London, July 8 (IANS): Scientists have identified an over-the-counter antacid that can help fight against the global pandemic tuberculosis that kills nearly 1.5 million people a year.

The team from the Swiss Federal Institute of Technology in Lausanne, Switzerland found the antacid called Lansoprazole to be effective against M. tuberculosis but only when the bacterium grows inside cells.

The researchers examined the underlying biology and found that Lansoprazole kills the bacterium after the human cells convert it into a sulphur-containing metabolite. It targets a particular enzyme that is crucial for the bacterium to produce energy, thereby killing it off.

"Being highly active against drug-resistant strains of M. tuberculosis, this novel class of drugs provides us with an excellent opportunity to treat tuberculosis," said lead researcher Stewart Cole.

In addition, when the scientists tested Lansoprazole against a wide range of other bacteria, it proved to be highly selective for M. tuberculosis, said the study published in the journal Nature Communications.

The EPFL researchers used a method they had previously developed which can reflect what happens when the bacterium infects a lung much better than conventional screening assays used in tuberculosis research.

The scientists screened a large panel of already approved drugs, and identified the blockbuster antacid Lansoprazole, known commercially as Prevacid, as a potential anti-tuberculosis medication.

Lansoprazole belongs to a class of drugs known as "proton-pump inhibitors" that keep the stomach from pumping too much acid, thus preventing heartburn and ulcers.