Page 248 - Pharmacognosy 2 PG303

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

enhancement of interferon formation. The isoflavonoids and glabridin as well as
licobenzofuran have antimicrobial activity.

2- As an antiphlogistic and spasmolytic in gastritis and stomach ulcers, as
well as in the prophylaxis of ulcers. glycyrrhizinic acid and its aglycone
glycyrrhetinic acid are an essential active component, whose antiphlogistic action
has been proved. They don't inhibit prostaglandin synthesis but rather the
movement of leucocytes towards the inflamed spot. Glycyrrhizin inhibits the
activity of phospholipase A and the formation of prostglandin E2 in activated
peritoneal macrophages. After oral administration, glycyrrhizin is partially
converted by the intestinal flora to its aglycone and to 3-dehydro-l8-β-
glycyrrhetinic acid. Glycyrrhizin and its aglycone reduce the toxic action of tetra-
chloro-methane on cultured hepatocytes, by functioning as antioxidants. The two
components are responsible for the mineralocorticoid effects of the drug, since
they have inhibitory effect on the 5B-reductase which has an important role in
regulating cortisol and aldosterone metabolism (11-oxo-function), so retarding the
excretion of corticosteroids leading to the extension of their biological half-life.
The spasmolytic effect brought about by some of the flavonoid content of the drug
by inhibiting monoamine oxidase (MAO).

3- Because of the intensely sweet taste, the drug is incorporated into
medicines, foodstuffs, and condiments to enhance the taste. In laxative herbal teas,
liquorice potentiates the action of anthraquinone drugs (raising the wettability of
the bowel contents, owing to the high surfactant activity of glycyrrhizin), so that
the smaller doses of these latter are required.

Side effects:
Owing to the mineralo-corticoid activity of glycyrrhizin and glycyrrhetin,

large doses (more than 50 gm drug a day), taken over a prolonged period of
time, lead to hypokalemia, hypernatremia, oedema, hypertension and cardiac
disorders. The problems disappear in a few days after stopping the drug.

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