Sakthivel M, Elanchezhian R, Ramesh E, Isai M, Jesudasan C Nelson, Thomas P A, Geraldine P
Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, India.
Exp Eye Res. 2008 Feb;86(2):251-9. doi: 10.1016/j.exer.2007.10.016. Epub 2007 Nov 5.
The present study sought to evaluate the efficacy of the naturally-occurring polyphenol, ellagic acid, in preventing selenite-induced cataractogenesis. In the present study, Wistar rat pups were divided into 3 groups of 15 each. Group I (normal) rats received an intraperitoneal (i.p.) injection of normal saline on postpartum day 10; group II (cataract-untreated) rats received a single subcutaneous (s.c.) injection of sodium selenite (19 micromol/kg body weight) on postpartum day 10; group III (cataract-treated) pups received a single s.c. injection of sodium selenite on postpartum day 10 and intraperitoneal injections of ellagic acid (200mg/kg body weight) on postpartum days 9-14. At the end of the study period (30th postpartum day), slit-lamp examination of both eyes of each rat pup revealed no lenticular opacification (cataract stage 0) in all eyes of group I pups, definite nuclear cataracts (stages 4-6) in the eyes of all (100%) group II rat pups and no lenticular opacification in eight (53%) and mild lenticular opacification (cataract stages 1-3) in seven (47%) of group III rats (changes in group II vs group III, P<0.01). The mean activities of the antioxidant enzymes catalase, glutathione peroxidase, superoxide dismutase and glutathione-S-transferase were significantly lower in lenses of Group II rats than in Group I or Group III rat lenses. In addition, the mean levels of GSH in lenses and erythrocytes were also significantly lower in Group II rats than in Group I or Group III rats. Conversely, the mean concentration of MDA (an indicator of lipid peroxidation) in lenses and erythrocytes was found to be significantly higher in Group II rats than that in Group I or Group III rats. Also, the mean concentration of calcium was found to be significantly higher in lenses of Group II rats than in those of Group I and Group III rats. The results suggest that ellagic acid can prevent or retard experimental selenite-induced cataractogenesis in Wistar rats. This protective effect in rat lenses appears to occur by maintaining the antioxidant defense system and inhibition of lipid peroxidation.
本研究旨在评估天然存在的多酚——鞣花酸在预防亚硒酸盐诱导的白内障形成方面的功效。在本研究中，将Wistar大鼠幼崽分为3组，每组15只。第I组（正常组）大鼠在出生后第10天腹腔注射生理盐水；第II组（未治疗白内障组）大鼠在出生后第10天皮下注射一次亚硒酸钠（19微摩尔/千克体重）；第III组（治疗白内障组）幼崽在出生后第10天皮下注射一次亚硒酸钠，并在出生后第9至14天腹腔注射鞣花酸（200毫克/千克体重）。在研究期结束时（出生后第30天），对每只大鼠幼崽的双眼进行裂隙灯检查，发现第I组幼崽的所有眼睛均无晶状体混浊（白内障0期），第II组所有（100%）大鼠幼崽的眼睛有明确的核性白内障（4至6期），第III组8只（53%）大鼠无晶状体混浊，7只（47%）有轻度晶状体混浊（白内障1至3期）（第II组与第III组的变化，P<0.01）。第II组大鼠晶状体中抗氧化酶过氧化氢酶、谷胱甘肽过氧化物酶、超氧化物歧化酶和谷胱甘肽-S-转移酶的平均活性显著低于第I组或第III组大鼠晶状体。此外，第II组大鼠晶状体和红细胞中谷胱甘肽的平均水平也显著低于第I组或第III组大鼠。相反，发现第II组大鼠晶状体和红细胞中丙二醛（脂质过氧化指标）的平均浓度显著高于第I组或第III组大鼠。而且，发现第II组大鼠晶状体中钙的平均浓度显著高于第I组和第III组大鼠。结果表明，鞣花酸可以预防或延缓Wistar大鼠实验性亚硒酸盐诱导的白内障形成。在大鼠晶状体中的这种保护作用似乎是通过维持抗氧化防御系统和抑制脂质过氧化而发生的。
