Xue-Hai Jin

Effects of fucoxanthin on lipopolysaccharide-induced inflammation in vitro and in vivo

The aim of the present study was to investigate the efficacy of fucoxanthin on endotoxin-induced uveitis (EIU) in rats. The effects of fucoxanthin on endotoxin-induced leucocyte and protein infiltration, nitric oxide (NO), prostaglandin (PG)-E2 and tumour necrosis factor (TNF)-alpha concentrations in rat aqueous humour, as well as on the cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) protein expression in a mouse macrophage cell line (RAW 264.7 cells) were studied. EIU was induced in male Lewis rats by a footpad injection of lipopolysaccharide (LPS). Immediately after the LPS injection, either 0.1, 1 or 10mgkg(-1) of fucoxanthin was injected intravenously. The aqueous humour was collected 24hr later from both eyes, and both the number of cells infiltrating into the aqueous humour and the aqueous humour protein concentration were measured. The levels of PGE2, NO and TNF-alpha were determined by enzyme-linked immunosorbent assay. The RAW 264.7 cells were pretreated with various concentrations of fucoxanthin for 24hr and subsequently incubated with LPS for 24hr. COX-2 and iNOS protein expression was analysed by the Western blotting method. Levels of PGE2, NO and TNF-alpha production were determined. Fucoxanthin suppressed the development of EIU in a dose-dependent fashion. Treatment with fucoxanthin resulted in a reduction in PGE2, NO and TNF-alpha concentrations in the aqueous humour. The expression of COX and iNOS protein in the fucoxanthin treated RAW264.7 cells decreased significantly compared to that the LPS group. It also significantly reduced the concentration of PGE2, NO and TNF-alpha production in the medium of cells. The present result indicate fucoxanthin suppresses the inflammation of EIU by blocking the iNOS and COX-2 protein expression and its anti-inflammatory effect on eye is comparable with the effect of predinisolone used in similar doses.

Inhibition of nuclear factor-kappa B activation attenuates hydrogen peroxide-induced cytotoxicity in human lens epithelial cells

Aims: Hydrogen peroxide (H2O2) is the major oxidant involved in cataract formation. Lens epithelial cells have been suggested to be the first site of oxidative damage. The authors investigated the relationship between H2O2-induced cytotoxicity and activation of nuclear factor kappa B (NF-κB) in human lens epithelial (HLE) cells. Methods: HLE B-3 cells were stimulated by various concentrations of H2O2 in the presence or absence of pyrrolidine dithiocarbamate (PDTC), a potent inhibitor of NF-κB. H2O2-induced cytotoxicity was measured by lactate dehydrogenase cytotoxicity assay. Translocation of NF-κB was examined by Western blot and immunocytochemistry using anti-p65 antibody. Results: H2O2-induced cytotoxicity increased in a concentration-dependent manner. PDTC treatment significantly suppressed the cytotoxicity induced by H2O2. After stimulated with H2O2, NF-κB was found translocated from cytoplasm into the nuclei. PDTC treatment also inhibited the translocation of NF-κB. Conclusions: NF-κB signal pathway may be important in the development of H2O2-induced damage in HLE cells that is involved in cataractogenesis.

Detection of human adenovirus hexon antigen using carbon nanotube sensors.

Human adenoviruses (HAdVs) have been implicated in a wide range of diseases affecting primarily the respiratory, ocular and gastrointestinal systems. A rapid and efficient method for the detection of HAdV hexon antigen is described using carbon nanotube (CNT) sensors. Anti-HAdV antibody was immobilised on the reverse surface of a CNT sensor. As a control, non-specific mouse IgG was immobilised on another CNT sensor. I-V(gate) curves were measured after incubation of various concentrations of recombinant HAdVs hexon antigen with anti-HAdVs antibody-immobilised or non-specific mouse IgG-immobilised sensors. The curves showed a positive shift that was dependent on the hexon antigen concentration in the anti-HAdV antibody-immobilised sensor, whereas no such shift was observed in the non-specific mouse IgG-immobilised sensor. The sensitivity of the CNT sensor method was greater than that of enzyme-linked immunosorbent assay. Hence, this method offers a new tool for HAdV detection by analysing antigen-antibody interactions.

Bacterial endophthalmitis caused by an intraocular cilium in a patient under treatment with infliximab

BackgroundWe report a case of bacterial endophthalmitis caused by an intraocular cilium in a patient without any history of trauma or ocular surgery.FindingsA 32-year-old Caucasian male showed symptoms of orbital myositis and scleritis, with no intraocular inflammation in the right eye. The patient had been treated with infliximab for Crohn’s disease. Three weeks after initiation of oral prednisolone therapy, he developed bacterial endophthalmitis. During pars plana vitrectomy, a cilium in the massive vitreous opacity was found. A focal scleral necrosis was detected just outside where the cilium was intraoperatively observed. Vitreous culture showed the presence of Staphylococcus aureus.ConclusionsThe intraocular cilium seemed to be the aetiology of the endophthalmitis in this case, which suggests that anti-tumour necrosis factor-α therapy may play a role in the migration of cilia into the globe and the occurrence of endophthalmitis.