Impact Assessment of Cadmium Toxicity and Its Bioavailability in Human Cell Lines (Caco-2 and HL-7702)

Abstract

Cadmium (Cd) is a widespread environmental toxic contaminant, which causes serious health-related problems. In this study, human intestinal cell line (Caco-2 cells) and normal human liver cell line (HL-7702 cells) were used to investigate the toxicity and bioavailability of Cd to both cell lines and to validate these cell lines as in vitro models for studying Cd accumulation and toxicity in human intestine and liver. Results showed that Cd uptake by both cell lines increased in a dose-dependent manner and its uptake by Caco-2 cells (720.15 µg mg−1 cell protein) was significantly higher than HL-7702 cells (229.01 µg mg−1 cell protein) at 10 mg L−1. A time- and dose-dependent effect of Cd on cytotoxicity assays (LDH release, MTT assay) was observed in both Cd-treated cell lines. The activities of antioxidant enzymes and differentiation markers (SOD, GPX, and AKP) of the HL-7702 cells were higher than those of Caco-2 cells, although both of them decreased significantly with raising Cd levels. The results from the present study indicate that Cd above a certain level inhibits cellular antioxidant activities and HL-7702 cells are more sensitive to Cd exposure than Caco-2 cells. However, Cd concentrations <0.5 mg L−1 pose no toxic effects on both cell lines.

Berberine Up-Regulates Hepatic Low-Density Lipoprotein Receptor through Ras-Independent but AMP-Activated Protein Kinase-Dependent Raf-1 Activation

“…HL-7702 cells, a normal human liver cell line, 13) were treated with BBR for different time intervals or at different concentrations; stimulation of Raf-1 signaling was revealed by Western blot analysis of p-Raf-1 (ser338) levels, as phosphorylation of Raf-1 at serine 338 is a hallmark of its activation. 16) In addition, as PMA, a kind of phorbol ester, was shown to activate Raf-1 and up-regulate LDL receptor in liver cells, 17) we used it as a positive control in order to verify the cell responsiveness and clearly show the activity of BBR on Raf-1 signaling.…”

“…In the present study, we explore the upstream signaling molecules of the ERK MAPK cascade after BBR administration and find that the efficacy of BBR on LDL receptor is dependent on AMPKmediated Raf-1 activation. Cell Culture HL-7702 cells, a normal human liver cell line, 13) were obtained from the Institute of Biochemistry and Cell Biology (SIBS, CAS, Shanghai, China). Cells were cultured in DMEM (high glucose) plus 10% FBS, 1% nonessential amino acids and antibiotics in an atmosphere of 5% CO 2 at 37°C.…”

Aloe-emodin Induces Apoptosis in Human Liver HL-7702 Cells through Fas Death Pathway and the Mitochondrial Pathway by Generating Reactive Oxygen Species

“…Moreover, aloe-emodin could induce primary damage to DNA in the cells of mouse livers and kidneys (Nesslany et al, 2009). The HL-7702 cells, which isolated from human normal liver, could express a distinct ultrastructure compared with hepatic carcinoma and is considered an ideal in vitro model for cytotoxicity investigation (Aziz et al, 2014;Sun et al, 2015). Currently, there are no available reports addressing the effects of aloe-emodin on apoptosis in human liver HL-7702 cells.…”

Human bioaccessibility and absorption by intestinal cells of potentially harmful elements from urban environmental matrices

“…DMEM (pH 6.5) to avoid cell lysis . The old medium was removed by vacuum aspirate and discarded; 5 mL of chyme + DMEM (pH 6.0 ± 0.2) was added to the cells and incubated for 2 h based on that proposed by Aziz et al (2014Aziz et al ( , 2015 and Ferruzza et al (2000). For the negative control, the cell line was treated with DMEM (pH 6.5) used to dilute the chyme and for the positive control the cells line were treated with DMEM (pH 6.5) and GI fluid.…”

“…The levels of PHE accumulated in the cells were expressed as ng mg -1 cell protein, according to the international units (Aziz et al, 2014). For that, aliquots of 20µL were withdrawn from each lysed cell sample to determine by the Bradford assay (Bradford, 1976) using bovine serum albumin (BSA) as the calibration standard.…”