Identification of the active compound from the Driselase‐treated fraction of rice bran that suppresses hypertension, hyperlipidemia, and hyperglycemia in stroke‐prone spontaneously hypertensive rats

Abstract

We previously demonstrated that a fraction of rice bran treated with Driselase—a mixture of plant cell wall‐degrading enzymes including cellulases, xylanases, and laminarinases—can reduce high blood pressure (BP) and improve plasma lipid parameters. In this experiment, we isolated and identified the active compound from the Driselase‐treated fraction (DF) of rice bran. The DF was fractionated by silica gel column chromatography and HPLC with an ODS column, and the obtained fractions were orally administered to stroke‐prone spontaneously hypertensive rats (SHRSP). By NMR analyses of the active fraction, the active compound was identified as adenosine, and it improved hypertension and the plasma triglyceride, glucose, and nitric oxide (NO) levels at 2 h after administration. Subsequently, the effects of chronic adenosine administration in SHRSP were studied. SHRSP aged 10 weeks were divided into a control and an adenosine group that were administered water or water with adenosine, respectively, for 3 weeks. The development of high BP was suppressed in the SHRSP from the adenosine group compared to those from the control group.　The plasma lipid, glucose, and NO levels and glucose tolerance were significantly improved in the adenosine‐treated SHRSP compared to the untreated SHRSP. In conclusion, adenosine appears to be beneficial for the suppression of hypertension, hyperlipidemia, and hyperglycemia.