Clinical Studies

European researchers have conducted a number of clinical studies over the past few decades. Pittler and Ernst17,18 summarized these studies in a literature review to evaluate the evidence for or against the use of HCSE and isolated escin in the management of venous insufficiency (summarized in Appendix 1).

Their review describes the protocols and findings of 13 randomized controlled trials of horse-chestnut seed extract. Eight of the studies were placebo-controlled trials and five were comparative evaluations against reference medications. 20 to 226 subjects participated in each of these placebo-controlled trials, for periods ranging from 20 days to eight weeks. Five trials comparatively evaluated HCSE against reference medications. Here the number of subjects ranged from 30 to 240 and the duration of treatment ranged from 4 to 12 weeks.

The results of the placebo-controlled trials suggested that treatment of CVI with horse-chestnut seed extract was effective in decreasing lower-leg volume and calf and ankle circumference in the subjects and offered protection against edema. Capillary filtration rate in patients who received HCSE was reported to be enhanced by 22%, in one study. All five of the randomized control trials against reference medications demonstrated the effectiveness of HCSE in the treatment of chronic venous insufficiency. However, in one study, the symptoms were observed to persist, in that, at the end of a six-week follow-up period the mean leg volume was not significantly different from that immediately after treatment.

A placebo-controlled study compared the effects of HCSE therapy (300 mg standardized for 50 mg escin, 2 capsules per day for 12 weeks) with leg compression stocking (the standard therapeutic measure for CVI)19. HCSE produced beneficial effects comparable to the compression therapy with better compliance.

Effect of HCSE Vs. Compression in CVI17

Figure 5 : Effect of HCSE Vs. Compression in CVI17

A German multi-centric study compared the clinical efficacy of two leading natural pharmacological measures in the management of CVI, oxerutins (a standardized mixture of hydroxyethyl derivatives of rutin) and standardized horse chestnut extract.20 155 female postmenopausal patients participated with 137 patients completing the 19 week study. A double-blind placebo controlled design with random allocation of the patients to the treatment groups was employed. Three different treatments were investigated: a)oxerutins 1000 mg/day (OX1000),

b) oxerutins 1000mg/dayinitial dose for 4 weeks followed by 500 mg/day maintenance dose (OX1000-500), c) horse chestnut extract 600 mg/day (HCSE supplied as capsules each containing 300 mg horse chestnut extract standardized to 50 mg escin/capsule). A one week placebo run was followed by 12 weeks drug treatment and a six weeks follow-up period without treatment.

The leg volume was measured initially and periodically during the treatment. The results are indicated in Figures 6 and 7

Anti-edema effects of oxerutins and horse chestnut extract over time

Figure 6 : Anti-edema effects of oxerutins and horse chestnut extract over time

Relative efficacy of oxerutins and horse chestnut extract

Figure 7 : Relative efficacy of oxerutins and horse chestnut extract

The results revealed that both oxerutins and horse chestnut extract were able to achieve a mean leg volume reduction of 100 ml after twelve weeks treatment in responding patients.


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