Hussein Ghazi, Nakamura Masami, Zhao Qi, Iguchi Tomomi, Goto Hirozo, Sankawa Ushio, Watanabe Hiroshi
International Research Center for Traditional Medicine, Toyama Prefecture, Japan.
Biol Pharm Bull. 2005 Jan;28(1):47-52. doi: 10.1248/bpb.28.47.
Astaxanthin is a natural antioxidant carotenoid that occurs in a wide variety of living organisms. We investigated, for the first time, antihypertensive effects of astaxanthin (ASX-O) in spontaneously hypertensive rats (SHR). Oral administration of ASX-O for 14 d induced a significant reduction in the arterial blood pressure (BP) in SHR but not in normotensive Wistar Kyoto (WKY) strain. The long-term administration of ASX-O (50 mg/kg) for 5 weeks in stroke prone SHR (SHR-SP) induced a significant reduction in the BP. It also delayed the incidence of stroke in the SHR-SP. To investigate the action mechanism of ASX-O, the effects on PGF(2alpha)-induced contractions of rat aorta treated with NG-nitro-L-arginine methyl ester (L-NAME) were studied in vitro. ASX-O (1 to 10 microM) induced vasorelaxation mediated by nitric oxide (NO). The results suggest that the antihypertensive effect of ASX-O may be due to a NO-related mechanism. ASX-O also showed significant neuroprotective effects in ischemic mice, presumably due to its antioxidant potential. Pretreatment of the mice with ASX-O significantly shortened the latency of escaping onto the platform in the Morris water maze learning performance test. In conclusion, these results indicate that astaxanthin can exert beneficial effects in protection against hypertension and stroke and in improving memory in vascular dementia.
虾青素是一种天然抗氧化类胡萝卜素，存在于多种生物体内。我们首次研究了虾青素（ASX - O）对自发性高血压大鼠（SHR）的降压作用。对SHR口服ASX - O 14天可导致动脉血压（BP）显著降低，但对正常血压的Wistar Kyoto（WKY）品系大鼠则无此作用。对易患中风的SHR（SHR - SP）长期给予ASX - O（50 mg/kg）5周可导致血压显著降低，还可延缓SHR - SP中风的发生率。为研究ASX - O的作用机制，在体外研究了其对用NG - 硝基 - L - 精氨酸甲酯（L - NAME）处理的大鼠主动脉PGF(2α)诱导收缩的影响。ASX - O（1至10 microM）诱导由一氧化氮（NO）介导的血管舒张。结果表明，ASX - O的降压作用可能归因于与NO相关的机制。ASX - O在缺血小鼠中也显示出显著的神经保护作用，可能是由于其抗氧化潜力。在用ASX - O预处理小鼠后，在莫里斯水迷宫学习性能测试中显著缩短了逃上平台的潜伏期。总之，这些结果表明虾青素在预防高血压和中风以及改善血管性痴呆的记忆力方面可发挥有益作用。
