Four Iranian scientists led by Abdolali Mohagheghzadeh of Shiraz University of Medical Sciences reviewed literature from 50 countries across five continents for remedies administered in the smoke form. "The advantages of smoke-based remedies are rapid delivery to the brain, efficient absorption by the body and lower costs of production,' says their September 2006 paper in the Journal of Ethnopharmacology. They stressed lack of knowledge of medicinal smoke and the vast potential of using it in modern medicine as a form of drug delivery.

"Most ancient drugs are still being used in the same dosage and form although smoking today is more often a form of drug abuse than therapeutic use,' they say, citing the example of marijuana. In India, they recorded that the smoke from mango leaves and date is used for treating certain skin diseases; smoke of custard apple leaves are used to treat convulsions. For modes of delivery, they found 71.5 per cent was through inhalation, 24.5 per cent through smoke directed to specific body part or organ, and only 4 per cent as ambient smoke (see p58).

Plant pathologist Y L Nene of the Asian Agri-History Foundation in Hyderabad says the size of the active particle of the plant is reduced to the microscopic scale during burning; this helps its delivery in the body. Smoke can also preserve seeds, assist germination, and enhance seedling vigour besides protecting it from harmful microbes.