Effect of Euglena(Euglena gracilis Z) with Enriched Docosahexaenoic Acid on Blood Pressure, Storoke Lesion and Life-Span in Stroke-Prone Spontaneously Hypertensive Rats.

Abstract

From 5 weeks of age, stroke-prone spontaneously hypertensive rats (SHRSP) were fed a diet based on dry cells of Euglena (Euglena gracilis Z; at 25% in diet) with enriched docosahexaenoic acid (DHA-Euglena) until natural death or sacrifice at 20 weeks of age, and the effects of the diet on blood pressure, incidence of stroke lesions and life-span were examined. Spontaneous elevation of blood pressure was depressed by the DHA-Euglena diet after the start of feeding, and after 10 weeks of age the blood pressure remained constant at 210 to 230mmHg. The life-span of the DHA-Euglena-fed group was marked longer than that of the control group, and the incidence of cerebral stroke lesions was lower than that in the control rats. On the other hand, a defatted Euglena diet (at 20% in diet) exerted little effect on blood pressure, but obvious prolongation of life-span was observed. Suppression of aortic hypertrophy was recognized in SHRSP fed the DHA-Euglena diet, and a high level of aortic elastin was maintained. The activities of angiotensin I-converting enzyme (ACE) in the thoracic aorta and mesenteric artery were lower in the DHA-Euglena group than in the control group (p<0.05). The lipid peroxide (TBARS) level and activities of related enzymes in the blood of the DHA-Euglena group showed no difference from those in the control group. Prevention of blood pressure elevation, reduction of the incidence of cerebral stroke lesions and prolongation of life-span in SHRSP were more evident after feeding with DHA-Euglena than with ordinary Euglena. These results indicate that Euglena rich in DHA has an augmented suppressive effect against hypertensive disease in SHRSP.

Suppressive Action of Docosahexaenoic Acid Enriched-Euglena on Reduction of Endothelium-Dependent Relaxation in Stroke-Prone Spontaneously Hypertensive Rats (SHRSP).

“…But similar to ACE inhibitor captopril, hypertrophy of the vascular wall was suppressed, pointing out that the alleviation of vascular resistance by lowering blood pressure is not the only important aspect. Similar results were noted in experiments using DHA Euglena diet (15) and fish meal as protein sources (29). Okamoto et al (30), using malignant SHRSP (M-SHRSP), studied the effects of a fish meal diet and anti hypertensive drug administration on cerebrovascular lesions, and found that a vascular protective action was exhibited by treatment with ACE inhibitor even if the blood pressure was not lowered in M-SHRSP.…”

“…The authors recently conducted similar experiments using Euglena enriched with docosahexaenoic acid (DHA), and found that it had a stronger suppressive action on blood pressure elevation and on stroke lesion than Euglena by ordinary cultivation (15). In this paper, the effects of Euglena enriched with DHA on the functional impairment of endothelial cells induced by the elevation of blood pressure in SHRSP are studied, and compared with the actions of antihypertensive drugs.…”