[Effects of allicin on insulin resistance and free fatty acid levels in obese rats with periodontitis].

PURPOSE: To explore the effects of allicin on insulin resistance and free fatty acids (FFAs) levels in obese rats with periodontitis. METHODS: Forty rats were randomly divided into healthy group, periodontitis group, and low, medium and high dose groups, with 8 rats in each group. The healthy group was healthy rats, and the other groups were induced by sodium glutamate(MSG). After successfully establishing an obesity model, the maxillary molars were ligated and smeared to establish a periodontitis model. Both the periodontitis group and the healthy group were given normal saline, and the allicin low, medium and high dose groups were given allicin 20，40 and 60 mg·kg-1·d-1, mixed with feed for oral administration. After 21 days of treatment, the fasting blood glucose(FPG), fasting insulin (FINS), insulin resistance index (HOMA-IR) scores and FFAs levels of the homeostatic model in rats were detected. The protein expression of TLR4/MyD88 signaling pathway were compared. Statistical analysis was performed with SPSS 22.0 software package. RESULTS: Compared with the healthy group, FPG, FINS levels, HOMA-IR, IL-6 and TNF-α levels of the periodontitis group were significantly increased, and the expression of TLR4 and MyD88 proteins was significantly increased(P＜0.05). Compared with the periodontitis group, FPG, FINS levels, HOMA-IR, IL-6 and TNF-α levels of low, medium and high-doses groups were significantly decreased, and the expression of TLR4 and MyD88 proteins was significantly decreased (P＜0.05). Compared with the low-dose group, the levels of FPG and FINS, HOMA-IR, IL-6 and TNF-α levels of the middle and high-dose groups were significantly decreased, and the expression of TLR4 and MyD88 proteins was significantly decreased (P＜0.05). Compared with the middle-dose group, the levels of FPG and FINS, HOMA-IR, IL-6 and TNF-α levels of the high-dose group were significantly decreased, and the expression of TLR4 and MyD88 proteins was significantly decreased (P＜0.05). After treatment, FFAs of the low, medium and high-dose groups were significantly lower than those before treatment(P＜0.05). Compared with the healthy group, FFAs levels of the periodontitis group, low-dose and medium-dose groups were significantly increased. Compared with the periodontitis group, FFAs levels of the low, medium and high-dose groups were significantly increased. Compared with the low-dose group, FFAs levels of the high-dose group were significantly increased. Compared with the middle-dose group, FFAs levels of the high-dose group were significantly increased (P＜0.05). CONCLUSIONS: Allicin can improve insulin resistance and obesity in obese rats with periodontitis, and its mechanism of action is related to the TLR4/MyD88 signaling pathway.

[Role of P2X7 receptor in osteogenic differentiation of human periodontal ligament stem cells].

PURPOSE: To investigate the role of P2X7 receptor (P2X7r) in osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs). METHODS: hPDLSCs were isolated from the premolars collected in the First Affiliated Hospital of Guiyang University of Traditional Chinese Medicine, and divided into four groups. Group A was cultured in conventional medium, group B was cultured in osteogenic induction medium, group C was cultured in osteogenic induction medium + 100 nmol/L adenosine triphosphate (ATP) solution, and group D was cultured in osteogenic induction medium + 100 nmol/L P2X7 receptor specific antagonist KN-62. After 7 days, alizarin red staining was used to observe the osteogenic effect of hPDLSCs in each group. The mRNA expression of osteocalcin (OCN), RUNX2 and P2X7r in hPDLSCs was detected by real-time PCR reaction (RT-PCR). The data were processed by SPSS 22.0 software package. RESULTS: Alisarin red staining showed that the morphology of hPDLSCs cells in group B and group C was significantly changed. The pale calcified nodules in group C were significantly more than those in group B, while very few calcified nodules were found in group A and group D. The mRNA expression of OCN, RUNX2 and P2X7r in hPDLSCs were the highest in group C, followed by group B(P<0.05), and no difference was found between group A and group D(P>0.05). CONCLUSIONS: P2X7 receptor can promote osteogenic differentiation of human periodontal ligament stem cells after being activated by ATP, which may provide a new direction for clinical treatment of periodontitis.