The objective of this study was to investigate the mechanisms by which berberine is transported in the secretory and absorptive directions across Caco-2 cell monolayers. The basolateral-to-apical (B-A) flux was 30-fold greater than the apical-to-basolateral flux and temperature dependent (i.e., drastic decrease at 4 degrees C compared with 37 degrees C). The above results suggest the involvement of a carrier-mediated active transport mechanism for the B-A transport of berberine. However, no significant concentration dependency for the permeability (P(app)) of berberine was observed for B-A transport over a concentration range of 5-300 microM, indicating that the K(m) value of berberine for the carrier system is greater than 300 microM. Well-documented P-glycoprotein (P-gp) substrates such as verapamil, daunomycin, and rhodamine123 inhibited the B-A flux of berberine, whereas tetraethylammonium and taurocholate did not, suggesting that P-gp is involved in the transport. For the case of daunomycin, the B-A flux, but not the apical-to-basolateral flux, was significantly increased after pretreatment of the cell monolayers with berberine. In addition, the uptake of 1 microM daunomycin into Caco-2 cells was decreased as a result of this pretreatment. These results suggest that the repeated administration of berberine may up-regulate P-gp functions in Caco-2 cells. If this occurs in the gastrointestinal epithelial cells, the repeated administration of berberine may reduce the gastrointestinal absorption of P-gp substrates including chemotherapeutic agents such as daunomycin.
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http://dx.doi.org/10.1002/jps.10268 | DOI Listing |
Cytotechnology
April 2025
University Centre for Research and Development, University Institute of Pharmaceutical Sciences, Chandigarh University, Gharuan, Mohali, 140413 India.
When juxtaposed with 2D cell culture models, multicellular tumor spheroids demonstrate a capacity to faithfully replicate certain features inherent to solid tumors. These include spatial architecture, physiological responses, the release of soluble mediators, patterns of gene expression, and mechanisms of drug resistance. The morphological and behavioural similarities between 3D-cultured cells and cells within tumor masses highlight the potential of these models in studying cancer biology and drug responses.
View Article and Find Full Text PDFNat Rev Phys
May 2020
Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona, Spain.
Living tissues are active multifunctional materials capable of generating, sensing, withstanding and responding to mechanical stress. These capabilities enable tissues to adopt complex shapes during development, to sustain those shapes during homeostasis, and to restore them during healing and regeneration. Abnormal stress is associated with a broad range of pathologies, including developmental defects, inflammatory diseases, tumor growth and metastasis.
View Article and Find Full Text PDFActive fluids are driven out of thermodynamic equilibrium by internally generated forces, causing complex patterns of motion. Even when both the forces and motion are measurable, it is not yet possible to relate the two, because the sources of energy injection and dissipation are often unclear. Here, we study how energy is transferred by developing a method to measure viscosity from the shear stresses and strain rates within an epithelial cell monolayer.
View Article and Find Full Text PDFIn confluent cell monolayers, patterns of cell forces and motion are systematically altered near topological defects in cell shape. In turn, defects have been proposed to alter cell density, extrusion, and invasion, but it remains unclear how the defects form and how they affect cell forces and motion. Here, we studied +1/2 defects, and, in contrast to prior studies, we observed both tail-to-head and head-to-tail defect motion occurring at the same time in the same cell monolayer.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
A fluoroalkyl-containing electron acceptor (Y-SSM) is designed and synthesized to control the orientation of the benchmark non-fullerene acceptor Y6 in thin films. Due to the low surface energy of the two fluoroalkyl chains at the terminal part of Y-SSM, it spontaneously segregates to the film surface during spin coating, forming a monolayer of edge-on oriented Y-SSM. The Y-SSM monolayer leads to crystallization of the underlying Y6 to induce a standing-up orientation in the bulk of the films, which is strikingly different from pure Y6 films that tend to be a face-on orientation.
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