No more needles

日期:2019-03-08 02:06:09 作者:戈躬 阅读:

By Jonathan Knight PILLS containing a chemical from a tree mould may one day replace insulin injections for people with diabetes. In diabetic mice, the chemical reduces high blood sugar levels to normal. Diabetics need insulin to prevent their blood sugar rising to a dangerously high level. Because insulin is broken down in the stomach, it can’t be taken orally. So diabetics often need several unpleasant injections of the hormone each day. To try to find an alternative, biochemist Bei Zhang and her colleagues at Merck Research Laboratories in Rahway, New Jersey, screened 50 000 natural and synthetic compounds for one that would mimic insulin. One compound, from an extract of the tree fungus Pseudomassaria, activated the insulin receptors in cultured cells. It also enhanced the effect of insulin itself. When fed to obese mice with symptoms of diabetes, the chemical did not break down in the stomach and reduced the amount of glucose in the animals’ blood almost to normal levels ( Science, vol 284, p 974). Several years ago, Chris Orvig of the University of British Columbia in Vancouver helped develop a drug containing the metal vanadium that amplifies the effects of insulin. The drug is now in clinical trials. This kind of drug would be most useful for types of diabetes in which some natural insulin still circulates in the body, Orvig says. In contrast, by mimicking insulin, the Merck compound might be useful in all types of the disease. “It’s very promising,” says Orvig. Zhang cautions that while the new compound works in rodents, this does not mean it will work in people. “We are still in the early stage of preclinical studies,