Thiamine Protects Glioblastoma Cells against Glutamate Toxicity by Suppressing Oxidative/Endoplasmic Reticulum Stress.

Thiamine (vitamin B1), which is synthesized only in bacteria, fungi and plants and which humans should take with diet, participates in basic biochemical and physiological processes in a versatile way and its deficiency is associated with neurological problems accompanied by cognitive dysfunctions. The rat glioblastoma (C6) model was used, which was exposed to a limited environment and toxicity with glutamate. The cells were stressed by exposure to glutamate in the presence and absence of thiamine. The difference in cell proliferation was evaluated in the XTT assay. Oxidative stress (OS) markers malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels, as well as endoplasmic reticulum (ER) stress markers 78-kDa glucose-regulated protein (GRP78), activating transcription factor-4 (ATF-4), and C/EBP homologous protein (CHOP) levels, were measured with commercial kits. Apoptosis determined by flow cytometry was confirmed by 4',6-diamidino-2-phenylindole (DAPI) staining. At all concentrations, thiamine protects the cells and increased the viability against glutamate-induced toxicity. Thiamine also significantly decreased the levels of MDA, while increasing SOD and CAT levels. Moreover, thiamine reduced ER stress proteins' levels. Moreover, it lessened the apoptotic cell amount and enhanced the live-cell percentage in the flow cytometry and DAPI staining. As a result, thiamine may be beneficial nutritional support for individuals with a predisposition to neurodegenerative disorders due to its protective effect on glutamate cytotoxicity in glioblastoma cells by suppressing OS and ER stress.

The effect of salmon calcitonin against glutamate-induced cytotoxicity in the C6 cell line and the roles the inflammatory and nitric oxide pathways play.

Recent evidence has shown that salmon calcitonin (sCT) has positive effects on the nervous system. However, its effect and mechanisms on glutamate-induced cytotoxicity are still unclear. The current experiment was designed to examine the effect of sCT on glutamate-induced cytotoxicity in C6 cells, involving the inflammatory and nitric oxide stress pathways. The study used the C6 glioma cell line. Four cell groups were prepared to evaluate the effect of sCT on glutamate-induced cytotoxicity. The control group was without any treatment. Cells in the glutamate group were treated with 10 mM glutamate for 24 h. Cells in the sCT group were treated with various concentrations (3, 6, 12, 25, and 50 µg/mL) of sCT for 24 h. Cells in the sCT + glutamate group were pre-treated with various concentrations of sCT for 1 h and then exposed to glutamate for 24 h. The cell viability was evaluated with an XTT assay. Nuclear factor kappa b (NF-kB), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), neuronal nitric oxide synthase (nNOS), nitric oxide (NO), cyclic guanosine monophosphate (cGMP), caspase-3, and caspase-9 levels in the cells were measured by ELISA kits. Apoptosis was detected by flow cytometry method. sCT at all concentrations significantly improved the cell viability in C6 cells after glutamate-induced cytotoxicity (p < 0.001). Moreover, sCT significantly reduced the levels of NF-kB (p < 0.001), TNF-α, and IL-6 levels (p < 0.001). sCT also decreased nNOS, NO, and cGMP levels (P < 0.001). Furthermore, it decreased the apoptosis rate and increased the live-cell rate in the flow cytometry (P < 0.001). In conclusion, sCT has protective effects on glutamate-induced cytotoxicity in C6 glial cells by inhibiting inflammatory and nitric oxide pathways. sCT could be a useful supportive agent for people with neurodegenerative symptoms.

Design, synthesis, and anticancer activity of novel 4-thiazolidinone-phenylaminopyrimidine hybrids.

4-Thiazolidinones and phenylaminopyrimidines are known as anticancer agents. Imatinib is the pioneer phenylaminopyrimidine derivative kinase inhibitor, which is used for the treatment of chronic myeloid leukemia. With a hybrid approach, a novel series of 5-benzylidene-2-arylimino-4-thiazolidinone derivatives containing phenylaminopyrimidine core were designed, synthesized, and tested for their anticancer activity on K562 (chronic myeloid leukemia), PC3 (prostat cancer), and SHSY-5Y (neuroblastoma) cells. Since superior anticancer activity was observed on K562 cells, further biological studies of selected compounds (8, 15, and 34) were performed on K562 cells. For the synthesis of designed compounds, thiourea compounds were converted to 2-imino-1,3-thiazolidin-4-ones with α-chloroacetic acid in the presence of sodium acetate. 5-Benzylidene-2-imino-1,3-thiazolidin-4-one derivatives were obtained by Knoevenagel condensation of 2-imino-1,3-thiazolidin-4-ones with related aldehydes. Compounds 8, 15, and 34 were evaluated for cell viability, apoptosis studies, cell cycle experiments, and DNA damage assays. IC50 values of compounds 8, 15, and 34 were found as 5.26 ± 1.03, 3.52 ± 0.91, and 8.16 ± 1.27 µM, respectively, in K562 cells. Preferably, these compounds showed less toxicity towards L929 cells compared to imatinib. Furthermore, compounds 8 and 15 significantly induced early and late apoptosis in a time-dependent manner. Compounds 15 and 34 induced cell cycle arrest at G0/G1 phase and compound 8 caused cell cycle arrest at G2/M phase. Based on DNA damage assay, compounds 8 and 15 were found to be more genotoxic than imatinib towards K562 cells. To put more molecular insight, possible Abl inhibition mechanisms of most active compounds were predicted by molecular docking studies. In conclusion, a novel series of 5-benzylidene-2-arylimino-4-thiazolidinone derivatives and their promising anticancer activities were reported herein.

Determination of biological activity of Tragopogon porrifolius and Polygonum cognatum consumed intensively by people in Sivas.

OBJECTIVE: This study was aimed to investigate the in vitro antioxidant, antimicrobial, cytotoxicity, and enzyme inhibition activities of Tragopogon porrifolius and Polygonum cognatum which are naturally grown and consumed intensively by people in Sivas, Turkey. METHODS: Plant materials were extracted with aqueous ethanol by maceration method. The components of the extracts were determined using the Gas Chromatography Mass Spectrometry. Antimicrobial, cytotoxic and enzyme inhibition activities of the extracts were investigated by micro dilution, XTT assay and 96-micro-well plate methods, respectively. The antioxidant activity evaluated using the DPPH radical scavenging, thiobarbituric acid and reducing power methods. The total phenol and total flavonoid content was also examined. RESULTS: GC-MS analysis revealed the presence of 31 compounds inP. cognatum extract and 29 compounds in T. porrifolius extract. According to the results, T. porrifolius extract showed high level of antioxidant activity in comparison to P. Cognatum extract. T. porrifolius exhibited higher α-glucosidase inhibitory activity, and both extract showed strong α-amylase inhibition activity compared to reference drug acarbose. T. porrifolius and P. cognatum ethanolic extracts exhibited antimicrobial activity in the concentration range of 0.039-2.5 mg/ml. Both extracts also exhibited significant anticancer effect on MDA-MB-231 breast cancer cells. The IC50 values of T. porrifolius and P. cognatum extracts in MDA-MB-231 cells were determined as 0.0625 mg/mL and 0.053 mg/mL, respectively. CONCLUSION: Our findings demonstrated that T. porrifolius and P. cognatum ethanolic extracts have promising effect on antioxidant, antimicrobial and cytotoxic activity as well as enzyme inhibition activity, and hence further studies required to identify specific compounds responsible for these activities.

In Vitro Evaluation of the Chemical Composition and Various Biological Activities of Ficus carica Leaf Extracts.

OBJECTIVES: The present study aimed to investigate the inhibitory activities of enzymes related to diabetes mellitus and Alzheimer's disease of the methanol and water extracts of Ficus carica leaf extracts. The bioactive compounds and anticancer, antioxidant, and antimicrobial effects of the extracts were also investigated. MATERIALS AND METHODS: The bioactive compounds in the extracts were determined by gas chromatography-mass spectrometry. The antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6 sulphonic acid) (ABTS) radical scavenging, total phenol and flavonoid content, ferric reducing power, and iron chelating method. The anticancer, anticholinesterase, and antimicrobial effects were investigated using the XTT assay, Ellman method, and microdilution, respectively. RESULTS: Our results showed that between the water and methanol extracts there was a difference in terms of chemical composition. The antioxidant results suggested that both extracts have strong antioxidant activity. Similarly, both extracts showed strong α-glucosidase and α-amylase inhibition activity, while the water extract had higher inhibition activity than the methanol extract against acetylcholinesterase and butyrylcholinesterase. The methanol extract of F. carica exhibited significant anticancer activity on MDA-MB-231 cells and showed moderate antimicrobial activities against Escherichia coli and Staphylococcus aureus. CONCLUSION: Our results suggest that F. carica leaves could be a valuable source for developing a promising therapeutic agent in cancer, diabetes, and Alzheimer's disease.

Determination of inhibitory activities of enzymes, related to Alzheimer's disease and diabetes mellitus of plane tree (Platanus orientalis L.) extracts and their antioxidant, antimicrobial and anticancer activities.

Plane tree (Platanus orientalis L.) leaves have been employed for centuries in various countries due to their pharmacological value. Therefore, determination of the biological activity of the leaves is of interest. The aim of the study was to evaluate the inhibitory effects against Alzheimer's disease-related enzymes Acetylcholinesterase (AChE) and Butyrylcholinesterase (BuChE), diabetes mellitus related enzymes α-glucosidase and α-amylase. The antioxidant, anticancer, and antimicrobial activities of the leaves were also studied. According to the results, both water and methanol extracts of P. orientalis demonstrated more α-glucosidase and α-amylase inhibition activity than the antidiabetic drug-acarbose at the same concentration level. In addition, extracts showed good inhibition activity against AChE and BuChE. Significant results were obtained regarding antioxidant, anticancer, and antimicrobial activities. These results are very promising especially for the improvement of pharmaceutical formulations to treat various diseases such as age-related diseases, cancer, diabetes etc. and it is necessary to conduct further experiments.

Investigating the effects of the Rho-kinase enzyme inhibitors AS1892802 and fasudil hydrochloride on the contractions of isolated pregnant rat myometrium.

OBJECTIVES: Rho-kinases (ROCKs), are one of the dynamic structures of the actin cytoskeleton and they mediate different biological processes, including regulation of calcium sensitivity of smooth muscle contraction. The activation of Rho A/ROCK system is thought to be effective on the termination time of the pregnancy process. The aim of this study, was to investigate in vitro effects of the ROCK enzyme inhibitors, clinically available fasudil hydrochloride, and a new promising inhibitor AS1892802, on the contractions of isolated pregnant rat myometrium. STUDY DESIGN: Term pregnant Wistar albino rats (n=12), weighing 200-220g, were used in this study. Myometrial tissues obtained from rats were dissected into four full-thickness longitudinal muscle strips and then myometrial tension was recorded isometrically. The inhibitory effects of cumulative concentrations of AS1892802 and of fasudil hydrochloride in the presence and absence of ODQ (guanylate cyclase inhibitor), l-NAME (nitric oxide synthase inhibitor) and l-NNA (endothelial nitric oxide synthase inhibitor) on oxytocin-induced myometrial contractions were measured, and values for -log10EC50 (pD2) and mean maximal inhibition (Emax) were compared. RESULTS: Both ROCK inhibitors, AS1892802 and fasudil hydrochloride starting from the concentrations of 10(-6)M reached statistical significance on contraction amplitude and frequency of myometrial strips (p<0.05). The inhibition of the amplitude and frequency of myometrial contractions was antagonized with ODQ (10(-5)M; only amplitude), l-NAME (3×10(-5)M) and l-NNA (10(-5)M) (p<0.05). CONCLUSION: These results suggest that fasudil hydrochloride and AS1892802 may contribute to the development of new tocolytic drugs. We conclude that AS1892802 and fasudil hydrochloride perform this inhibitory effect partially through ROCK inhibition and the NO/cGMP pathway.