Inhibition effect of curcumin on UVB-induced secretion of pro-inflammatory cytokines from corneal limbus epithelial cells

~ AIM： To study the effects of curcumin on the secretion of interleukin （IL） -6 and IL-8 by corneal limbus epithelial cells. METHODS： Human corneal Iimbus epithelial cells were isolated and cultured from donor eyes and irradiated by UVB at different dosages with or without curcumin. MTT test was used for studying the effects of UVB and curcumin on the cell viability. The role of mitogen-activated protein kinase （MAPK） and nuclear factor-kappa B （NF-KB） pathways on the UVB-induced secretion of IL.6 and IL-8 were tested by addition of their inhibitors to the culture with or without UVB-radiation. Levels of various signal pathways, IL-6 and IL-8 in the cells and in the conditioned culture medium were measured by ELISA analysis. RESULTS： UVB at 20 mJ/cm2 or less and curcumin at 20 IJmol/L or less did not affect the cell viability of culturedlimbus epithelial cells （P〉0.05）. UVB irradiation at 10 and 20 mJ/cm2 induced a significant increase of secretion of IL-6 and IL-8 and upregulated NF-KB and phosphorylated MAPK pathways of cultured limbus epithelial cells （P〈0.05）. Various signal pathway inhibitors, including SP600125 （JNK inhibitor）, SB203580 （p38 MAPK inhibitor） and BAY11-7082 （NF-KB inhibitor） significantly decreased the UVB-induced secretion of IL-6 and IL-8 secretion （P〈0.05）. Curcumin at 5-20 pmol/L significantly inhibited UVB- induced secretion of IL-6 and IL-8 by limbus epithelial cells in a dose-dependent manner; while curcumin alone did not affect the secretion of IL-6 and IL-8. The upregulation of NF-KB and MAPK pathways induced by UVB treatment was significantly inhibited by curcumin, suggesting that NF-KB and MAPK pathways are involved in the inhibitory effect of curcumin on UVB-induced production of IL-6 and IL-8.

RULEMAKING POSSIBILITIES： EFFORTS OF THE UNITED STATES JUDICIAL CONFERENCE ADVISORY COMMITTEE ON EVIDENCE RULES TO ADDRESS THE CHALLENGES TO FORENSIC EXPERT TESTIMONY

This piece is an echo to one of the main subjects of the Sixth International Conference on Evidence Law and Forensic Science which is to determine what evidentiary reforms are necessary for regulating forensic expert testimony, and how those reforms might be implemented. In United States, the predominant way of evidentiary reform is through rulemaking. As the Reporter of Judicial Conference Advisory Committee on the Federal Rules of Evidence since 1996, the author, with a pragmatic spirit throughout the article, examines such an effort at the federal level of U.S. in six parts （levels）, starting from the most general, abstract level till fmishing with the most detailed and substantive points. Part I begins with a brief introduction of the hierarchies of evidentiary rulemaking authorities at the federal level of the United States, various interested groups and their interesting interactions in the rulemaking process. The author then shifts to the general topic of writing rules with a specific focus on the level of detail that is to be provided in doing so; Part II further narrows down the scrutiny into writing a rule on forensic expert testimony with an emphasis on the necessity of making such a rule change to the current general standards of FRE; Part III directly addresses the challenges of drafting a rule on forensic evidence in FRE, including a comparation of various alternative drafting models; Part IV and Part V respectively discusses the Reporter＇s comments and the Justice Department＇s concerns over the drafted rules; and Part VI briefly discusses the feasibility and effectiveness of a Best Practices Manual on forensic evidence in lieu of rulemaking.