WHO monographs on selected medicinal plants - travolekar.ru

Fructus Myrtilli
oxidant activity of the berries of various Vaccinium cultivars (including
the crude drug) was performed (24). Total antioxidant capacity, measured
as oxygen radical absorbance capacity, ranged from 13.9 to 45.9 μmol/g of
fresh berries in the extract. Bilberry and the lowbush blueberries from
Nova Scotia had the highest antioxidant activity (44.6 and 45.9 μmol/g,
respectively).
Radical scavenging properties of an extract or tea of the fruit containing
anthocyanins was tested on the 1,1-diphenyl-2-picrylhydryl radical
using electron spin resonance spectroscopy. Both the extract and the tea
were effective 1,1-diphenyl-2-picrylhydryl radical scavengers. No direct
correlation was found between the scavenging activity and the content of
anthocyanosides and flavonoids in the extract, suggesting that the catechins
and ascorbic acid may also play a role (25).
Pharmacokinetics
Administration to rats of a fruit extract containing anthocyanins, at a dose
of 20–40 mg/kg bw (intravenous) or 25.0 mg/kg bw (intraperitoneal) underwent
rapid body distribution. Elimination occurred primarily in the
urine and bile, following a three-compartment pharmacokinetic model.
After 4 hours, 20% of the dose was eliminated in the urine, regardless of
route of administration, while at 24 hours, 15% and 18% of the dose was
eliminated in the bile after intravenous and intraperitoneal administration,
respectively. The anthocyanins possessed a greater affinity for some
tissues, namely kidneys (79.0 μg/g tissue) and skin (27.4 μg/g tissue) than
for plasma (19.0 μg/g) (26).
The pharmacokinetics were assessed after intravenous administration
of anthocyanosides (20.0–40.0 mg/kg bw) or oral administration to rats
(400.0 mg/kg bw). The results of the intravenous dose were the same as
those reported by Lietti and Forni (26). After a single oral administration,
the plasma concentrations of anthocyanins reached a peak after 15 minutes
and then rapidly declined within 2 hours. The extent of cumulative
urinary and biliary elimination, together with the gastrointestinal recovery,
demonstrated an absorption rate of approximately 5%. No hepatic
first-pass effect was observed. Despite the modest gastrointestinal absorption
and the low absolute bioavailability (1.2% of the administered
dose), the peak levels in plasma (2.0–3.0 μg/ml) measured after the oral
treatment are in the range of biological activity reported for these substances
(27).
Vascular permeability
The anthocyanins contained in the fruit are thought to have “vitamin P”
activity in that they increase the levels of intracellular vitamin C and de-
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