A polysaccharide from pumpkin induces apoptosis of HepG2 cells by activation of mitochondrial pathway

Abstract

Purified white polysaccharide (PPW) is a homogenous polysaccharide isolated from pumpkin, with an average molecular weight of 34 kDa. In this study, we aimed at examining the anti-proliferative activity of PPW against hepatocellular carcinoma (HCC) HepG2 cells and the underlying mechanisms. We found that PPW-induced inhibition of cell proliferation in HepG2 cells was associated with the induction of apoptosis. Exposure of HepG2 cells to PPW (100, 200, and 400 μg/mL) resulted in a loss of mitochondrial membrane potential (Δψm) and the release of cytochrome c from the mitochondria to the cytosol. Also, Western blot analysis revealed dose-dependent increase of pro-apoptotic Bax protein and decrease of anti-apoptotic Bcl-2 protein in PPW-treated cells. Besides, caspase-9 and caspase-3 activities were also enhanced in HepG2 cells followed by PPW treatment. Additionally, the cleavage of poly (ADP-ribose) polymerase (PARP) was observed in PPW-treated HepG2 cells, which altogether account for apoptotic cell death. These results suggested that PPW-induced apoptosis involved a caspase-3-mediated mitochondrial pathway and may have potential as a cancer chemopreventive and therapeutic agent for the prevention and treatment of HCC.

Protective effect of Agrimonia pilosa polysaccharides on dexamethasone‐treated MC3T3‐E1 cells via Wnt/β‐Catenin pathway

“…15 The western blot results indicated that pre-treatment with AAP-AW, S1, S2 and S3 significantly reversed the downregu- There is abundant evidence suggesting that the Wnt/β-catenin signalling pathway was involved in the pathogenesis of early-stage ANFH by regulating osteoblast differentiation and bone formation. 15 The western blot results indicated that pre-treatment with AAP-AW, S1, S2 and S3 significantly reversed the downregu- There is abundant evidence suggesting that the Wnt/β-catenin signalling pathway was involved in the pathogenesis of early-stage ANFH by regulating osteoblast differentiation and bone formation.…”

“…21,22 Furthermore, the changes in the expression of Runx2, BMP-2, OSX and OCN were also investigated in MC3T3-E1 cells in response to different and so on. 15 The western blot results indicated that pre-treatment with AAP-AW, S1, S2 and S3 significantly reversed the downregu- There is abundant evidence suggesting that the Wnt/β-catenin signalling pathway was involved in the pathogenesis of early-stage ANFH by regulating osteoblast differentiation and bone formation. 15 The downstream genes of the Wnt/β-catenin pathway, such as Bcl-2 and c-myc, are responsible for the cell cycle and cell apoptosis.…”

“…15 The cells stained with 5 μL Annexin V-FITC (10 μg/mL) and 5 μL propidium iodide (PI, 5 μg/mL) were immediately analysed on a FACScan flow cytometry using Cell-Quest software (Becton Dickinson). 15 The cells stained with 5 μL Annexin V-FITC (10 μg/mL) and 5 μL propidium iodide (PI, 5 μg/mL) were immediately analysed on a FACScan flow cytometry using Cell-Quest software (Becton Dickinson).…”

“…Cell apoptosis was assessed by double staining with Annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) followed by flow cytometry analysis as described previously. 15 The cells stained with 5 μL Annexin V-FITC (10 μg/mL) and 5 μL propidium iodide (PI, 5 μg/mL) were immediately analysed on a FACScan flow cytometry using Cell-Quest software (Becton Dickinson). In each analysis, 10 000 events were recorded.…”

iTRAQ-Based Quantitative Proteomic Analysis of the Inhibitory Effects of Polysaccharides from Viscum coloratum (Kom.) Nakai on HepG2 Cells

“…Polysaccharides from pumpkins 30 , apples 31 , Taxus chinensis var . mairei 32 , and Ampelopsis megalophylla 33 have induced cell proliferation inhibition and apoptosis in tumor cells.…”