Effects of lignans extracted from Eucommia ulmoides and aldose reductase inhibitor epalrestat on hypertensive vascular remodeling

Aim of the studyTo investigate the effects of lignans extracted from Eucommia ulmoides and epalrestat on vascular remodeling in spontaneously hypertensive rats.Materials and methodsTen-week-old male spontaneously hypertensive rats were randomly divided into 3 groups (12 rats each group), and treated orally with 100 mg/kg/d of captopril (an angiotensin-converting enzyme inhibitor), 100 mg/kg/d of epalrestat (an aldose reductase inhibitor) and 300 mg/kg/d of lignans by gavage daily for 16 weeks, respectively. Sex-, age-, and number-matched spontaneously hypertensive rats and normotensive Wistar Kyoto rats, were treated with distilled water (vehicle) as controls. The rats were weighed weekly. Mean arterial blood pressure and heart rate were measured periodically by non-invasive blood pressure monitoring. They were sacrificed at the end of experiment (26-week-old). Superior mesenteric artery and aorta were isolated for determination of histomorphometry and the expression of aldose reductase by immunohistochemistry.ResultsCaptopril and lignans, but not epalrestat, decreased mean arterial blood pressure in spontaneously hypertensive rats. Vascular remodeling was improved in all three treated groups by histomorphometry.ConclusionsBoth lignans and epalrestat reversed hypertensive vascular remodeling. Aldose reductase played a vital role in the pathologic process of hypertensive vascular remodeling rather than elevation of blood pressure. These data suggested that aldose reductase could be a new therapeutic target for the treatment of cardiovascular diseases.

The leaf and bark of Eucommia ulmoides is widely used in Chinese to treat hypertension. Eucommia ulmoides lignans could prevent hypertensive vascular remodeling and the effect may be related to inhibition of aldose reductase which is an enzyme sensitive to oxidative stress.Figure optionsDownload as PowerPoint slide