Prevention and therapy of squamous cell carcinoma of the rodent esophagus using freeze-dried black raspberries

摘要

＜正＞ Aim:This study was conducted to determine if short-term treatment of N-nitrosomethylbenzylamine （NMBA）-induced tumors in the rat esophagus withdietary freeze-dried black raspberries （FBR） would result in tumor regression andenhanced survival of the animals.Methods:Four-week-old male Fisher-344 ratswere administered an AIN-76A control diet and injected subcutaneously with 0.5mg/kg NMBA once per week for 15 weeks.At 19 weeks,when rats had an averageof 5-6 tumors （papillomas） per esophagus,they were given a control diet contain-ing either 5%,10%,or 20% FBR.After 7 weeks of berry treatment,all survivingrats were killed and tumor incidence,number and volume were determined.Results:Esophageal tumor incidences,numbers and volumes in NMBA-treated rats werenot influenced by any of the berry treatments.There were progressive increasesin the survival of NMBA-treated rats fed 5%-20% FBR diets;however,theseincreases were not significant.Conclusion:FBR at 5%,10%,and 20% of the diethad no effect on the development of NMBA-induced tumors in the rat esophagusor on animal survival when administered for 7 weeks beginning at the papillomastage of tumor development.Thus,FBR appear to have no therapeutic value inthe treatment of esophageal tumors.In contrast,dietary FBR are highly effectivein preventing the development of NMBA-induced esophageal tumors in rats whenadministered before and during NMBA treatment or shortly after NMBA treat-ment when the esophagi contain preneoplastic （dysplastic） lesions of varyingdegrees of severity.