Uchida S, Ohta H, Niwa M, Mori A, Nonaka G, Nishioka I, Ozaki M
Department of Pharmacology 2, Nagasaki University School of Medicine, Japan.
Chem Pharm Bull (Tokyo). 1990 Apr;38(4):1049-52. doi: 10.1248/cpb.38.1049.
The effects of persimmon tannin on pathophysiological changes in stroke-prone spontaneously hypertensive rats (SHRSP) were investigated. When the persimmon tannin was chronically ingested by SHRSP, the life span was significantly prolonged, yet the effect on blood pressure was slight. The incidences of brain hemorrhage and infarction were also significantly decreased by this treatment. To elucidate the mechanisms involved in these events, the effects of condensed tannins, including persimmon tannin, on free radicals and lipid peroxidation were examined in vitro. Using electron spin resonance analysis, we found that these tannins have a potent, concentration-dependent scavenging action toward active oxygen free radicals. These tannins strongly inhibited lipid peroxidation in rat brain homogenates, in a concentration-dependent manner. Persimmon tannin inhibited lipid peroxidation similarly to (-)-epigallocatechin. Persimmon tannin was 20 times more effective than alpha-tocopherol in terms of the 50%-inhibitory concentration. The radical scavenging action and inhibition of lipid peroxidation by persimmon tannin may explain, in part, the prolongation of the life span of the SHRSP ingesting persimmon tannin.
研究了柿单宁对易卒中型自发性高血压大鼠（SHRSP）病理生理变化的影响。当SHRSP长期摄入柿单宁时，其寿命显著延长，但对血压的影响较小。这种处理还使脑出血和梗死的发生率显著降低。为了阐明这些事件所涉及的机制，在体外研究了包括柿单宁在内的缩合单宁对自由基和脂质过氧化的影响。通过电子自旋共振分析，我们发现这些单宁对活性氧自由基具有强大的、浓度依赖性的清除作用。这些单宁以浓度依赖的方式强烈抑制大鼠脑匀浆中的脂质过氧化。柿单宁与（-）-表没食子儿茶素类似地抑制脂质过氧化。就50%抑制浓度而言，柿单宁的效果是α-生育酚的20倍。柿单宁的自由基清除作用和对脂质过氧化的抑制作用可能部分解释了摄入柿单宁的SHRSP寿命延长的原因。
