Effectiveness of lycopene in the prevention of radiation-induced esophagitis

Introduction and Purpose: Radiation-induced esophageal toxicity is a commonly seen complication in esophageal cancer irradiation and other cancer treatments which may cover esophagus within the radiotherapy field. The use of radioprotective agents is crucial in the prevention of acute radiation esophagitis. Therefore, we aimed to research whether lycopene could prevent acute esophageal side effects of thoracic radiotherapy in Wistar albino rats. Materials and Methods: 60 Wistar albino rats were included into the study. Rats were divided into five groups as Control (C), Lycopene (L), Radiotherapy (RT), Lycopene before Radiotherapy (L+RT), Lycopene before and after RT (L+RT+L). Group 1 was the control group. Group 2 received lycopene (Redivivo, DSM Nutritional Products, Netherlands) for 7 days. Group 3 received only radiotherapy. Group 4 received lycopene for 7 days before radiotherapy. Group 5 received lycopene for 7 days before radiotherapy and 7 days after radiotherapy. Rats were weighted on the first, seventh and fourteenth days of the study. After all these procedures, rats were sacrified by the collection of blood samples from their hearts. Lycopene levels were analyzed in serum. Rat esophagus was evaluated histopathologically and Ki-67 proliferation index was measured. Results: All histopathologic examinations showed that the groups receiving both lycopene and radiotherapy had significant improvements compared to only radiotherapy group. These improvements were unsignificantly better in L+RT+L group compared to L-RT group. Ki-67 proliferation index was zero in all groups. There was no weight difference between groups on the first day of the experiment (p=0.46). However, rats in the RT receiving (RT, L+RT, L+RT+L) groups were slimmer then the control group when the weights measured on the 14th day of the experiment were compared between groups. Lycopene receiving groups (L, L+RT, L+RT+L) had statistically higher lycopene levels compared to none lycopene (K, RT) receiving groups (p<0.001). Conclusion: All histopathologic examinations showed that the groups receiving both lycopene and radiotherapy had significant improvements compared to only radiotherapy group. These improvements were unsignificantly better in L+RT+L group compared to L-RT group. Clinical studies searching the effectiveness of lycopene in the prevention of radiation-induced esophagitis are needed. Key Words:Radiation-Induced Esophagitis, Lycopene, radiotherapy, Radioprotection