Oxidative-antioxidant imbalance in chronic sialadenitis of submandibular gland in human and rat.

Objectives This study aimed to evaluate the level of oxidative stress (OS) in human and rat chronic sialadenitis (CS) of the submandibular gland (SMG). Method We collected human SMG tissues and established a rat CS model using Wharton's duct partial ligation (PL). Morphological changes in the SMG were evaluated by HE, Sirius Red, AB/PAS, TUNEL, and IHC staining. Oxidative damage and antioxidant capacity were detected by ELISA, commercial assay kits, and IHC staining to evaluate their expression levels and locations in the SMG. Results Histopathological damage were observed in the human and rat CS. Compared to the control group, the rat PL group had significantly increased oxidative damage products (8-OHdG, AOPP, 8-iso-PGF2α, and H2 O2 ). For antioxidants, the PL group had markedly decreased T-AOC and CAT activity, but markedly increased SOD activity. IHC staining showed that 3-NT, 4-HNE, and MDA were expressed differently in different stages of CS; and antioxidant enzymes (CAT, SOD1, SOD2, GPX1, and GPX4) were mainly expressed in ducts. Conclusions The oxidative-antioxidant imbalance of CS in human and rats was revealed, the different expression of oxidative damage in different stages of CS was detected, and the different antioxidant reaction in acinar and ductal cells was demonstrated.