WHO monographs on selected medicinal plants - travolekar.ru

Cortex Berberidis
and Trichomonas vaginalis and induced morphological changes in the
parasites (49).
Cardiovascular effects
Berberine has been reported to have protective effects against cardiac arrhythmias
and severe congestive heart failure (50–52). This physiological
effect is due to the ability of berberine to prolong action potential duration
and inhibit the inward rectifier potassium current and outward delayed
rectifier potassium current (50–100 μM). Berberine has also been
shown to inhibit the human ether-a-go-go-related channel expression in
Xenopus oocytes (median effective dose was 95 μM). In rats, Langendorff
perfusion of an isolated heart was performed using verapamil to bring
about acute heart failure. Treatment of the heart with berberine (10 μmol/l)
before the use of verapamil significantly reduced the degree of heart failure
as compared with the control group (p < 0.001) (52).
Effects on smooth muscle
Berberine, at a concentration of 1 μM, relaxed norepinephrine-precontracted
isolated rat aorta strips (53). Berberine induced relaxation in isolated
precontracted rat mesenteric arteries at a concentration of 10 -5 M
(54, 55). At a concentration of 0.1–100 μM, berberine suppressed basal
tone and induced a concentration-dependent relaxation of phenylephrine-precontracted
rabbit corpus cavernosum in vitro (56). Intracavernous
injection of berberine to anaesthetized rabbits at a dose of 5.0 mg/kg
increased intracavernosal pressure from 12.7 to 63.4 mmHg, and the duration
of tumescence ranged from 11.5 to 43.7 minutes (56). Berberine
inhibited norepinephrine and phenylephrine-induced contractions in
prostate strips isolated from rabbit (57).
The effects and mechanism of berberine on the intracellular free calcium
concentration in the smooth muscle cells of guinea-pig colon were
assessed in vitro using bi-wavelength spectrophotometry in suspensions
of these cells. In the resting state, berberine had no significant effects on
free calcium concentration, but inhibited the increase in free calcium levels
induced by 60 mm potassium chloride in a concentration-dependent
manner. The median inhibitory concentration was 34.09 μM. At concentrations
of 30 and 100 μM, berberine inhibited the elevation of free calcium
evoked by 10 μM of acetylcholine in the presence or absence of extracellular
calcium. These data suggest that berberine inhibits the influx of
extracellular calcium and calcium release from intracellular stores in the
smooth muscle cells of colon, indicating that berberine may be a calcium
channel blocker (58).
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