To evaluate the antiproliferative and antifibrotic effects of α-tocotrienols in primary cultured orbital fibroblasts from thyroid-associated ophthalmopathy (TAO) patients.

Orbital fibroblasts were cultured (5 eyes from TAO patients, 5 eyes from normal patients) and classified into a control group, α-tocotrienol group and α-tocopherol group. The cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The proliferation of orbital fibroblasts was measured using the Click-iT™ assay. The collagen production of the control and α-tocotrienol groups was measured using a hydroxyproline assay.

The α-tocotrienol and α-tocopherol groups showed no cytotoxicity up to 150 µm in orbital fibroblasts from TAO and normal patients. The proliferation of orbital fibroblasts from TAO and normal patients was significantly inhibited with α-tocotrienol at 80 µm and 120 µm. The collagen production of orbital fibroblasts from TAO patients was significantly inhibited with α-tocotrienol at 120 µm.

The results from the present study indicate that non-toxic concentrations of α-tocotrienol have significant antiproliferative and antifibrotic effects on orbital fibroblasts from TAO patients.