Rats supplemented with extracts from the root of the kudzu plant experienced reductions in cholesterol, blood pressure, blood sugar, and insulin levels, according to results published in the Journal of Agricultural and Food Chemistry.
Scientists in Alabama and Iowa suggest that the extract may play a role in the prevention or improvement of symptoms related to the metabolic syndrome, a condition characterised by central obesity, hypertension, and disturbed glucose and insulin metabolism. The syndrome has been linked to increased risks of both type-2 diabetes and cardiovascular disease (CVD). In the US alone, about 50 million people are affected by the metabolic syndrome.
According to the researchers, led by J. Michael Wyss, kudzu root extracts have recently become available in Western dietary supplements marketed primarily for women’s health.
“Although the exact mechanisms remain to be determined, the present results suggest that incorporation of kudzu root supplements into a diet modulates glucose, lipids, and blood pressure,” wrote the researchers, led by J. Michael Wyss.
“Because the supplement appears to have no adverse or toxic effects at these dietary levels in rats, it may be useful to consider the use of kudzu polyphenols as complements to strategies used to reduce metabolic disorders.”
Dr Wyss and his co-workers used stroke-prone spontaneously hypertensive rats as a model for the metabolic syndrome. The animals were initially fed for two months on a polyphenol-free diet, and then randomly assigned to a standard diet or the standard diet supplemented with 0.2 per cent kudzu root extract.
Two months later the researchers noted that the kudzu root fed animals had arterial blood pressure between 11 and 15 mmHg lower than the control animals, total cholesterol levels about 50 per cent lower, and fasting blood glucose between 20 and 30 per cent lower than the control animals.
“This is the first report investigating the potential for long-term kudzu supplementation to decrease these interacting factors of the metabolic syndrome in an animal model,” stated the researchers.
Commenting on the potential mechanism, Dr Wyss and his co-workers proposed that kudzu root extract may regulate plasma glucose by affecting the expression of glucose transporters in the intestine, such as SGLT-1 and GLUT-2.
Another possible mechanism may involve the polyphenols and isoflavones in the kudzu, which could activate PPAR-gamma, a hormone receptor which reportedly plays a key role in the control of expression and differentiation of genes associated with fat cells.
“We suggest that individual phenolic compounds in kudzu extract are related to its beneficial effects. Kudzu root extract contains not only a high concentration of puerarin (25 per cent) but also other phenolic compounds,” wrote the researchers.
Source: Journal of Agricultural and Food Chemistry
Volume 57, Issue 16, Pages 7268-7273, doi: 10.1021/jf901169y
“Chronic Dietary Kudzu Isoflavones Improve Components of Metabolic Syndrome in Stroke-Prone Spontaneously Hypertensive Rats”
Authors: N. Peng, J.K. Prasain, Y. Dai, R. Moore, A. Arabshahi, S. Barnes, S. Carlson, J.M. Wyss