Pterostilbene 4′-β-Glucoside Protects against DSS-Induced Colitis via Induction of Tristetraprolin
TTP deficiency abolished the anti-inflammatory effect of 4-PG in a DSS-induced colitis model. To construct an acute colitis animal model, 10 weeks Ttp+/+ and Ttp−/− mice were administrated with 3% DSS dissolved in drinking water for 7 days in the presence or absence of 4-PG (10 mg/kg, i.p. injection). Then, the mice from 4-PG and DSS+ 4-PG groups were still administrated with 4-PG (10 mg/kg, i.p. injection) for another 3 days. After 10 days’ treatment, the mice were sacrificed, and the entire colon was removed from the cecum to the anus. (a) Representative images of 6 tests conducted in each group. (b) Bar graph represents the colon length from each group. (c) Colon tissues were excised, and representative colon histology was shown by hematoxylin and eosin staining. (d) Neutrophil infiltration into the colon was measured by the expression of myeloperoxide (MPO) in colon tissues. The protein level of proinflammatory cytokines, IL-6 (e) and TNF-α (f), were detected by ELISA kit from serum. (g, h) The mRNA and protein levels of TTP in colon tissues from Ttp+/+ and Ttp−/− mice were detected by RT-PCR and Western blot. 18S RNA and β-actin were used as internal controls. Data are expressed as means ± SE, . , , . ns: not significant.