Effects of an ethyl acetate extract of Daphne altaica stem bark on the cell cycle, apoptosis and expression of PPARγ in Eca­109 human esophageal carcinoma cells.

Daphne altaica Pall. (D. altaica; Thymelaeaceae) has long been used in traditional Kazakh medicine for the treatment of cancer and respiratory diseases. Previous studies have demonstrated the in vitro anticancer effects of D. altaica extract and its constituents in certain cancer cell lines; however, the underlying molecular mechanisms are not completely understooD. The present study aimed to investigate the molecular mechanisms underlying the activity of an ethyl acetate extract of D. altaica (Da­Ea) by assessing its effects on cell morphology, cell apoptosis, cell cycle progression and the expression levels of peroxisome proliferator­activated receptor γ (PPARγ) in Eca­109 cells. Cell morphology was observed under a phase contrast microscope. Cell apoptosis and cell cycle progression were assessed by flow cytometry following Annexin V/propidium iodide (PI) double staining and PI single staining, respectively. The mRNA and protein expression levels of PPARγ were determined by reverse transcription­quantitative PCR and western blotting, respectively. Compared with the control group, the percentage of apoptotic cells, cell cycle arrest at S phase and apoptotic morphological cell characteristics were increased in Da­Ea­treated Eca­109 cells. Furthermore, Da­Ea treatment upregulated the mRNA and protein expression levels of PPARγ compared with the control cells. High­performance liquid chromatography with diode­array detection indicated that daphnetin­7­O­ß­D­glucoside, daphnetin, demethyldaphnoretin­7­O­ß­D­glucopyranoside and genkwanol A were the main constituents of Da­Ea. Collectively, the results suggested that Da­Ea displayed antiproliferative activities in Eca­109 cells by inducing apoptosis and S phase cell cycle arrest, as well as upregulating PPARγ expression levels.

Inhibition of NLRP3 inflammasome-mediated pyroptosis in macrophage by cycloastragenol contributes to amelioration of imiquimod-induced psoriasis-like skin inflammation in mice.

Psoriasis is a common chronic inflammatory skin disease, and the infiltrated macrophages in psoriatic skin lesions play a key role in the progression of this uncontrolled cutaneous inflammation. However, the current therapeutic strategies for patients with psoriasis are not satisfactory. Here, we report that cycloastragenol (CAG), a natural active small compound isolated from Astragalus membranaceus, significantly ameliorated imiquimod (IMQ)-induced psoriasiform dermatitis in mice by targeting proinflammatory macrophages. CAG significantly reduced the clinical scores, decreased the epidermal thickness, and ameliorated the deteriorating histopathology observed in IMQ-induced mice. CAG treatment specifically reduced the dermal infiltration of macrophages, rather than of dendritic cells, neutrophils, or T lymphocytes, into psoriatic skin. CAG dose-dependently decreased the level of proinflammatory cytokines, including IL-1ß, TNF-α and IL-6, in murine psoriatic skin and serum, as well as in IMQ-stimulated, bone-marrow-derived macrophages. When compared to the control group, CAG significantly decreased IMQ-triggered NLRP3 inflammasome activation and gasdermin D-mediated cell pyroptosis in these proinflammatory macrophages. CAG also suppressed the assembly of the NLRP3 inflammasome complex. Taken together, the results show that CAG selectively modulates macrophage function by inhibiting NLRP3 inflammasome-mediated pyroptosis to ameliorate IMQ-induced psoriasis-like skin inflammation in mice. Our findings also identify an effective drug candidate for the treatment of psoriasis.

Dihydrochalcone-derived polyphenols from tea crab apple (Malus hupehensis) and their inhibitory effects on α-glucosidase in vitro.

Three dihydrochalcone-derived polyphenols, huperolides A-C (1-3), along with thirteen known compounds (4-16) were isolated from the leaves of Malus hupehensis, the well-known tea crab apple in China. Their chemical structures were elucidated by extensive spectroscopic analysis including NMR (HSQC, HMBC, 1H-1H COSY and ROESY), HRMS and CD spectra. Huperolide A is a polyphenol with a new type of carbon skeleton, while huperolides B and C are a couple of atropisomers, which were isolated from natural sources for the first time. The antihyperglycemic effects of the isolated compounds were evaluated based on assaying their inhibitory activities against α-glucosidase. As a result, phlorizin (4), 3-hydroxyphloridzin (5), 3-O-coumaroylquinic acid (12) and ß-hydroxypropiovanillone (15) showed significant concentration-dependent inhibitory effects on α-glucosidase. Therefore, those compounds might be responsible for the antihyperglycemic effect of this herb, and are the most promising compounds to lead discovery of drugs against diabetes.

Two New Chromone Glycosides from the Roots of Saposhnikovia divaricata.

Five chromone glycosides were isolated from the water-soluble portions of 70% EtOH extract of the roots of Saposhnikovia divaricata, including two new chromone glycosides 1 and 2. The structures of the chromone glycosides were identified as (3'S)-3'-O-ß-d-apiofuranosyl-(1 → 6)-ß-d-glucopyranosylhamaudol (1), (2'S)-4'-O-ß-d-apiofuranosyl-(1 → 6)-ß-d-glucopyranosylvisamminol (2), 3'-O-glucopyranosylhamaudol (3), 4'-O-ß-d-glucopyranosylvisamminol (4), and 4'-O-ß-d-glucopyranosyl-5-O-methylvisamminol (5) on the basis of extensive spectroscopic methods, and the absolute configurations of the new compounds were elucidated by the electronic circular dichroism (ECD) calculation and acid hydrolysis. The cytotoxic activities of the glycosides 1 - 5 against three human cancer cell lines (PC-3, SK-OV-3, and H460) were evaluated. The result showed that compounds 1 - 5 had weak cytotoxic activities against the human cancer cell lines with IC50 values in the range of 48.54 ± 0.80 - 94.25 ± 1.45 µm.