The kitchen cabinet may be the lab of the future. Over the years, evidence is slowly accumulating that plants such as turmeric and gooseberry may not just be useful for healthy skin or tempering an upset stomach but be harnessed to solve globally intractable diseases such as malaria.
According to an estimate last week by the Bill and Melinda Gates Foundation, malaria kills 7,25,000 people annually, making mosquitoes the “world’s deadliest animal”. Artemisinin, the mainline drug now used to treat malaria — and itself a plant extract — works by destroying the malarial parasite. Growing evidence from East Asia, however, suggests that the malarial parasite has found ways to beat artemisinin. That leads to recrudescence, or parasites lurking within the body and then launching a fresh infection, which is increasingly becoming a hallmark of malarial infections across the world.
Turmeric, a new weapon Turmeric has been known for millennia as a spice and herbal medicine but chemical analysis suggests that it is rich in curcuminoids, molecules that are now known to be a potent source of anti-inflammatory compounds. Govindrajan Padmanabhan, 78, a former director of the Indian Institute of Science and biochemist at the institute, holds that curcumin — the main curcuminoid in turmeric and responsible for its yellow colour — has an as-yet-unexplained way of triggering the body’s immune system to produce antibodies (or ammunition) that can buffer damage by the malarial parasite.
Artemisinin is always administered in combination with older malaria drugs to delay resistance. Dr. Padmanabhan, based on decades of work, has found that curcumin, combined with artemisinin, can prevent malarial recrudescence. His team has tested this combination on animals and noted 100 per cent recovery in all those artificially infected in the lab with cerebral malaria. “Curcumin alone can’t save them but we found that the animals recovered with only half the artemisinin now present in standard dosage,” says Dr. Padmanabhan.
The true test will begin late this year, he says, when nearly 100 patients will be part of a study. This will make it one of the rare full-fledged trials to follow the clinical drug-testing regime for testing a herbal extract in India.
All eyes on gooseberry Turmeric — also being tested as a potential treatment for cancer and other ailments — is not the only potential herbal anti-malarial weapon. The C. Abdul Hakeem College, Melvisharam, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi and Vellore Institute of Technology University have been studying various medicinal plants and are zeroing in on gooseberry leaves. Crude extracts of leaves of Phyllanthus acidus and Phyllanthus emblica (variants of the gooseberry family) showed “significant anti-plasmodial potency and the extracts are being characterized and standardized for bioactive constituents,” says a report of the Department of Biotechnology (DBT)-funded project.
Later this week, India pharma major Sun Pharma will formally announce a partnership with ICGEB to test a herbal drug that can potentially treat dengue, another mosquito-borne disease. The drug has been developed from Cissampelos pareira , a plant that is well known in Ayurveda and Chinese herbology.
K. Vijay Raghavan, Secretary, DBT, says the interest in plant trials comes from a more lenient view, in terms of the kind of tests required to prove a drug is safe and effective, by drug regulators towards plant-derived chemicals. Better technology over the last few decades also means well-known compounds can be tested more widely for their use as potential drug. “That gives a significant incentive for companies to patent and invest in developing drugs based on plant compounds,” he says.
jacob.koshy@thehindu.co.in
