[Protective effect of Ligustri Lucidi Ait Polysaccharide against lipopolysaccharide-induced inflammatory injury of Sertoli cells in rats].

Objective: To explore the effect of Ligustri Lucidi Ait Polysaccharide (LLP) on lipopolysaccharide (LPS)-induced inflammatory injury of Sertoli cells.

Methods: Rat Sertoli cells were isolated and cultured in vitro and then divided into five groups, blank control, LPS, LPS + low-dose LLP, LPS + medium-dose LLP, and LPS + high-dose LLP. After 48 hours of treatment, the proliferation of the cells was detected by CCK-8, their apoptosis determined by FMC, and the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) activity and malondialdehyde (MDA) in the supernatant of the cell culture medium measured by ultraviolet spectrophotometry. The contents of IL-1α, IL-6 and TGF-β in the culture medium were detected by ELISA before and after removal of LPS.

Results: The proliferation of the cells showed statistically significant differences among different groups (F = 153.93, P < 0.01), markedly reduced in the LPS group as compared with the blank control (P < 0.01), but remarkably increased in the high- and medium-dose LLP groups in comparison with the LPS group (both P < 0.01), and so did the apoptosis of the cells (F = 64.06, P < 0.01), significantly increased in the LPS group as compared with the blank control (P < 0.05), but markedly decreased in the high- and medium-dose LLP groups in comparison with the LPS group (both P < 0.01). Statistically significant differences were also observed among different groups in the levels of SOD (F = 56.07, P < 0.01), CAT (F = 41.57, P < 0.01), GSH-Px activity (F = 238.46, P < 0.01), and MDA (F = 285.31, P < 0.01), with decreased SOD, CAT and GSH-Px activity (P < 0.01) and increased MDA (P < 0.01) in the LPS group as compared with the control, but elevated SOD and CAT in the high- and medium-dose LLP groups and increased GSH-Px activity and decreased MDA concentration in all the three LLP groups in comparison with the LPS group (P < 0.01). Before the removal of LPS, the contents of IL-1α, IL-6 and TGF-β in the culture medium were markedly higher in the LPS than in the control group (all P < 0.01), that of IL-1α was increased significantly in the high- and medium-dose LLP groups (P < 0.01 and P < 0.05) while those of IL-6 and TGF-β showed no statistically significant differences in the three LPS groups as compared with the LLP group (P > 0.05). After the removal of LPS, the contents of IL-1α and IL-6 were remarkably reduced (t = 25.26 and 61.43, P < 0.01) and that of TGF-β increased (t = －18.16, P < 0.01), even more significantly in the LLP+LPS groups (P < 0.01).

Conclusions: Ligustri Lucidi Ait Polysaccharide plays a protective role in LPS-induced inflammatory injury of Sertoli cells by reducing cell apoptosis and regulating the contents of IL-1α, IL-6 and TGF-β from Sertoli cells in inflammation.