WHO monographs on selected medicinal plants - travolekar.ru

Fructus Myrtilli
histochemical data suggested that the anthocyanins protect the capillary
walls by a mechanism that involves increasing the endothelium barriereffect
through stabilization of the membrane phospholipids and by increasing
the biosynthetic processes of the acid mucopolysaccharides of
the connective ground substance, by restoring the altered mucopolysaccharidic
pericapillary sheet. A marked increase in newly formed capillaries
and collagen fibrils induced by the anthocyanins was also observed
(16). In another study, 47 patients with varicose veins were treated with a
commercial extract of the crude drug at a dose of 480 mg/day for 30 days
(14). Significant improvements in microcirculation, oedema, feelings of
heaviness, parasthesia, pain and skin dystrophy were observed (p < 0.01).
A significant reduction in oedema was observed by day 15 (p < 0.01). In
another similar study, 15 patients with polyneuritis due to peripheral vascular
insufficiency were given 480 mg/day of the extract and a significant
improvement in microcirculation was noted (43). Furthermore, a review
of uncontrolled trials from 1979 to 1985 involving a total of 568 patients
with venous insufficiency of the lower limbs showed that an anthocyanin-containing
extract of the crude drug was effective in rapidly decreasing
symptoms and improving both venous microcirculation and lymph
drainage (13).
Pharmacokinetics and toxicology
A randomized parallel dietary intervention study measured the serum
quercetin concentrations of 40 healthy subjects who were consuming
fruit (including the crude drug) or normal Finnish diets. Twenty subjects
consumed 100 g/day of berries (blackcurrants, lingon berries and bilberries)
for 8 weeks. Twenty subjects consuming their normal diets served as
controls. Fasting blood samples were obtained 2 weeks prior to the study,
at baseline, and at 2, 4 and 8 weeks. Intake of quercetin was assessed from
3-day food records collected at baseline and at 8 weeks. The serum quercetin
concentrations were significantly higher in the subjects consuming
berries than in subjects in the control group (p = 0.039; analysis of variance
with repeated measures). During the period of berry consumption
the mean serum concentrations of quercetin ranged between 21.4 and
25.3 g/l in the group consuming the berries; this was 32–51% higher
than in the control group. According to the 3-day food records, there was
no difference in quercetin intake at baseline, but at 8 weeks the intake was
12.3 mg/day (mean) in the group consuming the berries and 5.8 ± 0.6 mg/
day in the control group (p = 0.001) (44).
Long-term oral administration to humans of doses equivalent to
180 mg/kg anthocyanins per day for 6 months produced no toxic effects
(2).
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