Dietary freeze-dried black raspberry's effect on cellular antioxidant status during reflux-induced esophagitis in rats

Abstract

Introduction Esophageal cancer consists of two distinct types –esophageal adenocarcinoma (EAC) and squamous cell carcinoma (SCC), 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 SCC 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. Methods Male SD rats (8 wo; n=3–5) were randomized into 3 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 weeks after EDA surgery. Results Animals in 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 vs SH-CD) and in EDA-BRB group to 1.7 ± 0.06 (p< 0.001 vs 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 weeks, EDA-CD (0.58 ±0.12) showed an increase in MnSOD expression compared to SH-CD (0.34 ± 0.01). Conclusions In conclusion, our data suggests 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 long-term.

Effect of Freeze-Dried Berries on the Development of Reflux-Induced Esophageal Adenocarcinoma

“…Further, replacing MnSOD causes significant reduction in EAC incidence (37). In a recent publication, we showed that short-term feeding of 2.5% BRBs did not alter the levels of esophageal antioxidant enzymes such as MnSOD in rats exposed to reflux (19). Thus, the results from this study confirm the validity of MnSOD as an early biomarker of esophageal carcinogenesis in the EDA model.…”

“…In a previously published study, we showed that freeze-dried BRB supplemented at 2.5% (w/w) dose after 4 wk duration does not cause a significant reversal of reflux-induced changes in MnSOD expression (19). In a continuation of this study, we supplemented the diet of rats that underwent EDA surgery with a 2.5% (w/w) dose of either BRB or BB and looked at BE and EAC incidence at 12 and 24 wk after surgery to test whether the failure to modulate the early changes in MnSOD is linked to ineffectiveness in reducing EAC incidence.…”

“…All diets were stored at 4 • C until fed to the animals. Feed intake for the rats were measured for 1 wk at various time points during the study and calculated as described (19).…”

Component analysis and sensory evaluation of Korean black raspberry (Rubus coreanus Mique) wines

“…, 2008). Compounds in the black raspberry are known to have various physiological activities, including anti‐oxidative (Aiyer et al. , 2011), anti‐allergic (Shin, 2009), anti‐inflammatory (Yang et al.…”

The Effect of Black Raspberry Extracts on MnSOD Activity in Protection Against Concanavalin A Induced Liver Injury

“…For example, in our previous studies, we used 2.5% (w/w) BRB diet to treat the reflux esophagitis and esophageal cancer in male rats induced by an esophagoduodenal anastomosis (EDA) surgical procedure. Our data show that a dietary supplementation of freeze-dried BRB and BB at 2.5% (w/w) is not effective in the prevention of reflux-induced esophagitis and esophageal adenocarcinoma in the EDA animal model, even with an increase of cellular antioxidant enzymes such as MnSOD at the early stage of EDA animals 31;32 . This discrepancy between our findings and Stoner et al’s could be the BRB dosing in the animal diets, for which we used 2.5% (w/w) BRB diet but 5% (w/w) BRB by Stoner 30 .…”