Antioxidant and anti-inflammatory effects of DhHP-6 as a synthetic oxidase-mimickingmimicase enzyme in an experimental rat model of periodontitis

Abstract Deuterohemin-ala-his-thr-val-glu-lys (DhHP-6) is a new type of synthetic oxidase-mimicking enzyme, has antioxidant effects and the ability to scavenge free radicals. It also has the potential to act as an antioxidant enzyme. In this study, an oxidative stress model of human gingival fibroblasts (HGFs) in vitro and a rat periodontitis model in vivo were established to study the antioxidant effect of DhHP-6 and its mechanism, the inflammatory response of periodontitis, and the protective effect of DhHP-6 on alveolar bone resorption induced by periodontitis. DhHP-6 reduced oxidative stress and the expression of inflammatory factors in HGFs. DhHP-6 had a dose-dependent protective effect on alveolar bone absorption in rats with periodontitis, enhanced rat antioxidant capacity and reduced inflammation. Micro-CT scanning showed that DhHP-6 reduced alveolar bone loss and improved the bone structure of the left maxillary first molar of rats. HE staining results showed that, compared with the control, there were no obvious morphological and histological changes in the rat organs. These results suggest that DhHP-6 can be used to treat experimental periodontitis in rats by increasing the expression levels of antioxidant enzymes and antioxidants in systemic and local tissues, which reduces the content of oxidation products and cyto-inflammatory factors.