Effects of fisetin on the jejunal diamine oxidase (DAO) activity in heat-stressed rats. CON, rats were orally fed with 0.5% carboxymethylcellulose sodium; HS, rats were orally fed with 0.5% carboxymethylcellulose sodium and then subjected to heat treatment; HS-FIS, rats were orally fed with 100 mg FIS /kg body weight/day and then subjected to heat treatment. Results are expressed as mean and standard error (n=8). *P<0.05 was compared with the CON group; #P<0.05 was compared with the HS group.