WHO monographs on selected medicinal plants - travolekar.ru

<strong>WHO</strong> <strong>monographs</strong> on selected medicinal plants
crude drug to the culture medium at a concentration of 50.0 μg/ml (25).
In vitro studies have demonstrated that Vibrio cholerae grows in a medium
containing berberine, but fails to produce diarrhoea-inducing toxins
(26). It has been hypothesized that the antidysenteric activity of berberine
is due to localized effects on the intestinal tract and not due to bactericidal
activity. The suggested mechanism by which berberine exerts its
antidiarrhoeal activity is through the activation of 2
-adrenoceptors and
by reducing production of cyclic adenosine monophosphate through the
inhibition of the activity of adenylate cyclase (27), which in turn decreases
intestinal motility (28). Berberine inhibits in vivo and in vitro intestinal
secretions induced by cholera toxin (29–32).
Berberine at a concentration of 10.0 mg/loop reduced intestinal secretion
stimulated by the heat-labile toxin of Escherichia coli in the rabbit
ligated intestinal loop model by 70% in situ, and inhibited the secretory
response of the heat stable toxin of E. coli in mice (33, 34). Berberine at
concentrations up to 500.0 μM stimulated ion transport responses in human
colonic mucosa that were non-specific for calcium ions or cyclic adenosine
monophosphate-mediated signals. In cultured intestinal epithelial
monolayers, berberine inhibited calcium and cyclic adenosine monophosphate-mediated
responses, indicating that the drug exerts a direct antisecretory
effect on the epithelial cells through the inhibition of mucosal
chloride secretion (35).
Antihypertensive activity
Administration of a lyophilized aqueous extract of the crude drug in
drinking-water at a dose of 500.0 mg/kg body weight (bw) to rats for
20 days significantly reduced hypertension induced by heat stress or the
administration of metyrapone (p < 0.01) (36, 37). Intragastric administration
of a 70% ethanol extract of the crude drug at a dose of 600.0 mg/kg
bw to rats for 20 days reduced blood pressure (38).
Anti-inflammatory activity
A 50% ethanol extract of the crude drug reduced 12-O-tetradecanoylphorbol-13-acetate
and acetic acid-induced oedema and inhibited oxazoloneinduced
contact-delayed hypersensitivity ear oedema in mice after application
of 0.5 mg/ear (39). A 50% methanol extract (1:1) significantly
decreased granulation tissues in chick embryo chorioallantoic membranes,
indicating anti-inflammatory activity (p < 0.05) (40). Intragastric administration
of berberine to rats with trinitrobenzene sulfonic acid-induced
colitis at a dose of 7.5 or 15.0 mg/kg/day reduced histological lesions,
morphological damage and myeloperoxidase activity after 1 week of
treatment (41). Berberine also inhibited the production of the potent in-
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