Indian researchers used ayurvedic metallic preparations known as 'bhasmas' to develop nano-particle-based drug to treat diabetes.
Oral administration of zinc oxide nano-particles (ZON) resulted in significant reduction of blood glucose levels and increased insulin levels, they claim in a report published in a recent issue of the journal "Evidence-Based Complementary and Alternative Medicine".
"These results, reported for the first time, warrant further investigation for the development of ZON as an anti-diabetic agent," said, Kishore Paknikar, director of ARI and one of the authors.
In Ayurveda, metals that go through a purification and incineration process that turns them into ash are called 'bhasmas', which literally means ash. They are indicated for the treatment of several diseases. For instance, zinc-based bhasma (Jasada bhasma) is mentioned in ayurveda as the treatment of choice for diabetes.
To verify this, the ARI researchers synthesized Jasada bhasma using traditional method and carried out a study to evaluate its efficacy in treating rats in whom diabetes was induced chemically.
In case of Type-1 diabetic rats, Jasada bhasma treatment showed reduction of blood glucose levels comparable to the drug glibenclamide, Paknikar said.
In the case of Type-2 diabetic rats, treatment with Jasada bhasma was found to be comparable to the widely used drug pioglitazone.
While the study confirmed the anti-diabetic effect of Jasada bhasma, its synthesis involves laborious and time consuming procedures, Paknikar said. Therefore, the researchers decided to look at the composition of Jasada bhasma.
Using modern physico-chemical techniques such as scanning electron microscopy and X-ray spectroscopy, the researchers found that the traditionally prepared Jasada bhasma consisted of zinc oxide in the form of nano-particles of the size 200-500 nanometre (one nanometre is one billionth of a metre).
"Since our studies clearly demonstrated the presence of ZON in Jasada bhasma, we hypothesized that ZON should also be able to exert anti-diabetic effects. An elaborate study was therefore undertaken to investigate this possibility," Paknikar said.
For this study, zinc oxide nano-particles, of less than 10 nanometres in size, were procured from a company in the US.
Oral administration of ZON, after four weeks of treatment, resulted in improved glucose tolerance, higher serum insulin, reduced blood glucose and reduced triglycerides in diabetic rats, the researchers reported.
Most of the currently available drugs for the treatment of Type-2 diabetes are used in combination with each other or with insulin, increasing the treatment cost. None of them is free from adverse effects, Paknikar said.
"A single, cost-effective, oral, anti-diabetic treatment with minimal side effects is the need of the day."
According to Paknikar, it is evident from the rat studies that ZON can elicit potent anti-diabetic activity.
Administration of ZON resulted in sustained release of zinc up to 24 hours -- which is a desirable pharmacokinetics profile -- and was found non-toxic up to 100 times the efficacy dose, he added.
The researchers said that on the basis of their findings they were proposing "a new chemical entity - zinc oxide nano-particles -- as a promising anti-diabetic agent warranting further studies".
The report further said that the bhasma-inspired drug discovery approach followed by them to identify a diabetic drug could also be used to develop metal based nano-medicines for several other diseases.
"Once the active ingredients of bhasmas are identified, these metal oxides can be synthesized and evaluated as a new chemical entity in modern drug discovery."