Effect of Prunella vulgaris polysaccharides on cultured orbit fibroblasts in vitro from patients with thyroid-associated ophthalmopathy

To observe the effect of Prunella vulgaris polysaccharides (PVP) on cultured orbit fibroblasts in vitro from patients with thyroid-associated ophthalmopathy (TAO). PVP at different concentrations were used to treat different groups of fibroblasts from TAO patients and normal persons. Dexamethasone (Dex) was used as a positive control drug, and interferon-γ (IFN-γ) was used as a positive stimulant. The effects of PVP on the proliferation of orbital fibroblasts, the secretion of hyaluronic acid (HA), the expression of intercellular adhesion molecule-1 (ICAM-1/CD54) and apoptosis in orbital fibroblasts were determined. The experimental results showed when the concentration of PVP was greater than 400 μg/mL, it could significantly inhibit the proliferation of orbital fibroblasts from patients with TAO (P < 0.05). However, no definite inhibitory effect was observed in the orbital fibroblasts from the normal people. Dex could significantly inhibit the proliferation of orbital fibroblasts from patients with TAO and the normal people (P < 0.05). In contrast, every concentration of IFN-γ could promote the orbital fibroblasts from patients with TAO and the normal people proliferation. No groups had statistically significant stimulatory effect on HA secretion by orbital fibroblasts from normal people (P > 0.05). But the Dex group, IFN-γ+PVP-1600 group and IFN-γ+Dex group could significantly inhibit the secretion of HA from orbital fibroblasts of TAO patients. And there were no groups had statistically significant stimulatory effect on the expression of ICAM-1/CD54 in orbital fibroblasts from TAO patients (P > 0.05). PVP and Dex at all concentrations could significantly promote orbital fibroblast co-cultured with IFN-γ apoptosis (P < 0.05). But without IFN-γ, PVP and Dex at all concentrations could only significantly promote orbital fibroblast from TAO patients apoptosis (P < 0.05). These results suggest that PVP exerts its therapeutic effect by inhibiting the proliferation of orbital fibroblasts and promoting the apoptosis of orbital fibroblasts in TAO patients. In addition, in this process, HA secretion is suppressed. But the participation of IFN-γ is required. This effect is similar to that of Dex. And in the MTT experiment, the efficacy of PVP showed selectivity for TAO patients. This is different from Dex. This may be a feature of PVP that deserves attention.

Keywords: Fibroblasts; Orbit; Polysaccharides; Prunella vulgaris; Thyroid-associated ophthalmopathy.