|
Thursday, 23 April 2009 00:10 |
As a child in Sri Lanka, Mario Pinto would see his grandfather drink a tea brewed overnight with parts of an indigenous shrub. It was taken to control high blood sugar levels.
Decades later, Pinto, who is vice-president of research at Simon Fraser University, has a new scientific appreciation for that particular slice of India's traditional Ayurvedic medicine.
He and his colleagues have discovered exactly how extracts from the Salacia reticulata plant work to lower blood glucose levels in type-2 diabetics.
For hundreds of years, type-2 diabetes has been managed by Ayurvedic practitioners who have based their prescribing of plant remedies on oral traditions and spiritual texts.
Pinto decided to subject the treatments to rigorous scientific research and, with his two SFU co-authors, Jayakanthan Kumarasamy and Sankar Mohan, the chemical structure of the active compounds in the plant were identified and then synthesized.
On Tuesday, the trio's work was published in the Journal of the American Chemical Society, paving the way for such compounds to eventually be made into a drug to not only treat type-2 diabetics, but also prevent the disease.
"It is noteworthy that aqueous extracts of the roots and stems of the plant S. reticulata have been traditionally used in the Ayurvedic system of Indian medicine for the treatment of type-2 diabetes," the study states.
"Recent clinical trials on human patients with type-2 diabetes mellitus using the aqueous extract of the same plant have indicated good glycemic control and side effects comparable to the placebo control group."
Interviewed by phone from an airport between flights, Pinto said: "Yes, you can say I am going back to my roots, literally."
Pinto said after he saw his grandfather drinking the tea, "I didn't give it another thought for many years until I read a paper in 1998 by a Japanese group that had described the same class of compounds isolated from this natural remedy."
That's when Pinto got to work in his lab synthesizing compounds and proving how they lower blood glucose levels in rats.
Pinto, regarded as a pioneer in the field of chemical biology, is one of the founding members of the Vancouver-based Centre for Drug Research and Development, where animal research is continuing.
The compounds work by slowing the action of enzymes in the intestinal tract, thus reducing glucose levels in the blood after eating. "The enzymes, called glucosidases, break down different types of starch [carbohydrates] into glucose and are absorbed through the intestinal wall into the bloodstream. In type-2 diabetics, that mechanism is compromised," said Pinto.
"The next steps are twofold," he said, referring to further research. "We can go the western medicine, regular drug discovery route, but first we have to show prevention of the onset of type-2 diabetes in rats that are prone to getting this form of diabetes and then also show blood glucose control in rats that have type-2.
"Initially, we would look at this for disease control or treatment but our hope is that it may prevent the onset of the disease in individuals who are susceptible."
Scientists must validate the active ingredients in those herbal extracts and then seek to have all formulations "blessed by the Food and Drug Administration."
Pinto foresees a scenario in which people in China and India continue to use a purified, scientifically validated -- and cheaper -- herbal formula, while diabetes patients in the western world lean toward a pharmaceutical drug that either replaces or complements existing treatments that some people cannot take because of side-effects.
Mohan said a placebo-controlled, 2004 Journal of Ethno-Pharmacology study on 51 type-2 diabetes patients in Sri Lanka was one of the first to prove the tea (called Kothala Himbutu) was an effective, safe treatment.
|
