A facile boronophenylalanine modified polydopamine dual drug-loaded nanoparticles for enhanced anti-tumor immune response in hepatocellular carcinoma comprehensive treatment.

Hepatocellular carcinoma (HCC) has an insidious onset and high malignancy. Most patients have progressed to intermediate and advanced stages by the time of diagnosis, and the long-term efficacy of traditional treatments is not satisfactory. Immunotherapy has shown great promise in the treatment of HCC in recent years; however, the low immunogenicity and severe immunosuppressive tumor microenvironment result in a low response rate to immunotherapy in HCC patients. Therefore, it is of great significance to improve the immunogenicity of HCC and thus enhance its sensitivity to immunotherapy. Here, we prepared the boronophenylalanine-modified dual drug-loaded polydopamine nanoparticles by a facile method. This system used boronophenylalanine-modified polydopamine nanoparticles as a delivery vehicle and photothermal material for the chemotherapeutic drug doxorubicin and the immune agonist CpG oligodeoxynucleotides (CpG-ODN), with both active targeting and lysosomal escape functions. The cancer cells are rapidly killed by photothermal treatment, and then chemotherapy is used to further kill cancer cells that are inadequately treated by photothermal treatment. The combination of photothermal-chemotherapy synergistically induces the release of relevant antigens from tumor cells, thus initiating anti-tumor immunity; and then cooperates with CpG-ODN to trigger a powerful anti-tumor immune memory effect, potently and durably inhibiting HCC recurrence.

Near-infrared light and redox dual-activatable nanosystems for synergistically cascaded cancer phototherapy with reduced skin photosensitization.

Currently, activatable photodynamic therapy (PDT) that is precisely regulated by endogenous or exogenous stimuli to selectively produce cytotoxic reactive oxygen species at the tumor site is urgently in demand. Herein, we fabricated a dual-activatable PDT nanosystem regulated by the redox tumor microenvironment and near-infrared (NIR) light-induced photothermal therapy (PTT). In this study, photosensitizer chlorin e6 (Ce6) was conjugated to hyaluronic acid (HA) via a diselenide bond to form an amphiphilic polymer (HSeC) for loading PTT agent IR780 to produce HSeC/IR nanoparticles (NPs). The photoactivity of Ce6 for PDT was "double-locked" by the aggregation-caused quenching (ACQ) effect and the fluorescence resonance energy transfer (FRET) from Ce6 to IR780 during blood circulation. After selective accumulation into tumors, HSeC/IR NPs were subsequently dissociated due to the "double-key", which included diselenide bond dissociation under high redox conditions and IR780 degradation upon NIR laser irradiation, resulting in recovering Ce6. In vitro studies indicated that Ce6 photoactivity in HSeC/IR NPs was significantly suppressed when compared with free Ce6 or in HSeC NPs. Moreover, BALB/c mice treated with HSeC/IR NPs displayed distinctly alleviated skin damage during PDT. Synergetic cascaded PTT-PDT with superior tumor suppression was observed in SCC7 tumor-bearing mice. Therefore, the study findings could provide a promising treatment strategy for PTT-facilitated PDT with high antitumor efficacies and reduced skin phototoxicity levels.

Identification of Forsythia suspensa (Thunb.) Vahl in different harvest periods using intelligent sensory technologies, HPLC characteristic fingerprint coupled with chemometrics.

INTRODUCTION: Forsythia suspensa (Thunb.) Vahl (FS), the fruit of Oleaceae plants, as a large part of traditional Chinese medicine, is classified as "Qingqiao (Q)" and "Laoqiao (L)" based on the harvest time. Because the maturation of FS is a gradual process, its accurate identification based on different maturity levels is an important issue. OBJECTIVES: We suggest colorimetric, electronic tongue, and high-performance liquid chromatography (HPLC) characteristic fingerprints to discriminate FS in different harvest periods. MATERIAL AND METHODS: First, FS fruits from different harvest times were collected, and then, their colour parameters, E-tongue sensory properties, HPLC characteristic fingerprints, and contents of nominal ingredients were determined. Finally, multivariate statistical analyses, including three-dimensional scatter plots, hierarchical cluster, principal component, linear discriminant, similarity, and partial least squares discriminant analyses were performed. RESULTS: The results demonstrated that the three experimental techniques could effectively discriminate FS based on different harvest times with 100% accuracy. Under the qualitative conditions, nine common peaks were identified in the HPLC fingerprints of 60 samples, among which, six peaks [variable importance in projection (VIP) > 1] could be used as index peaks for qualitative identification. In fact, the contents of quality marker components, including forsythin, phillygenin, rutin and forsythoside A, were significant different (P < 0.001) at different harvest times. Interestingly, the quality markers not only accurately reflected the maturity of FS but also showed close correlations with the colour parameters and sensory E-tongue responses. CONCLUSION: In our present investigation, bionic technologies, including a colorimeter, E-tongue analysis, and HPLC characteristic fingerprints, combined with chemometrics, were employed to develop a novel and accurate method for discriminating FS based on different harvest times.

Research progress on excitotoxicity of glutamate and its modulators / 中国药理学通报

Excitotoxicity mainly refers to the toxic effect of the excitatory neurotransmitter glutamate.Long-term activation of glutamate receptors will cause a series of neurotoxicity, eventually leading to the loss of neuronal function and cell death.Triggering excitotoxicity may involve changes in glutamate and calcium metabolism, dysfunction of glutamate transporter, N-methyl-D-aspartate receptor(NMDAR)and mitochondria, and production of ROS.Therefore, we here review the occurrence of these mechanisms and introduce the pathological mechanism of glutamate excitotoxicity in Alzheimer's disease(AD), Parkinson's disease(PD), depression and epilepsy.Finally, this review briefly describes the regulatory effects of broad-spectrum glutamic satellite modulators, marine compounds and Chinese herbal medicines on the glutamatergic system.

Ag2S nanoparticle-mediated multiple ablations reinvigorates the immune response for enhanced cancer photo-immunotherapy.

Photothermal therapy (PTT) has been widely used in cancer treatment in recent years. However, it is difficult to completely eliminate tumors by single PTT, and the effects of single dose of PTT frequency on the therapeutic outcome of PTT and the multiple PTT-induced immune response in cancer therapy also remain unclear. Here, water-soluble Ag2S nanoparticles (NPs) with optimal particle size (~15 nm) were synthesized and used as the PTT agents. The in vitro and in vivo results demonstrated that Ag2S NPs had good photothermal conversion in response to the irradiation of an 808 nm laser, and the results indicated that the NPs have potential as contrast agents for photoacoustic imaging as well as good biocompatibility. The in vivo results further revealed that the frequency of the Ag2S NP-mediated PTT affected the cancer therapeutic outcome. The increase of frequency efficiently reduced the primary tumor recurrence and alleviated metastasis. The present study suggested that the mechanism involves multiple PTT cycles inhibiting the proliferation of primary tumor cells and stimulating the systematic immune response in the mouse breast cancer model. Therefore, frequency optimization in photothermal ablation may provide a promising strategy to enhance the therapeutic outcome in cancer therapy.

The Pharmacokinetics and Tissue Distributions of Nine Steroidal Saponins from Paris polyphylla in Rats.

BACKGROUND AND OBJECTIVES: Paris polyphylla (P. polyphylla) is a herb widely used in traditional Chinese medicine to treat various diseases. This study used ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to study the pharmacokinetics and tissue distributions of nine steroidal saponins from P. polyphylla. METHODS: P. polyphylla extract was administered to rats intravenously (i.v.) and orally (p.o.). The concentrations of the nine main bioactive components of the extract were determined in plasma and tissue samples using UPLC-MS/MS. The nine saponin compounds were also incubated in an anaerobic environment with intestinal flora suspension solution to investigate hydrolysis by intestinal flora. RESULTS: After oral administration of the P. polyphylla extract, polyphyllin VII was found to have the highest maximum concentration (Cmax, 17.0 ± 2.24 µg/L) of all nine components, followed by the Cmax values of dioscin (16.17 ± 0.64 µg/L) and polyphyllin H (11.75 ± 1.28 µg/L), while the Cmax values of polyphyllin I, polyphyllin II, progenin III, polyphyllin IV, gracillin, and polyphyllin were less than 10 µg/L. The bioavailabilities of all nine components were less than 1%. All the compounds were hydrolyzed by intestinal flora and were predominantly distributed in the liver and lungs. CONCLUSIONS: The nine compounds presented different pharmacokinetic parameter values, and multiple administrations did not accumulate in the body. The bioavailabilities of the compounds were low, partly because of hydrolysis by intestinal flora. The nine compounds were mainly distributed in the liver and lungs, which may be target organs.

Effects of warming, climate extremes and phosphorus enrichment on the growth, sexual reproduction and propagule carbon and nitrogen stoichiometry of Potamogeton crispus L.

Contemporary evidence suggests that submerged macrophytes are experiencing a global decline due to the multiple compounding anthropogenic stressors impacting shallow lake ecosystems. Eutrophication and climate change are two main widespread, often co-occurring stressors, yet evidence concerning their interactive effects on aquatic plants remains partial and fragmented. Predicting the response of submerged aquatic vegetation to the combined effects of nutrient pollution and compound climate warming (mean + variability) is therefore crucial for the conservation and management of these valuable and vulnerable ecosystems. Here, we present the results of an outdoor mesocosm experiment examining the combined effects of nutrient enrichment (phosphorus addition) and warming (a 4 °C increase in mean temperature above present ambient conditions applied as either a constant increase or a variable increase ranging between 0 and 8 °C to mimic the effect of extreme events but keeping an equivalent total amount of warming) on Potamogeton crispus L. Warming accelerated the growth and senescence of P. crispus suggesting a more important role in maintaining the clear water state in winter-early spring but concomitant to possible earlier turbid states in summer. Warming also consistently advanced the flowering phenology but had no significant effect on flowering duration. There were no significant differences in the life cycle between the two warming treatments, while phosphorus addition also had little effect. However, under phosphorus enrichment, P. crispus increased sexual reproduction investment producing higher seed setting rate per infructescence. In contrast, warming, especially variable warming, may decrease sexual reproduction investment by reducing the number of infructescences. Seed and turion stoichiometry were altered by the combination of warming and phosphorus addition, but the changes were complex and difficult to interpret.

A Strategy Based on GC-MS/MS, UPLC-MS/MS and Virtual Molecular Docking for Analysis and Prediction of Bioactive Compounds in Eucalyptus Globulus Leaves.

The discovery of medicinal plants is crucial for drug development. Eucalyptus globulus leaves are used as a traditional medicine in many areas of world due to herbicidal and insecticidal activity. While natural products are difficult to be separated and activity assayed, a new approach is needed to predict the active ingredients therein. In this study, a new method for screening active compounds extracted from E. globulus leaves was developed by GC-MS/MS and UPLC-MS/MS combined with molecular docking technology. Predicted compounds with high activity were proposed. Firstly, 35 volatile compounds and 34 aqueous extracted compounds were extracted from E. globulus leaves, and identified by GC-MS/MS and UPLC-MS/MS. The herbicidal receptor (1BX9) was then docked with the identified compounds by docking software, evaluated by docking models and seven scoring functions. The results showed that gallic acid had a strong inhibitory activity of 1BX9, which was speculated to be the main reason for the inhibitory effect of E. globulus leaves. Finally, allelopathic tests of gallic acid, citric acid, and isopulegol were carried out on grass seeds to verify its inhibitory activity against herbicide receptor 1BX9. The results show that the method can screen compounds with specific activity from a complex system of medicinal plants, which is very important for the screening of new active ingredients, confirmation of new medicinal ingredients, and the in-depth development of animal and plant medicines.

Dose-dependent roles of aspirin and other non-steroidal anti-inflammatory drugs in abnormal bone remodeling and skeletal regeneration.

The failure of remodeling process that constantly regenerates effete, aged bone is highly associated with bone nonunion and degenerative bone diseases. Numerous studies have demonstrated that aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) activate cytokines and mediators on osteoclasts, osteoblasts and their constituent progenitor cells located around the remodeling area. These cells contribute to a complex metabolic scenario, resulting in degradative or synthetic functions for bone mineral tissues. The spatiotemporal effects of aspirin and NSAIDs in the bone remodeling are controversial according the specific therapeutic doses used for different clinical conditions. Herein, we review in vitro, in vivo, and clinical studies on the dose-dependent roles of aspirin and NSAIDs in bone remodeling. Our results show that low-dose aspirin (< 100 µg/mL), which is widely recommended for prevention of thrombosis, is very likely to be benefit for maintaining bone mass and qualities by activation of osteoblastic bone formation and inhibition of osteoclast activities via cyclooxygenase-independent manner. While, the roles of high-dose aspirin (150-300 µg/mL) and other NSAIDs in bone self-regeneration and fracture-healing process are difficult to elucidate owing to their dual effects on osteoclast activity and bone formation of osteoblast. In conclusion, this study highlighted the potential clinical applications of low-dose aspirin in abnormal bone remodeling as well as the risks of high-dose aspirin and other NSAIDs for relieving pain and anti-inflammation in fractures and orthopedic operations.

Effects of ELK-1/JNK/c-Fos on apoptosis of rat hippocampal neurons cultured in vitro with Zuogui Jiangtang Jieyu Formula in simulated diabetes mellitus complicated with depression / 中国应用生理学杂志

OBJECTIVE@#To study the effects of Zuogui Jiangtang Jieyu Formula (ZGJTJYF, the Chinese Medicine) on hippocampal neuron apoptosis in diabetes mellitus complicated with depression (DD).@*METHODS@#The primary cultured hippocampal neurons were treated with high glucose (150 mmol/L) and corticosterone (200 micromol/L) to establish the cell model of DD in vitro. The cultured hippocampal neurons were randomly divided into five groups: blank serum group, normal group, Zuogui Jiangtang Jieyu recipe drug-containing serum group, positive drug (metformin + fluoxetine) drug-containing serum group and model group (three compound holes in each group). The model group and the normal group were given the same amount of culture medium, and the other groups were given the corresponding serum with 10% volume fraction for 18 hours. Hoechst staining, high content cell imaging and RT-PCR were used to detect the apoptosis of hippocampal neurons and the expressions of apoptosis-related ETS-like 1 transcription factor(ELK-1), C-Jun N-terminal kinase(JNK) and c-Fos proteins and genes.@*RESULTS@#Compared with the blank group, the apoptotic number of hippocampal neurons in the model group was increased significantly, and the expression levels of ELK-1, JNK and c-Fos were increased significantly (P＜0.05). Compared with the model group, the local bright spots of hippocampal neurons in the Zuogui Jiangtang Jieyu recipe-containing serum group and the positive drug-containing serum group were decreased significantly, and the number of apoptotic cells was decreased significantly. The expressions of JNK, c-fos protein and mRNA were down-regulated significantly (P＜ 0.05), and the neural network and dendritic junction were improved significantly.@*CONCLUSION@#Zuo Gui Jiang Tang Jie Yu Formula can reverse the expressions of ELK-1, JNK and c-Fos signals in hippocampal neurons under DD environment and play an anti-apoptotic effect.

Rapid and Integrated Quality Assessment of Organic-Inorganic Composite Herbs by FTIR Spectroscopy-Global Chemical Fingerprints Identification and Multiple Marker Components Quantification of Indigo Naturalis (Qing Dai).

This research aimed to develop an FTIR-based method for rapid and low-cost integrated quality assessment of organic-inorganic composite herbs, which are kinds of herbs composed of both organic and inorganic active ingredients or matrix components. A two-step quality assessment route was designed and verified using the example of Indigo Naturalis (Qing Dai). First, the FTIR spectra were used as global chemical fingerprints to identify the true and fake samples. Next, the contents of the organic and inorganic marker components were estimated by FTIR quantification models to assess the quality of the true samples. Using the above approaches, all the 56 true samples and five fake samples of Indigo Naturalis could be identified correctly by the correlation threshold of the FTIR chemical fingerprints. Furthermore, the FTIR calibration models provided an accurate estimation of the contents of marker components with respect to HPLC and inductively coupled plasma optical emission spectrometry (ICP-OES). The coefficients of determination (R²) for the independent validation of indigo, indirubin, and calcium were 0.977, 0.983, and 0.971, respectively. Meanwhile, the mean relative errors (MRE) for the independent validation of indigo, indirubin, and calcium were 2.2%, 2.4%, and 1.8%, respectively. In conclusion, this research shows the potential of FTIR spectroscopy for the rapid and integrated quality assessment of organic-inorganic composite herbs in both chemical fingerprints identification and marker components quantification.

D Rhamnose ß-Hederin against human breast cancer by reducing tumor-derived exosomes.

D Rhamnose ß-hederin (DRß-H), a novel oleanane-type triterpenoid saponin isolated from the traditional Chinese medicinal plant Clematis ganpiniana, has been demonstrated to be effective against various types of tumor. However, the exact role of DRß-H on breast cancer remains largely unresolved. In the present study, it was observed that DRß-H exhibited anti-proliferative and pro-apoptotic activity in human breast cancer cells (MCF-7/S). DRß-H was able to inhibit exosome secretion, and the level of exosomes was positively associated with cell growth after absorption and internalization by target breast cancer cells. By analyzing the miRNA profiles of exosomes and MCF-7/S, it was identified that several miRNAs were detected exclusively in exosomes. Knockdown of the top five exosomal miRNAs and an MCF-7/S proliferation assay indicated that exosomal miR-130a and miR-425 may enhance MCF-7/S cell viability. Target gene prediction and pathway analysis revealed the involvement of miR-130a and miR-425 in pathways associated with malignant cell proliferation. These results demonstrated that DRß-H inhibited MCF-7/S cell growth through reducing exosome release.

[Protective effect of Sambucus willamsii hance fruit oil on acute liver injury in mice].

OBJECTIVE: To study the protective effect of Sambucus willamsii Hance fruit oil on acute liver injury in mice. METHODS: Sixty male mice were randomly divided into six groups: normal control, model, positive control( salvianolic acid A, SAA) and Sambucus Willamsii Hance fruit oil groups( oil-H, oil-M and oil-L). The mice were daily administered Sambucus willamsii Hance fruit oil at the dosage of 2. 0, 4. 0 and 12. 0 g/kg for the groups of oil-L, oil-M, oil-H, respectively, while the same volume of 1% CMC was given to normal control groups and model ones for four weeks. After twenty-four hours from the last administration, the mice( except the normal control group) were injected intraperitoneally with CCl_4( 20 mg/kg). All the mice were sacrificed sixteen hours later, and serum and liver of the mice were collected for biochemical index determination. RESULTS: The result showed that compared with the model group, the serum aspartate aminotransferase( AST) and alanine aminotransferase( ALT) levels in the Sambucus willamsii Hance fruit oil groups decreased significantly( P < 0. 05). MDA levels reduced( P < 0. 05), while SOD and GSH-Px level increased( P < 0. 05). Moreover, the improvement effect of the above indexes was not different from that of the positive control group( P > 0. 05). CONCLUSION: Therefore, moderate intake of Sambucus willamsii Hance fruit oil exhibits a significantly protective effect on acute liver injury in mice.

[Standardization of preparation of rice fried Codonopsis Radix based on correlation analysis of functional component and shape index].

The quality standard of Chinese herbal medicine is the key in quality control, and the establishment of rice processing technology standard of rice fried Codonopsis Radix has important significance for the overall quality control. In this study, the color brightness (L*), red-green chromaticity coordinate (a*), yellow-blue chromaticity coordinate (b*) and total color value（E*ab）were determined by colorimeter and used as the shape indexes. Ethanol extractives, polysaccharide, lobetyolin and 5-hydroxymethyl furfural contents were determined by using high performance liquid chromatography (HPLC) and ultraviolet (UV), and used as chemical indexes in the analysis by normalization distance method. The two index methods were adopted to optimize the processing technology of rice fried Codonopsis Radix by taking processing temperature, processing time, rice types and rice dosage as factors. The correlation analysis between the two index methods was carried out by SAS 9.40 and JMP 11 software. The results showed that all the four factors had significant differences, and the best processing technology was as follows: polished round-grained rice as raw material, processing temperature at 140 °C, processing time of 10min, and the ratio of Codonopsis pilosula and rice is 100:30. Chemical indexes showed significant positive correlations with shape indexes, providing basis for the quality evaluation of rice fried Codonopsis Radix in processing.

[Impacts of multicomponent environment on intrinsic dissolution rate of berberine in biopharmaceutics classification system of Chinese materia medica].

To illustrate the intrinsic dissolution rate(IDR) involved in biopharmaceutics classification system of Chinese materia medica(CMMBCS), investigate the effect of artificial multicomponent environment on IDR of berberine, by using a non-disintegrating disk, and summarize related rules by using the obtained data. Progressive levels design was used to investigate the effects of single component environment (puerarin, baicalin, and glycyrrhizic acid); double-component environment(puerarin+baicalin, puerarin+ glycyrrhizic acid, baicalin+glycyrrhizic acid); and triple-component environment(puerarin+baicalin+glycyrrhizic acid) on IDR of berberine, laying a foundation for further researches on the absorption mechanism of multiple components.

A Simple and Portable Screening Method for Adulterated Olive Oils Using the Hand-Held FTIR Spectrometer and Chemometrics Tools.

Extra virgin olive oil has been one of the most common targets for economically motivated food adulteration. This research employed the hand-held FTIR spectrometer to develop the simple and portable screening methods for extra virgin olive oils adulterated with other cheaper vegetable oils. With the help of the ATR probe and chemometrics tools, oil samples can be measured directly without any pretreatment, then the spectra can be interpreted automatically to determine the possibility of adulteration and estimate the content of adulterant oil. A feasibility study of the hand-held FTIR screening method was carried out using olive oils adulterated with canola oil, peanut oil, corn oil, soybean oil, and sunflower oil. The SIMCA model using the hand-held FTIR spectra can identify different kinds of vegetable oils correctly and recognize olive oils with not less than 10% of adulterant oils. Meanwhile, the content of adulterant oil in the range of 5% to 45% can be estimated by the PLS model using the hand-held FTIR spectra within an error of 3%. This research shows the potential of the hand-held FTIR technique in the rapid and field screening of olive oils adulterated with some cheaper vegetable oils. PRACTICAL APPLICATION: This research provide a rapid and automatic detection method for olive oils adulterated with other cheaper vegetable oils. An oil sample can be measured directly within one minute, and the hand-held instrument can be used anywhere needed.

[Study on biopharmaceutics classification system for Chinese materia medica of extract of Huanglian].

One of the advantages of biopharmaceutics classification system of Chinese materia medica (CMMBCS) is expanding the classification research level from single ingredient to multi-components of Chinese herb, and from multi-components research to holistic research of the Chinese materia medica. In present paper, the alkaloids of extract of huanglian were chosen as the main research object to explore their change rules in solubility and intestinal permeability of single-component and multi-components, and to determine the biopharmaceutical classification of extract of Huanglian from holistic level. The typical shake-flask method and HPLC were used to detect the solubility of single ingredient of alkaloids from extract of huanglian. The quantitative research of alkaloids in intestinal absorption was measured in single-pass intestinal perfusion experiment while permeability coefficient of extract of huanglian was calculated by self-defined weight coefficient method.

[Overall intestinal permeability of multiple components in lotus leaf by in situ single pass intestinal perfusion models].

To investigate the overall intestinal permeability of multiple components in lotus leaves and make clear the interaction in composition absorption process. Rat single-pass intestinal perfusion technique was used, and the results showed that the Peff values of nuciferine, demethylanuciferine, rutin, quercetin, kaempferol from lotus leaf were greater than 0.5×10⁻4 cm•s⁻¹. In the biopharmaceutics classification system (BCS) intestinal permeability property, these ingredients were high permeable components, while the hyperin was low permeable component. However, in the multi-component environment of the lotus leaf extract, component permeation was changed. Semi quantitative analysis of the unclear components showed that under the multi-component environment, four in seven components with relatively high contents had a Peff value less than 0.5×10⁻4 cm•s⁻¹, indicating these 4 components were of low permeability, while other 3 components were of high permeability. The results could be valuable to make clear the overall intestinal permeability of multiple components in lotus leaf, and lay a foundation for studying the mechanism of the lipid-lowering effect of lotus leaf.

[Validation of in situ single pass perfusion model based on P-gp].

To validate in situ rats intestinal single pass perfusion model based on P-glycoprotein (P-gp). Firstly, phenol red perfusion was carried out to verify the close connection structure of intestinal epithelial cells, and the integrity of the intestinal epithelium, with a gravimetric method for correcting water flux. The level of phenol red was determined by high performance liquid chromatography (HPLC) both before and after perfusion. Secondly, the positive drug digoxin specified by FDA was used to validate the model. After different mass concentrations of verapamil were given in the rats, the absorption parameters of digoxin in ileum of rats were observed and compared. The results showed that the phenol red was absorbed in rats ileum segment, with an effective permeability coefficient of (1.09±0.62)×10 ⁻6 cm•s ⁻¹. The experiment results indicated that the close connection structure of intestinal epithelial cells was normal, and the integrity of the intestinal epithelium was maintained well. In digoxin perfusion experiment, in case no verapamil was given, digoxin showed certain degree of absorption in rat ileum, with an effective permeability coefficient (Peff) of (1.07±0.59)×10 ⁻5 cm•s ⁻¹; after mass concentrations of 0.01,0.1 mmol•L ⁻¹ verapamil were given, the absorption of digoxin was on the rise in rat ileum, with an effective permeability coefficient Peff of (1.58±0.69)×10 ⁻5, (3.28±0.95)×10 ⁻5 cm•s ⁻¹ respectively (P<0.05). Digoxin perfusion experiment verified that P-gp expression in small intestine epithelium was intact and can be used in the research of P-gp efflux transporter.