Dengue treatment researched
WELLINGTON: New Zealandgrown papaya is being studied to find out if an extract from its leaves could be an effective treatment for dengue fever.
The first extracts from the leaves of the fruit grown at a Northland research orchard are now part of a clinical study at universities in the UK and in Asia.
The project is spearheaded by Queenstown company Fuller Young International.
Managing director Raymond Young said research and development within New Zealand has been supported by Crown institutes, Plant and Food Research and Callaghan Innovation.
Mr Young said papaya had long been used in traditional herbal remedies in tropical areas for illnesses associated with the mosquitorelated virus, plus general agerelated illnesses.
The genesis was a request from his Singaporebased daughter, who was concerned about the risks to her children from the dengue virus.
‘‘She’d heard that papaya extract worked against the dengue virus and we thought, ‘Maybe we should try some ourselves’, and that’s led us to five or six years down the track to actually growing it, and extracting compounds that show in the early clinical studies to overcome the virus.’’
Mr Young said noone really knew what was in the leaf that made it an effective treatment for the dengue virus, so they set about looking into extracts of leaf and how to make it more efficient.
Once they found out what it was, they began looking at methods of manufacturing, but soon discovered papaya was hard to obtain. ‘‘Although it’s grown in many places, to get it in reasonable quantities was hard, so we set about trying to grow our own papaya in Japan.’’
Mr Young had family connections in the country.
‘‘After a fiveyear investment in that we had our own papaya variety and we worked to see if it would grow in northern New Zealand.’’
After talking with Plant and Food Research, the company grew its first variety called Wakatengu, which was planted out in the spring before fruit and leaves were harvested before winter.
The 1ha plantation holds about 700 trees, similar in scale to the operation in Japan, but where the winters were much colder and the summers hotter.
‘‘It was very successful. We adjusted the growing method and got the same result.
‘‘We harvested the leaf and, working with Callaghan, we worked on extracting the active ingredient.’’
Mr Young said it was interesting that the compounds believed to be beneficial in treating the dengue virus were more potent in the leaves of the crop grown in New Zealand.