Effects of spermine supplementation on the morphology, digestive enzyme activities, and antioxidant capacity of intestine in weaning rats.

The main objective of this study was to investigate the effects of different doses of spermine and its extended supplementation on the morphology, digestive enzyme activities, and intestinal antioxidant capacity in weaning rats. Nineteen-day-old male rats received intragastric spermine at doses of 0.2 and 0.4 μmol/g BW for 3 or 7 d, whereas control rats received similar doses of saline. The results are as follows: 1) In the jejunum, the seven-day supplementation with both doses of spermine significantly increased crypt depth (P < 0.05) compared with the control group; the supplementation extension of the high spermine dose increased villus height and crypt depth (P < 0.05); in the ileum, the low spermine dose significantly increased villus height and crypt depth compared with the control group for 7 days (P < 0.05). 2) The 3-day supplementation with high spermine dose increased alkaline phosphatase activity in the jejunum (P < 0.05). 3) In the jejunum, the anti-hydroxyl radical (AHR), total superoxide dismutase (T-SOD), catalase (CAT), and total antioxidant capacity (T-AOC) activities were increased (P < 0.05); however, the malondialdehyde (MDA) content was reduced (P < 0.05) in groups supplemented with the high spermine dose relative to those in the control groups after 3 and 7 d; moreover, the anti-superoxide anion (ASA) and glutathione (GSH) contents increased with the high spermine dose that lasted for 3 days (P < 0.05). Furthermore, the T-SOD and CAT activities (after 3 and 7 d), ASA (after 3 d), and AHR (after 7 d) increased with the high spermine dose compared with those of the low spermine dose (P < 0.05). Extending the supplementation duration (7 d) of the high spermine dose decreased the MDA content and ASA and T-AOC activities (P < 0.05). These results suggested that spermine supplementation can modulate gut development and enhance the antioxidant status of the jejunum in weaning rats, and a dosage of 0.4 μmol spermine/g BW had better effects than the dosage of 0.2 μmol spermine/g BW on accelerating gut development and increasing antioxidant capacity.