ObjectiveThis paper aims to investigate the efficacy and related actions of Guizhi Fulingwan in intervening in the mice with colitis-associated colon cancer （CAC） based on the immunosuppressive microenvironment associated with myeloid-derived suppressor cells （MDSCs）. MethodsSixty male C57BL/6 mice were randomly assigned to a blank group， a model group， an aspirin group （0.04 g·kg^-1）， and low-， medium-， and high-dose Guizhi Fulingwan groups （4.87， 9.75， and 19.50 g·kg^-1）， with ten mice per group. The CAC mouse model was established via combined induction of azoxymethane （AOM）/dextran sulphate sodium （DSS）. Drug intervention commenced in week five， with continuous intragastric administration for nine weeks. The food intake， body weight， fecal characteristics， and haematochezia were observed and recorded， and disease activity index （DAI） scores were calculated according to scoring criteria. Hematoxylin and eosin （HE） staining was used to observe the histopathological changes in the colon tissues of the mice. Immunohistochemistry was used to determine proliferating cell nuclear antigen-67 （Ki67） expression in the colon tissues， and enzyme-linked immunosorbent assay （ELISA） was used to detect the contents of interleukin-6 （IL-6）， IL-1β， and tumor necrosis factor-α （TNF-α） in the serum of the mice. Flow cytometry was employed to determine the proportion levels of MDSCs， CD4⁺ T cells， and CD8⁺ T cells in the spleen tissues of the mice. The mRNA expressions of MDSC-associated effector molecules， including arginase 1 （Arg1） and inducible nitric oxide synthase （iNOS）， were detected by real-time quantitative polymerase chain reaction （Real-time PCR）. After that， an in vitro co-culture model of MDSCs and CD8⁺ T cells was established， and drug-containing serum of Guizhi Fulingwan was used for intervention. The Flow cytometry was employed to assess the effects of drug-containing serum of Guizhi Fulingwan with different concentrations on the levels of reactive oxygen species （ROS） and iNOS in MDSCs and the proliferation of CD8⁺ T cells. The levels of granzyme B （GZMB） and interferon-γ （IFN-γ） in cell supernatant were detected by ELISA. ResultsCompared with those in the control group， the mice in the model group exhibited significantly reduced body weight， elevated DAI scores， shortened colon length （P<0.01）， increased number of tumors and Ki67 expression （P<0.01）， and significantly elevated contents of IL-6， IL-1β， and TNF-α in the serum （P<0.01）. Significant increases in the number of MDSCs were observed in mouse spleens， alongside marked reductions in the levels of CD4⁺ T and CD8⁺ T cells （P<0.01）. Furthermore， the mRNA expressions of MDSC function-associated effector molecules Arg1 and iNOS were significantly upregulated （P<0.01）. Compared with those in the model group， the mice in the middle-dose Guizhi Fulingwan group exhibited increased body weight and significantly decreased DAI scores （P<0.05， P<0.01）. The mice in the middle- and high-dose Guizhi Fulingwan groups exhibited significantly improved colon shortening， significantly decreased number of tumors and Ki67 expression （P<0.05， P<0.01）， and significantly decreased contents of IL-6， IL-1β， and TNF-α in the serum （P<0.05， P<0.01）. Furthermore， administration of Guizhi Fulingwan markedly reduced MDSC infiltration in the spleen of the mice， with different degrees of increase in the levels of both CD4⁺ T and CD8⁺ T cells （P<0.05， P<0.01）， alongside significant decreases in the mRNA expressions of Arg1 and iNOS （P<0.05， P<0.01）. In vitro cell co-culture shows that administration of drug-containing serum of Guizhi Fulingwan significantly decreases the activity levels of ROS and iNOS in MDSCs and promotes the proliferation of CD8⁺ T cells and the secretion of GZMB and IFN-γ （P<0.05， P<0.01）. ConclusionGuizhi Fulingwan can reduce pro-inflammatory cytokine secretion and inhibit tumor proliferation in the colon tissues of CAC mice. Its potential mechanism may involve reducing MDSC infiltration， enhancing effector T cells， particularly CD8⁺ T cell response， and improving the tumor immunosuppressive microenvironment.

Background Laser peripheral iridoplasty (LPI) is widely used in the treatment of glaucoma by flattening the iris and widening angle of anterior chamber (AA).However,no evidence suggests the optimal site of LPI in iris.Objective This study was to compare the therapeutic effects of LPI at different sites of iris for glaucoma.Methods Glaucoma models were established in the right eyes of 40 healthy adult male pigment rabbits by intrachamber injection of 0.1 ml compound carbomer solution with 0.3％ carbomer and 0.025％ dexamethasone.The models were randomly divided into model control group,corneoscleral limbus group,one spot from corneoscleral limbus group and two spots from corneoscleral limbus group.LPI was performed at corresponding site of iris by 532 nm argon laser with the spot diameter 500 μm,energy 300 mW,exposure time 0.3 seconds and laser number 24 spots,and the rabbits in the model control group did not receive LPI.Intraocular pressure (IOP),coefficient of outflow facility (C value) were measured and calculated with Schi(o)tz tonometer before LPI and 2,4,7,14 and 30 days after LPI,and anterior chamber depth (ACD),AA,anterior chamber angle opening distance within 500 μm radius from scleral spur (AOD500) were measured with ultrasound biomicroscope (UBM).The eyeballs were extracted 30 days after LPI,and the chamber angle were observed under the optical microscope after hematoxylin and eosin staining.The use and care of the animals complied with the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health.Results UBM showed that compared with the model control group,the anterior chamber angle was evidently widened in all the LPI groups,with the best effectiveness in the one spot from corneoscleral limbus group and the worst one in the two spots from corneoscleral limbus group.Compared with the model control group,the IOP was evidently reduced,and C values,AA and AOD500 were significantly increased in the corneoscleral limbus group,one spot from corneoscleral limbus group and two spots from corneoscleral limbus group after LPI,showing significant differences among the four groups (IOP:Fgroup =16.848,P ＜ 0.01;C value:Fgroup =9.629,P ＜ 0.01;AA:Fgroup =62.336,P＜0.01;AOD500:Fgroup =77.779,P ＜ 0.01).IOP was reduced and C value,AA and AOD500 were increased in 2,4,7,14 and 30 days after LPI as compared with before LPI,with significant differences over time (IOP:Ftime =3.041,P =0.011;C value:Ftime =4.311,P＜0.01;AA:Ftime =14.627,P＜0.01;AOD500:Ftime =20.378,P＜0.01).Compared with the model control group,the ACD was significantly increased in the corneoscleral limbus group and one spot from corneoscleral limbus group,and that in the two spots from corneoscleral limbus group was significantly reduced,and the ACD was insignificantly increased over time after LPI (Fgroup =18.017,P＜0.01;Ftime =0.022,P =1.000).Hematoxylin and eosin staining showed that the trabecular meshwork and adhesion of tissure were reopened and the anterior chamber angle was widened after LPI.Conclusions LPI can widen anterior chamber angle and lower the IOP.The best therapeutic outcome for glaucoma is displayed when LPI is performed at the iris site corresponding to one spot from the corneoscleral limbus.