Glycyrrhizin exhibits potential chemopreventive activity on 12-O-tetradecanoyl phorbol-13-acetate-induced cutaneous oxidative stress and tumor promotion in swiss albino mice

Figures & data

Figure 1 Structure of Glycyrrhizin.

Table I.  Effect of prophylactic treatment of animals with glycyrrhizin on TPA–mediated cutaneous glutathione, and glutathione-S-transferase in murine skin.

Treatment groups	Reduced glutathione (nmol GSH/gm tissue)	Glutathione-S-transferase (nmol CDNB conjugate formede/min/mg protein)
Acetone (0.2 mL/animal	25.64 ± 1.00	337.33 ± 4.37
TPA (20 nmol/0.2 mL acetone/animal)	17.85 ± 0.53^###	278.7 ± 0.76^###
Glycyrrhizin (2 mg/0.2 mL acetone/animal) + TPA (20 nmol/0.2 mL acetone/animal)	19.21 ± 0.59*	284.88 ± 2.52^***
Glycyrrhizin (4 mg/0.2 mL acetone/animal) + TPA (20 nmol/0.2 mL acetone/animal)	21.21 ± 0.59^**	326.41 ± 0.59^***
Glycyrrhizin (4 mg/0.2 mL acetone/animal)	23.90 ± 0.79	332.90 ± 0.78

Each value represents mean ± SE of six animals. Values marked with hatch differ significantly from the corresponding value for the acetone-treated control (p < 0.05, p < 0.01, ^###p < 0.001). Values marked with asterisks differ significantly from the corresponding value for mice treated with the TPA – treated control (*p < 0.05, ^**p < 0.01, ^***p < 0.001).

Table II.  Effect of prophylactic treatment of animals with glycyrrhizin on TPA-mediated cutaneous glutathione peroxidase and glutathione reductase in murine skin.

Treatment groups	Glutathione peroxidase (nmol NADPH oxidized/min/mg protein)	Glutathione reductase (nmol NADPH oxidized/min/mg protein)
Acetone (0.2 mL/animal	333.75 ± 5.62	198.53 ± 4.73
TPA (20 nmol/0.2 mL acetone/animal)	263.39 ± 3.67^###	90.32 ± 3.11^###
Glycyrrhizin (2 mg/0.2 mL acetone/animal) + TPA (20 nmol/0.2 mL acetone/animal)	281.84 ± 2.87^***	120.41 ± 4.79*
Glycyrrhizin (4 mg/0.2 mL acetone/animal) + TPA (20 nmol/0.2 mL acetone/animal)	312.41 ± 2.69^***	158.85 ± 4.82^***
Glycyrrhizin (4 mg/0.2 mL acetone/animal)	320.29 ± 2.56	187.62 ± 4.57

Each value represents mean ± SE of six animals. Values marked with hatch differ significantly from the corresponding value for the acetone-treated control (p < 0.05, p < 0.01, ^###p < 0.001). Values marked with asterisks differ significantly from the corresponding value for mice treated with the TPA treated-control (*p < 0.05, ^**p < 0.01, ^***p < 0.001).

Table III.  Effect of prophylactic treatment of animals with glycyrrhizin on TPA-mediated cutaneous catalase and lipid peroxidation in murine skin.

Treatment groups	Catalase (nmol H2O2 consumed/min/mg protein)	Lipid Peroxidation (nmol malondialdehyde formed/hr/gm tissue)
Acetone (0.2 mL/animal)	37.84 ± 0.72	5.43 ± 0.062
TPA (20 nmol/0.2 mL acetone/animal)	11.74 ± 0.82^###	7.22 ± 0.054^###
Glycyrrhizin (2 mg/0.2 mL acetone/animal) + TPA (20 nmol/0.2 mL acetone/animal)	19.11 ± 0.39*	4.01 ± 0.050^***
Glycyrrhizin (4 mg/0.2 mL acetone/animal) + TPA (20 nmol/0.2 mL acetone/animal)	23.98 ± 0.29^***	3.58 ± 0.055^***
Glycyrrhizin (4 mg/0.2 mL acetone/animal)	32.47 ± 0.419	4.63 ± 0.034

Each value represents mean ± SE of six animals. Values marked with hatch differ significantly from the corresponding value for the acetone-treated control (p < 0.05, p < 0.01, ^###p < 0.001). Values marked with asterisks differ significantly from the corresponding value for mice treated with the TPA-treated control (*p < 0.05, ^**p < 0.01, ^***p < 0.001).

Figure 2 Effect of pretreatment of mice with Glycyrrhizin on TPA – mediated enhancement of ornithine decarboxylase (ODC) activity and ³H incorporation in skin DNA in mice. Each value represents mean ± SE of six animals. Acetone-treated group served as control. Values marked with asterisks differ significantly from the corresponding value for mice treated with TPA – treated control (^***p < 0.001). Values marked with hatch differ significantly from the corresponding value for acetone-treated control (^###p < 0.001).