Effect of atractylone on the viability and apoptosis of hepatoma HepG2 cells and related mechanism / 临床肝胆病杂志

Objective To investigate the effect of atractylone on the viability and apoptosis of hepatoma HepG2 cells and its mechanism of action. Methods Hepatoma HepG2 cells were selected and divided into low-, middle-, and high-dose atractylone groups (5, 10, and 20 μmol/L), and the cells in the control group were added with an equal volume of DMSO. MTT colorimetry was used to measure the viability of HepG2 cells after treatment with different concentrations of atractylone; flow cytometry was used to measure the apoptosis rate and mitochondrial membrane potential of HepG2 cells; the DCFH-DA fluorescent probe labeling method was used to measure the level of reactive oxygen species (ROS) in HepG2 cells; Transwell assay was used to evaluate the effect of atractylone on the migration ability of HepG2 cells; Western blot was used to measure the protein expression levels of Bcl-2, Bax, and cleaved caspase-3. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t -test was used for comparison between two groups. Results After 24 and 48 hours of treatment with atractylone, compared with the control group, the low-, middle-, and high-dose atractylone groups had a tendency of reduction in cell viability (all P < 0.05), with a half inhibitory concentration of 26.19 μmol/L in atractylone treatment of HepG2 cells for 72 hours. The low-, middle-, and high-dose atractylone groups had a significantly higher apoptosis rate than the control group (14.34%/29.32%/50.12% vs 0.32%, all P < 0.05). Compared with the control group, the low-, middle-, and high-dose atractylone groups had a significant increase in the fluorescence intensity of ROS in HepG2 cells (all P < 0.05). After 48 hours of treatment with atractylone, compared with the control group, the low-, middle-, and high-dose atractylone groups had a significant reduction in the number of migrated cells (132.67±18.36/57.00±9.26/31.00±2.45 vs 258.11±38.54, P < 0.05). Compared with the control group, the low-, middle-, and high-dose atractylone groups had a significant reduction in the expression of the anti-apoptotic factor Bcl-2 and significant increases in the expression of the apoptotic factors Bax and cleaved caspase-3 (all P < 0.05). Conclusion Atractylone can induce the apoptosis and inhibit the migration of HepG2 cells, which provides an experimental basis for further development and utilization of atractylone.

High dose nanocrystallization of etoposide and its blood-brain barrier permeability in vitro / 中国药理学与毒理学杂志

OBJECTIVE To improve the poor water solubility and evaluating poor acitivity of etoposide (VP-16) by preparing VP-16 nanoparticle suspension (VP-16 NP) and its penetration through the blood-brain barrier (BBB).METHODS VP-16 NP was prepared with the anti-solution exchange method.The shape structure and diameter were observed with transmission electron microscopy (TEM) and scanning electron microscopy (SEM) and dynamic light scattering (DLS), respectively. The drug release profiles of the VP-16 powder and VP-16 NP were measured.The effect of VP-16 NP on the growth of KB cells was observed via MTT assay. In addition, primary brain microvascular endothelial cells from 1stto 2nd generation of SD rats at two weeks of age were used to construct an in vitro BBB model.The classic 4 h leak test,trans-epithelial electrical resistance (TEER) test and fluorescein disodium salt(FLU)perme?ability test were conducted to verify whether the in vitro BBB model was successfully established.RESULTS VP-16 NP was a solid sphere with a size of 140 nm detected by TEM,SEM and DLS.The cumulative release rate of VP-16 NP was 3 times that of VP-16 powder. The results of MTT colorimetric assay showed that VP-16 powder had no inhibitory effect on KB cells,while VP-16 NP could effectively inhibit KB cells. In the 4 h leakage experiment, the top and bottom chambers of the Transwell cell model could maintain a liquid surface distance of >0.5 cm,indicating that the in vitro BBB model was initially formed.The effective resistance value of the TEER experiment was 223 Ω·cm2,indicating that the in vitro BBB model was basically established. In FLU permeability experiments, the permeability coefficients were respectively (0.33±0.04)×10-3,(0.42±0.07)×10-3,and (0.52±0.06)×10-3cm·min-1at 15,30 and 60 min, indicating that the model had low permeability.The above three experiments suggested that the BBB in vitro model was successfully constructed. On this basis, the in vitro BBB model was used to evaluate the penetration of VP-16 NP at a permeability coefficient of (1.87±0.03)×10-3cm·min-1at 30 min,showing high permeability.VP-16 NP showed better penetration of BBB.CONCLUSION VP-16 NP is success?fully prepared,which increases the release rate of the drug,enhances the killing effect of the cells,and shows good penetration through the in vitro BBB model evaluation.

Protective Effects of Epigallocatechin Gallate after UV Irradiation in Cultured Human Retinal Pigment Epithelial Cells

PURPOSE: To evaluate the protective effects of Epigallocatechin gallate (EGCG) against UV irradiation in cultured human retinal pigment epithelial (RPE) cells. METHODS: UV irradiation was produced by a UV lamp for 30 seconds with an irradiance of 3.3 mW/cm2. After 5 minutes and 1 hour, we administered different concentrations of EGCG (0, 5, 10, 15, 25, 50, 100 uM). The cell count was determined under a microscope using a counting chamber and the cell activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The cell count of cultured human RPE cells after UV irradiation was markedly increased in the EGCG administration group, compared with the non-administrated group. The cell activity of the cultured human RPE cells after UV irradiation was markedly increased in the EGCG administration group and was increased in a dose-dependent way as determined by the MTT assay. CONCLUSIONS: The administration of EGCG increased the cell count and the cell activity after UV irradiation in cultured human retinal pigment epithelial cells; this suggests that EGCG provided protection against UV damage in cultured human retinal pigmented epithelial cells.

Antimicorbial effect of Zea Mays L. and Magnoliae cortex extract mixtures on periodontal pathogen and effect on human gingival fibroblast cellular activity / 대한치주과학회지

Zea Mays L. has been known to be effective for improving tissue health and Magnoliae cortex to have effective antibacterial and antimicrobial activity against pathogenic microbes. The purpose of this study was to examine the antimicrobial effects of Zea Mays L. and Magnoliae cortex extract mixtures on periodontal pathogens(Prevotella intermedia, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Streptococcus mutans )and to examine the effects on human gingival fibroblast cellular activity. Zea Mays L. and Magnoliae cortex extracts and their mixtures were prepared with various mixing ratios (0.5:1, 1:1, 1.5:1, 2:1). These extracts were loaded to periodontal pathogen cultured petri dish for antimicrobial test and also loaded to cultured human gingival fibroblast for cellular activity test. Each test was repeated 3 times and data were analyzed by one-way ANOVA with 95% confidence level. Mixture of these two extracts showed greater amount of inhibition area on periodontal pathogen and more improved gingival fibroblast activity as Zea Mays L. ratio reduced. So, mixture ratio 0.5:1 (Zea Mays L. : Magnoliae cortex) group showed statistical significance in antimicrobial activity and cellular activity among various mixtures(p<0.05). In conclusion, 0.5:1 (Zea Mays L. : Magnoliae cortex) mixture possessed best gingival fibroblast cellular activity and antimicrobial activity toward periodontal pathogens.

Antibacterial Effects and Cytotoxicity of Crassirhizomae Rhizoma / 대한치주과학회지

The purpose of this study was to evaluate the antimicrobial activity of Crassirhzimae rhizoma and its possible use as an oral antiseptics for prevention of periodontitis. Its antibacterial activity against periodontopathic microorganisms including Actinobacillus actiomycetemcomitans, Capnocytophaga ochracea, Streptococcus mutans, Porphyromonas gingivalis, Prevotella intermedia, Actinomyces viscosus, Fusobacterium nucleatumwas evaluated via modified stab culture method. The cytotoxicity against gingival fibroblasts and rat osteoblasts was investigated via [3H]thymidine incorporation and cellular activity was investigated via MTT assay. Chlorhexidine was used as control group. Crassirhizomae rhizoma was prepared at concentrations of 0.2, 0.15, 0.1, 0.05%. Chlorhexidine was also prepared at the same concentration. Crassirhizomae rhizoma showed lower antimicrobial antivity against these microorganism than chlorhexidine, but this difference was not significant. And, Crassirhzomae rhizoma showed more cellular activity and less cytotoxicity than chlorhexidine on human gingival fibrablast and rat osteoblast. This study suggests that Crassirhzomae rhizoma might be a candidate for a safe oral antiseptic for the prevention and treatment of periodontal disease.

IMMUNOHISTOCHEMICAL STUDY FOR THE DETECTION OF THE TUMOROUS CHANGES OF REMAIND ENAMEL EPITHELIUM IN THE IMPACTED HUMAN TOOTH FOLLICLE

In order to investigate the potential cellular activity of remaind enamel epithelium of impacted tooth follicle, we have examined 75 tooth follicular tissues from impacted teeth by immunohistochemical methods. Particular focus on the proliferation, differentiation and apoptosis-antiapoptosis of remaind enamel epithelium was made. Follicular tissues were removed from impacted teeth, fixed in neutral formalin and prepared for 4micrometer thick 20 serial sections. Hematoxylin & eosin staining was done routinely, and the mucopolycharide materials of myxoid odontogenic mesenchyme was detected by histochemical reactions of toluidin blue, PAS, Van Gieson, Masson's trichrome Various antibodies, i.e., PCNA(proliferating cell nuclear antigen) and Ki-67 for proliferative activity, transglutaminase-C, transglutaminase-K, transglutaminase-E, TGF-beta1, bcl-2, and p53 were used. Apop-tag staining was also done to detect the phenomenon of apoptosis. Both of the reduced enamel epithelium in the luminal side of tooth follicle and the enamel epithelial rests scattered in the wall of tooth follicle showed frequent positive reaction for the PCNA and Ki-67, and these cells were also positive for the transglutaminase-C, K, E. On the other hand the enamel epithelium was not stained by Apop-tag staining but weakly positive for bcl-2 and p53. Relatively high amount of myxoid odontogenic mesenchyme was also diffusely observed in the tooth folliclular tissue, and the distribution of the myxoid odontogenic mesenchyme was closely related with the distribution of enamel epithelial rest infiltration. Taken together, these data may suggest that the remaind enamel epithelial cells are biologically acitive rather than the dormant state after the completion of tooth formation, and that the remaind enamel epithelium may has interaction with odontogenic mesenchyme and will not be degraded easily but may have a potential for the odontogenic tumors.

The effect of 1,25-dihydroxyvitamin D3 on the viability of periodontal ligament cells and the experimental tooth movement in rats / 대한치과교정학회지

. Vitamin D is known to exert its action by activating DNA and RBA within target cells to produce proteins and enzymes that can be used in bone resorption process. Particularly, the active form of vitmain D, 1,25-dihydroxycholecalciferol [1,25-(OH)2D3], is considered to be one of the most potent stimulators of osteoclatic acitivity in vitro. The purpose of this study was to evaluate the effect of1,25-Dihydroxyvitamin D3 on the avtivity of periodotal ligament cells and, the experimental tooth movement. Human periodontal ligament cells were collected from the first premolar tooth extracted for the orthodontic treatment, and were incubated in the environment of 37degreesC, 5% CO2 and 95% humidity. Microtitration{(MIT) assay was done at 10, 25, 50 and 100ng/ml of 1,25-Dihydroxyvitamin D3. 21 Sprague-Daft rats were divided into a control gmup(3), and experimental groups(18) where 100g of force from helical spring was applied across the maxillary incisors 1,25-Dihydroxyvitamin D3 was injected into periodontal ligament at the mesial or distal surface of maxillary incisors so that we can compare the control side and the experimental side. Expreimental groups were sac rifled at 12, 24, 36, 48, 72hours and 7 days after force application, respectively. And the obtained tissues were evaluated histologically. The observed results were as follows. 1. The activity of periodontal ligament cells in l0ng/ml or 25ng/ml of 1,25-Dihydroxyvitamin D31,25-Dihydroxyvitamin D3 was not significantly different to the control at the cultivation of 1, 2 and 3 days. 2. The activity of periodontal ligament cells was significantly increased at 3 days in 50 ng/ml of 1,25-Dihydroxyvitamin D3 and 2, 3 days in 100g/ml of 1,25-Dihydroxyvitamin D3. 3. Up to 7 days after force application, there was no difference in osteoblastic activity, tearing of periodontal ligament and proliferation of capillary at tension side between 1,25-Dihydroxyvitamin D3 injection side and the control side. 4. The osteoclastic activity and the resorption of alveolar bone was greater in 1,25-Dihydroxyvitamin D3 injection side than the control side at 36 hours after force application.

Tissue regenerative activity of Magnolia and Zizyphi fructus extract mixtures / 대한치주과학회지

The purpose of this study was to perform on the biological activity of Magnolia and Zizyphi fructus extract mixtures on the wound healing of defected rat calvaria. For the determination of the mixture ratio of two extracts for oral administration, preliminary experiments were performed with the mixture combination of 2000 and 3000microgram/ml of Magnolia extract, and also 20, 30, 200, 300, 2000 and 3000microgram/ml of Zizyphi fructus extract, respectively and divided into 6 groups. The combination of extracts mixture were tested on the enhancing effect of cellular activity. The effect of the extracts mixture on the cellular activity was evaluated using MTT method and measured on the results with optical density by ELISA reader. The ability to tissue regeneration of the extracts mixture was performed by measuring new bone and new connective tissue regeneration on the 5mm defected rat calvaria for 1, 2 and 3 weeks after oral administration of 2 different dosages groups : 10:1(0.1g/kg) and 10:1(0.5g/kg). It was employed the same dosages of unsaponifiable fraction of Zea Mays L as positive controls. Each group of rat was sacrificed and en bloc section for histological examination. The effect on the cellular activity of each mixture ratio showed significantly higher in 2000microgram/ml of Magnolia extract and 200microgram/ml of Zizyphi fructus extract group to compare with other groups. These preliminary results showed that appropriate mixture ratio of two extracts was 10:1 of Magnolia and Zizyphi fructus extract. Histological examination on the activity of tissue regeneration of each group showed that 2weeks and 3weeks specimens of 0.5g/kg of 10:1 extract mixture of Magnolia and Ziziphi fructus administrated rat calvaria revealed significantly more osteoid and new bone formation of defected calvaria with unification of defected area than the specimens of any other negative and positive controls. Even though the specimen administrated the same dosages of unsaponifiable fraction of Zea Mays L, positive controls, showed the trend that they promote significantly the repair of calvarial defect, their bone reparative activities were less inductive than the same dosages of Magnolia and Ziziphi fructus extract mixture. These results implicated that the mixture of Magnolia and Zizyphi fructus extracts should be highly effective on the wound healing of bony defected site and might have potential possibilities as an useful drug to promote periodontal tissue regeneration.