Evaluation of photodynamic efficiency of an endogenous enzyme-NQO1 activated hypericin

OBJECTIVE To investigate the therapeutic efficiency of an endogenous enzyme-NQO1 activated hypericin in photodynamic therapy.METHODS An endogenous enzyme-NQO1 responsive photo sensitizer was designed and synthesized by conjugating aquinonebased ligand to a natural photosensitizer derived from Chinese herb.The photophysical and photochemical properties were investigated through UV-visible and fluorescence spectrophotometer,and the photodynamic activity was evaluated with MTT assay.RESULTS An endogenous enzyme-NQO1 activated hypericin was prepared and fully characterized with various spectroscopic methods.The electronic absorption was almost the same with the free hypericin,indicating the introducing of the ligand to hypericin has little effect to its ground state,while there is almost no detected fluorescence and reactive oxygen species(ROS)generation in PBS solution indicating the introducing of the ligand can effectively quench the fluorescence emission and ROS generation.The in vitro study showed that both compounds have almost no dark toxicity,but they are highlyphotocytoxic with an IC50 less than 1μmol·L-1 against A549 cell lines indicating the modified compound can be activated in the intracellular environment.CONCLUSION A simple and efficient hypericin-based activated photosensitizer was prepared.The ROS generation was quenched in PBS solution and it would be activated inside A549 cell lines.It may be served as apromising tumor selective fluorescent probe and photosensitizer for targeted photodynamic therapy.

Anti-inflammation and anti-fibrosis actions of resveratrol on experimental pneumoconiosis

OBJECTIVE To investigate the therapeutic effects and related signaling pathways involved in the actions of resveratrol on experimental pneumoconiosis in vivo and in vitro.METHODS The pneumoconiosis animal model was induced by exposing male SD rats to 15mg·m-3 silica aerosol in an inhalation chamber system for 6h·d-1,5d·week-1 for up to 8 weeks.The vehicle or resveratrol(10or 20mg·kg-1)was preventively or remedially administered to the rats during or after the 4-or 8-week silica exposure(SE)period,respectively.After 4-,8-,and up to 14-week treatment,in vivo near-infrared fluorescence imaging analysis and histological analysis were performed to evaluate the pathological changes in rat lung.Inflammatory cytokines level in bronchoalveolar lavage fluid(BALF)was measured by ELISA testing,and the deposition of fibrotic collagen proteins in lung parenchyma was determined by western blotting and immunohistochemistry analysis.Microarray analysis was performed to screen the signaling pathways involved in the actions of resveratrol on pneumoconiosis in vitro models.Anti-inflammation action and signaling of resveratrol was evaluated on silica-stimulated rat alveolar macrophage,which is one of the crucial effector cells for silica-induced inflammatory response;anti-fibrosis action and signaling of resveratrol was evaluated on TGF-β-induced human lung fibroblast,which acts as a promoter in the later fibrotic process of pneumoconiosis.RESULTS Silica aerosol exposure significantly increased macrophage infiltration and matrix metalloproteinases activity in lung tissue concomitant with the increased levels of inflammatory mediators in BALF.Preventive treatment with resveratrol(20mg·kg-1·d-1)reversed all these biochemical indices as well as histopathological alterations induced by silica exposure.Post-SE resveratrol treatment mildly reduced silica-induced inflammatory response in rat lung with no statistical significance.In vitro study revealed that resveratrol could inhibit alveolar macrophage cell death and decrease the levels of IL-1β and TNF-αinduced by silica particle exposure to cultured alveolar macrophages.Resveratrol was further shown to inhibit the nuclear transition of NF-κB and formation of cleaved caspase-1.Encouragingly,resveratrol preventively attenuated the lung fibrosis,evidenced by less fibrotic nodules formation and collagen proteins expression.No significant improvement on lung fibrosis was observed with post-SE resveratrol treatment.Invitrostudy further demonstrated that resveratrol suppressed TGF-β-induced lung fibroblast proliferation and collagen deposition,concomitant with the depressed activity of TGF-β/Smad signaling in lung fibroblast.CONCLUSION Resveratrol shows the anti-inflammation and anti-fibrosis actions on experimental pneumoconiosis in vivo and in vitro models.The depression of NF-κB,NALP3-inflammasome,and TGF-β/Smad signaling pathways may be involved in the anti-inflammation and anti-fibrosis actions of resveratrol,respectively.Resveratrol could be a potential therapeutic agent for the intervention of pneumoconiosis.