Turmeric against filaria
doi:10.1038/nindia.2010.6 Published online 29 January 2010
Wild turmeric could stop the spread of lymphatic filariasis, a disease caused by a worm and transmitted to humans by mosquito, new research has found.
Researchers from the Vector Biology Research Lab of University of Mysore in Karnataka have found that wild turmeric can destroy the larvae of the mosquito (Culex quinquefasciatus) that ferries the parasitic worm (Wuchereria bancrofti) which triggers lymphatic filariasis in humans.
With drugs showing toxic effects and no vaccine in sight, controlling lymphatic filariasis has been difficult for public health workers. Researchers have turned their attention towards controlling the mosquito responsible for outbreak of filariasis. But insecticides have unleashed the negative impact on biosphere with exposure in humans linked to various forms of cancers. In addition, the mosquito has also shown resistance to insecticides.
This led the researchers to search plants having ingredients to kill larvae or adult mosquito. Wild turmeric (Curcuma aromatica Salisb), a traditional Chinese herb, has already shown its lethal activity against mosquitoes and larvae. But no report has identified active compounds from the extracts of this herb.
Crude plant extracts of wild turmeric were found to contain 9-oxoneoprocurcumenol and neoprocurcumenol, two organic compounds, which the researchers used on the larval stage of Culex mosquito.
Larval mortality ranged between 10% and 90% with concentration ranging from 4.0 to 8.0 ppm (parts per million) for 9-oxoneoprocurcumenol and 10.0 to 18.0 ppm for neoprocurcumenol. Between the two, the first one produced highly significant larvicidal effect.
Both the products gave pleasant aroma similar to cinolic. It was interesting that the neoprocurcumenol exhibited less efficacy than the parent extract. This may be due to the synergistic activity of the mixture of the bioactive constituents present in the extract.
"Our result suggests that crude extracts are better than active isolates," says lead researcher V. A. Vijayan from the Vector Biology Research Lab, Department of Studies in Zoology of University of Mysore, Karnataka. Wild turmeric is easily available in the market. One or two spoons of this powder in stored water (of flower vases, plant pots and even drinking water) could inhibit the breeding of mosquitoes, he says.
The team had earlier shown that the extracts of wild turmeric could be used in combination with other plant extracts.
- Madhu, K. S. et al. Efficacy of bioactive compounds from Curcuma aromatica against mosquito larvae. Acta Tropica 113, 7-11 (2010) | Article | PubMed |
Madhu, K. S. et al. Evaluation of the larvicidal efficacy of extracts from three plants and their synergistic action with propoxur against larvae of the filarial vector Culex quinquefasciatus (Say). Toxicol. Environ. Chem. 92, 115-126 (2010) | Article |