ABSTRACT
BACKGROUND/AIM: The outlook for patients with high grade glioma (HGG) remains dismal. Hence, attention has focused on numerous innovative treatments. Our group has proposed a strategy on the use of a combination of polyphenols, as anti-invasive agents for the management of these neoplasms. MATERIALS AND METHODS: The aim of this study was to evaluate the in vitro effects of citrus flavonoids (tangeretin, nobiletin, naringin and limonin) and berry extracts (chokeberry, elderberry and bilberry) on selected mediators of invasion in 2 HGG cell cultures. RESULTS: The IC50 values could only be determined for tangeretin and chokeberry extract. The rest were non-functional in this context. Immunocytochemistry and flow cytometry results showed that chokeberry extract was most effective in down-regulating the expression of CD44. Similarly, RT-PCR data supported its ability to reduce gene expression of MMP-14 and EGFR. 2D invasion assays confirmed that inhibition is greater with chokeberry extract. CONCLUSION: Both polyphenols have anti-invasive potential but chokeberry extract is a stronger agent for glioma management.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Brain Neoplasms/drug therapy , Cell Movement/drug effects , Fruit , Glioma/drug therapy , Plant Extracts/pharmacology , Polyphenols/pharmacology , Antineoplastic Agents, Phytogenic/isolation & purification , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cell Line, Tumor , Citrus , ErbB Receptors/genetics , ErbB Receptors/metabolism , Fruit/chemistry , Glioma/genetics , Glioma/metabolism , Glioma/pathology , Humans , Matrix Metalloproteinase 14/genetics , Matrix Metalloproteinase 14/metabolism , Neoplasm Invasiveness , Plant Extracts/isolation & purification , Polyphenols/isolation & purification , Prunus , Tissue Inhibitor of Metalloproteinases/genetics , Tissue Inhibitor of Metalloproteinases/metabolism , Vaccinium myrtillusABSTRACT
BACKGROUND/AIM: The tetrazolium-based MTT cytotoxicity assay is well established for screening putative anti-cancer agents. However, it has limitations including lack of reproducibility with glioma cells treated with polyphenols. The aim of this study was to evaluate whether a flow cytometric assay with the anthraquinone, DRAQ7, was a better alternative than the colorimetric MTT assay for measuring cell viability. MATERIALS AND METHODS: Two glioma cell lines (IPSB-18, U373) and 1 pancreatic cancer cell line (AsPC-1) were treated with 4 polyphenols, namely red grape seed extract, red clover extract, anthocyanin-rich extract and curcumin. Cell viability was assessed using MTT assay and DRAQ7 staining. RESULTS: Limitations of MTT assay included lack of sensitivity and interference with the structure and absorbance spectra of polyphenols. Also, DMSO was toxic to glioma cells. Microscopic observations of cells treated with polyphenols confirmed the range of IC50 values evaluated by DRAQ7, but not by the MTT assay. CONCLUSION: DRAQ7 is a better alternative than MTT for measuring viability of glioma cells treated with brightly coloured polyphenols.
