A Comparative Analysis of Photobiomodulation-Mediated Biological Effects of Single Versus Double Irradiation on Dental Pulp Stem Cells: An In Vitro Study.

Objective: In recent years, fractionated irradiation protocols, rather than a simple plan of exposure, have been proposed as a more effective method in the field of tissue regeneration. Thus, this study aimed at a comparative analysis of single versus double irradiation of an 808-nm diode laser, in terms of dental pulp stem cells' (DPSCs) viability and proliferation in vitro. Methods: Subcultured DPSCs were either irradiated, or not (control group), with energy densities of 3, 7, and 12 J·cm-2 in a single- or double-session manner (24 h apart). On 0, 12, 24, 48, and 72 h postirradiation, cell viability and proliferation were evaluated through Trypan Blue and alamarBlue assays, respectively. Results: During the first 48 h postirradiation, the highest rates of DPSC proliferation were assigned to double irradiation at 3 or single exposure to 7 J⋅cm-2, with no cytotoxic effects on cell viability. Inversely, single irradiation at 12, or a double session of exposure to 7 or 12 J⋅cm-2, led to a significant descent in the rates of proliferation and cell viability. Conclusions: Within the limitations of this study, evidence suggests a positive impact on the biological responses of DPSCs following double session of exposure to lower energy densities as well as a single irradiation at a higher energy dosage.

Evaluation of the Cytotoxic and Apoptogenic Effects of Glabridin and Its Effect on Cytotoxicity and Apoptosis Induced by Doxorubicin Toward Cancerous Cells.

Purposes: In the present study, we tried for the first time to examine the anti-proliferative and anti-apoptogenic effect of Glabridin (Glab) toward three groups of cancer cells (SKNMC, H1299, and A2780). Furthermore, the possibility of co-administration of Glab with doxorubicin (DOX) to these cells was also examined to find out whether Glab can potentiate the cytotoxic effect of this chemotherapy agent. Methods: Different cellular assays (MTT, caspase-3 activity, MMP, RT-PCR analysis) were carried out on the cancer cells treated with Glab. Results: Cellular toxicity assay revealed that Glab can potentially reduce the viability of these cells with IC50 concentrations up to 10, 12, and 38 µM toward A2780, SKNMC, and H1299 cell lines, respectively. The results of MMP and caspase-3 activity assays, in association with the results corresponding to the BAX and Bcl-2 gene expressions, altogether revealed that Glab can exert apoptogenic effect on these cells. The intrinsic mitochondrial pathway was found to be the main mechanism, in which Glab induced apoptosis toward H1299 cells and SKNMC cells, while the apoptosis mechanism for A2780 cells could be probably through extrinsic pathway. Glab also potentiated the cytotoxic effect of DOX and its accumulation in H1299 cell line. Conclusion: The results of this study revealed the promising cytotoxic role of Glab on different carcinoma cells. These data also suggested that co-chemotherapy method using Glab could be effective for treatment of cancer, but further in-vivo and clinical studies are still needed to assure these results.

Bioassay-guided Isolation of Neuroprotective Fatty Acids from Nigella sativa against 1-methyl-4-phenylpyridinium-induced Neurotoxicity.

OBJECTIVE: Parkinson's disease, a slowly progressive neurological disease, is associated with degeneration of the basal ganglia of the brain and a deficiency of the neurotransmitter dopamine. The main aspects of researches are the protection of normal neurons against degeneration. Fatty acids (FAs), the key structural elements of dietary lipids, are carboxylic straight chains and notable parameters in nutritional and industrial usefulness of a plant. MATERIALS AND METHODS: Black cumin, a popular anti-inflammatory and antioxidant food seasoning, contains nonpolar constituents such as FAs which were extracted using hexane. Different fractions and subfractions were apt to cytoprotection against apoptosis and inflammation induced by 1-methyl-4-phenylpyridinium (MPP+) in rat pheochromocytoma cell line (PC12) as a neural cell death model. The experiment consisted of examination of cell viability assessment, mitochondrial membrane potential (MMP), caspase-3 and -9 activity, and measurement of cyclooxygenase (COX) activity. RESULTS: MPP+ induced neurotoxicity in PC12 cells. Pretreatment with subfractions containing FA mixtures attenuated MPP+-mediated apoptosis partially dependent on the inhibition of caspase-3 and -9 activity and increasing the MMP. A mixture of linoleic acid, oleic acid, and palmitic acid also decreased the COX activity induced by MPP+ in PC12 cells. CONCLUSION: Our observation indicated that subtoxic concentration of FA from Nigella sativa may exert cytoprotective effects through their anti-apoptotic and anti-inflammation actions and could be regarded as a dietary supplement. SUMMARY: MPP+ induced neurotoxicity in PC12 cellsNigella sativa contains bioactive fatty acidsPretreatment with fatty acids attenuated MPP+ mediated apoptosis through inhibition of caspase 3 and 9 activityA mixture of linoleic acid, oleic acid, and palmitic acid decreased the COX activity induced by MPP+ in PC12 cellsDue to cytoprotective, anti apoptotic and anti inflammation actions of N. sativa, it could be regarded as a dietary supplement. Abbreviations used: ANOVA: Analysis of variance; Ca: Calcium; CDCl3: Chloroform; COX: Cyclooxygenase; DMSO: Dimethyl sulfoxide; EA: Elidic acid; EDTA: Ethylene diamine tetraacetic acid; ELISA: Enzyme Linked Immunosorbent Assay; ESI-MS: Electron spray mass spectroscopy; FAs: Fatty acids; FBS: Fetal bovine serum; GC: Gas chromatography; 1HNMR: Hydrogen nuclear magnetic resonance; LA: Linoleic acid; MPP+: 1-Methyl-4-phenylpyridinium; MPTP: 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine; MTT: 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide; N. sativa: Nigella sativa; OA: Oleic acid; PA: Palmitic acid; PBS: Phosphate buffer saline; PC12: Rat pheochromocytoma cell line; PD: Parkinson's disease; PDA: Photo diode array detector; PGE2: Prostaglandin E2; TLC: Thin layer chromatography; TMPD: N,N,N',N'-tetramethyl-p-phenylenediamine; USA: United states of America.