Insights into the binding of buspirone to human serum albumin using multi-spectroscopic and molecular docking techniques.

Buspirone is an anxiolytic drug that plays a significant role in managing anxiety disorders and alleviating their symptoms as well. Several techniques were utilized to study the interaction between buspirone and human serum albumin under physiological conditions, including UV-vis absorption spectroscopy, fluorescence emission spectroscopy, circular dichroism, Fourier transform infrared spectroscopy (FT-IR), equilibrium dialysis, and molecular docking. The results of this study demonstrated that buspirone quenched the intrinsic fluorescence of human serum albumin through a mixed mechanism. Moreover, the binding constants (Kb), the quenching constants (Ksv), and thermodynamic parameters were calculated at various temperatures. The binding process of buspirone to human serum albumin showed a cooperative binding pattern, confirmed by the Scatchard diagram and Hill coefficient. Molecular docking results showed that buspirone interacted with the IIA, IIIA, and IIB subdomains of human serum albumin and slightly changed its conformation. It was also found that hydrophobic forces played a major role in this interaction. This study consequently proves that BSH as a drug can be transported by blood albumin. Additionally, due to its ratiometric response in absorbance upon binding to a biological target, HSA can be used as a molecular probe to follow biomolecular interactions.

Gallic Acid Ameliorates Cadmium Effect on Osteogenesis by Activation of Alkaline Phosphatase and Collagen Synthesis.

OBJECTIVE: We previously reported that cadmium (Cd) inhibits osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). In addition, gallic acid (GA) improves BMSC differentiation. Here, we aim to study the ability of GA to prevent osteogenic inhibition induced by Cd. MATERIALS AND METHODS: In this experimental study, BMSCs were extracted and purified from Wistar rats and their viability was determined in the presence of Cd and GA. The results indicated that 1.5 µM Cd and 0.25 µM of GA were appropriate for further investigation. After 20 days in osteogenic medium, matrix production was analysed by alizarin red, calcium content, and alkaline phosphatase (ALP) activity. Osteogenic-related genes and collagen 1A1 (COL1A1) protein expressions were investigated. The preventive effect of GA on oxidative stress and metabolic change induced by Cd was estimated. RESULTS: GA counteracted the inhibitory effect of Cd on matrix production and significantly (P=0.0001) improved the osteogenic differentiation ability of BMSCs. Also, GA prevented the toxic effect of Cd on osteogenic-related gene expressions and nullified the reducing effect of Cd on COL1Al and ALP activity. A significant reduction (P=0.0001) in malondialdehyde and lactic acid concentration showed that GA counteracted both oxidative stress and metabolic changes caused by Cd. CONCLUSION: GA prevented the toxic effect of Cd, an environmental pollutant and a factor in osteoporosis.

The P53/microRNA network: A potential tumor suppressor with a role in anticancer therapy.

MicroRNAs (miRNAs) are endogenous and small non-coding RNAs that have been identified as mediators of tumor suppression as well as stress responses mediated by p53 suppressors. MiRNAs may act as tumor suppressors under certain conditions. MiRNAs regulated by p53 may control the expression of processes such as cell cycle progression, cell survival, and angiogenesis. P53 activity and expression are also controlled by miRNA; consequently alterations in the p53-miRNA network may be essential for tumor initiation and progression. Future studies on the p53-miRNA network presumably would find it helpful in diagnostic and therapeutic approaches or as tools for various cancers.

microRNAs: Novel Markers in Diagnostics and Therapeutics of Celiac Disease.

microRNAs (miRNAs) are a novel class of single-stranded RNAs with a key role in the regulation of gene expression. miRNA main mechanism of action involves interaction with the mRNA transcribed from the genes, leading to the target mRNA silencing and degradation. Indeed, it is easy to conceive that a defective miRNA-based mRNA regulation may compromise normal cell function and cause genetic diseases. A wide spectrum of studies has focused on the identification and introduction of regulatory diseases-specific miRNAs for the past decade. Overexpression or downregulation of several miRNAs can potentially stimulate or inhibit pathways related to the pathogenesis of celiac disease (CD). CD is a chronic inflammatory disease characterized by small intestinal mucosal injury and nutrient malabsorption in genetically susceptible individuals after the dietary ingestion of gluten. The disease is characterized by villous atrophy, intraepithelial lymphocyte infiltration, and chronic inflammation and activation of lamina propria T cells. The common genetic background in CD is the presence of heterodimeric human leukocyte antigen class II molecules DQ2 or DQ8 that account for ∼40% of the genetic predisposition in this disease. In fact, by minute identification of these miRNAs and related targets and mechanisms, specific therapeutics can be developed to suppress these pathophysiological pathways through the enhancement or inhibition of miRNAs. This development can open a new prospect for personalized medicine.

The role of adiponectin and adipolin as anti-inflammatory adipokines in the formation of macrophage foam cells and their association with cardiovascular diseases.

Obesity is one of the major public health concerns that is closely associated with obesity-related disorders such as type 2 diabetes mellitus (T2DM), hypertension, and atherosclerosis. Atherosclerosis is a chronic disease characterized by excess cholesterol deposition in the arterial intima and the formation of foam cells. Adipocytokines or adipokines are secreted by the adipose tissue as endocrine glands; adiponectin and adipolin are among these adipokines that are associated with obese and insulin-resistant phenotypes. Adipolin and adiponectin are cytokines that exert substantial impact on obesity, progression of atherosclerosis, insulin resistance, and glucose metabolism. In this paper, we review the formation of macrophage foam cells, which are associated with atherosclerosis, and the macrophage mechanism, which includes uptake, esterification, and release. We also summarize current information on adipose tissue-derived hormone and energy homeostasis in obesity. Finally, the role of adipokines, e.g., adipoline and adiponectin, in regulating metabolic, cardiovascular diseases is discussed.

Study of Crocin & Radiotherapy-induced Cytotoxicity and Apoptosis in the Head and Neck Cancer (HN-5) Cell Line.

Malignant tumors of head and neck carcinomas are the sixth most common type of cancer. Current systemic therapies for cancer show side effects in normal tissues and short-term efficacy due to drug resistance. Consequently, there is much interest in identifying new drugs for cancer treatment. Crocin (an active ingredient of saffron) has been shown to have cytotoxic effects on cancer cell lines. Chemo radiotherapy is the standard treatment for head and neck cancer. In the present study, the cytotoxic effects, inducing apoptosis and the radiation sensitivity of crocin were evaluated in the head and neck cancer cell line (HN-5). HN-5 cells were cultured in a DMEM medium and incubated with different concentrations of crocin (12.5-1000 µg/mL). They were exposed to 2 Gy γ-rays. Cell viability was quantified by the MTT assay. Apoptotic cells were determined using PI staining of DNA fragmentation by flowcytometry (sub-G1 peak). Crocin decreased cell viability in HN-5 cells in a time and concentration dependent manner. Crocin also induced a sub-G1 peak in the flowcytometery histogram of treated cells compared with the control, suggesting that apoptotic cell death is caused by its toxicity. Crocin was also shown to sensitize cells to radiation-induced toxicity and apoptosis. The simultaneous use of crocin and radiation therefore increases radiation sensitivity and cell death. Thus, after further study crocin can be considered as a potential drug and sensitizer in cancer treatment.

Effect of irinotecan on HMGB1, MMP9 expression, cell cycle, and cell growth in breast cancer (MCF-7) cells.

Irinotecan is a natural alkaloid agent widely used in cancer therapy. High-mobility group protein B1 as a non-histone chromosomal protein plays a fundamental role in gene expression and inflammation. In this study, the effect of irinotecan on high-mobility group protein B1 and MMP9 content, gene expression, cell cycle, and cell growth in human breast cancer cells (MCF-7) was investigated. The cells were exposed to various concentrations of irinotecan and the viability determined by trypan blue exclusion and 3-(4,5-dimethylthiazal-2-yl)-2,5-diphenyltetrazolium bromide assays. High-mobility group B proteins were extracted from the control and drug-treated cells and analyzed by immunoblot. High-mobility group protein B1 and MMP9 messenger RNA expression was studied by reverse transcription polymerase chain reaction. The results demonstrated reduction of cell viability upon increasing irinotecan concentration, up-regulated high-mobility group protein B1 gene expression, and down-regulated MMP9 mRNA. Although the content of high-mobility group protein B1 was decreased in chromatin extract upon drug action, no high-mobility group protein B1 release to extracellular space was detected by immunoblot analysis. Irinotecan decreased H3K9 acetylation and increased poly ADP-ribose polymerase fragmentation to 89 kDa and anion superoxide production suggesting induction of apoptosis in these cells. Propidium iodide staining of the cells 24 h after the drug treatment revealed arrest of the cells in S-phase. From the results, it is concluded that overexpression of high-mobility group protein B1 in the presence of irinotecan precedes breast cancer cells into apoptosis and in this response the binding of irinotecan to chromatin or high-mobility group protein B1 may condense/aggregate chromatin, preventing high-mobility group protein B1 release from chromatin.

Spectroscopic analysis of the interaction of valproic acid with histone H1 in solution and in chromatin structure.

Histone H1 is a basic chromosomal protein which links adjacent nucleosomes in chromatin structure. Valproic acid (VPA), a histone deacetylase inhibitor, is widely used as an antiepileptic drug for the treatment of various cancers. In this study the interaction between VPA and histone H1, chromatin and DNA in solution was investigated employing spectroscopic techniques. The results showed that VPA binds cooperatively to histone H1 and chromatin but exhibited very weak interaction with DNA. The association constants demonstrated higher affinity of VPA to H1 compared to chromatin. Fluorescence emission intensity was reduced by quenching value (Ksv) of 2.3 and 0.83 for H1 and chromatin respectively. VPA also altered ellipticity of chromatin and H1 at 220nm indicating increase in α-helix content of H1/chromatin proteins suggesting that the protein moiety of chromatin is the site of VPA action. Moreover, thermal denaturation revealed hypochromicity in chromatin Tm profiles with small shift in Tm values without any significant change in DNA pattern. It is concluded that VPA, apart from histone deacetylase inhibition activity, binds strongly to histone H1 in chromatin structure, demonstrating that VPA may also exert its anticancer activity by influencing chromatin proteins which opens new insight into the mechanism of VPA action.

Investigation of the interaction between berberine and nucleosomes in solution: Spectroscopic and equilibrium dialysis approach.

Berberine is a natural plant alkaloid with high pharmacological potential. Although its interaction with free DNA has been the subject of several reports, to date there is no work concerning the effect of berberine on nucleoprotein structure of DNA, the nucleosomes. The present study focuses on the binding affinity of berberine to nucleosomes and histone H1 employing various spectroscopic techniques, fluorescence, circular dichroism, thermal denaturation as well as equilibrium dialysis. The results showed that the binding of berberine to nucleosomes is positive cooperative with Ka=5.57×103M-1. Berberine quenched with the chromophores of protein moiety of nucleosomes and reduced fluorescence emission intensity at 335nm with Ksv value of 0.135. Binding of berberine to nucleosomes decreased the absorbance at 210 and 260nm, produced hypochromicity in thermal denaturation profiles and its affinity to nucleoprotein structure of nucleosomes was much higher than to free DNA. Berberine also exhibited high affinity to histone H1 in solution and the binding was positive cooperative with. Ka=3.61×103M-1. Moreover berberine decreased fluorescence emission intensity of H1 by quenching with tyrosine residue in its globular core domain. The circular dichroism profiles demonstrated that the binding of drug induced secondary structural changes in both DNA stacking and histone H1. It is concluded that berberine is genotoxic drug, interacts with nucleosomes and in this process histone H1 is involved to exert its anticancer activity.

Anti-tumor activity of safranal against neuroblastoma cells.

OBJECTIVE: Safranal (2,6,6-trimethyl-1,3-cyclohexadiene-1-carboxaldehyde, C10H14O) is an active ingredient in the saffron, which is used in traditional medicine, and also, the biological activity of saffron in anti-cancer is in development. It has been reported to have anti-oxidant effects, but its anti-tumor effects remain uncertain. The aim of this study was to evaluate effects of safranal on anti-tumor on neuroblastoma cells. MATERIALS AND METHODS: Neuroblastoma cells were cultured and exposed to safranal (0, 10, 15, 20, 50 µg/ml). Cell proliferation was examined using the 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Apoptotic cells, cell cycle distribution, and sub-G1 fraction were analyzed using flow cytometric analysis after propidium iodide staining. RESULTS: Safranal inhibited the growth of malignant cells in a dose-and time-dependent manner. The IC (50) values against the neuroblastoma cell line were determined as 11.1 and 23.3 µg/ml after 24 and 48 h, respectively. Safranal induced a sub-G1 peak in the flow cytometry histogram of treated cells compared to control cells indicating that apoptotic cell death is involved in safranal toxicity. CONCLUSIONS: Our pre-clinical study demonstrated a neuroblastoma cell line to be highly sensitive to safranal-mediated growth inhibition and apoptotic cell death. Although the molecular mechanisms of safranal action are not yet clearly understood, it appears to have potential as a therapeutic agent.

Numerical investigation of Al2O3/water nanofluid laminar convective heat transfer through triangular ducts.

In this article, laminar flow-forced convective heat transfer of Al2O3/water nanofluid in a triangular duct under constant wall temperature condition is investigated numerically. In this investigation, the effects of parameters, such as nanoparticles diameter, concentration, and Reynolds number on the enhancement of nanofluids heat transfer is studied. Besides, the comparison between nanofluid and pure fluid heat transfer is achieved in this article. Sometimes, because of pressure drop limitations, the need for non-circular ducts arises in many heat transfer applications. The low heat transfer rate of non-circular ducts is one the limitations of these systems, and utilization of nanofluid instead of pure fluid because of its potential to increase heat transfer of system can compensate this problem. In this article, for considering the presence of nanoparticl: es, the dispersion model is used. Numerical results represent an enhancement of heat transfer of fluid associated with changing to the suspension of nanometer-sized particles in the triangular duct. The results of the present model indicate that the nanofluid Nusselt number increases with increasing concentration of nanoparticles and decreasing diameter. Also, the enhancement of the fluid heat transfer becomes better at high Re in laminar flow with the addition of nanoparticles.