Immunosuppressive activity on the murine immune responses of glycyrol from Glycyrrhiza uralensis via inhibition of calcineurin activity

Figures & data

Figure 1.  Chemical structure of glycyrol (MW = 366.367).

Figure 2.  Inhibition of CN activity by glycyrol. The phosphopeptide ³²P-RII was used as a substrate. The CN activity is shown as percentage of control group in the normal condition. The data represent mean ± SD of three independent experiments. The degree of freedom between groups is 10, as well as 22 within groups.

Table 1.  Inhibition of Con A-induced lymphocyte proliferation by glycyrol in vitro.

Groups	Concentration (μM)	OD570 value	Inhibitory rate (%)
control	0	0.262 ± 0.004	—
+glycyrol	3	0.250 ± 0.006	—
	6	0.236 ± 0.004*	9.92
	12	0.134 ± 0.013**	48.96
	30	0.094 ± 0.008**	64.21
	60	0.055 ± 0.003**	79.01

Data are the mean ± SD of three separate wells. *p < 0.05, **p < 0.001 versus control group. The degree of growth inhibition was calculated by the following equation: Inhibitory rate (%) = [(OD₅₇₀ of glycyrol group − OD₅₇₀ of control group)/OD₅₇₀ of control group] × 100. The degree of freedom between groups is 5, as well as 12 within groups.

Table 2.  Inhibition of lymphocyte proliferation by glycyrol in MLR in vitro.

Groups	Concentration (μM)	OD570 value	Inhibitory Rate (%)
control	0	0.093 ± 0.003	—
+glycyrol	3	0.09 ± 0.008	—
	6	0.089 ± 0.07*	4.3
	12	0.073 ± 0.001*	21.51
	30	0.025 ± 0.003**	73.12
	60	0.02 ± 0.001**	78.49

Data are the mean ± SD of three separate wells. *p < 0.05, **p < 0.01 versus control group. The degree of growth inhibition was calculated by the following equation: Inhibitory rate (%) = [(OD₅₇₀ of glycyrol group − OD₅₇₀ of control group)/OD₅₇₀ of control group] × 100. The degree of freedom between groups is 5, as well as 12 within groups.

Figure 3.  Effects of glycyrol on DTH response to sRBC. (A) Delayed type hypersensitivity (DTH) response was induced by immunization with 1 × 10⁸ cells/20 g body weight (b.w.), s.c. in the neck at day 0, challenge with 1 × 10⁹ cells/20 g b.w., s.c. in the left hind paw at day 5 and evaluation of footpad thickness (Vernier caliper) 24 h after challenge. On day 0, mice were treated intraperitoneally and daily for five days with vehicle, glycyrol (10, 20, and 40 mg/kg), or CsA (40 mg/kg). (B)The mice were sacrificed, and their spleen lymphocyte number was counted. Values represent mean ± SD of three independent experiments (n = 8-10/group in each experiment). **p < 0.01 and ***p < 0.001 versus vehicle.

Figure 4.  Effect of glycyrol on allograft rejection in mice. The data represent mean ± SD of three independent experiments with ten animals per groups. *p < 0.05 versus the control group. Graft survival time (%) = [(Graft rejection time of treated group − Graft rejection time of untreated group)/Graft rejection time of untreated group] × 100.

Figure 5.  Effect of glycyrol on PMA/Io-induced IL-2 mRNA expression in Jurkat cells. Cells were pre-incubated with glycyrol (20, 40, and 60 μM) or 1 μM CsA for 6 h, and after addition of PMA (25 ng/mL) and Io (1 μg/mL), they were further incubated for 4 h (note that all the cultures contain 0.1% DMSO as control). RNAs were prepared from the cells, and RT-PCR was performed for IL-2 and β-actin expression. After RT-PCR, amplified product was run on 1% agarose gel.