Zinc Picolinate Mitigates Colonic Inflammation and Enhances Barrier Function in a Rat Model of Ulcerative Colitis

Zinc deficiency may exacerbate the symptoms of ulcerative colitis, but the effects of zinc picolinate in this context remain unclear. This study aimed to investigate the protective effects of zinc picolinate supplementation in a rat model of acetic acid (AA)-induced colitis. Male Sprague Dawley rats (n = 49) were divided into control (saline, zinc, or zinc picolinate) and colitis (saline, zinc, zinc picolinate, or sulfasalazine) groups. The agents were administered intraperitoneally (6 mg/kg) or orally (sulfasalazine, 100 mg/kg) for 10 days before colitis induction with AA (1 ml, 5%). Colon tissues were collected for macroscopic, oxidative, biochemical, and molecular analyses. In the colitis group pretreated with saline, fecal, macroscopic, and edema scores, as well as malondialdehyde (MDA), myeloperoxidase (MPO), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and histopathological scores, were significantly increased compared to controls (p < 0.01-0.001). In contrast, zinc, antioxidant glutathione (GSH), occludin, and claudin-1 levels were reduced (p < 0.01-0.001). Zinc and zinc picolinate pretreatments attenuated colonic damage, oxidative stress, and inflammation while enhancing antioxidant status and tight junction proteins (p < 0.05-0.001). These findings suggest that zinc picolinate may exert protective effects against experimental colitis by reducing oxidative and inflammatory damage and supporting intestinal barrier integrity.