Liquorice root

From the "Encyclopaedia of Natural Medicine," Michael Murray, N.D. and Joseph Pizzorno, N.D.

The recommended dosage of Liquorice (Glycyrrhiza glabra) for hepatitis of all kinds is:

(Doses 3 times per day)

·         Dried root (or as tea, 1 to 2 g.

·         Tincture (1:5), 4-6ml (1 to 1.5 tsp)

·         Fluid extract (1:1), 0.5-2.0 ml (1/4 to 1/2 tsp)

·         Powdered solid extract (4:1), 250-500 mg

If liquorice is used over a long time it is necessary to increase the intake of potassium rich foods.

Double-blind studies have shown a liquorice component to be effective in treating viral hepatitis, particularly chronic active hepatitis. This activity is probably due to its well documented antiviral activity. A glycyrrhizin-containing product (Stronger Neo-minophagen C), consisting of 0.2 per cent glycyrrhizin, 0.1 per cent cysteine and 2.0 per cent glycine in physiological saline solution, is widely used intravenously in Japan for the treatment of hepatitis. The other components, glycine and cysteine, appear to modulate glycyrrhizin's actions. Glycine has been shown to prevent the sodium- and water-retaining effects of glycyrrhizin, while cysteine aids in detoxification via increased glutathione synthesis and cystine conjugation.

From "Licorice as a liver herb" by Paul Bergner

Licorice root (Glycyrrhiza glabra) is a time-honoured herbal medicine in all world herbal traditions. It is used as a primary herb in perhaps more categories than any other medicinal plant. It is used with success for acute respiratory problems, gastric ulcers, gastritis, inflammatory conditions in general, and adrenal exhaustion. Components of licorice root have both estrogenic and anti-estrogenic activity (Leung; Kraus; Kumagai et al; Sharaf and Goma; Tamaya et al). It is thus an important herb for treating hormone-related female problems. It has not traditionally been used as a liver herb, but medical research over the past two decades in Japan and China has shown that licorice is also an important liver herb with strong hepatoprotectant properties. This should not be thought of as just another minor use for licorice. It is as significant a hepatoprotectant as the better-known milk thistle seed, and acts through separate mechanisms than that herb. The two together should be considered in any hepatoprotectant formula or treatment plan. Form and dose Most of the Asian clinical research and practice has been with glycyrrhizin, a major constituent of licorice root. The product in most Japanese trials is Strong Neominophagen-C (SNMC) which contains 40 mg glyzyhhrizin, 20 mg cysteine, and 400 mg glycine in 20 ml saline solution. Cysteine and glycine are amino acids. A typical treatment for hepatitis is 40 ml of SNMC a day for thirty days delivering 80 mg of glycyrrhizin per day (Hikino). The upper range of clinical trials has been 200 ml SNMC (400 mg glycyrrhizin) (Mori et al, 1989, 1990), but trials above 100 ml (200 mg glycyrrhizin) have been rare, due to concern over possible side effects (see below) (Hikino). Oral extracts Comparable therapeutic levels of glycyrrhizin can probably be reached with oral preparation; important active constituent of licorice, and therapeutic levels for a wide variety of conditions are easily achieved with oral administration. Licorice root (G. glabra) contains 6-14% glycyrrhizin (Merck), so an oral dose of 7-8 grams powdered licorice would deliver the highest range of glycyrrhizin used in the hepatitis trials to the gut. This compares to a traditional Chinese oral dose of 3-12 grams G uralensis (Bensky). How much of this would reach the plasma, and thus be equivalent to the intravenous trials, has not been tested. Oral administration of glycyrrhizin alone or as licorice root extract has been tested in mice (Ozaki et al), and found to be comparable, with each form achieving similar levels of glycyrrhizin or its active metabolites in the plasma.

Hepatitis

Clinical trials for hepatitis, especially chronic active hepatitis, have been so successful in Japan that glycyrrhizin is now a standard medical treatment there (Kumada et al; Matsunami et al.; Ohta et al; Su et al; Suzuki et al; Wang; Zhang et al).

Mechanisms of hepatoprotection

The mechanisms of hepatoprotection are diverse, and include antioxidant activity (Kiso et al; Abdugafurova et al; Tan; Ju et al), direct antiviral effects (Hikino; Crance), enhancement of interferon production (Hikino; Shinada); enhanced antibody production (Hikino), enhancement of extrathymic T-Cell activity in the liver (Kimura et al), and protection from immunological (auto-immune) injuries (Hikino; Mizoguchi et al). A number of animal and in vitro trials have shown that glycyrrhizin can protect liver cells from damage from a variety of chemical or immunological agents (Nakamura et al; Mizoguchi et al; Shibayama; Shiki et al; Zhao et al).

Other Clinical trials

Glycyrrhiza has also been effective in treating HIV/ARC in haemophiliacs, and, notably, improved liver dysfunction in these patients (Mori et al, 1990; Mori et al, 1989). It has also been effective in preventing the hepatic side effects of chemotherapy with a methotrexate combination or interferon (Akimoto et al; Hayashi et al), and in treating general hepatic failure (Acharya).

Enterohepatic cycling

One reason licorice is so effective in treatment of the liver is that it enters the enterohepatic loop, that is, it is excreted in the bile, then reabsorbed in the gut to recycle repeatedly through the liver (Ichikawa; Ishida).

Side effects and drug interactions

Licorice produces well-documented side effects when taken in large doses (>>50 g/day) or for long duration (>>six weeks) (Wichtl). No such side effects have been observed in clinical trials of 40 ml SNMC/day for thirty days, or with 100 ml SNMC (200 mg glycyrrhizin/day) ~for a short period~ (Hikino). With widespread use of SNMC in japan, hyperaldosteronism was seen with larger doses and extended use (SNMC). The side effect is reversible on discontinuation of glycyrrhizin. Licorice or glycyrrhizin may also interact with herbs or other medications containing cardiac glycosides.

From: CD-ROM "The Herbalist" by David L. Hoffman, B.Sc.

The root of licorice, Glycyrrhiza glabra L. and Chinese licorice, G. uralensis, is an important medicine around the world. Glycyrrhizin is one of the main components of licorice root. During the course of such clinical use, glycyrrhizin preparations were found to be effective for chronic hepatitis and have been widely used for chronic hepatitis and liver cirrhosis in Japan.

·         Glycyrrhizin inhibits liver cell injury but does not reverse reduced protein synthesis. It is effective against carbon tetrachloride, benzene hexachloride, PCB and GalN.

·         Antibody production is enhanced by glycyrrhizin. When mononuclear cells from human peripheral blood were stimulated with pokeweed mitogen in the presence of glycyrrhizin, polyclonal antibody production was significantly enhanced. Glycyrrhizin may facilitate antibody formation through the production of interleukin I.

·         glycyrrhizin inhibits the growth of several DNA and RNA viruses, inactivating Herpes simplex virus particles irreversibly.

·         its effect against chronic hepatitis was demonstrated in a double-blind test with 133 patients. Elevated serum transaminase and y-GTP levels were reduced.

·         it appears to be effective on the pretreatment of post-transfusion hepatitis. In one trial comparing glycyrrhizin and an inactive placebo in 336 patients, a significant reduction of the incidence of non-B hepatitis after transfusion was observed in the treated group. Because a remarkable reduction of the incidence of post-transfusion hepatitis was observed from 2 weeks to 6 weeks after transfusion, suggesting that the incidence of short-incubation post-transfusion hepatitis might be suppressed by using glycyrrhizin.

·         it helps prevent post-transfusion hepatitis. When i.v. administration was continued for about 2 weeks, starting on the day of transfusion, the incidence of hepatitis was reduced from 17.6 to 12.8%. From these and other results, it was concluded that the use of this phytochemical is effective for the prevention of post-transfusion hepatitis.