A team of Indian researchers from International Centre For Genetic Engineering And Biotechnology, JNU, has been able to achieve 100-fold reduction in TB bacterial load in lungs of mice after 60 days of treatment using bergenin — a phytochemical isolated from tender leaves of sakhua or shala tree (Shorea robusta). Unlike the regularly used antibiotic drugs that target the TB bacteria, the bergenin compound modulates the immune system to kill the bacteria found inside the macrophages (a type of white blood cells). The results were published in the journal Frontiers in Cellular and Infection Microbiology.
The researchers undertook several studies to understand the mode of action of the compound. The compound was unable to directly kill TB bacteria when treated with the compound. However, in the case of in vitro studies, the compound was able to kill the bacteria found inside infected cells. In mice infected with TB and treated with the compound, there was significant reduction in the bacterial load in the lungs. The bacterial load was 100-fold lower in mice treated with the compound compared with controls. These findings strongly suggest that the immune response enhanced by the compound is able to increase the capacity to clear the TB bacteria.