The influence of harvest time on total phenolic and flavonoid contents, antioxidant, antibacterial and cytotoxicity of Rheum khorasanicum root extract.

INTRODUCTION: For many centuries, medicinal herbs and their derivatives have been used to treat or prevent various diseases. However, environmental factors such as the season for collection of plant may change the therapeutic efficacy. The present work investigates seasonal variations of phenolic, flavonoid content, antioxidant, antibacterial, and cytotoxic potential of hydroalcoholic extract of Rheum khorasanicum (HER). METHODS: R. khorasanicum was collected in three different months: December, February, and April. The Folin-Ciocalteu assay was applied to measure the total phenolic content of HER. Antioxidant activities (DPPH and FRAP) were also determined. Next, the extracts were evaluated for antibacterial potential against some Gram-positive and Gram-negative strains. The minimal inhibitory concentration (MIC) was determined by the microdilution method. Finally, the effect of extracts on the viability of C6, A549, and HT-29 cells was evaluated via the MTT assay. RESULTS: All three extracts contained considerable phenolic and flavonoid contents and showed desirable antioxidant activity. The April sample exhibited the greatest phenolic and flavonoid content and significant antioxidant activity potential in the FRAP test. In addition, the April sample had the highest antibacterial activity and cytotoxic effect on the cancerous cell lines. CONCLUSION: The April extract showed more antioxidant, antibacterial and cytotoxic effect, probably because of its higher phenolic and flavonoid contents than other samples. These results demonstrate that the harvest timing of R. khorasanicum affects the plant's phenolic content and its antioxidant and cytotoxicity activities.

The effect of hydro alcoholic extract of Nigella sativa seeds on inflammatory mediators in C6 glioma cell line.

SUBJECT: Nigella sativa (N. sativa) is a highly valued nutritional plant, which has long been used in traditional medicine to treat a variety of human diseases. The multifaceted pharmacological impacts of N. sativa, such as attenuating oxidative stress and inflammation, make it a suitable therapeutic candidate against cardiovascular, hepatic, and neurological disorders as well as cancer. Therefore, the current study aimed to evaluate the effect of the hydroalcoholic extract of N. sativa seeds on several pro-inflammatory cytokines in the C6 glioma cell line and to compare it with the effect of the extract on the normal fibroblast cell line. METHODS: C6 and fibroblast cell lines were treated with the extract of N. sativa seeds, and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was performed to determine the half-maximal inhibitory concentration (IC50) after 72h of treatment. Real-time polymerase chain reaction (RT-PCR) was carried out to assess the expression levels of interleukin (IL)-6, IL-10, tumor necrosis factor-alpha (TNF-α), and transforming growth factor- ß1 (TGF-ß1) at the mRNA level in both cell lines after 72h of treatment with non-toxic and IC50 concentrations obtained from C6 cell line. RESULTS: The IC50 values for the hydroalcoholic extract of N. sativa seeds were 260±20µg/mL in the C6 cell line and 398±27µg/mL in fibroblast cells. The real-time PCR results indicated that the treatment of C6 and fibroblast cells with the extract at the IC50 value of N. sativa in C6 for 72h could increase the mRNA expression levels of IL-10 and reduce the mRNA expression levels of IL-6, TNF-α, and TGF-ß1 in C6 and fibroblast cells. The N. sativa extract showed a higher anti-inflammatory effect on C6 cells in comparison with fibroblast cells. CONCLUSIONS: Regarding the anti-inflammatory effect of Nigella sativa in C6 cell line, it may be considered a promising candidate to fortify antitumor actions in combination with other therapeutic options in the treatment of patients with GBM.

Intense THz Pulses with large ponderomotive potential generated from large aperture photoconductive antennas.

We report the generation of free space terahertz (THz) pulses with energy up to 8.3 ± 0.2 µJ from an encapsulated interdigitated ZnSe Large Aperture Photo-Conductive Antenna (LAPCA). An aperture of 12.2 cm2 is illuminated using a 400 nm pump laser with multi-mJ energies at 10 Hz repetition rate. The calculated THz peak electric field is 331 ± 4 kV/cm with a spectrum characterized by a median frequency of 0.28 THz. Given its relatively low frequency, this THz field will accelerate charged particles efficiently having very large ponderomotive energy of 15 ± 1 eV for electrons in vacuum. The scaling of the emission is studied with respect to the dimensions of the antenna, and it is observed that the capacitance of the LAPCA leads to a severe decrease in and distortion of the biasing voltage pulse, fundamentally limiting the maximum applied bias field and consequently the maximum energy of the radiated THz pulses. In order to demonstrate the advantages of this source in the strong field regime, an open-aperture Z-scan experiment was performed on n-doped InGaAs, which showed significant absorption bleaching.

Cord blood T cells retain early differentiation phenotype suitable for immunotherapy after TCR gene transfer to confer EBV specificity.

Adoptive T cell therapy can be effective for Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease and melanoma. Transducing high-affinity TCR genes into T lymphocytes is an emerging method to improve potency and specificity of tumor-specific T cells. However, both methods necessitate in vitro lymphocyte proliferation, generating highly differentiated effector cells that display reduced survival and antitumor efficacy postinfusion. TCR-transduction of naive lymphocytes isolated from peripheral blood is reported to provide superior in vivo survival and function. We utilized cord blood (CB) lymphocytes, which comprise mainly naive cells, for transducing EBV-specific TCR. Comparable TCR expression was achieved in adult and CB cells, but the latter expressed an earlier differentiation profile. Further antigen-driven stimulation skewed adult lymphocytes to a late differentiation phenotype associated with immune exhaustion. In contrast, CB T cells retained a less differentiated phenotype after antigen stimulation, remaining CD57-negative but were still capable of antigen-specific polyfunctional cytokine expression and cytotoxicity in response to EBV antigen. CB T cells also retained longer telomeres and in general possessed higher telomerase activity indicative of greater proliferative potential. CB lymphocytes therefore have qualities indicating prolonged survival and effector function favorable to immunotherapy, especially in settings where donor lymphocytes are unavailable such as in solid organ and CB transplantation.

Anti-tumour necrosis factor-alpha therapy for severe enteropathy in patients with common variable immunodeficiency (CVID).

We present three common variable immunodeficiency (CVID) patients with severe inflammatory bowel disease of unknown aetiology, resistant to steroid treatment, treated with infliximab. After exclusion of any infection, infliximab was given at a dose of 5 mg/kg every 4 weeks for a 3 month induction followed by every 4-8 weeks depending on clinical response. Two of these patients had predominantly small bowel disease; they both showed clinical response to infliximab with weight gain and improvement of quality of life scores. The third patient had large bowel involvement with profuse watery diarrhea; this patient improved dramatically within 48 hours of having infliximab treatment. All three patients have been maintained on infliximab treatment for between 5 and 53 months (mean 37 months) with no evidence of increased susceptibility to infections in the patients with small bowel disease, although the third patient developed two urinary tract infections and a herpes zoster infection following therapy. This is the first small case series to show that infliximab is a useful addition to current therapy in this rare group of patients with potentially life threatening enteritis.

The T cell response to persistent herpes virus infections in common variable immunodeficiency.

We show that at least half of patients with common variable immunodeficiency (CVID) have circulating CD8(+) T cells specific for epitopes derived from cytomegalovirus (CMV) and/or the Epstein-Barr virus (EBV). Compared to healthy age-matched subjects, more CD8(+) T cells in CVID patients were committed to CMV. Despite previous reports of defects in antigen presentation and cellular immunity in CVID, specific CD4(+) and CD8(+) T cells produced interferon (IFN)-gamma after stimulation with CMV peptides, and peripheral blood mononuclear cells secreted perforin in response to these antigens. In CVID patients we found an association between a high percentage of circulating CD8(+) CD57(+) T cells containing perforin, CMV infection and a low CD4/CD8 ratio, suggesting that CMV may have a major role in the T cell abnormalities described previously in this disease. We also show preliminary evidence that CMV contributes to the previously unexplained severe enteropathy that occurs in about 5% of patients.

Defective maturation of dendritic cells in common variable immunodeficiency.

Monocyte-derived dendritic cells (MdDCs) from many patients with common variable immunodeficiency (CVID) have been shown recently to have reduced expression of surface molecules associated with maturity. Using flow cytometry and confocal microscopy, we now show that this is due to a partial failure to fix Class II DR molecules on the surface during procedures that induce full maturation in vitro in cells from normal subjects. Major histocompatibility complex (MHC) class I, CD86 and CD83 expression were expressed normally, but CD40 was reduced. These abnormalities are unlikely to be due to prior in vivo exposure of monocytes to lipopolysaccharide (LPS), as addition of LPS to monocytes from normal subjects in vitro caused a different pattern of changes. CVID MdDCs retained Class II DR in the cytoplasm during maturation, showed increased internalization of cross-linked Class II DR surface molecules and were unable to polarize DR within a lipid raft at contact sites with autologous lymphocytes. These cells retained some features of monocytes, such as the ability to phagocytose large numbers of fixed yeast and fluorescent carboxylated microspheres and expression of surface CD14. These abnormalities, if reflected in vivo, could compromise antigen presentation and may be a fundamental defect in the mechanism of the antibody deficiency in a substantial subset of CVID patients.

IgG subclass response to Helicobacter pylori and CagA antigens in children.

Specific serum IgG subclass antibodies against Helicobacter pylori antigens and recombinant CagA were analysed in 75 symptomatic children with histologically confirmed H. pylori infection. H. pylori stimulated an IgG1 predominant response, and IgG3 titres showed a positive association with peptic ulcer disease, chronicity of antral inflammation and density of H. pylori colonization. Two methods used for assessing serum IgG CagA antibody status, i.e. Western blotting and enzyme-linked immunosorbent assay (ELISA), were concordant. CagA stimulated an IgG1 and IgG3 predominant humoral response. Total CagA IgG titres were higher in children with active and more severe chronic antral inflammation. These findings suggest that in children the systemic humoral immune response to H. pylori infection may reflect gastroduodenal pathology.