Narrow Results

The isolation and characterization of rat lens aldose reductase inhibitors from the Viola hondoensis W. Becker et H Boss were conducted. The extracts and organic fractions from V. hondoensis were tested. The MeOH extract and EtOAc fraction were found to exhibit potent rat lens aldose reductase inhibition in vitro, their IC₅₀ being 1.2 and 0.6 μg/ml, respectively. One major isoflavonoid glycoside was isolated from the ethyl acetate soluble fraction of V. hondoensis. Kakkalide was found to be the potential rat lens aldose reductase inhibitor (IC₅₀ = 0.34 μg/ml), and may be useful for the prevention and/or treatment of diabetic complications.

The lignan extracts from the tree bark of Eucommia ulmoides Oliv., a famous traditional Chinese medicine, have been demonstrated to have inhibitory effects on aldose reductase activity in spontaneously hypertensive rat myocardium. This study was aimed to investigate the hypertensive cardiac remodeling effects of the lignan extracts together with epalrestat. Ten-week-old male spontaneously hypertensive rats were randomly divided into three groups (n = 12, each) and administered 100 mg/kg/d of captopril (angiotensin converting enzyme inhibitor), 100 mg/kg/d of epalrestat (aldose reductase inhibitor) or 300 mg/kg/d of lignan extracts by gavage for 16 weeks. Sex-, age-, and number-matched normotensive Wistar Kyoto rats with spontaneously hypertensive rats were treated with distilled water (vehicle) as controls. Systolic blood pressures were measured periodically. Echocardiography examination was taken when rats were 24 weeks old. We found that both captopril and lignan extracts lowered blood pressure, and inhibited aldose reductase activity similarly to epalrestat. Echocardiography examination and histomorphometry indices were improved in all treated groups (p < 0.05). Therefore, lignan extracts could prevent hypertensive cardiac remodeling, which is likely related to aldose reductase inhibition.