BCG is normally effective only against disseminated and meningeal TB in children—the immune response triggered by the vaccine doesn’t last into adulthood.
Sceptics dismiss home remedies all too readily, but scientific evidence now shows that at least one of these may have more than a germ of medical rationale.
Turmeric, or haldi, has long been celebrated in India as an immuno-booster. A study published in the journal Infection and Immunity—by researchers at the Jawaharlal Nehru University, in collaboration with KIIT University, Bhubaneswar, and Vanderbilt University School of Medicine, the US—finds that curcumin, a compound abundant in turmeric, enhances the body’s response to the BCG vaccine, which protects against tuberculosis. Mice studies showed that curcumin, in its nanoparticle form, prolongs the vaccine’s effect by inducing the immune system to guard against adult pulmonary TB. BCG is normally effective only against disseminated and meningeal TB in children—the immune response triggered by the vaccine doesn’t last into adulthood. Given TB kills 2 million annually, with most deaths happening in India, the discovery has considerable import.
The vaccine triggers the immune system to produce two types of immune cells against the TB pathogen—effector memory T-cells, and central memory T-cells. The first are part of the immediate immune response while the central memory T-cells help in longer-term protection. However, the concentration of the latter falls with time. Hence, BCG confers no protection to adults. Immunomdulators that increase the number of central memory T-cells in the body, therefore, are key to offering extended protection. This is where nanocurcumin becomes the prosaic white knight. Central memory T-cells’ differentiation into into effector memory T-cells is facilitated by the potassium-ion channel. Nanocurcumin blocks this channel, and thus changes the ratio naturally maintained between the two memory T-cells. Curcumin also enhances the various functions (autophagy, and regulation of inflammatory cytokines) of the antigen-presenting cells of the immune system, such as macrophages and dendritic cells. It also causes an enhancement in the number of TB-specific acquired central memory T-cells of the Th1 and Th17 lineages. Nanoncurcumin also impedes Th2 and Tregs cells that inhibit the activity of Th1 and Th17. Mice treated with nanocurcumin, the study found, had significantly lower bacterial load in their lungs and spleen than the controls .
This is not the first study to discuss the effects of curcumin (read haldi) in battling TB. Earlier this year, a paper by Iranian medical researchers also discussed curcumin’s immunomodulatory role. There are other signs of the West, where faith in modern medicine is unshakeable, waking up to some of the wisdom of traditional medicine. There is ongoing and published research on the anti-microbial properties of tulsi, and of neem. The 2015 Nobel in Medicine for Tu Youyou is a proxy nod to traditional Chinese medicine (TCM), having been given for research on the role of artemisinin in treating malaria—artemisinin is a derivative of sweet wormwood, widely described in texts on TCM. While all the “wisdom of the ancients” may not ring true the way it has for haldi or artemisinin, policymakers and science advocates would do well to take the loud scepticism of traditional medicine a bit sceptically, lest they miss a big reveal like haldi’s while the West rushes to appropriate intellectual property rights. Indeed, many may have mocked, rightly or wrongly, prime minister Narendra Modi for calling Ganesha’s head transplant the first example of “plastic surgery”, but that Columbia University’s Irving Medical Centre talks of the ancient Indian text Sushruta Samhita containing detailed instructions for performing complex surgical procedures—including three types of skin grafts and reconstruction of the nose—should make one think.