Liposomal Morin Attenuates DMH-Associated Colonic Oxidative Stress, Inflammation, and Apoptosis/Autophagy-Related Dysregulation in Rats

Abstract

Background/Objectives: Oxidative stress, chronic inflammation, disrupted apoptosis, and altered autophagy are biological processes implicated in colorectal tumor development. Morin is a plant-derived flavonoid with antioxidant and anti-inflammatory properties, but its limited solubility and bioavailability may limit its biological activity. This study evaluated the effects of free morin and morin-loaded liposomes (MOR-Lips) on 1,2-dimethylhydrazine (DMH)-associated colonic biochemical, molecular, and histopathological alterations in rats. Methods: Rats were randomly assigned to six groups—vehicle control, MOR, MOR-Lips, DMH, DMH + MOR, and DMH + MOR-Lips—and treated for 10 weeks. Serum and colonic tissues were evaluated for cancer-associated biomarkers (CEA, CA19-9, CA125, HMG-CoA reductase), oxidative stress and antioxidant indices, nitrosative and oxidative DNA-damage markers (MDA, NO, 8-OHdG), inflammatory mediators (TLR4/NF-κB/COX-2, cytokines, MPO), proliferative indices (Ki-67, PCNA), apoptotic and autophagy-related regulators (Bax, caspase-3, p53, cytochrome c, BCL-2, p-AKT, LC3-II, Beclin-1, p62), and histopathological and immunohistochemical changes. Results: DMH exposure was associated with increased CEA, CA19-9, CA125, HMG-CoA reductase, MDA, NO, 8-OHdG, TLR4/NF-κB/COX-2, cytokines, MPO, Ki-67, and PCNA. DMH also reduced NRF2/HO-1 signaling and antioxidant defenses, shifted apoptosis-related markers toward a pro-survival profile, altered autophagy-related markers, and produced marked colonic histopathological abnormalities. Both free MOR and MOR-Lips attenuated several of these DMH-associated alterations, with MOR-Lips generally producing greater effects than free MOR. MOR-LIP treatment was associated with restoration of antioxidant marker profiles, reduced levels of inflammatory and proliferative markers, a shift toward a pro-apoptotic marker profile, partial normalization of autophagy-related markers, and improved colonic histopathological appearance. Conclusions: In DMH-exposed rats, MOR-Lips were associated with more favorable redox, inflammatory, proliferative, apoptosis-related, autophagy-related, and histopathological profiles than free MOR. These findings support further investigation of MOR-Lips as a formulation strategy for improving the biological activity of morin. Because quantitative preneoplastic and neoplastic endpoints were not measured, the results do not establish inhibition of colorectal carcinogenesis or chemopreventive efficacy.