Protective Effects of Phoenixin-14 Peptide in the Indomethacin-Induced Duodenal Ulcer: An Experimental Study

Phoenixin-14‎ (PNX‎-14‎) is a newly identified neuropeptide with potential anti-inflammatory effects in the gastrointestinal tract. In this study, we evaluated the protective effect of PNX-14 against the formation of experimental indomethacin (IND)-induced duodenal ulcer. Thirty-two‎ male Sprague-Dawley rats were randomly assigned to the four following study groups: (1) negative control (2) IND (7.5 mg/kg subcutaneous IND), (3) famotidine (FA) (7.5 mg/kg subcutaneous IND followed by 40 mg/kg intraperitoneal‎ FA), and (4) PNX-14 (7.5 mg/kg subcutaneous IND followed by 50 µ/kg intraperitoneal‎ PNX-14). Outcome measures included macroscopic evaluation of duodenal lesion, serum levels of IL-1ß, TNF-α, IL-6, and IL-12, and tissue biochemical parameters of oxidative stress, including malondialdehyde (MDA)‎‏,‏‎ myeloperoxidase ‎‎(MPO) activity, superoxide dismutase (SOD) ‎activity, and catalase activity. Results The macroscopic grade of duodenal lesions were significantly smaller in the PNX-14 group than in the IND group (p < 0.001). Serum inflammatory cytokines were significantly increased in the IND group. PNX-14 treatment significantly decreased the serum levels of inflammatory cytokines (p < 0.0001). Oxidative contents (MDA and MPO activity) were significantly smaller in the PNX-14 group compared with the IND group (p < 0.0001), while anti-oxidative contents (SOD and catalase activity) were significantly more (p < 0.0001). PNX-14 was superior to FA in several anti-inflammatory properties, such as inhibiting the release of inflammatory cytokines and increasing the catalase activity. PNX-14 showed significant protective effects against the formation of IND-induced duodenal ulcers. These results suggest a promising therapeutic implication for PNX-14 in the treatment of gastrointestinal inflammatory disorders.