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Viagra makes flowers stand up straight

Judy Siegel-Itzkovich , Jerusalem

Viagra (sildenafil citrate) is good not only for treating male impotence. Israeli and Australian researchers have discovered that small concentrations of the drug dissolved in a vase of water can also double the shelf life of cut flowers, making them stand up straight for as long as a week beyond their natural life span.

They have already tested Viagra on strawberries, legumes, roses, carnations, broccoli, and other perishables. In this latest research they found that 1 mg of the drug (compared with 50 mg in one pill taken by impotent men) in a solution was enough to prevent two vases of cut flowers from wilting for as much as a week longer than might be expected.

Professor Yaacov Leshem, a plant researcher at Bar-Ilan University in Ramat Gan, Israel, and Professor Ron Wills of the food technology department of the University of Newcastle, Australia, also patented a safe, cheap process for increasing the shelf life of fruit, vegetables, and cut flowers using nitric oxide. The produce and cut flowers were fumigated with the colourless, odourless gas, an environmental pollutant that in minute quantities acts as the body's most important signalling molecule.

The results of the applied research on nitric oxide were first fully reported in late 1998 in Plant Physiology and Biochemistry (1998;36:825-33) and have since been the topic of discussion at international conferences of the food storage and packaging industry. Professor Leshem will present his discovery at the opening plenary session of the September 1999 international conference on fresh cut produce in England.

An unexpected finding of Professor Leshem's group is that Viagra has a similar effect on plant ripening as it does on men's sexual organs. Viagra increases the vase life of flowers by retarding the breakdown of cyclic guanosine monophosphate (cGMP) (the production of which is mediated by nitric oxide).

Both chemicals could provide the food industry with entirely new, dramatically improved processes for preserving agricultural produce, Professor Leshem said.

"Nitric oxide is practically free and plentiful, with no identifiable side effects at the very low concentrations we used," he added. "Right now, Viagra costs much more but does have certain advantages over nitric oxidefor example, it's easier to use in cut flowers. It is now up to industry to develop the engineering methods for large scale, pretreatment of produce based on our discoveries."

(Credit: KEVIN SUMMERS/TONY STONE IMAGES) In need of some Viagra?