Quercetin and Mesenchymal Stem Cell Metabolism: A Comparative Analysis of Young and Senescent States

Abstract

Quercetin is a natural flavonoid renowned for its potent antioxidant, anti-inflammatory, anti-diabetic, and antibacterial properties, making it a highly promising candidate for the treatment of various medical conditions. Our current study investigates the influence of quercetin on energy metabolism, fatty acid composition, oxidative stress gene expression, and sirtuin expression in early- and late-stage passages of stem cells derived from human exfoliated deciduous teeth (SHEDs). Mitochondrial respiration was analyzed by measuring oxygen consumption following a 24 h quercetin treatment, while fatty acid profiles were examined using gas chromatography-mass spectrometry (GC-MS). Additionally, quantitative PCR (qPCR) was used to assess the expression of oxidative stress genes and sirtuins. In younger SHEDs, quercetin enhances metabolic activity and mitochondrial respiration, although higher doses may decrease mitochondrial activity. Conversely, in older, senescent SHEDs, quercetin supports mitochondrial function at lower concentrations but appears to inhibit respiration at higher doses. These results suggest that quercetin may hold therapeutic potential for maintaining SHED viability and function, especially at lower doses in older cells. Further research is essential to fully elucidate a dose-dependent effect of quercetin and optimize its applications in regenerative medicine.

Keywords: antioxidants; fatty acids; human exfoliated deciduous teeth; mitochondria; senescence.

Figure 1

β-galactosidase activity was assessed in SHED cells at early (P5) and late passages (P16). Senescent cells stained blue due to β-galactosidase activity, allowing for visual quantification under a Zeiss Axio Observer Z1 microscope, at magnifications of 200× (A,C) and 400× (B,D). Passage 5 (A,B) represents cells at a younger stage, showing a baseline level of senescence, while passage 16 (C,D) reflects an advanced stage with likely higher senescence levels. The increase in blue-stained cells at higher passages reflects a greater accumulation of senescent cells as cell passage advances. The percentage of senescent cells was determined by calculating the ratio of β-gal-positive cells to the total cell count, expressed as a percentage for early-passage (E) and late-passage (F) cells.

Figure 2

MTT assay. Effect of quercetin on cell proliferation in younger (P5) and older (P16) SHED cell passages across quercetin dose groups (1 µM, 3 µM, 7 µM, and 10 µM) after 24 h of treatment. Data are presented as mean ± SD relative to cells cultured in control media. No significant differences in cell viability were observed.

Figure 3

Oxygen consumption rates of SHED cells following quercetin treatment, measured with the Oroboros O2k System. Oxygen consumption was evaluated in early-passage (P5) and late-passage (P16) SHED cells to determine the effects of quercetin treatment at 1 µM and 10 µM. The impact of quercetin on routine respiration (R), maximum respiration (M), leak respiration (L), and oxidative phosphorylation (OXPHOS) is shown. Statistically significant differences between control and quercetin-treated groups are indicated by asterisks ** p < 0.001; *** p < 0.0001. Representative Oroboros oxygraphs illustrating oxygen consumption and basal respiration, measured using high-resolution respirometry, are available in the Supplementary Files (Figure S1).

Figure 4

Effect of quercetin on the fatty acid profile in younger and older SHEDs. Data are presented as mean ± SD from three independent experiments. Statistically significant differences between control and quercetin-treated groups are indicated by asterisks * p < 0.05; ** p < 0.001; *** p < 0.0001.

Figure 5

Effect of quercetin (1 µM and 10 µM) on saturated and unsaturated fatty acid levels in younger (P5) and older (P16) SHEDs, as analyzed by GC-MS. Data are presented as mean ± SD from three independent experiments. Statistically significant differences between the older quercetin-treated group and both the younger and older passage control groups are marked with asterisks (p < 0.0001).

Figure 6

Oxidative stress gene expression levels (PPARγ, ACC, Ahr, SOD, and CYP1A1) in SHEDs were measured by qPCR, with GAPDH used as the reference gene. Data are presented as the mean  ±  SEM from three independent experiments. Statistical significance is indicated as * p < 0.05; ** p < 0.001; *** p < 0.0001.

Figure 7

Sirtuins gene expression levels were measured by qPCR, with GAPDH as the reference gene. Data are presented as the mean  ±  SEM from three independent experiments. Statistical significance is indicated as * p < 0.05; ** p < 0.001; *** p < 0.0001.