OBJECTIVETo investigate the effects of garlicin on the expression of transcription factors T-bet and GATA-3 in blood lymph cells of experimental rats with allergic rhinitis.

METHODSThirty healthy SD rats were randomly divided into 3 groups, with 10 rats for each. Ten rats (pharmacological group) were sensitized and intranasally challenged by ovalbumin (OVA), aluminium hydroxide hydrate gel and Bordetella pertussis (B. pertussis) inactive microorganism suspension adjuvants, as the allergic rhinitis models, and then injection of garlicin (0.4 ml) intraperitoneally per day for 10 days. Ten rats in the control group were immunized as the pharmacological group, and then injection of physiological saline as equal volume as garlicin. Ten rats in the negative control group were investigated using physiological saline only. Plasma and lymph cells were separated from 2 ml blood which was extracted from rat heart. Enzyme linked immunosorbent assay (ELISA) was utilized to detect the levels of plasma IL-4 and IFN-γ, and RT-PCR was utilized to detect the expression of T-bet and GATA-3.

RESULTSThe levels of IL-4 (x(-) ± s) were (6.292 ± 1.734), (14.252 ± 1.971), (4.916 ± 0.600) pg/ml, respectively, and the levels of IFN-γ were (24.338 ± 2.375), (12.364 ± 1.749), (16.136 ± 2.012) pg/ml, respectively, among the pharmacological, control and negative control groups. The plasma level of IL-4 in the pharmacological group rats was lower than that of control group rats (t = 4.23, P < 0.05), while there was no significant difference between the pharmacological and negative control group rats (t = 1.01, P > 0.05). The plasma level of IFN-γ was increased significantly in the pharmacological group rats when compared with the value of control group rats (t = 4.61, P < 0.05) and with the negative control group (t = 5.79, P < 0.05), respectively. There was no significant difference (t = 1.17, P > 0.05) in plasma level of IFN-γ in the control group rats when compared with the negative control group. Relative quantization of expression of GATA-3 (median) was 0.826, 1.029 and 0.474, and those of T-bet (median) were 1.245, 0.280 and 0.544, respectively, among the pharmacological, control and negative control groups. There were significant difference among 3 groups (chi² = 6.599, P = 0.019; chi² = 9.884, P = 0.007, respectively). Relative quantization of expression of GATA-3 in the control group rats was significantly higher than that in the negative control group and pharmacological group rats (chi² value were 10.113 and 2.384, respectively, all P < 0.05), and that of GATA-3 in the pharmacological group rats was increased as compared to the negative control group rats (chi² = 3.784, P < 0.05). The level of expression of T-bet in pharmacological group rats was elevated markedly with a significant difference as compared to both control (chi² = 16.021, P < 0.05) and negative control groups (chi² = 14.103, P < 0.05).

CONCLUSIONSGarlicin may upregulate the expression of T-bet dramatically and downregulate the expression of transcription factor GATA-3 in the experimental models of allergic rhinitis.