To compare the protective effects of saponin and non-saponin Sun-ginseng extract fractions in a selenite-induced rat cataract model.

A total of 101 Sprague-Dawley rat pups were divided into four groups by treatment: Sun-ginseng, saponin fraction, non-saponin fraction, and control. For induction of cataracts, sodium selenite 15 nmol/g was injected subcutaneously in 13 day-old rat pups. Sun-ginseng extract 100 µg/g (Group I, Ginseng Science, Seoul, Korea), saponin fraction 100 µg/g (Group II), non-saponin fraction 100 µg/g (Group III), and phosphate buffered saline (Control group) were injected intraperitoneally every two days for a total of seven injections. The rats were sacrified and their lenses were dissected and photographed at day 7 and 14, and the cataracts were graded according to the ratio of the cataract area to the total lens area. The blind method was used for the evaluation of the cataract area.

At day 14, cataract formation rates (CFR) were 33.3% in group I, 76.4% in group II, 41.2% in group III, and 77.7% in the control group. The mean cataract area (MCA) was 13.4±20.8% in group I, 14.4±11.7% in group II, 5.7±7.7% in group III, and 15.8±12.1% in the control group. Group III showed statistically significant results compared with those of control group (CFR p =0.001, MCA p =0.001). We observed significantly lower incidence and smaller mean cataract area in Group I and Group III at day 7 compared with the control group (Group I, CFR p =0.018; Group III, CFR p =0.032, MCA p =0.005).

The protective effects of Sun-ginseng extract are caused by the components in the non-saponin fraction, not by those in the saponin fraction, in a selenite-induced cataract rat model.