Gastroprotective effect of the protease‐rich extract from sheep abomasum against stress‐induced gastric ulcers in rats. Issue 5 (6th May 2018) - Liu, Bing
Abstract: In this study, ultrasound‐assisted extraction method (UAE) was developed to obtain the protease‐rich extract from sheep abomasum (SAE). UAE parameters were first optimized using response surface methodology. Ultrasonic time of 18 min, ultrasonic power of 260 W, and a liquid/solid ratio of 22 mL/g resulted in the highest proteolytic activity and yield of the SAE (4, 951.3 U/g, 14.3%, respectively). Then we investigated SAE's gastroprotective effect against gastric ulcers induced by water immersion‐restraint stress in rats. After 7 days of intragastric administration of the SAE (0.2 g/kg/day), the ulcer index (2.71 ± 0.97; p < .05) decreased significantly compared with that in the model group, and the ulcer inhibition ratio was 66.5%. In addition, the response to stress was significantly attenuated by balancing the levels of norepinephrine, 5‐hydroxytryptamine, and dopamine in brain regions. Practical applications: Sheep abomasum is the main waste of the sheep meat industry. Converting those wastes to value‐added products would be beneficial for both environment and economy. Results of this study presented that UAE resulted in a higher proteolytic activity and yield of SAE with a shorter extraction time than the conventional extraction method. The SAE obtained in this study may be a promising agent for prophylaxis and treatment of stress‐induced ulcers.