Scientists Aroused by Viagra’s Other Uses
The little blue pill that is extending men’s sex lives is hardly a one-trick pony. Scientists are discovering other uses for Viagra and will start clinical trials to use the erectile dysfunction drug to fight obesity and cancer.
Many people may not be surprised that Viagra is linked to weight loss given its intended purpose. But when rats were dosed with sildenafil, the active ingredient in the little blue pill they didn’t gain weight. And it’s not because they were busy burning calories through procreation.
Scientists at the Max Planck Institute in Germany found that Viagra mice burn more excessive fat because they are using more energy. Research published in The Journal of the Federation of American Societies for Experimental Biology showed that sildenfil citrate helps turn white fat cells into brown or brite fat cells. Brite cells burn off as energy, releasing heat, whereas white cells are the reserves that the body has on hand just in case the food supply runs out.
Dr. Alexander Pfeifer fed Viagra to the mice for seven days and saw that the undesirable white fat cells — the sub-dermal underlier in love handles — were converted into brown fat cells at a higher rate than usual. He tells the New York Times the research is “very promising.” But he cautions that the FDA has only approved Viagra for one reason so far. Using it to fight obesity or anything else is a ways off. He adds, “The idea to have one pill and then obesity goes away, that is a dream, but not easy to come by. What we are up to is basic research in mice.”Viagra was originally developed as a heart medication and then after discovering one very big side-effect it was repositioned as a drug the solve a growing problem of erectile dysfunction.
Now scientists are exploring other avenues of use for the little blue pill.
Combining green tea with Viagra may stop cancer from growing. Japanese researchers are going to begin testing this theory later this year. Here’s how it works.
In 2004 Hirofumi Tachibana discovered that an enzyme in green tea suppressed cancer activity. But doctors refuted its potency. Dr. Tachibana suspected that the human enzyme PDE5 might be weakening its effectiveness. So he went to work trying to figure out how to inhibit the enzyme to turn green tea into a better cancer fighter.
It turns out that Viagra and other erectile dysfunction drugs block PDE5. So Tachibana injected the cocktail into mice with blood cancer and watched as the cancer cells stopped growing. When he tried the same technique on mice implanted with breast cancer cells the malignant cells stopped growing too.
According to a study published last week in the Journal of Clinical Investigation Tachibana’s treatment also proved more effective than current cancer treatments in stopping the growth of pancreatic, stomach and prostate tumors.
And the National Institutes of Health is going back to sildenafil’s original purpose — treating heart disease. NIH is funding a multicenter trial of sildenafil for the treatment of heart failure patients.
One of Viagra’s side-effects is widening arteries enough to lower blood pressure. That side-effect may also prove another future use — fighting hypertension. Other possible medical applications include fighting mountain sickness, allowing exercise in low-oxygen environments and improving circulation in fingers and toes. Some of these suggested uses are outlined in the August 2007 issue of Harvard Me’s Health Watch
Then there’s Ya’acov Leshem. The Israeli plant physiologist discovered that dissolving the little blue pill in water will keep flaccid flowers standing tall up to a week after they should have wilted. This could be a significant boost to the cut-flower industry that normally deals with very short shelf lives.
British television gardener David Domoney says, “You only need a tiny amount of Viagra to stiffen things up nicely.”
The same process in Viagra that relaxes the muscles in blood vessels also slows down the dying process in plants and may help treat jet lag, heart failure, obesity, premature ejaculation, diabetes symptoms, multiple sclerosis, pain, premature birth, chronic pelvic pain, memory loss and cancer.Finding new uses for Viagra and other drugs is part of the pharmaceutical drug development pipeline and is called recycling or repurposing.
Drug repurposing has been gaining popularity among big drug makers in the last few years. After all, it’s much cheaper to recycle an existing drug for a new purpose than it is to create one from scratch. The drug development cycle takes anywhere from ten to 15 years, costs about $1.3 billion and about 95 percent of the drugs fail.
But those failures just may be the future winners.
In November Roche decided to allow the Broad Institute to review 300 dead drugs it has in its portfolio to see which can be revived and turned into a new blockbuster.
Of course, Pfizer, the company that makes Viagra is all too familiar with this process. After the heart medication it was developing flopped it was almost shelved as a failure. In addition to giving healthy test subjects erections days after the pill was taken and muscle aches it had a negative interaction with nitrates, which were commonly used to treat angina. Sildenafil citrate decreased blood pressure in heart patients and was a contributing factor in it being discontinued as a heart medication.
Ian Osterloh was on the team that discovered a lackluster heart medication would make a brilliant erectile dysfunction drug. He says, “I was as surprised as anyone when my research on a potential treatment for heart disease revealed a side effect that sparked a sexual health revolution.”
Now other scientists are hoping to use the molecule called UK-92480 to combat the obesity epidemic and to stop cancer in its tracks.