The research, conducted by a team of researchers at the Nelson Mandela Metropolitan University (NMMU) in Port Elizabeth, discovered that a Sutherlandia frutescens extract lowered the blood-sugar levels of diabetic rats, reversed their insulin resistance and decreased intestinal glucose uptake.
Sutherlandia frutescens is a hardy herbal plant that has for over a century been used by local peoples medicinally for treating a variety of ailments, including diabetes.
Investigate efficacy of traditional herb
The aim of the NMMU study was to verify the claims made for diabetes treatment and to investigate the safety of the plant’s usage. The study was conducted over a six year period.
Using a specific Sutherlandia frutescens extract, the team managed to reduce the blood sugar levels of diabetic rats to normal within a few days. Rats were used because the development of diabetes in these animals is very similar to that of humans.
The results of the findings were published in the Journal of Ethnopharmacology.
The University of the Western Cape undertook a clinical toxicity study on the plant in 2007 and declared it safe for human use.
The plant has however not yet been shown to be effective for the treatment of diabetes in humans.
Sugar levels return to normal
Dr Saartjie Roux, who conducted the research alongside Dr Maryna van de Venter and a team of post-graduate students in the Department of Biochemistry and Microbiology at NMMU, also found that the rats’ blood sugar levels remained stable and within normal range. The levels also did not drop too low, as often occurs when diabetics accidentally inject too much insulin.
"The wonder of this plant is that it never decreases the blood sugar levels too much," said Roux. "It normalises the physiological levels." This means that it won't cause hypoglycaemia (when sugar levels become dangerously low), even when used in conjunction with diabetes medication.
When investigating the plant’s interaction with a popular type-2 diabetes medication, the researchers found that Sutherlandia frutescens decreased intestinal glucose uptake more significantly than the medication. No drug interactions or unwanted side effects were evident when the plant extract was administered simultaneously with the diabetics drug.
They also studied the effects of Sutherlandia frutescens on blood sugar when insulin was administered simultaneously, and found that the blood sugar remained at stable, normal levels and neither compound was influenced by the other.
More possible benefits
The study suggests that Sutherlandia frutescens can restore a pre-diabetic state in rats (the earlier stages before full-blown diabetes develops) to normal levels of blood glucose and insulin. It further indicated that Sutherlandia frutescens could reverse insulin resistance in rats by increasing glucose uptake by muscle and fat tissue.
Identified compounds contributing to the efficacy of Sutherlandia frutescens are L-canavanine, a non-protein amino acid; pinitol, a type of sugar that occurs naturally in certain plants; GABA, an amino acid and important neuro-transmitter (brain messenger); and asparagine, a non-essential amino acid.
It is thought that the anti-diabetic action of Sutherlandia frutescens is brought about by the combined action of more than one chemical compound in the plant and this research is ongoing.
Source: Journal of Ethnopharmacology