Table 4

Systematic reviews of clinical trials of herbal medicines

Features

Author

Indication

Intervention

Comparisons

Studies

1/2/3/

Results

Author's Conclusion

Year

4/5

Vogler 99

various

aloe

placebo, other

6 RCT,4

y/y/y/

Positive results for genital

Promising results, but overall

[54]

& no treatment

CCT

y/n

herpes, psoriasis, hyper-

evidence insufficient

lipidemia, diabetes;

contradictory for wound healing

Pittler 98

cholesterol

artichoke

placebo

1 RCT

y/y/y/

Effects over placebo only in the

More trials needed

[55]

lowering

leave

n/n

subgroup of participants with

extract

serum cholesterol > 210 mg/dl

Morse 89

atopic

evening

placebo

9

?/n/n/

Epogam significantly better

No conclusion drawn

[56]

eczema

primrose oil

RCT/CCT

y/y

than placebo for most

(Epogam)

outcomes

Vogler 98

migraine

feverfew

placebo

5 RCT

y/y/y/

Majority of trials favor feverfew

Effectiveness has not been

[57]

y/n

over placebo

established beyond reasonable

doubt

Ernst 2000

nausea and

ginger root

placebo,

6 RCT

y/y/y/

2 of 3 trials on postoperative

Evidence promising but insufficient

[58]

vomiting

metoclopramide

y/p

nausea positive (best

to draw firm conclusions

negative), trials on

seasickness, morning sickness

and chemotherapy-induced

nausea positive

Vogler 99

various

ginseng root

placebo, other

16 RCT

y/p/y/

Contradictory results re.

The efficacy of ginseng root extract

[59]

extract

treatment (1

y/n

physical performance (7 trials),

is not established beyond

trial)

psychological function (5),

reasonable doubt for any of these

immunomodulation (2),

indications

positive results in diabetes and

herpes simplex (1 trial

respectively)

Pittler 98

venous

horse

placebo, other

13 RCT

y/y/y/

Significant effects over placebo

horse chestnut seeds seem to be

[60]

insufficieny

chestnut

treatment

y/n

and similar effects compared to

effective; further tials needed

seeds

other treatments

(confirmation, long-term results,

combination)

Pittler 2000

anxiety

kava

placebo

7 RCT

y/y/y/

All trials suggest superiority

Available data suggest that kava is

[61]

p/p

over placebo; 3 trials with data

a treatment option for anxiety.

for meta-analysis show sign.

Further studies needed

superiority

Lawrence

liver

milk thistle

placebo, other

33 RCT,

y/y/y/

Variety of conditions studied,

Efficacy is not established.

2000 [62]

diseases

& no treatment

1 CCT

y/y

studies often poor quality.

Possible benefit shown most

Mixed and inconsistent findings

frequently for aminotransferases.

Ernst 99

musculoskel.

Phytodolor^®

placebo, other

10 RCT

y/p/y/

Placebo-controlled trials show

The data suggest that the

[63]

pain

populus,

treatments

y/n

superiority over placebo and

combination is effective in the

fraxinus,

similar effects as NSAIDs

symptomatic treatment of

solidago

muskuloskeletal pain

MacDonald

ben. prostata

rye grass

placebo, other

4 RCT

y/y/y/

Signif. improvement over

Available evidence suggests that

2000 &

hyperplasia

pollen

therapy

y/y

placebo in subjective, but not

Cernilton^® is well tolerated and

Wilt 2000

extract

objective symptoms; no

modestly improves subjective

[64,65]

differences compared to

symptoms. Further studies needed

tadenan and paraprost

Ernst 2000

dermatologic

tea trea oil

placebo, other

4 RCT

y/y/y/

2 trials vs. placebo positive, 3

Data promising but insufficient

[66]

conditions

treatment

y/n

trials vs. other treatments

similar effects

Stevinson

insomnia

valerian root

placebo

9 RCT

y/y/y/

Highly heterogeneous studies

Available evidence is promising but

2000 [67]

y/n

with sometimes contradictory

not fully conclusive. Further,

and inconsistent findings

rigorous trials needed

Renfrew

breast

cabbage

usual care

1 RCT

y/y/n/

fewer women stopping breast

Further research desirable

84 [68]

engorgement

leaves

y/n

feeding among those receiving

cabbage leaves

Armstrong

atopic

Chinese

placebo

2 RCT

y/y/n/

2 positive studies by the same

Evidence encouraging but

99 [69]

eczema

herbal

y/n

insufficient given the potential of

therapy

treat analysis

relevant side effects

Ernst 97

hypoglyc.

all plants

no treatment,

7 RCT, 4

y/p/n/

Most studies low quality. Most

Use of hypoglcemic plant remedies

[70]

activity

placebo, none

CCT, 10

y/n

papers report positive effects

not supported by rigorous

UCS

on a variety of plants

research. Further studies required

Ernst 2000

analgetic or

various

placebo

18 RCT

y/y/y/

Trials on evening primrose oil,

The results suggest that several

[71]

inflamm.

y/n

blackcurrant seed oil, borage

herbal remedies have potential in

treatment

oil, harpagophytum, willow

alleviating the pain of rheumatic

bark, feverfew, and 3

diseases. More research urgently

combinations; almost all trials

needed

positive

legend see table 1

Linde et al. BMC Complementary and Alternative Medicine 2001 1:5   doi:10.1186/1472-6882-1-5