Histopathological and biochemical evaluation of the effect of Paeoniflorin on the periodontium during and after periodontitis formation in rats

Preventive effects of systemic Pistacia eurycarpa Yalt. administration on alveolar bone loss and oxidative stress in rats with experimental periodontitis

OBJECTIVE

This study aimed to investigate the effects of systemic administration of P. eurycarpa Yalt. plant extract on alveolar bone loss and oxidative stress biomarkers in gingival tissue in a rat model of experimental periodontitis.

METHODOLOGY

32 male Wistar albino rats, weighing 200-250 g, were divided into four groups (n=8): Healthy control (HC), Experimental periodontitis control (EPC), Experimental periodontitis 400 mg/kg (EP400), Experimental periodontitis 800 mg/kg (EP800). Experimental periodontitis was induced using the ligating method. Distilled water was administered to the HC and EPC groups and the plant extract was administered to the EP400 and EP800 groups by oral gavage at doses of 400 mg/kg and 800 mg/kg, respectively. The rats were sacrificed on the 15th day. The values of glutathione peroxidase GSH-Px, malondialdehyde (MDA), superoxide dismustase (SOD), interleukin-1β (IL-1β), interleukin-10 (IL-10), total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI) in the gingival tissues were analyzed by ELISA tests. Alveolar bone loss was assessed using micro-CT images of the maxilla.

RESULTS

Although the IL-1β, TOS, OSI results of the healthy control group were lower than those of the other groups, the TAS values were higher (p<0.05). No significant difference was found in the biochemical parameters among the EPC, EP400, and EP800 groups (p>0.05). Alveolar bone loss was significantly reduced in the extract groups compared to the EPC group (p<0.001).

CONCLUSION

Within the limitations of this study, it was observed that the systemic P. eurycarpa extract application reduced alveolar bone loss in a rat model of experimental periodontitis. Further studies are needed to elucidate the beneficial effects of P. eurycarpa.

Paeoniflorin Ameliorates Skeletal Muscle Atrophy in Chronic Kidney Disease via AMPK/SIRT1/PGC-1α-Mediated Oxidative Stress and Mitochondrial Dysfunction

Skeletal muscle atrophy is a common and serious complication of chronic kidney disease (CKD). Oxidative stress and mitochondrial dysfunction are involved in the pathogenesis of muscle atrophy. The aim of this study was to explore the effects and mechanisms of paeoniflorin on CKD skeletal muscle atrophy. We demonstrated that paeoniflorin significantly improved renal function, calcium/phosphorus disorders, nutrition index and skeletal muscle atrophy in the 5/6 nephrectomized model rats. Paeoniflorin ameliorated the expression of proteins associated with muscle atrophy and muscle differentiation, including muscle atrophy F-box (MAFbx/atrogin-1), muscle RING finger 1 (MuRF1), MyoD and myogenin (MyoG). In addition, paeoniflorin modulated redox homeostasis by increasing antioxidant activity and suppressing excessive accumulation of reactive oxygen species (ROS). Paeoniflorin alleviated mitochondrial dysfunction by increasing the activities of electron transport chain complexes and mitochondrial membrane potential. Furthermore, paeoniflorin also regulates mitochondrial dynamics. Importantly, paeoniflorin upregulated the expression of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), and phosphorylation of AMP-activated protein kinase (AMPK). Similar results were observed in C2C12 myoblasts treated with TNF-α and paeoniflorin. Notably, these beneficial effects of paeoniflorin on muscle atrophy were abolished by inhibiting AMPK and SIRT1 and knocking down PGC-1α. Taken together, this study showed for the first time that paeoniflorin has great therapeutic potential for CKD skeletal muscle atrophy through AMPK/SIRT1/PGC-1α-mediated oxidative stress and mitochondrial dysfunction.

Paeonol suppresses lipid formation and promotes lipid degradation in adipocytes

Paeonol can regulate a variety of physiological and pathological processes such as thrombosis, oxidative stress, inflammation and atherosclerosis. However, its potential role and underlying mechanisms in obesity and lipid metabolism remain to be elucidated. In the present study, 3T3-L1 cells were differentiated and collected on days 4, 6 and 8. The expression levels of fatty-acid-binding protein 4 (FABP4) and microRNA (miR)-21 were detected using reverse transcription-quantitative PCR and western blot analyses. Cell viability was assessed using a Cell Counting Kit-8 assay. A miR-21 mimic was constructed and transfected into 3T3-L1 preadipocytes. Adipocyte differentiation was detected using Oil Red O staining. The proteins CD36, glucose transporter 4, peroxisome proliferator-activated receptor γ (PPAR-γ) and adipocyte protein 2 (Ap2) were detected using western blot analysis. The expression levels of FABP4 and miR-21 were increased in differentiated 3T3-L1 cells. Paeonol exhibited no effects on cell activity, whereas it inhibited the expression levels of miR-21 in the 3T3-L1 differentiated adipocytes. Paeonol suppressed the differentiation of 3T3-L1 adipocytes and its effect was partially reversed by the overexpression of miR-21. In addition, paeonol promoted the lipid degradation of 3T3-L1 adipocytes, increased the expression levels of PPAR-γ and Ap2, and suppressed triglyceride synthesis in these cells. These effects were partially reversed by the overexpression of miR-21. In conclusion, the findings of the present study indicated that paeonol may exert protective effects against lipid formation and promote lipid degradation in adipocytes. These data provide evidence of the regulatory effect of paeonol on adipocyte differentiation and highlight its pathological significance.