Pine bark extract may benefit blood pressure-related kidney health

By Stephen Daniells, 05-Mar-2010

Supplements of an extract from French maritime pine bark may improve kidney health by improving blood flow and reducing the risk of hypertension-related kidney damage, says a new study.

Following six months of supplementation with the pine bark extract, Pycnogenol, to a normal ACE-inhibiting intervention produced improvements in blood flow of about 10 per cent in the kidneys, according to findings published in the Journal of Cardiovascular Pharmacology and Therapeutics.

In addition, kidney function improved when the extract was used in conjunction with anti-hypertensive medication Ramipril, with urinary protein levels, a measure of kidney function, resuming to almost sufficient levels, report researchers from G D’Annunzio University in Italy.

“Kidney disease is a common problem for people with hypertension and is an equally ‘silent’ threat to the body. There are no warning signals and inefficient fluid removal may further increase the blood pressure, causing a vicious circle to set in,” said research Dr Gianni Belcaro.

“The results of this study demonstrated Pycnogenol’s ability not only to reduce blood pressure, but also to relieve the kidney damage caused by chronic hypertension.”

Chronic kidney disease (CKD) is linked to increased prevalence in all-cause mortality, cardiovascular events and hospitalization. These people are at an increased risk of cardiovascular disease, and modifiable risk factors include high blood pressure (hypertension) – J. Hypertension Vol. 27, pp. 1863-1872.

Study details

Dr Belcaro and his co-workers recruited 55 hypertensive patients to participate in the randomized, controlled study. Subjects were assigned to receive Ramipril (10 mg per day), and 29 of these people were randomly selected to also receive Pycnogenol (150 mg per day).

Urinary albumin was used as a measure of kidney function – albumin is the most abundant protein in human serum and in people with kidney problems the protein leaks from the kidney into the urine. At the start of the study average albumin levels were 89 mg per 24-hour period, significantly more than the 30 mg representative of sufficient function.

After six months in the Ramipril-only group the albumin levels decreased by 26 per cent to 64 mg per 24-hour period, while additional Pycnogenol produced levels that averaged 39 mg per 24-hour period, equivalent to a 57 per cent decrease, said the researchers.

Statistically significant decreases in patients’ blood pressure were also observed, with systolic and diastolic blood pressures dropping by more than 30 and 8 per cent, respectively in the Ramipril-only group, and by a further 3 to 6 per cent in the combination group.

Diastolic and systolic blood flow improved by 8 and 12 per cent, in the combination group, added the researchers.

“Pycnogenol has been demonstrated in various previous studies to have a favourable effect for normalizing blood pressure, and this effect has been attributed to an improved endothelial function,” wrote the researchers. “Our study extends the knowledge on antihypertensive effects of Pycnogenol to kidney protective effects.

“The addition of Pycnogenol to Ramipril did not lower blood pressure so much more that the improved kidney function may merely result from better blood pressure. The improved endothelial function may also contribute to better kidney cortical flow, resulting in better kidney function.

“This is a new observation indicating a role for Pycnogenol for both kidney function protection and a specific reduction in the diffuse vasospasm present in participants at the kidney level,” they added.

Source: Journal of Cardiovascular Pharmacology and Therapeutics
Doi: 10.1177/1074248409356063
“Kidney Flow and Function in Hypertension: Protective Effects of Pycnogenol in 1 Hypertensive Participants – A Controlled Study”
Authors: M.R. Cesarone, G. Belcaro, S. Stuard, F. Shonlau, A. Di Renzo, M.G. Grossi, M. Dugall, U. Cornelli, M. Cacchio, G. Gizzi, L. Pellegrini