[In vitro study on cytotoxicity, osteogenic potential and antibacterial activity of silicate root canal sealers].

PURPOSE: To evaluate the in vitro biocompatibility and antibacterial activity of a new type of strontium silicate-based C-Root SP root canal sealer, and to provide a reference for clinical selection of sealers. METHODS: C-Root SP, iRoot SP and AH Plus extracts were prepared, L929 cells and MC3T3-E1 cells were cultured in vitro, and the cytotoxicity and osteogenic potential of the three sealers were compared. Fresh sealers were mixed with Enterococcus faecalis solution and the antibacterial activity of the sealer was determined by direct contact text (DCT). SPSS 25.0 software package was used for statistical analysis. RESULTS: At 24, 48, and 72 h, the cytotoxicity of the sealers in each group were significantly different (P＜0.01). Compared with AH Plus, the cytotoxicity of C-Root SP was lower (P＜0.01). C-Root SP was superior to AH Plus in promoting the activity of alkaline phosphatase(ALP) (P＜0.01). iRoot SP was the strongest in promoting the formation of mineralized nodules, followed by C-Root SP, and the weakest was AH Plus(P＜0.01). C-Root SP inhibited the growth of Enterococcus faecalis, and its antibacterial rate was significantly higher than AH Plus(P＜0.01). CONCLUSIONS: The strontium silicate root canal sealer C-Root SP has low cytotoxicity, certain osteogenic potential and antibacterial activity against Enterococcus faecalis, so it can be used for root canal filling.

Betulin isolated from Pyrola incarnata Fisch. inhibited lipopolysaccharide (LPS)-induced neuroinflammation with the guidance of computer-aided drug design.

This study aims to investigate active phytochemicals isolated from Pyrola incarnata Fisch. (P. incarnata) and their protection against neuroinflammation induced by LPS. Betulin, accompanied with other 9 compounds, were isolated from P. incarnata and elucidated by spectroscopic analysis (1H-, 13C NMR). ELISA kits and the measurement of NO production based on Griess reaction showed that betulin (5) (250 µg/mL) could suppress LPS-induced activation of microglial cell BV-2 better than others by inhibiting inflammatory cytokines (TNF-α, IL-6, IL-1ß) expression and NO production. With the guidance of computer-aided drug design and the analysis of biological experiment, we demonstrated betulin could reduce LPS-induced iNOS expression, prevent JNKs pathways, and down-regulate the phosphorylation levels of NF-κB/p65. In conclusion, betulin isolated from P. incarnata possessed outstanding anti-neuroinflammation potential, presumably related to iNOS expression, JNKs and NF-κB/p65 pathways. Therefore, Pyrola incarnata may be a valuable natural resource and betulin is a potential drug for the treatment of neurodegenerative disorders by inhibiting inflammatory mediators.

Pyrola incarnata demonstrates neuroprotective effects against ß-amyloid-induced memory impairment in mice.

This study aims to investigate the neuroprotective effects of Pyrola incarnata against ß-amyloid-induced memory impairment in mice. Ethanol extract of Pyrola incarnata (EPI) was obtained and led to eleven phytochemicals successfully by isolation and purification, which were elucidated by spectroscopic analysis (1H NMR, 13C NMR and HR-ESI-MS). Thereinto, ursolic acid was gained as most abundant monomer. C57BL/6 mice were intracerebroventricular injected with aggregated Aß25-35. Open-field test, Barnes maze test and Morris water maze were conducted for evaluating cognition processes of EPI and ursolic acid. EPI significantly improved learning and memory deficits, attenuated the Aß25-35 level of deposition immunohistochemically. Further studies revealed that ursolic acid as bioactive phytochemical of P. incarnata improved spatial memory performance and ameliorated Aß25-35 accumulation by activating microglia cells and up-regulating Iba1 level in the hippocampus. These findings suggest P. incarnata could improve the cognition of mice and be a promising natural source for the treatment of neurodegenerative disease.

The in silico and in vivo evaluation of puerarin against Alzheimer's disease.

The root of Pueraria lobata has been utilized as a food source for thousands of years in China. Puerarin is the major bioactive and the most abundant secondary metabolite obtained from the root of P. lobata. The potential therapeutic effect of puerarin against Alzheimer's disease was screened by in silico methods and confirmed by the amyloid ß-peptide-induced Alzheimer's disease (AD) rat model. The in silico study displayed that puerarin had the potential to penetrate across the blood-brain barrier and had high stability in molecular docking and dynamics simulation with acetylcholinesterase (AChE), cyclooxygenase-2 (COX-2) and caspase-3 (C3), which play a central role in the development of AD. The in vivo results showed that puerarin could restrain the AChE activity, restore the activities of antioxidant defense substances toward normal levels, and decrease the expression of inflammatory factors and apoptosis genes in the brain, especially down-regulating the expressions of COX-2 and C3. The histopathological examination of brain sections and behavioral testing also verified the biochemical observations, which further validates the in silico study. These results not only suggest that puerarin, as a potential compound, could relieve AD, but also broaden the applications of puerarin.

Hyperoside attenuates OVA-induced allergic airway inflammation by activating Nrf2.

Allergic airways disease (AAD) is one of the most common medical illnesses that is associated with an increased allergic airway inflammation. Hyperoside, an active compound isolated from Rhododendron brachycarpum G. Don, has been reported to have anti-inflammatory effect. The aim of this study was to analyze the protective effect of hyperoside on OVA-induced allergic airway inflammation in mice. In the present study, the mouse asthma model was induced by given OVA and hyperoside was administrated 1h before OVA challenge. The levels of IL-4, IL-5, IL-13, and IgE were detected by ELISA. H&E staining was used to assess lung histopathological changes. The expression of NF-κB p65, IκB, HO-1, and Nf-E2 related factor 2 (Nrf2) were measured by western blot analysis. The results showed that hyperoside significantly reduced the inflammatory cells infiltration and the levels of IL-4, IL-5, IL-13, and IgE. Hyperoside significantly inhibited OVA-induced oxidative stress as demonstrated by decreased MDA, and increased GSH and SOD levels. Treatment of hyperoside also inhibited OVA-induced airway hyperresponsiveness (AHR). Furthermore, the results showed that treatment of hyperoside significantly inhibited LPS-induced NF-κB activation. In addition, hyperoside was found to activate Nrf2/HO-1 signaling pathway. In conclusion, these results suggest that hyperoside ameliorates OVA-induced allergic airway inflammation by activating Nrf2 signaling pathway.

Quantitative study of cellular heterogeneity in doxorubicin uptake and its pharmacological effect on cancer cells.

Cellular heterogeneity in doxorubicin (DOX) uptake and its relationship with pharmacological effect on cancer cells were quantitatively investigated for the first time. An in vitro experimental model was established by treating human leukemia K562 and breast cancer MCF-7 cells with different schedules of DOX with or without surface P-glycoprotein (P-gp) inhibitor verapamil (VER). The cellular heterogeneity in DOX uptake was quantitatively examined by single-cell analysis using capillary electrophoresis coupled with laser-induced fluorescence detection. The corresponding cytotoxic effect was tested by cellular morphology, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium and flow cytometry assays. The expression of cellular membrane surface P-gp was determined by flow cytometry. Results showed that the cellular heterogeneity exists in DOX uptake. The single-high DOX schedule leads to lower uptake heterogeneity and higher mean drug uptake. The cellular heterogeneity in DOX uptake was found to be negatively correlated with drug cytotoxicity and surface P-gp expression, with r = -0.7680 to ~ -0.9587. VER reduces the cellular variation in DOX uptake, suggesting that surface P-gp may be one of the causes of the cellular heterogeneity in DOX uptake. This research demonstrates the importance of quantitative study of cellular heterogeneity in drug uptake and its potential application in drug schedule design, response prediction and therapy modulation.

Cytotoxic alkaloids from the bulbs of Fritillaria hupehensis.

Phytochemical investigation of the bulbs of Fritillaria hupehensis resulted in the isolation and structural elucidation of four new steroidal penta- and hexacyclic veratraman- and cevan-based alkaloids, respectively, compounds 1-4. They were obtained together with the known constituents ebeinine (5) and zhebeinine (6), which were isolated for the first time from this plant. The structures of the new isolates were established by spectroscopic and mass-spectrometric analyses, in combination with chemical methods. All compounds were assayed for their cytotoxic effects towards HeLa and HepG2 cell lines. Compounds 1 and 2 showed significant inhibitory effects against both types of tumor cells, with IC(50) values in the range 2.52-0.23 microM, similar as those for 5-fluorouracil used as positive control.