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Herba Bidentis
ity in vivo against aspirin-induced ulcers, but the extracts were inactive
against indomethacin-induced ulcers (50).
Photoprotective activity
Haemolysis induced in vitro by psoralen and UV-A radiation (PUVAhaemolysis)
was inhibited by the presence of an extract of the aerial
parts of the plant in the medium during irradiation, or by the addition
of the extract to the medium after PUVA-treatment. The inhibition effect
was more pronounced when the extract was added during irradiation
(51).
Toxicology
An ethanol-aqueous extract (1:1) of the aerial parts administered intraperitoneally
to mice had a median lethal dose of 750 mg/kg bw (52).
Clinical pharmacology
Aerial parts of the plant were used in an open clinical trial, without a control
group, to treat 500 patients with dysentery, 65 with acute enteritis and
248 with chronic enteritis. Several different dosage forms of the herb were
used: 200 g of fresh whole herb and 100 g of dried herb in decoctions (in
three divided doses per day); granules containing 5 g of dried aqueous
extract, three times daily; 0.5 g tablets of dried aqueous extract, 10 tablets
each time, three times daily; and injection, 2 ml per injection (dose not
stated), 2–3 times daily. The herbal preparations were administered for
3–10 days to patients who had already had diarrhoea for 7–15 days. Of
the 500 patients with chronic dysentery, 387 were reported to have been
cured; 13 had not responded within 3 days. All 313 patients with enteritis
were reported to have been cured (12 of the patients with chronic enteritis
relapsed later) (35).
In an open clinical trial without a control group, a 70% ethanol extract
of the aerial parts of the plant and an ointment containing 2.5% of the
extract were administered to 53 patients with psoriasis. After oral administration
of the extract (20 drops three times daily) and simultaneous application
of the ointment to the affected areas of the skin once a day, the
combination was found to have anti-inflammatory activity as well as an
ability to stimulate adrenal functions. After one week of treatment, desquamation
of the skin was decreased, and a decoloration of the psoriatic
plaques was observed. A clinical recovery was recorded for 29 of the patients;
an improvement in condition was recorded for 22 patients; and a
failure of treatment for 2 patients (17).
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