Chrysin as an Anti-Cancer Agent Exerts Selective Toxicity by Directly Inhibiting Mitochondrial Complex II and V in CLL B-lymphocytes.

We investigated the effect of chrysin on isolated normal and chronic lymphocytic leukemia (CLL) B-lymphocytes and their isolated mitochondria. We report that a selective and significant increase in cytotoxicity, intracellular reactive oxygen species, mitochondrial membrane potential collapse, ADP/ATP ratio, caspase 3 activation and finally apoptosis in chrysin-treated CLL B- lymphocytes. Also we determined that chrysin selectively inhibits complex II and ATPases in cancerous mitochondria. In this study we proved that the ability of chrysin to promote apoptosis in CLL B-lymphocytes performed by selectively targeting of mitochondria. Our findings may provide a potential therapeutic approach for using chrysin to target mitochondria in CLL B-lymphocytes.

Recombinant human lipocalin 2 acts as an antibacterial agent to prevent platelet contamination.

BACKGROUND: Bacterial contamination of platelet products is the major infectious risk in blood transfusion medicine, which can result in life-threatening sepsis in recipient. Lipocalin 2 (Lcn2) is an iron-sequestering protein in the antibacterial innate immune response, which inhibit bacterial growth. This study was aimed to evaluate the antibacterial property of Lcn2 in preventing bacterial contamination of platelets. METHODS: Recombinant Lcn2 was expressed in a eukaryotic expression system and following purification and characterization of the recombinant Lcn2, its minimum inhibitory concentration was determined. Then, platelet concentrates were inoculated with various concentrations of Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterococcus faecalis, and the antibacterial effects of Lcn2 was evaluated at 20-24 °C. RESULTS: Results revealed that Lcn2 effectively inhibited the growth of 1.5 × 10(4) CFU/ml S. epidermidis, P. aeruginosa, K. pneumoniae, E. coli, and E. faecalis at 40 ng/ml. At this concentration, Lcn2 also inhibited the growth of 1.5 × 10(3) CFU/ml Staphylococcus aureus and Proteus mirabilis. CONCLUSION: Recombinant Lcn2 inhibited growth of a variety of platelet-contaminating bacteria. Therefore, supplementation of platelet concentrates with Lcn2 may reduce bacterial contamination.

HESA-A Exerts Its Cytoprotective Effects through Scavenging of Free Radicals: An in Vitro Study.

BACKGROUND: Natural medicines have been recently considered more reasonable for human use most notably due to their safety and tolerance. HESA-A is a marine-originated herbal medicine with a variety of healing effects. However, its exact biological mechanism is not clear. The present study aimed at the evaluation of the HESA-A antioxidant effect. METHODS: Chinese hamster ovary (CHO) and human embryonic kidney (HEK293T) cells were treated with different concentrations of HESA-A and H(2)O(2) followed by cell proliferation assays. The antioxidant effect of the HESA-A preparations was evaluated by an antioxidant assay kit. RESULTS: The viability of CHO and HEK293T cells were about 89% following their incubation with 100 and 200 ng/ml HESA-A, respectively for 1.5 hrs. However, when the cells were incubated with concentrations of 300 ng/ml or more, the cell viability significantly decreased to 48% compare to the control cells. The cytotoxic effects of H(2)O(2) were observed after 2 hrs of incubation of the HEK293T or CHO cells with 10 mM or 16 mM H(2)O(2), respectively, while in the presence of HESA-A the cytotoxicity was significantly decreased. Antioxidant assay revealed that HESA-A scavenges free radicals. CONCLUSION: The findings indicate that HESA-A had cytoprotective effects in vitro, and that such an effect might be due to antioxidant properties.