Table 3 Systematic reviews of clinical trials of herbal medicines (at least 2 reviews per herb)
From: Systematic reviews of complementary therapies – an annotated bibliography. Part 2: Herbal medicine
Features | |||||||
|---|---|---|---|---|---|---|---|
Author | Indication | Intervention | Comparisons | Studies | 1/2/3/ | Results | Author's Conclusion |
Year | 4/5 | ||||||
Echinacea ( Echinacea purpurea, angustifolia and pallida ) | |||||||
Barrett | upper resp. | echinacea | placebo | 13RCT | y/p/y/ | Overall quality modest. All 4 | Echinacea may be beneficial for |
99 [40] | infections | (incl. | y/n | prevention studies show only | early treatment of acute upper | ||
combinations) | minor trends, 8 of 9 treatment | respiratory infections; little evidence | |||||
studies with generally positive | to support the prolonged use for | ||||||
results | prevention | ||||||
Melchart | common | echinacea | placebo, no | 16 RCT | y/y/y/ | Minor effects in prevention and | Echinacea extract can be efficacious |
99 [41] | cold | (incl. | treatment | y/p | treatment, promising effects in | for the common cold, but evidence | |
combinations) | early treatment. Heterogen. | insufficient for recommendations | |||||
preparations | |||||||
Melchart | immuno- | echinacea | placebo, no | 18 RCT, 8 | y/y/y/ | Most studies low quality. Most | Echinacea extracts can be |
94 | stimulation | (incl. | treatment | CCT | y/n | studies show immunostimulating | efficacious immunostimulators, but |
combinations) | effects | evidence insufficient for | |||||
recommendations | |||||||
Cranberries ( Vaccinium macrocarpon ) | |||||||
Jepson | urinary | cranberries | placebo | 4 RCT | y/y/y/ | In 3 of 4 trials cranberries effective | Insufficient evidence, further research |
98 [44] | tract inf. | y/n | for at least one of the outcomes of | needed | |||
(prevent) | interest | ||||||
Jepson | urinary | cranberries | O RCT | y/y/-/ | No trials meeting the inclusion | No evidence available | |
98 [45] | tract inf. | -/- | criteria | ||||
(treatm.) | |||||||
Mistletoe ( Viscum album ) | |||||||
Kleijnen | cancer | mistletoe | placebo, no | 11 | y/y/y/ | Most studies low quality. Most | Insufficient evidence to recommend |
94 [46] | treatment | RCT/CCT | n/n | studies show longer survival with | mistletoe outside of clinical trials | ||
mistletoe but not the best trial | |||||||
Kiene 89 | cancer | mistletoe | no treatment, | 2 RCT, 33 | y/n/n/ | Most studies low quality. 9 of 12 | Available evidence supports positive |
none | CCT, 11 | y/n | interpretable studies suggest | effects of mistletoe | |||
other | positive effects on survival | ||||||
studies | |||||||
Peppermint ( Mentha piperita ) | |||||||
Jailwala | irritable | 1. peppermint | placebo | 1. 3 RCT | p/y/y/ | Chinese herbal therapy trial rated | In both cases efficacy not clearly |
2000* | bowel | oil | 2. 1 RCT | n/n | as positive, one of three | established | |
[49] | syndr. | 2. Chinese | peppermint oil trials rated as | ||||
herbal | positive | ||||||
therapy | |||||||
Pittler 98 | irritable | peppermint | placebo, | 8 RCT | y/y/y/ | Global improvement rates | The role of peppermint oil for IBS |
[50] | bowel | oil | other | y/y | significantly higher compared to | has not been established beyond | |
syndr. | treatment | placebo. Quality of trials doubtful | reasonable doubt | ||||
Saw palmetto ( Serenoa repens ) | |||||||
Boyle | ben. | Permixon® | placebo, | 11 RCTs, | ?/n/n/ | peak urine flow 2.20 (95% Cl 1.20– | Despite some limitations strong |
2000 [51] | prostate | (saw | other | 2 UCS | y/y | 3.20) ml/s increase over placebo; | evidence that the extract tested has |
hyperplasia | palmetto) | treatment | significant decrease nocturia | beneficial effects | |||
Wilt 2000 | ben. | saw palmetto | placebo, | 14 RCT | y/y/y/ | Saw palmetto superior to placebo | Evidence suggests that saw |
&98 | prostate | other | (plac), | y/y | for nocturia, self rating, peak urine | palmetto improves urological | |
hyperplasia | treatment | 5 RCT | flow; similar effects as finasteride | symptoms and flow measures. | |||
(other) | Further studies needed | ||||||