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Description
Liquiritin (LIQ, Liquiritoside, Liquiritigenin-4'-O-glucoside) is a main component among the licorice flavonoids, and possesses anti-inflammatory and anti-cancer abilities.
In vitro
Liquiritin exerts neuroprotective and neurotrophic effects on primary cultured hippocampal cells. Liquiritin may enhance cell survival by increasing the protein expression level of glucose-6 phosphate dehydrogenase. Liquiritin potentiates neurite outgrowth induced by nerve growth factor in PC12 cells. It affects particular types of cells such as neurons in the central nervous system. Liquiritin increases the proliferation of B65 neuroblastoma cells.
In vivo
Liquiritin at doses of 50-100 mg/kg significantly improves the cognitive ability, restores the abnormal activities of glutathione peroxidase and superoxide dismutase, and decreases the levels of malondialdehyde,8-hydroxy-2′-deoxyguanosine and protein carbonyl in the hippocampus of rats with Alzheimer's disease. Liquiritin can significantly ameliorate Aβ1-42-induced spatial learning and memory impairment by inhibiting oxidative stress and neural apoptosis. It is also frequently used to treat injury or swelling owing to its life-enhancing properties, as well as detoxification in traditional oriental medicine. It exerts significant antidepressant-like effects on the forced swimming and tail suspension tests in mice. It can also produce obvious neuroprotective effects on focal cerebral ischemia/reperfusion induced by middle cerebral artery occlusion. Liquiritin can protect neurons from Aβ-induced neurotoxicity. This ability probably involves the suppression of oxidative stress and neuron apoptosis in a rat model of Alzheimer disease (AD) induced by subsequent bilateral intrahippocampal (IH) injections of aggregated soluble oligomeric Aβ1-42. Liquiritin provides beneficial effects on the cognitive impairments observed in an Aβ1-42-induced model of AD. The neuroprotective effects of liquiritin are closely associated with its effects of inhibiting oxidative stress and neuronal apoptosis.
Protocol (from reference)
- Cell lines: B65 neuroblastoma cells
- Concentrations: --
- Incubation Time: 24, 48 and 72 h
- Method: The proliferation of B65 neuroblastoma cells was investigated by a WST-8 assay using a Cell Counting Kit-8. Once cells became confluent, they were plated into 96-well microplates at a density of 5×104/mL (5×103/well) and incubated with glycyrrhizin, isoliquiritin and liquiritin, which were first dissolved in dimethyl sulfoxide (DMSO). When cells were treated with these compounds, the final concentration of DMSO was set at 0.1% in the culture medium. When cells were treated with various cytotoxic reagents, such as hydrogen peroxide, monosodium glutamate, or menadione sodium bisulfate, these agents were directly dissolved in culture media following the description in each experiment. In general, this assay was performed after cells were cultured with each compound or reagent for 24, 48 and 72 h. After culture, the cells were incubated with WST-8 solution at 37℃ for 2 h, and the spectrophotometric absorbance of WST-8-formazan produced by dehydrogenase activity in the living cells at 450 nm.
Animal Research:
- Animal Models: Adult male Sprague-Dawley rats
- Dosages: 100, 50, or 25 mg/kg
- Administration: orally administered