Spectroscopic and molecular docking investigation of polynucleotides and DNA binding affinity to Nile blue dye.

We used UV-vis absorption spectroscopy, fluorescence spectrophotometry and molecular docking calculations to investigate intermolecular interaction between the cationic dye, Nile blue (NB), and synthetic polynucleotides, poly(A-T), poly(G-C) and calf thymus DNA (Ct-DNA) at physiological pH. Strong hypsochromic absorbance and fluorescence quenching were observed that showed strong binding of NB to these polynucleotides and DNA. The binding affinity values derived from maximum absorption of the spectra of NB bound to various polynucleotides and Ct-DNA concentrations suggests that NB exhibits greater binding affinity to poly(G-C) than to poly(A-T). The thermodynamic parameters suggested that hydrogen bonds and van der Waals forces might play a major role in the binding of NB to DNA. The molecular docking results suggested that NB was an intercalator of the stacked base pairs of Ct-DNA.

Immunomodulatory efficacy of ethanol extract of propolis on tumor-bearing mice with disseminated candidiasis.

OBJECTIVE: This study was aimed at investigating the effect of propolis on immunosurveillance by measuring the levels of serum interleukin (IL)-4, IL-10, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-γ in tumor-bearing mice with disseminated candidiasis. METHODS: The ethanol extract of propolis was selected for this study. Balb/C female mice were infected with Candida albicans (C. albicans) and inoculated with spontaneous mouse mammary tumor (SMMT). The serum levels of tissue inhibitor of metalloproteinase-1(TIMP-1) were assessed by enzyme- linked immunosorbent assay (ELISA). Mice were treated daily with propolis solution (100mg/kg, 0.1 mL, orally) for 3 days before IV challenge with C. albicans and SC challenge with SMMT and continued for 10 days. The rates of survival and tumor growth of understudy mice were investigated as well. The levels of TNF-α, IFN-γ, IL-4, IL-10 and IL-17 cytokines in culture supernatants were determined by ELISA. RESULTS: The mean tumor size was significantly increased in tumor-bearing mice infected with C. albicans (16.98 ± 0.49 mm(2)) as compared to other mice groups (P<0.05). The results showed a significant decline of IL-4 and IL-10 levels after propolis administration to tumor-bearing mice infected with C. albicans (53.41 pg/mL, 156.81 pg/mL and 63.45 pg/mL) (P < 0.05). The increment of TNF-α (433.85 pg/mL) and IFN-γ (120.43 pg/mL) levels were also observed. CONCLUSION: Data revealed that propolis has remarkable immunomodulatory effect, which provides a scientific validation for the popular use of this natural substance, and further investigation will help to understand propolis usefulness during immunosuppressive conditions.

Altered immune responses in patients with chronic mucocutaneous candidiasis.

OBJECTIVE: The purpose of this study was to investigate the lymphocyte transformation responses and cytokine secretion of peripheral blood mononuclear cells (PBMC) from patients with chronic mucocutaneous candidiasis (CMC). METHODS: Phytohaemagglutinin (PHA) mitogen and Candida albicans (C. albicans) antigen proliferation assays were performed by culturing PBMCs in RPMI 1640. The levels of interleukin (IL)-2, IL-10, IL-17 and interferon (IFN)-γ present in the supernatant of cultures were determined using enzyme-linked immunosorbent assay (ELISA). RESULTS: The results showed that most patients (92.3%) had a low proliferative response to C. albicans antigens and PHA. PBMCs from CMC patients produced lower levels of T (h)-1 cytokines IL-2 (78.5±59.8 pg/mL) and IFN-γ (115.1±43.3 pg/mL) in response to Candida antigens when compared to controls (Il-2: 177±103.6 pg/mL; IFN-γ: 330.3±21.6 pg/mL) (P<0.05). Conversely, we observed a partial enhancement of IL-10 in the patients (213.7±86.1 pg/mL). Production of IL-17 indicated no significant differences between patients and controls when stimulated by Candida antigens (21.5±8.6 pg/mL versus 32.4±12.2 pg/mL) and PHA (27.7±11.5 pg/mL versus 36.2±9.1 pg/mL), respectively. CONCLUSION: These findings suggest that Candida antigens trigger a Th2 instead of Th1 cytokine response in patients with CMC. For better understanding, further studies require on a larger number of patients into the future.