate respiration of cells and prevent the formation of Mtb persister cells.

When TB drugs are added to the mix, the increased respiration leads to rapid death of the cells, “thus enabling the action of isoniazid and rifampicin.”

Tuberculosis is a major worldwide public health problem, infecting the lungs and other organs.

In 2016, 10 million people around the world contracted tuberculosis, and 1.7 million died from it. In Kenya, the National TB Prevalence Survey of 2015 showed that there were 558 cases for every 100,000 people and most were not co-infections with HIV.

“A clinical trial of vitamin C with TB chemotherapies could demonstrate that such an adjunct therapy could reduce patients’ exposure to toxic TB drugs and also reduce the spread of TB from infected individuals,” said Dr Jacobs.

One infected and untreated person can spread the germs to up to 15 people, fueling the spread of the disease. Therefore, a shorter and more effective treatment regimen is a welcome breath of fresh air.

The research was published in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology.