Clinical Research Review Clinical Studies Evaluating Herbs

Clinical Research Review
e-Monitor No. 21 May 2008
by Michelle Morgan
Clinical Studies Evaluating Herbs
Preliminary results of a clinical study on the effects of Rosmarini folium pulvis (2 x 0.5 g/d)
treating arterial hypotony.[In German]
Scarlat MA, Tamas M. Z Phytother 2006; 27(3): 120-131
A placebo-controlled trial investigated the effect of rosemary leaf on the blood pressure of patients with chronic low
blood pressure (systolic blood pressure: less than or equal to 85 mm Hg). Forty patients received rosemary (Rosmarinus
officinalis) or placebo for a period of 8 weeks. Powdered rosemary leaf with known amounts of flavonoids and
rosmarinic acid was administered as 1.0 g/day in capsules. All those receiving rosemary reported feeling better at the
conclusion of the trial. From the second week onwards these patients showed an increase in systolic blood pressure of
20–40 mm Hg (105–125 mm Hg). Diastolic blood pressure was not changed, and there was no change in the blood
pressure of the placebo group.
Key Finding: Rosemary improved blood pressure in hypotensive patients.
Effect of Ginkgo biloba extract EGb 761 on dizziness and tinnitus in patients with dementia.
Hoerr R, Napryeyenko O, Borzenko I. Focus Altern Complement Ther 2007; 12: 26-27
Part of a double-blind, placebo-controlled trial of standardised Ginkgo extract in dementia investigated the effects on
dizziness and tinnitus. The trial involved outpatients aged 50 years or older with mild to moderate dementia with
neuropsychiatric symptoms. After receiving standardised Ginkgo extract (240 mg/day) for 22 weeks, the mean severity
score for dizziness improved from 4.35 to 2.09 and the severity score for tinnitus decreased from 4.02 to 1.91. There
were only slight improvements in the placebo group, from 4.22 to 3.88 for dizziness and from 3.90 to 3.75 for tinnitus.
Dizziness was improved in 86% of Ginkgo recipients and in 28% of the placebo group. Improvement rates for tinnitus
were 84% of the Ginkgo-treated patients versus 20% of the placebo group. The differences were significant between
Ginkgo and placebo on all measures (p < 0.001).
Key Finding: Standardised Ginkgo extract improves symptoms of dizziness and tinnitus in patients with dementia.
Efficacy and safety of a combination of Sabal and Urtica extract in lower urinary tract
symptoms--long-term follow-up of a placebo-controlled, double-blind, multicenter trial.
Lopatkin N, Sivkov A, Schlafke S et al. Int Urol Nephrol 2007; 39(4): 1137-1146
The long-term efficacy and safety of a combination of saw palmetto (Sabal) and nettle root (Urtica) extracts was
investigated in elderly men with moderate or severe lower urinary tract symptoms (LUTS) caused by benign prostatic
hyperplasia (BPH). Two hundred and fifty-seven patients were randomly treated with the combination or placebo for 24
weeks. This was followed by a 24-week 'control' period during which all participants received the herbal combination.
(The results of this trial were reported: World J Urol 2005; 23(2): 139-146.) A further 48-week period using the herbal
combination was then offered to all participants, resulting in a total observation period of 96 weeks. Two hundred and
nineteen patients participated in the follow-up. The herbal combination was prescribed with a daily dose approximately
equivalent to dried herb: 3.9 g of saw palmetto (Serenoa repens) fruit and 2.5 g of nettle (Urtica dioica) root.
Assessment of efficacy included the I-PSS (International Prostate Symptom Score) self-rating questionnaire, urinary flow
and sonographic parameters.
© Copyright 2008 MediHerb Pty Ltd. Not for Public Distribution. For Education of Health Care Professionals Only.
e-Monitor No. 21 May 2008
Between baseline and the end of observation (week 96) significant results were obtained:
• I-PSS total score was reduced by 53%
• peak and average urinary flow (both) increased by 19%
• residual urine volume decreased by 44%
During follow-up 61 adverse events were reported, which corresponded to one adverse event in 1181 days of
treatment with the herbal combination. A causal relationship with intake of the herbal combination could not be
excluded in only one event (mild intestinal dysbacteriosis).
Key Finding: Treatment with a combination of saw palmetto and nettle root extracts provided efficacy and safety in
benign prostatic hyperplasia over a period of 96 weeks.
Safety, Adverse Reactions, Herb-Drug Interactions
Lack of pharmacokinetic interaction between St. John's wort and prednisone.
Bell EC, Ravis WR, Chan HM et al. Ann Pharmacother 2007; 41(11): 1819-1824
A clinical study investigated the effect of administration of St John's wort on the pharmacokinetics of prednisone and its
metabolite prednisolone in healthy male volunteers. A single dose of prednisone (20 mg) was taken on two occasions:
firstly to establish a baseline, and secondly after 4 weeks of consuming St John's wort. According to the product label,
an extract of St John's wort (300 mg, three times per day) standardised for hypericin (0.3%) and hyperforin (4%) was
used. Blood samples were taken at intervals up to 16 hours after dosing with prednisone. No significant alterations in
the pharmacokinetic parameters for prednisone or prednisolone were observed after treatment with St John's wort.
Key Finding: St John's wort extract had no effect on the pharmacokinetics of prednisone.
Effect of Ginkgo biloba (EGb 761) and aspirin on platelet aggregation and platelet function
analysis among older adults at risk of cardiovascular disease: a randomized clinical trial.
Gardner CD, Zehnder JL, Rigby AJ et al. Blood Coagul Fibrinolysis 2007; 18(8): 787-793
A randomised, double-blind, placebo-controlled trial investigated the potential adverse effects of standardised Ginkgo
extract (300 mg/day) in patients taking aspirin (325 mg/day). Participants included patients with peripheral arterial
disease (PAD) or those at risk for PAD (due to either a family history of cardiovascular disease or elevated
cardiovascular disease risk factors). Ginkgo or placebo was administered for 4 weeks, and 60 participants completed the
study (although a smaller number produced viable test results). The addition of Ginkgo to daily aspirin intake did not
have a detectable effect on platelet function as assessed by two standard methods. Reports of bleeding or bruising
were infrequent and similar for both groups.
Key Finding: A relatively high dose of standardised Ginkgo extract (300 mg/day) did not have adverse effects in
patients also taking aspirin.
Disease Understanding, Diet, Lifestyle
Longitudinal association between prostatitis and development of benign prostatic
St Sauver JL, Jacobson DJ, McGree ME et al. Urology 2008; 71(3): 475-479
A longitudinal, population-based study involving 2447 men in the United States found an association between
medically-diagnosed prostatitis and the later development of benign prostatic hyperplasia (BPH)-associated events.
BPH-associated events include (medically-diagnosed) prostatism, enlarged prostate or BPH. Baseline characteristics of
men with and without prostatitis were compared. A total of 9.3% of participants received a medical diagnosis of
prostatitis prior to any occurrence of BPH-associated events. Prostatitis was associated with a 2.4-fold increased odds of
receiving a later diagnosis of prostatism, enlarged prostate or BPH. Prostatitis was also associated with a 70% increase
© Copyright 2008 MediHerb Pty Ltd. Not for Public Distribution. For Education of Health Care Professionals Only.