Department of Surgery, Division of Surgical Oncology, University of Louisville School of Medicine, Louisville, Kentucky, USA.
Nutrition. 2011 Feb;27(2):182-7. doi: 10.1016/j.nut.2010.01.007. Epub 2010 Jun 11.
Esophageal cancer consists of two distinct types, esophageal adenocarcinoma (EAC) and squamous cell carcinoma, both of which differ significantly in their etiology. Freeze-dried black raspberry (BRB) has been consistent in its ability to modulate the biomarkers and reduce the incidence of carcinogen-induced squamous cell carcinoma in rats. In our previous studies in the esophagoduodenal anastomosis (EDA) model, we have shown that the early modulation of manganese superoxide dismutase (MnSOD) significantly correlates with the development of reflux-induced EAC in rats. In this study we looked at the short-term effects of a BRB-supplemented diet on the modulation of antioxidant enzymes in reflux-induced esophagitis.
Male SD rats (8 wk old; n = 3-5) were randomized into three groups--sham-operated, fed control AIN-93M diet (SH-CD), EDA operated and fed either control diet (EDA-CD) or 2.5% (w/w) BRB diet (EDA-BRB). The effect of both reflux and dietary supplementation was analyzed 2 and 4 wk after EDA surgery.
Animals in the EDA groups had significantly lower weight gain and diet intake compared to SH-CD (P < 0.05). The sham-operated animals received an average esophagitis score of 0.1 ± 0.1; this increased significantly in EDA-CD animals to 1.8 ± 0.14 (P < 0.001 versus SH-CD) and in EDA-BRB group to 1.7 ± 0.06 (P < 0.001 versus SH-CD), with BE changes also present. However, dietary supplementation of BRB did not alter or ameliorate the grade of esophagitis or the induction of BE. BRB diet caused a 43% increase in MnSOD levels compared to EDA-CD (0.73 ± 0.16; P = 0.09); however, this effect was not statistically significant and at 4 wk, EDA-CD (0.58 ± 0.12) showed an increase in MnSOD expression compared to SH-CD (0.34 ± 0.01).
In conclusion, our data suggest that dietary BRB does not increase the levels of cellular antioxidant enzymes or reduce the levels of lipid peroxidation compared to a control diet, in a short-term study of gastroesophageal reflux induction in the EDA animal model. However, it remains to be tested whether this is indicative of its ineffectiveness to inhibit reflux-induced EAC incidence over the long term.
食管癌由两种不同类型组成，食管腺癌（EAC）和鳞状细胞癌，它们在病因上有很大的不同。冻干黑莓（BRB）一直能够调节生物标志物并降低致癌物诱导的大鼠鳞状细胞癌的发生率。在我们之前在食管胃吻合术（EDA）模型中的研究中，我们已经表明，锰超氧化物歧化酶（MnSOD）的早期调节与大鼠反流诱导的 EAC 的发展密切相关。在这项研究中，我们研究了 BRB 补充饮食对反流性食管炎中抗氧化酶调节的短期影响。
雄性 SD 大鼠（8 周龄；n = 3-5）随机分为三组 - 假手术组，给予对照 AIN-93M 饮食（SH-CD），EDA 手术组给予对照饮食（EDA-CD）或 2.5%（w/w）BRB 饮食（EDA-BRB）。在 EDA 手术后 2 和 4 周分析了反流和饮食补充的影响。
与 SH-CD 相比，EDA 组的动物体重增加和饮食摄入明显减少（P < 0.05）。假手术组动物的食管炎评分平均为 0.1 ± 0.1；在 EDA-CD 动物中显著增加到 1.8 ± 0.14（P < 0.001 与 SH-CD 相比），在 EDA-BRB 组增加到 1.7 ± 0.06（P < 0.001 与 SH-CD 相比），也存在 BE 变化。然而，BRB 饮食并没有改变或改善食管炎的严重程度或 BE 的诱导。BRB 饮食使 MnSOD 水平比 EDA-CD 增加 43%（0.73 ± 0.16；P = 0.09）；然而，这种影响并不显著，并且在 4 周时，与 SH-CD（0.34 ± 0.01）相比，EDA-CD（0.58 ± 0.12）的 MnSOD 表达增加。
总之，我们的数据表明，与对照饮食相比，在 EDA 动物模型的短期胃食管反流诱导研究中，饮食 BRB 不会增加细胞抗氧化酶的水平或降低脂质过氧化水平。然而，是否这表明其长期抑制反流诱导的 EAC 发生率无效，还有待测试。
