Clinical Abstracts
With Comments by Adriane Fugh-Berman, MD
Echinacea purpurea and Herpes
August 2001; Volume 3; 64
Source: Vonau B, et al. Does the extract of the plant Echinacea purpurea influence the clinical course of recurrent genital herpes? Int J STD AIDS 2001;12:154-158.
Design/Setting/Subjects: A double-blind, placebo-controlled crossover trial of 50 patients (24 men and 26 women) with a minimum of four genital herpes recurrences in the previous year or prior to suppressive acyclovir. The median number of recurrences prior to trial entry was seven (4-25) over a one-year period. Of the 50 patients, 71.4% of were serology-positive for HSV-1 and HSV-2; 20.4% serology-positive for HSV-2; and 8.2% were serology-positive for HSV-1 (with positive genital cultures).
Treatment: Echinacea purpurea extract (Echinaforce, containing 95% plant extract and 5% root extract) 800 mg bid or placebo for six months, after which subjects were crossed over to the other arm.
Results: There were no statistically significant differences in frequency or duration of herpes recurrences, pain scores, or CD4, CD8, or neutrophil counts. Only 31 patients completed the trial. One patient who received echinacea experienced severe diarrhea and withdrew after two months. Eight withdrawals were for unknown reasons, two because of pregnancy or desire for pregnancy, four for time restrictions, four for adverse events (mainly diarrhea), and one (on echinacea) for depression. Nausea was reported by four patients on echinacea and two on placebo.
Funding: Not stated. Bioforce (manufacturer of Echinaforce) provided study drug, placebo, and scientific support.
Comments: Echinacea has not proven to be an effective prophylactic for viral infections—first colds, now genital herpes. A Cochrane review found echinacea extracts unimpressive for preventing colds.1 Neither of the methodologically acceptable prevention trials found that echinacea decreased incidence of colds, shortened duration of illness, or decreased infection severity.2,3 A recent double-blind prophylaxis trial (not included in the above review) randomized 109 patients with recurrent colds or upper respiratory infections (URI) to 4 ml fluid extract of E. purpurea or placebo for eight weeks.4 Sixty-five percent (35/54) of the echinacea group and 74% (40/54 ) of placebo group had at least one cold or URI; there was no significant difference between groups in incidence, duration, or severity of colds and respiratory infections. Echinacea has immuno-modulatory properties in vitro and in vivo, but it may be more effective as a treatment than as a prophylactic, possibly because it may lose its immunostimulating effects over time. There is no reliable evidence to date that supports its prophylactic use against viruses.
References
1. Melchart D, et al. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev 2000;(2):CD000530.
2. Melchart D, et al. Echinacea root extracts for the prevention of upper respiratory tract infections: A double-blind, placebo-controlled randomized trial. Arch Fam Med 1998;7:541-545.
3. Schoneberger D. Einflu [latin sharp s] der immunstimulierenden Wirkung von Pre [latin sharp s] saft aus Herba Echinaceae purpureae auf Verlauf und Schweregrad von Erkaltungskrankheiten. Forum Immunologie 1992;2:18-22.
4. Grimm W, Müller HH. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med 1999;106: 138-143.
August 2001; Volume 3; 64
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