Objective To prepare the curcumin self-microemulsion, observe the morphology and size diameter distribution of the microemulsion, and compare the absorption kinetics of curcumin microemulsion and micelle. To investigate the best absorption segment of curcumin microemulsion in intestnum tenue and the absorption of curcumin self-microemulsion in mouse gastrointestinal tract. MethodsThe intestine in rats was cannulated in situ recirculation. The absorption of curcumin microemulsion was calculated by its decrement in intestnum tenue.The inabsorbable curcumin in all content together with feces in mouse gastrointestinal tract was obtained and used to calculate the absorption rate of curcumin. ResultsThe curcumin microemulsion presented as small spherical drops or something similar under transmission electron microscope (TEM) with the average diameter of about 21.6 nm. The absorption constants of curcumin microemulsion and micelle was 0.042 5 and 0.019 5 /h , the main segments of curcumin microemulsion absorption were intestinum duodenum and intestinum jejunum. The absorption rate of curcumin self-microemulsion was 2.5 times as much as curcumin. ConclusionThe curcumin self-microemulsion could improve the absorption of curcumin in vivo in animal evidently.

Objective:To analyze the differential expression of silent information regulator transcript-1 (SIRT1) in tissues and cells of nasopharyngeal carcinoma (NPC), to explore the effects of SIRT1 on the proliferation and migration of NPC cells, as well as the effects on and mechanisms of lipid metabolism in NPC cells.Methods:Experimental subjects: In this study, tissue specimens were obtained from patients who visited the Department of Otolaryngology and performed nasopharyngeal tissue biopsy in the Affiliated Hospital of Nantong University from 2019 to 2020. Among them, 6 cases were male, 6 cases were female, age range: 27-72 years old, including 7 cases of NPC diagnosed by pathology and 5 cases of normal nasopharyngeal mucosa. Experimental methods and outcome measures: Western Blot and quantitative real time polymerase chain reaction (qRT-PCR) were used to detect the protein and mRNA levels of SIRT1. CNE2 cell line was selected for subsequent experiments. Cell viability and migratory ability were evaluated by CCK8, wound healing and Transwell assays respectively. Animal xenograft tumor model was used to explore the role of SIRT1 inhibitor Ex527 on tumor growth in nude mice. Oil red and Bodipy were used to stain intracellular lipids. For the mechanical investigation, the interactions between SIRT1 and hypoxia inducible factor-1α (HIF-1α) were analyzed by immunoprecipitation (IP) and chromatin immunoprecipitation (ChIP). Finally, statistical analysis was performed by SPSS 26.0 software, P<0.05 was considered statistically significant. Results:The levels of SIRT1 protein (1.005±0.168) and mRNA (5.829±2.395) in NPC tissues were higher than those in normal nasopharyngeal mucosa (0.181±0.042,1.995±1.605). Differences were statistically significant ( t values were 6.438 and 2.759, both P<0.05). The mRNA and protein levels of CNE1, CNE2, 5-8F and 6-10B cell lines were also higher than those in normal nasopharynx epithelial cell line NP69. Besides, overexpression of SIRT1 correlated with the proliferation and migration of NPC cells. The tumorigenesis ability of nude mice in the Ex527 group was lower than that in the control group. The low SIRT1 expression reduced the protein level of the key enzymes of liposynthesis in NPC cells, improved the expression of lipolysis enzymes, while HIF-1α overexpression promoted lipid synthesis enzymes in NPC cells. SIRT1 inhibited HIF-1α transcription by enhancing deacetylation levels. The binding ability of HIF-1α to SIRT1 promoter regions decreased when NPC cells were hypoxic. Conclusions:SIRT1 promotes the proliferation, migration and lipid metabolism of nasopharyngeal carcinoma cells, which might be expected to provide new theoretical basis for prognosis judgment and gene therapy.