[Gender differences in antidepressant effect of raw Rehmanniae Radix].

For the first time, this study evaluated the gender differences and mechanisms of the antidepressant effects of raw Rehmanniae Radix(RRR) based on the classic depression model with traditional Chinese medicine syndrome of Yin deficiency and internal heat. The depression model with Yin deficiency and internal heat was established by the widely recognized and applied method of thyroxine induction of the classic depression model with Yin deficiency and internal heat(chronic unpredictable mild stress). Male and female mice were simultaneously treated with RRR. The study analyzed indicators of nourishing Yin and clearing heat, conventional antidepressant efficacy test indicators, and important biomolecules reflecting the pathogenesis and prevention and treatment mechanisms of depression, and conducted a correlation analysis of antidepressant efficacy, Yin-nourishing and heat-clearing efficacy, and biological mechanism in different genders, thereby comprehensively assessing the antidepressant effects of RRR on depression of Yin deficiency and internal heat, as well as its gender differences and mechanisms. RRR exhibited antidepressant effects in both male and female mouse models, and its antidepressant efficacy showed gender differences, with a superior effect observed in females. Moreover, the effects of RRR on enhancing or improving hippocampal neuronal pathology, nucleus-positive areas, postsynaptic dense area protein 95, and synaptophysin protein expression were more significant in females than in males. In addition, RRR significantly reversed the abnormal upregulation of nuclear factor(NF)-κB/cyclooxygenase 2(COX2)/NOD-like receptor thermal protein domain associated protein 3(NLRP3) pathway proteins in the hippocampus of both male and female mouse models. The antidepressant effects of RRR were more pronounced in depression female mice with Yin deficiency and internal heat syndrome, possibly due to the improvement of neuronal damage and enhancement of neuroplasticity. The antidepressant mechanisms of RRR for depression with Yin deficiency and internal heat syndrome may be associated with the downregulation of the NF-κB/COX2/NLRP3 pathway to reduce neuronal damage and enhance neuroplasticity.

[Toxicity attenuation processing technology and mechanism of Rhizoma Dioscoreae Bulbiferae stir-fried with Paeoniae Radix Alba decoction].

This study explored toxicity attenuation processing technology of Rhizoma Dioscoreae Bulbiferae stir-fried with Paeoniae Radix Alba decoction for the first time, and further explored its detoxification mechanism. Nine processed products of Rhizoma Dioscoreae Bulbiferae stir-fried with Paeoniae Radix Alba decoction were prepared by orthogonal experiment with three factors and three levels. Based on the decrease in the content of the main hepatotoxic component diosbulbin B before and after processing of Rhizoma Dioscoreae Bulbiferae by high-performance liquid chromatography, the toxicity attenuation technology was preliminarily screened out. On this basis, the raw and representative processed products of Rhizoma Dioscoreae Bulbiferae were given to mice by gavage with 2 g·kg~(-1)(equival to clinical equivalent dose) for 21 d. The serum and liver tissues were collected after the last administration for 24 h. The serum biochemical indexes reflecting liver function and liver histopathology were combined to further screen out and verify the proces-sing technology. Then, the lipid peroxidation and antioxidant indexes of liver tissue were detected by kit method, and the expressions of NADPH quinone oxidoreductase 1(NQO1) and glutamate-cysteine ligase(GCLM) in mice liver were detected by Western blot to further explore detoxification mechanism. The results showed that the processed products of Rhizoma Dioscoreae Bulbiferae stir-fried with Paeoniae Radix Alba decoction reduced the content of diosbulbin B and improved the liver injury induced by Rhizoma Dioscoreae Bul-biferae to varying degrees, and the processing technology of A_2B_2C_3 reduced the excessive levels of alanine transaminase(ALT) and aspartate transaminase(AST) induced by raw Rhizoma Dioscoreae Bulbiferae by 50.2% and 42.4%, respectively(P<0.01, P<0.01). The processed products of Rhizoma Dioscoreae Bulbiferae stir-fried with Paeoniae Radix Alba decoction reversed the decrease protein expression levels of NQO1 and GCLM in the liver of mice induced by raw Rhizoma Dioscoreae Bulbiferae to varying degrees(P<0.05 or P<0.01), and it also reversed the increasing level of malondialdehyde(MDA) and the decreasing levels of glutathione(GSH), glutathione peroxidase(GPX), and glutathione S-transferase(GST) in the liver of mice(P<0.05 or P<0.01). In summary, this study shows that the optimal toxicity attenuation processing technology of Rhizoma Dioscoreae Bulbiferae stir-fried with Paeoniae Radix Alba decoction is A_2B_2C_3, that is, 10% of Paeoniae Radix Alba decoction is used for moistening Rhizoma Dioscoreae Bulbiferae and processed at 130 ℃ for 11 min. The detoxification mechanism involves enhancing the expression levels of NQO1 and GCLM antio-xidant proteins and related antioxidant enzymes in the liver.

[Preliminary exploration of detoxification mechanism of processing methods on cardiotoxicity induced by radix Tripterygium wilfordii in mice via Nrf2/HO-1 pathway].

This study aims to investigate the detoxification effects of different processing methods on the cardiotoxicity induced by radix Tripterygium wilfordii, and preliminarily explore the detoxification mechanism via the nuclear factor E2-related factor 2(Nrf2)/heme oxygenase 1(HO-1) pathway. The raw and processed products [stir-fried product, product stir-fried with Lysimachiae Herba(JQC), product stir-fried with Phaseoli Radiati Semen(LD), product stir-fried with Paeoniae Radix Alba(BS), product stir-fried with Glycyrrhizae Radix et Rhizoma(GC), and product stir-fried with vinegar(CZ)] of radix T. wilfordii were administrated to mice by gavage at a dose of 2 g·kg~(-1)(based on crude drugs) for 28 days. Twenty-four hours after the last administration, we measured the serum biochemical indexes of mice to evaluate the detoxification effect. Furthermore, we determined the expression of key proteins of Nrf2/HO-1 pathway in mouse heart tissue by Western blot and some oxidation/antioxidation-related indexes by corresponding kits to explore the detoxification mechanism. The administration of the raw product elevated the levels of serum creatine kinase, lactate dehydrogenase, and malondialdehyde, a product of cardiac lipid peroxidation(P<0.01), down-regulated the protein levels of Nrf2 and HO-1(P<0.01), and reduced the levels of total superoxide dismutase, glutathione, glutathione peroxidase, and glutathione S-transferase(P<0.01). However, after the administration of the products stir-fried with JQC, LD, BS, GC, and CZ, the abnormalities of the above indexes induced by the raw product were recovered(P<0.05 or P<0.01). In particular, the product stir-fried with JQC showed the best performance. Taken all together, the cardiotoxicity induced by radix T. wilfordii could be attenuated by stir-frying with JQC, LD, BS, GC, and CZ, and the stir-frying with JQC showed the best detoxification effect. The mechanism might be associated with the cardiac antioxidant defense and oxidative damage mitigation mediated by the up-regulated Nrf2.

[Processing technology for reducing toxicity of fried Tripterygium wilfordii in Lysimachia christinae decoction].

On the basis of the previous work of the research group, the orthogonal design method was further used to optimize the processing technology for reducing toxicity of fried Tripterygium wilfordii in Lysimachia christinae Decoction. A total of 9 processed products of T.wilfordii in L.christinae decoction were prepared by four factors and three levels orthogonal design table. The contents of triptolide in T.wilfordii were determined by high performance liquid chromatography(HPLC) before and after processing: 4.27, 3.92, 3.57, 2.75, 2.42, 2.66, 3.51, 1.87, 1.75, 2.03 µg·g~(-1). On this basis, the above processed products were orally given to mice for 28 days. 12 hours after the last administration, food fasting except water was provided, and 24 hours later, the eyeballs were taken for blood and liver tissue. Serum biochemical indexes, liver lipid peroxidation and antioxidant related indexes were detected by kit method. Twenty-eight days after oral administration of raw T.wilfordii, the levels of serum alanine aminotransferase(AST), alanine aminotransferase(ALT), alkaline phosphatase(ALP) and liver malondialdehyde(MDA) in mice increased by 91%(P<0.01), 46%(P<0.05), 73%(P<0.01) and 99%(P<0.01), while the liver antioxidant indexes such as superoxide dismutase(SOD), glutathione(GSH), glutathione peroxidase(GPX) and glutathione-S transferase(GST) significantly decreased(P<0.01). After administration of the processed products, the above indexes were significantly reversed(P<0.01 or P<0.05). Especially, the processing conditions of A_3B_2C_1D_3 had the best detoxification effect on T.wilfordii, which decreased the high levels of AST, ALT, ALP and MDA by 49%(P<0.01), 32%(P<0.01), 42%(P<0.01), and 17%(P<0.05). Therefore, the best processing conditions for T.wilfordii in L.christinae decoction were A_3B_2C_1D_3, namely "15% mass fraction of L.christinae, 1 h moistening time, 160 ℃ frying temperature, and 9 min frying time".

Nrf2 participates in mechanisms for reducing the toxicity and enhancing the antitumour effect of Radix Tripterygium wilfordii to S180-bearing mice by herbal-processing technology.

Context: Radix Tripterygium wilfordii Hook. f. (Celastraceae) (LGT) has outstanding curative efficacy; however, side effects include high toxicity, particularly hepatotoxicity and nephrotoxicity. Objective: To investigate detoxification mechanisms of LGT through processing separately with each of these medicinal herbs including Flower Lonicera japonica Thunb. (Caprifoliaceae) (JYH), Radix Paeonia lactiflora Pall. (Ranunculaceae) (BS), Herba Lysimachia christinae Hance (Primulaceae) (JQC), Radix et Rhizoma Glycyrrhiza uralensis Fisch. (Fabaceae) (GC) and Seed Phaseolus radiatus L. (Fabaceae) (LD) in S180-bearing mice by involving nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Materials and methods: LGT raw and processed products were orally administered at 60 mg/kg to KM male mice inoculated with S180 tumour cells for 14 consecutive days, and blood, tumour, liver and kidney were taken to observe the detoxifying effects and biological mechanisms. Results: Herbal-processing technology significantly weakened hepatotoxicity and nephrotoxicity evoked by LGT with ED50 of the converted triptolide in each processed-herb product for serum alanine transaminase, aspartate transaminase, creatinine and urea nitrogen of 9.3, 16.6, 2.5 and 4.2 µg/kg, for liver glutathione, glutathione S-transferase, catalase, tumour necrosis factor-α and interleukin-10 of 114.9, 67.8, 134.1, 7.7, 4171.6 µg/kg, and for kidney 21.9, 20.5, 145.0, 529.7, 19.4 µg/kg, respectively. Moreover, herbal-processing technology promoted the accumulation of Nrf2 into the nucleus, and upregulated mRNA expression of Nrf2 and heme oxygenase-1. Additionally, herbal-processing technology enhanced the tumour inhibition rate with ED50 12.2 µg/kg. Discussion and conclusions: Herbal-processing technology improves the safety and effectiveness of LGT in cancer treatment, and future research may be focused on the Nrf2-related molecules.

Pharmacokinetics and Tissue Distribution of Gingerols and Shogaols from Ginger (Zingiber officinale Rosc.) in Rats by UPLC⁻Q-Exactive⁻HRMS.

Gingerols and shogaols are recognized as active ingredients in ginger and exhibit diverse pharmacological activities. The preclinical pharmacokinetics and tissue distribution investigations of gingerols and shogaols in rats remain less explored, especially for the simultaneous analysis of multi-components. In this study, a rapid, sensitive, selective, and reliable method using an Ultra-Performance Liquid Chromatography Q-Exactive High-Resolution Mass Spectrometer (UPLC-Q-Exactive⁻HRMS) was established and validated for simultaneous determination of eight compounds, including 6-gingerol, 6-shogaol, 8-gingerol, 8-shogaol, 10-gingerol, 10-shogaol, Zingerone, and 6-isodehydrogingenone in plasma and tissues of rats. The analytes were separated on a Syncronis C18 column (100 × 2.1 mm, 1.7 µm) using a gradient elution of acetonitrile and 0.1% formic acid in water at a flow rate of 0.25 mL/min at 30 °C. The method was linear for each ingredient over the investigated range with all correlation coefficients greater than 0.9910. The lowest Lower Limit of quantitation (LLOQ) was 1.0 ng/mL. The intra- and inter-day precisions (Relative Standard Deviation, RSD%) were less than 12.2% and the accuracy (relative error, RE%) ranged from -8.7% to 8.7%. Extraction recovery was 91.4⁻107.4% and the matrix effect was 86.3⁻113.4%. The validated method was successfully applied to investigate the pharmacokinetics and tissue distribution of eight components after oral administration of ginger extract to rats. These results provide useful information about the pharmacokinetics and biodistribution of the multi-component bioactive ingredients of ginger in rats and will contribute to clinical practice and the evaluation of the safety of a Chinese herbal medicine.

Detoxication mechanisms of Radix Tripterygium wilfordii via compatibility with Herba Lysimachia christinae in S180-bearing mice by involving Nrf2.

The combined administration between Radix Tripterygium wilfordii Hook F (LGT) and Herba Lysimachia christinae Hance (JQC) belongs to mutual detoxication compatibility of seven emotions in traditional Chinese medicine (TCM) theory. However, until now, the compatibility detoxication mechanisms remain unknown. The present study was undertaken to observe detoxication mechanisms of LGT through compatibility with JQC in tumor-bearing mice by involving NF-E2-related factor 2 (Nrf2)-mediated antioxidant defenses. In addition, influence of compatibility on antitumor activity was also investigated here. Our results demonstrated that compatibility with JQC administration significantly reversed LGT-elevated serum alanine/aspartate transaminase (ALT/AST) levels and alleviated hepatocytes' swelling or degeneration damage, and at the ratio 2/1 (LGT/JQC) produced the strongest detoxication effect. Besides, compatibility with JQC administration reversed not only LGT-elevated hepatic malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α) but also the LGT lowered GSH, glutathione-s transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), and interleukin (IL)-10 levels. Furthermore, compatibility with JQC administration significantly up-regulated protein expression of Nrf2 and mRNA expression of it regulated downstream antioxidant genes such as heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase-1 (NQO1), and glutamate cysteine ligase catalytic subunit (GCLC). In addition, compatibility with JQC further decreased LGT-decreased tumor weight and at the ratio 2/1 (LGT/JQC) also exerted the strongest synergistic effect. Collectively, through compatibility with JQC exerted detoxication effect on LGT-induced hepatotoxicity and the mechanisms could be at least partly attributed to up-regulation of Nrf2 and its downstream signals, thereby enhancing antioxidant defenses, and inhibiting lipid peroxidation, oxidative stress, and inflammation. Additionally, at the ratio 2/1 (LGT/JQC) exerted the strongest effects on both detoxication and synergism.

Structure-Activity Relationship of Xanthones as Inhibitors of Xanthine Oxidase.

Polygala plants contain a large number of xanthones with good physiological activities. In our previous work, 18 xanthones were isolated from Polygala crotalarioides. Extented study of the chemical composition of the other species Polygala sibirica led to the separation of two new xanthones-3-hydroxy-1,2,6,7,8-pentamethoxy xanthone (A) and 6-O-ß-d-glucopyranosyl-1,7-dimethoxy xanthone (C)-together with 14 known xanthones. Among them, some xanthones have a certain xanthine oxidase (XO) inhibitory activity. Furthemore, 14 xanthones as XO inhibitors were selected to develop three-dimensional quantitative structure-activity relationship (3D-QSAR) using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models. The CoMFA model predicted a q² value of 0.613 and an r² value of 0.997. The best CoMSIA model predicted a q² value of 0.608 and an r² value of 0.997 based on a combination of steric, electrostatic, and hydrophobic effects. The analysis of the contour maps from each model provided insight into the structural requirements for the development of more active XO inhibitors.

Ethanol extract of Rehmannia glutinosa exerts antidepressant-like effects on a rat chronic unpredictable mild stress model by involving monoamines and BDNF.

The dried roots of Rehmannia glutinosa Libosch. (Scrophulariaceae) are of both medicinal and nutritional importance. Our previous study has found that the 80% ethanol extract of R. glutinosa (RGEE) produced antidepressant-like activities in mouse behavioral despair depression models. However, its mechanisms are still unclear. The present study aimed to observe the antidepressant-like mechanisms of RGEE on a rat chronic unpredictable mild stress (CUMS) model by involving monoaminergic neurotransmitters and brain-derived neurotrophic factor (BDNF). CUMS-stressed rats were orally given RGEE daily (150, 300, and 600 mg/kg) or fluoxetine hydrochloride (FH) for 3 weeks after starting the CUMS procedure. Sucrose preference test was carried out to observe depression-like behavior, and serum and brain tissues were used for neurochemical and fluorescent quantitative reverse transcription PCR analysis. Results demonstrated that CUMS induced depression-like behavior, whereas RGEE and FH administration inhibited this symptom. Furthermore, CUMS caused excessively elevated levels of serum corticosterone (CORT), an index of hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, in a manner attenuated by RGEE and FH administration. RGEE administration also further elevated monoamine neurotransmitters and BDNF levels, up-regulated the mRNA expression of BDNF and tropomyosin-related kinase B (TrkB) in hippocampus of rats suffering CUMS. Together, our findings suggest that RGEE can improve CUMS-evoked depression-like behavior, and indicate its mechanisms may partially be associated with restoring HPA axis dysfunctions, enhancing monoamineergic nervous systems, and up-regulating BDNF and TrkB expression.

Analysis of bacterial diversity in two oil blocks from two low-permeability reservoirs with high salinities.

The community diversities of two oil reservoirs with low permeability of 1.81 × 10(-3) and 2.29 × 10(-3) µm(2) in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher bacterial and phylogenetic diversity. The addition of the nutrient activator increased the diversity of the bacterial community structure and the diversity differences between the two blocks. The results of the core simulation test showed that the bacterial community in the reservoir with a salinity level of 17,500 mg/L did not show significant higher MEOR efficiency compared with the reservoir with 40,900 mg/L i.e. MEOR efficiency of 8.12% vs 6.56% (test p = 0.291 > 0.05). Therefore, salinity levels affected the bacterial diversities in the two low permeability oil blocks remarkably. But the influence of salinity for the MEOR recovery was slightly.

[Effect of matrine on Fas, VEGF, and activities of telomerase of MCF-7 cells].

OBJECTIVE: To study the effect of matrine on Fas, VEGF, and activities of telomerase of MCF-7 cells. METHODS: In vitro cultured human breast cancer MCF-7 cells were randomly divided into the experimental group and the control group. The matrine solution was added in cells of the experimental group. Equal volume of culture medium was added in cells of the control group or the negative control group. Zedoary Turmeric Oil, the telomerase inhibitor was added in cells of the positive control group. Morphological changes were observed under an inverted microscope. The telomerase activity was detected by TRAP-ELISA. Expressions of Fas and VEGF protein were detected by immunocytochemical assay. RESULTS: Matrine obviously inhibited the growth and induced apoptosis of breast cancer cells. MCF-7 cells were treated by matrine of different concentrations at 24, 48, and 72 h, the telomerase activity gradually decreased along with increased matrine concentration and prolonged action time, showing dose-effect and time-effect positive relations. Matrine could up-regulate Fas protein expression and downregulate VEGF protein expression of MCF-7 cells. CONCLUSION: Matrine showed obvious effect in inhibiting the growth of MCF-7 cells and promoting the apoptosis, which might be achieved by up-regulating the expression of Fas protein, inhibiting telomerase activity induced apoptosis of breast cancer cells, down-regulating the expression of VEGF protein, and inhibiting the tumor vascular formation.

Antitumor activity of Dioscorea bulbifera L. rhizome in vivo.

Antitumor activities of water extract (fraction A), ethanol extract (fraction B), ethyl acetate extract (fraction C), non-ethyl acetate extract (fraction D) and compound diosbulbin B isolated from Dioscorea bulbifera L. (DB) were investigated in vivo in this present study. The results showed that fractions B and C both decreased tumor weight in S180 and H22 tumor cells bearing mice, while fractions A and D had no such effect. Furthermore, fraction C altered the weight of spleen and thymus, and the amounts of total leukocytes, lymphocytes and neutrophils in tumor-bearing mice. Further results showed that compound diosbulbin B demonstrated anti-tumor effects in the dose-dependent manner at the dosage of 2 to 16 mg/kg without significant toxicity in vivo. Furthermore, on the basis of chemical analysis of the above extracts by high-performance liquid chromatography (HPLC) with a diode array detector (DAD), diosbulbin B was found to be the major antitumor bioactive component of DB. These results suggest that DB has potential anti-tumor effects which may be related to influencing the immune system for the first time, and the compound diosbulbin B is the major antitumor component of DB.

[Evaluation on hepatotoxicity caused by Dioscorea bulbifera based on analysis of bile acids].

Metabolic profile of bile acids was used to evaluate hepatotoxicity of mice caused by ethanol extraction of Dioscorea bulbifera L. (ethanol extraction, ET) and diosbulbin B (DB), separately. Ultra-performance liquid chromatography coupled with quadrupole mass spectrometry (UPLC-MS) was applied to determine the contents of all kinds of endogenous bile acids including free bile acids, taurine conjugates and glycine conjugates. Obvious liver injuries could be observed in mice after administrated with ET and DB. Based on the analysis using principle components analysis (PCA), toxic groups could be distinguished from their control groups, which suggested that the variance of the contents of bile acids could evaluate hepatotoxicity caused by ET and DB. Meanwhile, ET and DB toxic groups were classified in the same trends comparing to control groups in the loading plot, and difference between the two toxic groups could also be observed. DB proved to be one of the toxic components in Dioscorea bulbifera L. Bile acids of tauroursodeoxycholic acid (TUDCA), taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), taurodeoxycholic acid (TDCA), cholic acid (CA) and others proved to be important corresponds to ET and DB induced liver injury according to analysis of partial least square-discriminant analysis (PLS-DA) and the statistical analysis showed that there were significant differences between the control groups and toxic groups (P < 0.01). Furthermore, good correlation could be revealed between the foregoing bile acids and ALT, AST. It indicated that taurine conjugated bile acids as TUDCA, TCDCA, TCA and TDCA along with CA could be considered as sensitive biomarkers of ET and DB induced liver injury. This work can provide the base for the further research on the evaluation and mechanism of hepatotoxicity caused by Dioscorea bulbifera L.

Steroidal saponins from the rhizomes of Dioscorea bulbifera and their cytotoxic activity.

Two new steroidal saponins, diosbulbisides D (1) and E (2), along with five known saponins (3- 7) were isolated from the rhizomes of Dioscorea bulbifera L. Their structures were elucidated on the basis of spectral data. Compounds 6 and 7, two 3- O-trisaccharides of diosgenin spirostanes, showed moderate cytotoxic activity against human hepatocellular carcinoma cells, with IC50 values of 3.89 µM and 7.47 µM on SMMC7721, and 10.87 µM and 19.10 µM on Bel-7402 cell lines, respectively.

[Study on the triterpenoids from the fruits of Ligustrum lucidum].

OBJECTIVE: To study the triterpenoids from the fruits of Ligustrum lucidum. METHODS: The constituents were extracted with 95% EtOH, partitioned with different solvents, isolated and purified by silica gel, Sephadex LH-20 and PHPLC column chromatography. The structures were elucidated by physicochemical properties and spectroscopic data. RESULTS: Thirteen compounds were isolated and identified as methyl oleanolate (1), 3-O-acetylursolic acid (2), 3-ketooleanolic acid (3), 19alpha-hydroxyl ursolic acid (4), lupeol (5), 3-O-acetyl oleanolic acid (6), oleanolic acid (7), betulin (8), ursolic acid (9), fouquierol (10), 19alpha-hydroxyl acetylursolic acid (11), 3-O-cis-P-coumaroyl maslinic acid (12) and 3-O-trans-P-coumaroyl maslinic acid (13). CONCLUSION: Compounds 1 - 4 are obtained from this plant for the first time.

[Protective effect of electrical stimulating cerebellar fastigial nucleus on ischemia and reperfusion-injury of rat retina].

OBJECTIVE: To study the protective effect of electrical stimulating cerebellar fastigial nucleus on ischemia-reperfusion-injury of rat retina. METHODS: Rats were divided randomly into group of ischemia-reperfusion, group of electrical-stimulation-treated and group of sham-operated. The duration ischemia was 1 hour except sham-operated. In treated group, harvests of retinas followed electrical stimulation of cerebellar fastigial nucleus for 60 min after reperfusion for 6 hours; in reperfusion group, retinas were harvested only after 6 hours reperfusion. Retinal ischemia was produced in rats by ligating vessels and the optic nerve for 1 hour. Expression of inducible nitric oxide synthase (iNOS) in retina was measured by NADPH-NDP histochemistry; Apoptosis was measured by Tdt-dUTP terminal nick-end labeling (TUNEL) method. Morphology change was observed with the help of HPIAS-1000 auto-medical-imagined computer analyzer. RESULTS: (1) The thickness of inner retinal (including outer plexiform layer, inner nuclear layer, ganglion cell layer, optic nerve fiber and inner limiting membrane) and the inner plexiform layer were increased significantly in ischemia-reperfusion group than those in treated group. (2) The morphological changes of the scattered and condensed nucleus were observed more slightly under light microscopy in treated group than those in ischemia-reperfusion group. (3) Expression of inducible nitric oxide synthase (iNOS) in retinal ganglion cell in treated group is more significant than in ischemia-reperfusion group. (4) The amount of apoptosis cells in retina in treated group is significantly less than thatin ischemia-reperfusion group. CONCLUSIONS: (1) The results indicated that ischemia-reperfusion injury can induce retinal apoptosis. Retinal apoptosis can be inhibited by electrical stimulation cerebellar fastigial nucleus. (2) iNOS maybe involved in the mechanism of apoptosis. (3) Cerebellar fastigial nucleus electrical stimulation can protect ischemia-reperfused retina.