Figure 1
Radical-scavenging capacity of GRE determined with the DPPH (A) and ABTS assays (B), expressed as a percentage of inhibition. GRE – yellow gentian (Gentiana lutea L.) root extract; DPPH – 2,2-diphenyl-1-picrylhydrazyl; ABTS – 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid
Figure 2
Genotoxicity (MN frequency, A and C panels) and cytotoxicity (CBPI, B and D panels) in PBMC cultures treated with GRE or HU alone. *P<0.05, **P<0.01, ***P<0.001 treatments vs control. CBPI – cytokinesis-block proliferation index; GRE – yellow gentian (Gentiana lutea L.) root extract; HU – hydroxyurea; MN – micronucleus; PBMC – peripheral blood mononuclear cell
Table 1
Frequencies of micronuclei, nuclear buds, and nucleoplasmic bridges in individual treatments (optimisation experiment) and PBMC cultures pre-treated with GRE followed by HU treatment
| Micronucleus frequency (per 1000 binuclear cells) | Nuclear bud frequency (per 1000 binuclear cells) | Nucleoplasmic bridge frequency (per 1000 binuclear cells) | |
|---|---|---|---|
| Optimisation experiment | |||
| Control | 8.17±0.4 | 6.33±0.49 | / |
| HU 50 µmol/L | 13.07±0.4 | 12±0.89 | 1.66±0.31 |
| HU 100 µmol/L | 18.67±0.33 | 17.83±0.95 | 3.17±0.31 |
| HU 200 µmol/L | 20.25±0.63 | 18.67±1.28 | 4.67±0.49 |
| GRE 0.25 mg/mL | 5.75±0.44 | 8.83±0.6 | / |
| GRE 0.5 mg/mL | 4.67±0.54 | 8.5±0.76 | / |
| GRE 1 mg/mL | 5.67±0.4 | 9.5±0.92 | / |
| GRE 2 mg/mL | 8.25±0.6 | 10.83±0.83 | / |
| Pre-treatment (100 µmol/L HU+GRE) | |||
| Control | 7.83±0.7 | 5.5±0.43 | / |
| HU 100 µmol/L | 16.83±0.48 | 16.17±0.87 | / |
| GRE 0.25 mg/mL+HU | 11.92±1.19 | 25.67±0.84 | / |
| GRE 0.5 mg/mL+HU | 10.58±0.8 | 25.17±0.65 | / |
| GRE 1 mg/mL+HU | 11.33±0.67 | 35.67±1.98 | / |
| GRE 2 mg/mL+HU | 9.25±0.93 | 30.17±1.2 | / |
Figure 3
Representative photomicrographs of binuclear cells (CBMN assay): HU treatment (A, B, C), micronuclei (red arrows) and nucleoplasmic bridges (blue arrows); GRE pre-treatment and HU treatment (D, E, F), micronuclei (red arrows) and nuclear buds (green arrows) (scale bar=10 µm). CBMN – cytokinesis-block micronucleus; GRE – yellow gentian (Gentiana lutea L.) root extract; HU – hydroxyurea
Figure 4
Genoprotective potential of GRE (CBMN assay): MN frequency (A) and CBPI (B) in PBMC cultures pre-treated with GRE followed by HU treatment. #P<0.05; ##P<0.01; ###P<0.001 – GRE pre-treatment vs HU treatment; ***P<0.001 – HU treatment vs control. CBPI – cytokinesis-block proliferation index; GRE – yellow gentian (Gentiana lutea L.) root extract; HU – hydroxyurea; MN – micronucleus; PBMC – peripheral blood mononuclear cell
Figure 5
Oxidative stress parameters (A and B panels) and gene expression (C panel) in PBMC in cultures exposed to GRE and HU. #P<0.05 – GRE pre-treatment vs HU treatment; **P<0.01 and ***P<0.001 – GRE pre-treatment vs control. GRE – yellow gentian (Gentiana lutea L.) root extract; GSH – reduced glutathione; HU – hydroxyurea; PAB – pro-oxidant/antioxidant balance; PBMC – peripheral blood mononuclear cell