Flavonoids have antitumoral properties and may be attractive candidates as anticancer therapy. Isoliquiritigenin which is a constituent of licorice (Glycyrrhiza inflata), a plant commonly used in traditional Uyghur medicine in Xinjiang, China, was studied for antiproliferative and apoptotic activity in human cervical cancer cells, Ca Ski, SiHa, HeLa, and C-33A. Its molecular mechanism of action was specifically examined in Ca Ski cells. Isoliquiritigenin decreased cell viability, induced cell accumulation in G2/M and morphological and biochemical features of apoptosis in the four cancer cell lines. In Ca Ski cells, isoliquiritigenin led to a downregulation of HPV16 E6 expression associated with an increase of p53 and p21 levels, enhanced expression of Bax and decreased expression of Bcl-2 and Bid proform triggering dissipation of the mitochondrial membrane potential, released cytochrome c to the cytosol followed by activation of caspase cascade with cleavage of caspase-9, caspase-3, and PARP. Caspase-8 was also cleaved. Moreover treatment with a pan-caspase inhibitor prevented apoptosis. As Ca Ski cells are representative of carcinoma naturally occurring in the cervix, our results suggest a potential benefit of isoliquiritigenin for cervical cancer prevention and treatment.

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The polysaccharide extract (PE) of Uyghur medicinal preparation Alhagi-honey was prepared by water extraction and alcohol precipitation method. The purified polysaccharide AP1-1 was obtained from PE by macroporous adsorption resin chromatography, DEAE cellulose chromatography, and Sephadex gel chromatography; the homogeneity and the molecular weight of AP1-1 were determined by gel filtration; and the acid hydrolysis, periodate oxidation, Smith degradation, and NMR analysis were used to analyze the chemical structure of AP1-1. The result showed that AP1-1 was a homogeneous polysaccharide, whose relative molecular weight was 9.97 × 10(4). Through high-performance capillary electrophoresis analysis, we found that its molecular structure was composed of mannose, glucose, galactose, and galacturonic acid with a molar ratio of about 1.1:1.9:3.9:2.1. The main chain of AP1-1 was mainly made up of → 4)β-d-GalpA-(1 → 4)β-d-GalpA-(1 → 4)-β-d-Galp-(1 → 4)-β-d-Galp-(1 → 6)α-d-Glcp-(1 → 4)α-d-Glcp(1 → , while the side chain is composed of → 6)-α-d-Glcp and 2-CH3-α-d-Man.