Evaluation of Calu-3 cell lines as an in vitro model to study the inhalation toxicity of flavoring extracts.

This study aimed to evaluate the characteristics of Calu-3 cells as a model to examine the toxicological responses of inhalable substances. Calu-3 cells were grown to the confluence at an air-liquid interface (ALI) using a Transwell® permeable support system. The ALI resulted in biomimetic native bronchial epithelium displaying pseudostratified columnar epithelium with more microvilli and secretory vesicles. We further characterized and optimized the Calu-3 cell line model using ALI culturing conditions, immunolabeling of protein expression, ultrastructural analysis using scanning electron microscopy (SEM), and transepithelial electrical resistance (TEER) measurements, and then screened for the cytotoxicity of tobacco flavoring extracts. Calu-3 cells displayed dose-dependent responses when treated with the flavoring extract. Within 8-10 days, cell monolayers developed TEER ≥1000 Ω·cm2. During this time, Calu-3 cells exposed to flavoring extracts X01 and X06 exhibited a loss of cellular integrity and decreased ZO-1 and E-cadherin protein expression. In conclusion, we investigated the Calu-3 cell line culture conditions, culture time, and barrier integrity and tested the effect of six new synthetic tobacco flavoring extracts. Our data demonstrate that the Calu-3 human bronchial epithelial cell monolayer system is a potential in vitro model to assess the inhalation toxicity of inhalable substances.

Comparative anti-inflammatory effect of curcumin at air-liquid interface and submerged conditions using lipopolysaccharide stimulated human lung epithelial A549 cells.

BACKGROUND: Inhalation of aerosolized drugs is a promising entry route for rapid and non-invasive therapeutics delivery to the lung. Curcumin exhibits potent anti-inflammatory properties, which are effective for use in lung diseases. The anti-inflammatory properties of curcumin have been widely studied in vitro with cells cultured in submerged conditions, however, the effectiveness using air-liquid interface (ALI) exposure is currently unknown. METHODS: The anti-inflammatory effect of curcumin under both ALI and submerged conditions was investigated in the present study. Lipopolysaccharide (LPS) stimulated A549 cells were exposed to curcumin under ALI (10-100 µM) using a dose-controlled air-liquid interface cell exposure (ALICE)-CLOUD system and submerged cell culture conditions (1-20 µM). The expression of pro-inflammatory cytokines (interleukin (IL)-6, IL-8), cell viability and cytotoxicity were studied for each exposure scenario. The cellular uptake behaviour of curcumin was studied with an equipotent cell-based dose (200 pmol/106 cell) at various time points up to 24 h. RESULTS: The ALI delivery profile proved to be rapid, efficient and reproducible. For the doses studied, no significant effect on cell viability and cytotoxicity were observed. ALI exposure of curcumin was more effective in reducing pro-inflammatory cytokines expression in lung epithelial cells compared with submerged cell cultures. Furthermore, rapid cellular uptake and higher intracellular doses were achieved by ALI conditions. CONCLUSIONS: The ALICE-CLOUD system combined with lung epithelial cells cultured under ALI conditions offers a reliable and relevant in vitro method for preclinical aerosolized drug screening. Curcumin might be a promising anti-inflammatory candidate drug for inhalation therapy of lung diseases.

Determination of d-limonene in mice plasma and tissues by a new GC-MS/MS method: Comparison of the pharmacokinetics and tissue distribution by oral and inhalation administration in mice.

The aim of the present study was to develop a method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) to determine and quantify the d-limonene in mouse plasma and tissue samples. This new method was validated for the quantification of d-limonene with the linearity ranges 1.0-1000.0 ng/mL (r2 > 0.9952) for plasma samples and 5.0-5000.0 ng/g (r2 > 0.9940) for tissue samples. The intra- and inter-day assay of precisions in plasma and tissues were <13.4% and the accuracies were within 91.1-105.8%. In the oral/inhalation administration pharmacokinetics and tissue distribution studies, the main pharmacokinetic parameters were the peak concentration = (97.150 ± 34.450)/(4336.415 ± 1142.418) ng/mL, the area under the curve = (162.828± 27.447)/(2085.721 ± 547.787) h ng/mL and the half-life = (3.196 ± 0.825)/(0.989 ± 0.095) h. The tissue distribution of d-limonene in mice after oral/inhalation administration demonstrated a decreasing tendency in different tissues (liver > kidney > heart > lung > spleen).

[Study on early change features of microRNA in the peripheral blood of Sophorae tonkinensis radix et rhizoma induced liver injury rats].

OBJECTIVE: To study early change features of microRNA (miRNA) in the peripheral blood of Sophorae Tonkinensis Radix et Rhizoma induced liver injury rats, and to look for the miRNA biomarkers in the peripheral blood of early liver injury. METHODS: Sixty Wistar rats were randomly divided into the control group and the Sophorae Tonkinensis Radix et Rhizoma (abbreviated as STRR) group, 30 in each group. Rats in the STRR group was administered with STRR decoction at 12 g/kg (2 mL/100 g), while equal volume of the distilled water was given to those in the control group. Rats were anesthetized on day 3, 7, 14, and 28, and 28 days after withdrawal. The serum samples were withdrawn. The alanine aminotransferase (ALT), aspartate transaminase (AST), total bile (TBIL), alkaline phosphatase (ALP), total protein (TP), and albumin (ALB) were detected. The globulin (GLO) level was calculated. HE staining was performed on the liver tissue to observe the pathomorphological changes. The whole blood was collected on day 7, 14, and 28 to perform the microarray test. The differentially expressed miRNAs were screened and verified by RT-PCR. RESULTS: The ALT activity obviously increased on day 7 - 28 in the STRR group (P <0.05). The histopathological results showed the degeneration and swelling of the liver cells on day 28. In the microarray test, there were 11, 22, and 13 up regulated expressed miRNAs on day 7, 14, and 28, respectively. There were 1, 13, 2 down regulated expressed miRNAs on day 7, 14, and 28, respectively. By target gene prediction and pathway analysis of differentially expressed miRNA on day 7, 14, and 28, they involved in regulating and controlling signal transduction, cellular interaction, cytoskeleton. Differentially expressed miRNA might possibly participate in the process of liver injury. The RT-PCR result of the expression of miR-291a-5p with the peak time efficiency on day 7 showed that the expressions of miR-291a-5p in the peripheral blood and the liver tissue were basically identical. CONCLUSION: miR-291a-5p could early indicate the liver injury, which could be taken as one of an early marker in STRR induced liver injury.