Related Experiment Video
Updated: Oct 28, 2026

Mitochondrial Respiration Quantification in Yeast Whole Cells
Published on: November 8, 2024
Quercetin Differentially Modulates MTT-Derived Cellular Metabolic Activity and Apoptosis-Related Gene Expression in
Deniz Özkan Vardar1, Tuğçe Duran2, Merve Aydın3
1Pharmacy Services Program, Vocational School of Health Services, Lokman Hekim University, 06510 Ankara, Türkiye.
Background/Objectives:
Quercetin is a dietary flavonoid with potential anticancer activity, but comparative effects in malignant and non-malignant lung-derived epithelial cells remain incompletely characterized.
Methods:
A549 and BEAS-2B cells were exposed to quercetin (1-250 µM) for 24, 48, and 72 h, and MTT-derived cellular metabolic activity was measured. Mean normalized concentration-response curves from three independent biological experiments (n = 3) were fitted with four-parameter logistic models, and Greenhouse-Geisser-corrected cell line × concentration × time interactions were tested. Apoptosis-related gene expression was assessed by qRT-PCR after exposure to 45 µM quercetin for 48 h; 45 µM was not a discrete concentration in the MTT series and was close to the directly tested 40 µM condition.
Results:
Apparent MTT-derived IC50 values were 58.28 µM (95% CI 44.18-74.81) for A549 and 121.22 µM (89.50-164.66) for BEAS-2B at 48 h, and 2.73 µM (2.31-3.67) and 1.49 µM (1.27-1.77), respectively, at 72 h. Cell line × concentration interactions were significant at all exposure times, as was the cell line × concentration × time interaction; transcriptional profiles differed descriptively between cell lines.
Conclusions:
The fitted IC50 ordering reversed between 48 and 72 h, so a stable cancer-selective response is not supported. MTT reflects metabolic activity rather than cell death, and transcript changes do not establish functional apoptosis.
