Glycyrrhizic acid (GA), belonging to a class of triterpenes, is a conjugate of two molecules, namely glucuronic acid and glycyrrhetinic acid. It is naturally extracted from the roots of licorice plants. With its more common uses in the confectionery and cosmetics industry, GA extends its applications as a herbal medicine for a wide range of ailments. At low appropriate doses, anti-inflammatory, anti-diabetic, antioxidant, anti-tumor, antimicrobial and anti-viral properties have been reported by researchers worldwide. This review summarizes the effects of GA on metabolic syndrome, tumorigenesis, microbes and viruses, oxidative stress, and inflammation, as well as the reported side effects of the drug.

The purpose of this study was to investigate the possible mechanisms of Salvia miltiorrhiza (Sm) in carbon tetrachloride (CCl(4))-induced acute hepatotoxicity in rats. Male Wistar rats received a single dose of CCl(4) (2 ml/kg in corn oil, intraperitoneally). Three hours after CCl(4) intoxication, rats received either Sm (100 mg/kg) or silymarin (100 mg/kg) by gastrogavage twice a day for 2 consecutive days. CCl(4)-induced liver damage was shown by significant elevation of serum aminotransferase levels. Additionally, a significant decrease was observed in hepatic microsomal P450 2E1 protein content and hepatic concentrations of antioxidant enzymes. In contrast, rats given both Sm and silymarin supplement had less elevation of serum aminotransferase concentrations associated with less severe lobular damage of hepatocytes than rats receiving CCl(4) alone. Sm administration restored the reduction of hepatic microsomal P450 2E1 protein content as well as inducing an increase in hepatic glutathione concentration. On the other hand, administration of silymarin resulted in an elevation of hepatic superoxide dismutase levels. Moreover, both Sm and silymarin treatment inhibited the elevation of hepatic inducible nitric oxide (iNOS) protein content and nitrite concentration in liver homogenate 24 h after CCl(4) intoxication. We concluded that administration of Sm is effective in amelioration of CCl(4)-induced hepatotoxicity. This effect may be due to its ability to decrease the metabolic activation of CCl(4) by an increase in P450 2E1 protein content and its antioxidant activity associated with less increase in hepatic iNOS protein content.

Polycystic ovarian syndrome (PCOS) is an endocrine problem causing female infertility in about 5-10% of women at their reproductive age. It has strong association with the disruption of normal menstrual cycle in patients, particularly the elevation of androgen level. The causal factors to hyperandrogenism in PCOS include hyperglycemia, hyperinsulinemia, obesity, dyslipidemia and elevated luteining hormone: follicle stimulating hormone (LH:FSH) ratio. The current major treatments to PCOS are aiming at the targets that lower the androgen levels, in which insulin-sensitizing agents are the most commonly prescribed drugs. However, serious side effects have been reported with the current drugs, with such drawbacks, the discovery of new drug is therefore inevitable. Glycyrrhizic acid (GA), a triterpenoid saponin isolated from licorice root, was fed ad libitum to Sprague-Dawley PCOS female rats with 100mg/kg for 30 days. GA treatment led to general improvement in the lipid profile (P<0.05), serum glucose level (P<0.05) and improvement in the estrous cycle of PCOS rats. In the lipid profile of PCOS rats, GA significantly lower triglyceride by 50.61%, followed by total cholesterol (29.04%). Serum glucose of GA-treated PCOS rats was reduced by 20.32% compared to non-GA treated PCOS rats. Besides, there were 55.55% of GA-treated PCOS rats showed normalization of estrous cycle after 30 days of treatment.