Dietary licorice root supplementation reduces diet‐induced weight gain, lipid deposition, and hepatic steatosis in ovariectomized mice without stimulating reproductive tissues and mammary gland

Abstract

Scope We studied the impact of dietary supplementation with licorice root components on diet-induced obesity, fat accumulation and hepatic steatosis in ovariectomized C57BL/6 mice as a menopause model. Materials and Methods We evaluated the molecular and physiological effects of dietary licorice root administered to ovariectomized C57BL/6 mice as root powder (LRP), extracts (LRE) or isolated isoliquiritegenin (ILQ) on reproductive (uterus and mammary gland) and non-reproductive tissues important in regulating metabolism (liver, perigonadal, perirenal, mesenteric and subcutaneous fat). Quantitative outcome measures including body weight, fat distribution (MRI), food consumption, bone density and weight (DXA) and gene expression were assessed by the degree of restoration to the premenopausal health state. We characterized histological (H&E and oil red O staining) and molecular properties (expression of certain disease markers) of these tissues, and correlated these with metabolic phenotype as well as blood levels of bioactives. Conclusions Although LRE and ILQ provided some benefit, LRP was the most effective in reducing body weight gain, overall fat deposition, liver steatosis, and expression of hepatic lipid synthesis genes following ovariectomy. Our data demonstrate that licorice root provided improvement of multiple metabolic parameters under conditions of menopausal low estrogen and high-fat diets without stimulating reproductive tissues.

Isoliquiritigenin induces apoptosis of human bladder cancer T24 cells via a cyclin-dependent kinase-independent mechanism

“…Licorice is frequently used for culinary purposes in western countries (11–13), and is one of the most commonly used herbs in China for therapeutic effects on different diseases ranging from duodenal ulcers to cancers (14–16). ISL is a natural flavonoid isolated from the root of licorice ( Glycyrrhiza uralensis ).…”

Effects of isoliquiritigenin on ovarian antral follicle growth and steroidogenesis

“…Taking into account this paucity of information, a broad range of concentrations was chosen for the present study. The doses of 0.6 μM and 6 μM fall within the range of estimated human exposure to isoliquiritigenin (1–2 mg/kg) [6]. These doses are also representative of the plasma isoflavone levels that have been found in humans for other phytoestrogens such as daidzein and genistein [1, 19].…”

“…Licorice has been used extensively in traditional Asian and European medicine to treat conditions ranging from peptic ulcers, pharyngitis, and abdominal pain, to asthma, insomnia, malaria, and other infections [5]. Licorice may also be effective in weight loss and metabolic syndrome [5, 6]. Dietary supplements containing licorice are popular among women for relief from symptoms associated with premenopausal syndrome and menopause [5, 7].…”

“…Thus, exposure to isoliquiritigenin commonly occurs through various licorice-containing foods and products, as well as through the clinical use of isoliquiritigenin and licorice supplements for a wide variety of medical conditions. Average daily human exposure to isoliquiritigenin through the diet and/or supplements is estimated to be 1–2 mg/kg [6]. Chronic exposure is possible with high intake of licorice-flavored tobacco and in individuals consuming licorice tablets or capsules as a heath product [3].…”

“…Chronic exposure is possible with high intake of licorice-flavored tobacco and in individuals consuming licorice tablets or capsules as a heath product [3]. The female population may be more likely to be exposed to isoliquiritigenin, especially postmenopausal women seeking alternatives to traditional hormone replacement therapy [6, 7]. …”