An extract from an african leaf fungus may someday set diabetics free, replacing painful and endless insulin injections with a simple pill.
Diabetes occurs when the body can't produce or process insulin, a key protein regulating how the cells use glucose. Because digestive juices break down insulin, diabetics must inject it directly into the bloodstream. Biochemist Bei Zhang and her team at Merck Research Laboratories screened 50,000 chemical combinations searching for a molecule that could duplicate insulin's effects yet survive a trip through the stomach. The researchers finally found their miracle molecule in a sample of a leaf fungus the company collected outside Kinshasa, in the Democratic Republic of Congo.
Just like insulin, the fungal compound kick-starts a chain of events in the cells that allows them to process glucose. But the small molecule is not a protein, so "it is not subject to the action of digestive enzymes," says Zhang. There have been no major side effects in animal tests, and the fungus nearly matched insulin at suppressing blood sugar levels when the researcher fed it to diabetic mice.
Zhang isn't saying when human trials might begin, but she is confident that the fungal extract or some variant will prove successful. "We've demonstrated that it's feasible to selectively activate the insulin receptor," she says. So other, still more effective drugs may turn up among plants of the jungle. Zhang plans to leave no stone--or fungus--unturned in her search for a diabetes pill.
