The Effects of Co-administration of Immobilization Stress and Aloe vera on Serum Carcinoembryonic Antigen in Rats

Immobilization has been used extensively and accepted widely for studying stress-induced alterations. To determine the protective effects of Aloe vera leaf extract, we evaluated the effects of co-administration of immobilization stress and Aloe vera leaf extract on serum level of carcinoembryonic antigen (CEA) tumor marker in male rats. In this experimental study, 45 male Wistar rats were randomly divided into 9 groups of 5 rats in each including: 1) control, 2) normal saline receiving, 3) Aloe vera extract receiving, 4) acutely immobilized, 5) chronically immobilized, 6) acutely immobilized+Aloe vera extract, 7) chronically immobilized+Aloe vera extract, 8) acutely immobilized+normal saline and 9) chronically immobilized + normal saline. The animals were exposed to chronic or acute immobilization stress for 2 h/day or 8 h/day for a period of 3 weeks or one week, respectively. Aloe vera extract (300 mg/kg/day) was fed by gavage feeding orally. Blood samples were collected and following serum collection, CEA level was determined by radioimmunoassay method. Data were compared statistically between groups using ANOVA. Serum CEA level was significantly increased in acutely (0.640±0.025 ng/mL) or chronically immobilized (0.647±0.023 ng/mL) rats compared with control animals group (0.564±0.014 ng/mL) (p<0.001). However, there was no significant difference between serum CEA levels of acutely or chronically immobilized Aloe vera extract received animals compared with control rats (0.622±0.027 ng/m and 0.616±0.044 ng/mL, respectively). Our findings indicate that immobilization stress enhances serum CEA level, however, intake of Aloe vera extract can withstand against.