Thesis (MNutr)-- Stellenbosch University, 2011.ENGLISH ABSTRACT: Background:
Oxidative stress has been implicated in the development of a number of conditions including
amongst others cancer, arthritic disorders and cardiovascular disease. Pycnogenol is a
herbal dietary supplement derived from French maritime pine bark extract. Pycnogenol is
standardised to contain 70 ± 5% procyanidin which is a powerful antioxidant. Pycnogenol is
marketed as a supplement for preventing or treating a wide range of chronic conditions.
Although several randomised controlled trials of Pycnogenol have been conducted to date,
this evidence has not yet been systematically reviewed.
Objectives: The aim was to carry out a systematic review in order to assess the efficacy and safety of
Pycnogenol for the treatment of chronic disorders.
Search methods
The electronic databases CENTRAL (until 18 September 2010), MEDLINE (until 18
September 2010) and EMBASE (until 13 October 2010) were searched, as well as three trial
registries. Furthermore the manufacturer of Pycnogenol was contacted and bibliographies of
included studies were hand-searched.
Selection criteria: Randomised controlled trials (RCTs) evaluating the effectiveness of Pycnogenol in adults or
children with any chronic disorder were included. The primary outcomes were any clinical
outcomes directly related to the disorder (stratified as participant- and investigator-reported)
as well as all-cause mortality. Adverse events and biomarkers of oxidative stress were also
assessed.
Data collection and analysis: Two authors independently assessed trial eligibility, extracted all data and judged
methodological quality. A third author additionally extracted information on outcomes and
results. With two exceptions, results for outcomes across studies could not be pooled mainly
due to poor quality reporting. Study authors were contacted for additional information.
Results: This review includes 15 RCTs with a total of 791 participants that have evaluated
Pycnogenol for the treatment of seven different chronic disorders. The disorders included
asthma (2 studies; N = 86), attention deficit hyperactivity disorder (1 study; N = 61), chronic
venous insufficiency (2 studies; N = 60), diabetes mellitus (4 studies; N = 201), erectile
dysfunction (1 study; N = 21), hypertension (2 studies; N = 69) and osteoarthritis of the knee
(3 studies; N = 293). Two of the studies were conducted exclusively in children; the others
involved adults. Due to small sample size, limited numbers of trials per condition, variation in
selected outcomes and outcomes measures and the risk of bias no definitive conclusions
regarding the efficacy or safety of Pycnogenol are possible.
Authors’ conclusions: Current evidence is insufficient to support Pycnogenol use for the treatment of any chronic
disorder. Well designed, adequately powered trials are recommended to establish the value
of this treatment.AFRIKAANSE OPSOMMING: Inleiding:
Oksidatiewe stres blyk ’n rol te speel in die ontwikkeling van ’n verskeidenheid siektes onder
andere kanker, artritis en kardiovaskulêre siektes. Pycnogenol, ‘n kruie-bevattende
dieetaanvulling wat uit Franse denneboombas vervaardig word, is gestandaardiseer om 70 ±
5% prosianidien – ’n kragtige anti-oksidant – te bevat. Die produk word bemark om ‘n wye
reeks chroniese siektes te voorkom of te behandel. Alhoewel daar tot op hede verskeie
kliniese proewe op Pycnogenol uitgevoer is, is die uitkomstes nog nie met behulp van ‘n
stelselmatiese oorsig geëvalueer nie.
Doelwitte: Die doel van hierdie studie was om met behulp van ‘n stelselmatiese oorsig die
doeltreffendheid en veiligheid van Pycnogenol ten opsigte van die behandeling van
chroniese siektes te evalueer.
Soektogstrategie: Die elektroniese databasisse CENTRAL (tot 18 September 2010), MEDLINE (tot 18
September 2010) en EMBASE (tot 13 Oktober 2010) is deursoek, asook drie registers met
kliniese proewe. Verder is die vervaardiger van Pycnogenol gekontak en is daar met die
hand deur bibliografieë van ingeslote studies gesif.
Keuringskriteria: Ewekansige gekontroleerde proewe (RCT’s) is ingesluit waarin die effektiwiteit van
Pycnogenol in volwassenes of kinders met enige chroniese siekte geëvalueer is. Enige
kliniese uitkomste wat direk aan die chroniese siekte verwant is (gesorteer as deelnemer- of
ondersoeker-gerapporteerde uitkomstes) asook mortaliteit (enige oorsake) is as die primêre
uitkomstes ondersoek.
Dataversameling en -ontleding: Twee navorsers het onafhanklik van mekaar proewe gekeur, alle relevante data onttrek en
gehalte van die metodiek beoordeel. ‘n Derde navorser het die resultate van die uitkomstes
bykomend onttrek. Met twee uitsonderings, kon resultate van uitkomstes van die
verskillende ingeslote studies kon nie statisties saamgevoeg word nie, hoofsaaklik as gevolg
van swak rapportering. Skrywers van die ingeslote studies is in verband met die verlangde
inligting gekontak.
Resultate: Vyftien RCT’s met ‘n totaal van 791 deelnemers is ingesluit. In hierdie studies is Pycnogenol
vir die behandeling van sewe verskillende chroniese siektes geëvalueer: asma (2 studies; N
= 86), aandagafleibaarheid-hiperaktiwiteitsgebreksindroom (1 studie; N = 61), chroniese
veneuse ontoereikendheid (2 studies; N = 60), diabetes mellitus (4 studies; N = 201),
erektiele disfunksie (1 studie; N = 21), hipertensie (2 studies; N = 69) en osteo-artritis van
die knie (3 studies; N = 293). Twee van hierdie studies is uitsluitlik met kinders gedoen; die
res was volwassenes. As gevolg van klein steekproewe, ‘n beperkte aantal studies per
siekte, wisseling in uitkomstes en die risiko vir sydigheid kan geen definitiewe gevolgtrekking
oor die doeltreffendheid en veiligheid van Pycnogenol gemaak word nie.
Skrywers se gevolgtrekking: Tans is daar nie voldoende wetenskaplike bewyse om Pycnogenol-gebruik vir die
behandeling van enige chroniese siekte aan te beveel nie. Goed ontwerpte proewe met ‘n
voldoende aantal deelnemers word aanbeveel om die waarde van hierdie behandeling
onomwonde vas te stel
