WHO monographs on selected medicinal plants - travolekar.ru

<strong>WHO</strong> <strong>monographs</strong> on selected medicinal plants
antisecretory drug for treatment of Escherichia coli-induced diarrhoea,
but had only a modest antisecretory effect in cholera patients, in whom
the activity of tetracycline alone was superior (17).
A clinical study was conducted in primary-school children with ocular
trachoma. Ninety-six children with this disease were selected for a blinded
study. Patients were advised to instil the drops containing 0.2% berberine
into the eye three times daily and to apply an ointment containing
0.2% berberine at bedtime to both eyes for a period of 3 months. The
comparison drugs tested were berberine drops plus 0.5% neomycin ointment
at bedtime; 20% sodium sulfacetamide drops with 6% sodium sulfacetamide
ointment at bedtime, or placebo (normal saline) drops. The
children treated with berberine had a response rate of 87.5%, whereas
those treated with berberine and neomycin had a response rate of 58.83%.
The study showed that 83.88% were clinically cured but only 50% became
microbiologically negative when treated with berberine alone (21).
Berberine has been used therapeutically for the treatment of cutaneous
leishmaniasis, commonly referred to as “oriental sore”, by subcutaneous
injection of berberine near the site of the lesion (22–24). In patients with
cutaneous leishmaniasis caused by Leishmania tropica, injection of a
preparation containing 2% berberine into lesions was an effective treatment
(22, 23).
Pharmacokinetics and pharmacodynamics
In animal models, berberine has poor bioavailability because it is a quaternary
ammonium compound. It has been suggested that the poor bioavailability
of berberine may be due to the activation of P-glycoprotein
(67). In an investigation on enhancing its bioavailability, the effect of P-
glycoprotein inhibitors cyclosporin A, verapamil and the monoclonal
antibody C219 were investigated using in vivo and in vitro models of
intestinal absorption to determine the role of P-glycoprotein in berberine
absorption (51). In the rat re-circulating perfusion model, berberine absorption
was improved sixfold by co-administration of P-glycoprotein
inhibitors. In the rat intestinal sac model, berberine serosal-to-mucosal
transport was significantly decreased by cyclosporin. In Ussing-type
chambers, the rate of serosal-to-mucosal transport across rat ileum was
threefold higher than in the reverse direction and was significantly decreased
by cyclosporin. In Caco-2 cells, berberine absorption was significantly
increased by P-glycoprotein inhibitors and by monoclonal antibody
C219. P-glycoprotein appears to contribute to the poor intestinal
absorption of berberine, indicating that P-glycoprotein inhibitors could
be of therapeutic value by improving its bioavailability (51).
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