Dezheng Gong

Dalian Medical University, Lü-ta-shih, Liaoning, China

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Publications (17)34.98 Total impact

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    ABSTRACT: Green tea polyphenols (GTPs) are now being considered possible protective agents in neurodegenerative diseases such as Alzheimer's disease (AD). Previous studies suggested that GTPs could inhibit amyloid fibril formation and protect neurons from toxicity induced by β-amyloid. However, whether GTPs can ameliorate learning and memory impairments and also reduce tau hyperphosphorylation induced by okadaic acid (OA) in rats remains unclear. The aim of this study was to determine if GTPs have neuroprotection against OA-induced neurotoxicity. In this work, rats were pretreated with GTPs by intragastric administration for 4 wk. Then OA was microinjected into the right dorsal hippocampus. Morris water maze tests were used to test the ethologic changes in all groups, and tau protein hyperphosphorylation was detected both in vivo and in vitro. The ethologic test indicated that the staying time and swimming distance in the target quadrant were significantly decreased after OA treatment, whereas rats pretreated with GTPs stayed longer in the target quadrant. Methyl thiazolyl tetrazolium assay and lactate dehydrogenase leakage showed that GTPs greatly ameliorated primary hippocampal neurons damage induced by OA. Furthermore, reduced hyperphosphorylated tau protein was detected with GTPs pretreatment. Taken together, our results suggest that GTPs have neuroprotection against OA-induced neurotoxicity.
    Nutrition 03/2014; 30(3):337-342. · 2.86 Impact Factor
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    ABSTRACT: The objective of the present study was to investigate the effect of the fucoxanthin (FUCO) alone and in combination with glucosamine hydrochloride (GAH) on carrageenan/kaolin-induced inflammatory arthritis model in rats and to explore its underlying mechanisms. Joint swelling, muscle weight ratio (%), histopathological examination and scoring, and proteoglycan degradation were examined. Pro-inflammatory interleukin (IL-1β) and tumor necrosis (TNF-α) levels, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase(iNOS) protein expression and nitric oxide (NO) level in knee synovial tissue extract were analyzed using enzyme-linked immunosorbent assay, western blotting analysis, and Griess reagent assay, respectively. FUCO and FUCO + GAH not only may significantly reduce degrees of knee joint swelling and prevent against muscle atrophy, but also may significantly attenuate inflammation in synovial tissue, cartilage erosion, and proteoglycan loss. The efficacies of FUCO + GAH were stronger than that of GAH or FUCO. FUCO alone and FUCO + GAH can significantly inhibit upregulation of COX-2 and iNOS protein expressions, decrease of IL-1β and TNF-α levels, and reduce NO production in knee synovial tissue extract. These results indicated that FUCO is an effective anti-arthritis agent through an antiinflammation mechanism. FUCO may enhance therapeutic effect of GAH on rat arthritis through mechanism of antiinflammation. Copyright © 2013 John Wiley & Sons, Ltd.
    Phytotherapy Research 12/2013; · 2.07 Impact Factor
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    ABSTRACT: Insulin resistance (IR) increases with age and plays a key role in the pathogenesis of type 2 diabetes mellitus. Oxidative stress and mitochondrial dysfunction are supposed to be major factors leading to age-related IR. Genipin, an extract from Gardenia jasminoides Ellis fruit, has been reported to stimulate insulin secretion in pancreatic islet cells by regulating mitochondrial function. In this study, we first investigated the effects of genipin on insulin sensitivity and the potential mitochondrial mechanisms in the liver of aging rats. The rats were randomly assigned to receive intraperitoneal injections of either 25mg/kg genipin or vehicle once daily for 12days. The aging rats showed hyperinsulinemia and hyperlipidemia, and insulin resistance as examined by the decreased glucose decay constant rate during insulin tolerance test (kITT). The hepatic tissues showed steatosis and reduced glycogen content. Hepatic malondialdehyde level and mitochondrial reactive oxygen species (ROS) were higher, and levels of mitochondrial membrane potential (MMP) and ATP were lower as compared with the normal control rats. Administration of genipin ameliorated systemic and hepatic insulin resistance, alleviated hyperinsulinemia, hyperglyceridemia and hepatic steatosis, relieved hepatic oxidative stress and mitochondrial dysfunction in aging rats. Furthermore, genipin not only improved insulin sensitivity by promoting insulin-stimulated glucose consumption and glycogen synthesis, inhibited cellular ROS overproduction and alleviated the reduction of levels of MMP and ATP, but also reversed oxidative-stress associated JNK hyperactivation and reduced Akt phosphorylation in palmitate-treated L02 hepatocytes. In conclusion, genipin ameliorates age-related insulin resistance through inhibiting hepatic oxidative stress and mitochondrial dysfunction.
    Experimental gerontology 09/2013; · 3.34 Impact Factor
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    ABSTRACT: Monosodium iodoacetate (MIA) is an inhibitor of glyceraldehyde-3-phosphate dehydrogenase activity, and causes dose-dependent cartilage degradation resembling the pathological changes of human osteoarthritis (OA). In this study, we assessed the apoptosis induced by MIA and clarified the underlying mechanisms using the primary rat chondrocytes. The apoptosis of primary rat chondrocytes was analyzed by flow cytometry. The levels of mitochondrial membrane potential (ΔΨm) were evaluated using fluorescence spectrophotometer. The production of reactive oxygen species (ROS) was determined by fluorescence spectrophotometer. Apoptosis-related protein cytochrome c and procaspase-3 expressions were examined by Western blotting. We found that MIA treatment induces apoptosis in chondrocytes, as confirmed by increases in the percent of apoptotic cells, up-regulation of cytochrome c and caspase-3 protein levels. Treatment with MIA increases ROS production and decreases the levels of ΔΨm. The antioxidant, N-acetylcysteine (NAC), significantly prevented the production of ROS, the reduction of ΔΨm, the release of cytochrome c and the activation of caspase-3. Further, NAC completely protected the cells from MIA-induced apoptosis. Together these observations suggest that the mechanisms of MIA-induced apoptosis are primarily via ROS production and mitochondria-mediated caspase-3 activation in primary rat chondrocytes. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
    Journal of Orthopaedic Research 11/2012; · 2.88 Impact Factor
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    ABSTRACT: Pyrroloquinoline quinone PQQ is a naturally occurring redox cofactor that acts as an essential nutrient, antioxidant, and redox modulator. PQQ has been demonstrated to oxidize the redox modulatory site of N-methyl-d-aspartic acid (NMDA) receptors. Such agents are known to be neuroprotective in experimental stroke models. However, there is not report about the therapeutic effect of PQQ on neuropathic pain. We tested the effects of oral administration of PQQ on neuropathic pain of rats with chronic constriction injury (CCI) of the sciatic nerve. The repeated oral administration of PQQ (20 and 40mg/kg, once a day for 4 weeks, from day 1 after the injury) attenuated both thermal and mechanical hyperalgesia, and also attenuated the muscle atrophy. The anti-hyperalgesic activity of PQQ was associated with a significant reduction of pro-inflammatory mediators such as tumor necrosis factor alpha (TNF-α) and lipid peroxide malondialdehyde (MDA) levels. In the present investigation, PQQ is shown to have analgesic effect which was found in the first time, probably through reducing the release of pro-inflammatory mediator and inhibiting oxidative stress.
    European journal of pharmacology 10/2012; · 2.59 Impact Factor
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    ABSTRACT: Olive leaf extract (OLE) has antioxidant and antiinflammatory actions. However, the role of OLE in mechanical inflammatory arthritis (osteoarthritis, OA) is unclear. This study investigated the effect of OLE on the development of kaolin and carrageenan-induced arthritis, a murine model of OA. Administration of OLE significantly ameliorated paw swelling, the paw Evans blue content and the histopathological scores. In the human monocyte cell line, THP-1, the OLE reduced the LPS-induced TNF-α production and was dose dependent. Croton oil-induced ear edema in mice also revealed that treatment with OLE suppressed ear edema, myeloperoxidase (MPO) production and was dose dependent. These results indicated that OLE is an effective antiarthritis agent through an antiinflammation mechanism. Also OLE may be beneficial for the treatment of OA in humans.
    Phytotherapy Research 07/2011; 26(3):397-402. · 2.07 Impact Factor
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    ABSTRACT: We investigated the restorative effect of orally administered olive leaf extract (OLE) on experimentally produced cartilaginous injuries in rabbits. In total, three holes in the left stifle joint, including one in the medial trochlear ridge and two in the trochlear sulcus (proximal and distal) of articular cartilage, were prepared surgically using a drill. For the control group only tap water alone was administered daily, and for the OLE group a water-based solution of OLE (500 mg/kg/day) was administered daily. The injured areas were observed macroscopically and histologically at 3 weeks after the operation. The results indicate that OLE facilitated healing of the three holes and increased the weight of the biceps femoris muscle. Histological examination revealed that in the OLE group, matured cartilage tissues and connective tissues were mixed with regenerated or maturing cartilage tissues with massive proliferation in the injured parts, around which the proliferation of undifferentiated blast cells and the tissue with cartilage substrates were observed. The histological score of the OLE group was significantly lower than that of the control group. The percentage of proliferating cell nuclear antigen-positive cartilage cells in the OLE group was higher than in the control group. Mean density of the restored area observed with Safranin O staining was higher in the OLE group than in the control group. Therefore, OLE is effective for enhancing the healing of cartilaginous injuries. OLE may also have a beneficial effect of slowing and reducing the pathogenesis of degenerative joint diseases in humans.
    Journal of medicinal food 03/2011; 14(3):268-75. · 1.39 Impact Factor
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    ABSTRACT: Female sex hormones may have protective effects against arrhythmias, including reperfusion arrhythmias (RAs), but the mechanisms are still not completely known. Serial changes in rat hearts (rhythm, apoptosis and the its infuencing factors; cardiac vinculin mRNA expression and connexin43 (Cx43) dephosphorylation) were examined during periods of ischemia-reperfusion with and without estrogen treatment. After reperfusion, although the incidence of arrhythmias became higher in both the vehicle-group and estrogen-group, compared with the ischemia period, estrogen prevented reperfusion-induced upregulation of the incidence of arrhythmias, especially ventricular premature beats (VPB) and ventricular tachycardia (VT). The duration of VT and fibrillation, and the number of VPB and VT, were all significantly decreased in the estrogen-group. The expression of cardiac vinculin mRNA decreased significantly in the vehicle-group but not in the estrogen-group. Cx43 dephosphorylation and myocyte apoptosis increased in both groups, but the values for the estrogen-group were all markedly lower than those for the vehicle-group. A selective estrogen receptor (ER) beta agonist prevented reperfusion-induced upregulation of the incidence of both VPB and VT significantly; a selective ERalpha agonist had no significant influence. Estrogen can protect the heart against RAs, at least in part, mediated through gap junctions. Upregulation of ERbeta but not ERalpha mediated most of the estrogen-induced cardioprotection against RA.
    Circulation Journal 02/2010; 74(4):634-43. · 3.58 Impact Factor
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    ABSTRACT: This study describes a simple and stable cervical heterotopic kidney transplantation method in rats that uses artery sleeve anastomosis, vein cuff anastomosis and preserving-bag techniques. The donor graft, consisting of kidney, renal vein (RV), renal artery (RA) and a ureterocystic flap, was removed en bloc and perfused in situ. The donor RA was end-to-end anastomosed to the recipient left common carotid artery (CCA) using a sleeve anastomosis, and the donor RV was connected to the recipient right external jugular vein (EJV) using a cuff technique. During the vascular anastomosis, the kidney graft was placed in a lactated Ringer's solution ice-water preserving bag. The donor bladder patch was exteriorized to form cervical cutaneous stoma. A total of 104 heterotopic renal transplantations were performed, which included pre-experimental (62 operations) and experimental stages (42 operations). The success rates of the two stages were 80.6% and 95.2%, respectively. The time for surgery was 40 +/- 6 min, the average time for donor surgery was 20 +/- 5 min, the preparation time for the graft was 8 +/- 2 min, the operative time for the recipient was 18 +/- 3 min that included the time for the arterial anastomosis (5 +/- 2 min) and venous anastomosis (2 +/- 1 min), the cold ischaemic time of the graft was 15 +/- 3 min and the warm ischaemic time of the graft was 2 +/- 1 min. We developed an easy and reliable model of cervical heterotopic kidney transplantation that may provide a useful tool for investigating kidney transplantation rejection and retransplantation pathology.
    Nephrology Dialysis Transplantation 05/2009; 24(9):2708-13. · 3.37 Impact Factor
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    ABSTRACT: Although the precise mechanisms of transient hypotension after intravenous infusion of hypertonic saline (HTS) are not yet clarified, a rapid infusion of HTS is widely used as the initial therapy of hypovolemia. We investigated the effect of the intravenous infusion of a small dose of 0.97-9.7% NaCl solutions in anesthetized rats. Intravenous infusion of HTS at a rate of 0.3 ml/kg/min for 1 min produced the transient hypotension lasting for several minutes. The depressor response to HTS was not abolished by bilateral cervical vagotomy. The HTS infusion into the femoral vein evoked the depressor response with a larger magnitude and a shorter latency than that into the aortic arch. While the arterial baroreceptor pressure was kept constant at the baseline level of systemic arterial pressure, HTS-induced hypotension was significantly augmented. The gain factor of the arterial baroreflex was reduced by intravenous HTS. Pretreatment with bretylium tosylate completely abolished the depressor response without affecting the baseline level of arterial pressure. These results suggest that the depressor response to the very small dose of intravenous HTS is the sympathosympathetic neural reflex with cardiopulmonary afferents and vasomotor efferents.
    The Chinese journal of physiology 02/2009; 52(1):8-15. · 0.75 Impact Factor
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    ABSTRACT: This study aimed to investigate the protective effect of nicotine on dopaminergic neurons and its mechanisms in mice with Parkinson disease (PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). C57BL/6J mice were injected with MPTP for 8 days to establish a PD model. Nicotine was given for 10 days in the nicotine therapeutic group. Animals were examined behaviorally with the pole test and traction test. Tyrosine hydroxylase (TH) and γ-aminobutyric acid (GABA) were determined by using the immunocytochemistry (ICC) method. The ultrastructural changes of the caudate nucleus (CN) were observed under electron microscopy. The results showed that pretreatment with nicotine could improve the dyskinesia of PD mice markedly. Simultaneously, TH-positive (P<0.01) neurons and GABA-positive (P<0.05) neurons in the nicotine therapeutic group were significantly more than those in the model group. The ultrastructural injury of the nicotine therapeutic group was also ameliorated. Nicotine has protective effects on the γ-aminobutyric acid neurons and dopaminergic neurons in the MPTP-treated mice.
    Frontiers of Medicine in China 01/2009; 3(3):330-335.
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    ABSTRACT: Uncoupling protein 2 (UCP(2)), an inner mitochondrial membrane protein, can limit the generation of reactive oxygen species (ROS) and protect cells from injuries mediated by oxidative stress. We investigated the effect of upregulation of UCP(2) in the regenerating liver 96 h after 68% partial hepatectomy (PH) on the self-protection of regenerating liver against carbon tetrachloride (CCl(4)) poisoning. Hepatotoxicity was induced in vivo by administering CCl(4) to rats that had undergone PH. After CCl(4) poisoning, the regenerating liver appeared to have less histological damage and lower serum alanine aminotransferase (ALT) levels. Lower malondialdehyde production and higher glutathione contents were also observed in the regenerating liver compared with the sham-operated liver after CCl(4) poisoning. UCP(2) expression was markedly elevated in the regenerating liver, and further increased after CCl(4) intoxication. Mitochondrial membrane potential and adenosine triphosphate stores maintained higher levels in the regenerating liver than in sham-operated liver after CCl(4) intoxication. The results showed that the regenerating liver exhibited a potent ability to resist CCl(4) intoxication, and the autoprotection of regenerating liver might result from reduction of ROS by UCP(2) and maintenance of higher ATP stores.
    Digestive Diseases and Sciences 01/2009; 54(9):1918-25. · 2.26 Impact Factor
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    ABSTRACT: Hydroxytyrosol (HT) is a simple phenol compound extracted from olive leaves. The content of HT in the studied preparation was about 20%, and the preparation was called hydroxytyrosol-20 (HT-20). HT has antioxidant and antiinflammatory activities. There has been no report so far on the efficacy of HT-20 in carrageenan-induced acute inflammation and hyperalgesia in rats. Therefore, the aim of this study was to assess the inhibitory role of HT-20 on carrageenan-induced swelling and hyperalgesia of rat paw. Paw inflammation was assessed by the increase in paw volume and hyperalgesia. The rat paws were cut out under ether anesthesia at 270 min after administration of carrageenan. The tissue of the right paw was isolated separately from the individual rat. The levels of the tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta) and interleukin 10 (IL-10) mRNA in the tissue were estimated by reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the paw pressure thresholds of rats orally administered HT-20 significantly increased at 210, 240 and 270 min after administration of carrageenan, compared with corresponding basal paw pressure thresholds; the degree of swelling of the right hind paw showed a statistically significant reduction, compared with rats in the carrageenan-treated control. In this model, HT-20 appears to decrease pro-inflammatory cytokines IL-1beta and TNF-alpha and not to increase the antiinflammatory cytokine mRNA expression of IL-10.
    Phytotherapy Research 01/2009; 23(5):646-50. · 2.07 Impact Factor
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    ABSTRACT: To establish a simple and stable cervical ectopic renal transplantation rat model that increase surgical successful rate. A total of 208 male inbred Wistar rats (weighing 220-260 g) were randomly served as donors and recipients. The graft consisting of kidney, renal vein (RV) and renal artery (RA) was obtained, and perfused in situ. The donor RA was end-to-end anastomosed to the recipient left common carotid artery (CCA) by using of "sleeve" anastomosis, and the donor RV to the recipient right external jugular vein by using of "cuff" technique. The distal end of the ureter was brought out to form cervical cutaneous stomas. A total of 104 ectopic renal transplantations were performed in rats, including stages of the pre-experiment (62 operations) and experiment (42 operations). The success rates of the two stages were 80.6% and 95.2%, respectively. The causes of failure in the pre-experimental stage were anesthesia accidents, thrombosis of the arterial anastomosis, massive hemorrhage, air embolism and phlebemphraxis. In the experimental stage, 2 rats died due to late anastomotic hemorrhage and thrombosis. The remaining 40 transplanted kidney survived more than 6 months. The time for surgery was (40 +/- 6) minutes, the average time for donor surgery was (20 +/- 5) minutes, the preparation time for the graft was (8 +/- 2) minutes, the operative time for the recipient was (18 +/- 3) minutes, including the time for the arterial anastomosis (5 +/- 2) minutes and venous anastomosis (2 +/- 1) minutes, the cold ischemia time of graft was (15 +/- 3) minutes. The cervical ectopic renal transplantation technique has the advantages of easy-and fast-to-perform, shorter operation and cold ischemia time, higher successful rate.
    Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 08/2008; 22(7):873-6.
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    ABSTRACT: The anti-atherogenic effect of olive leaf extract is supposed to be related to its activities of anti-oxidation and anti-inflammation. To prove the effect of anti-atherosclerosis by olive leaf extract (OLE) and to elucidate the mechanism behind. Twenty-four rabbits were assigned to the control, high lipid diet (HLD) and OLE group that were fed with standard diet, HLD and HLD supplemented with OLE, respectively. Serum levels of atherosclerosis related markers, triglyceride (TG), total cholesterol (T-CHO), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and malondialdehyde (MDA) were detected at the ends of week 2, 4 and 6. Surface lesions and thickness of intimas were measured at the end of week6. The protein and/or mRNA expressions of inflammation factors, monocyte chemoattractant protein (MCP)-1, vascular cell adhesion molecule (VCAM)-1, nuclear factor-kappa B (NF-kappaB) and tumor necrosis factor alpha (TNF-alpha) were investigated by immunohistochemistry and RT-PCR. Atherosclerotic lesions were found in the HLD and OLE groups but not in the control group. In comparison with that in the HLD group, reduced size and thickness of intima (0.31 +/- 0.26 in the HLD group versus 0.10 +/- 0.03 mm in the OLE group) were found in the OLE group. The MDA level, an indicator of antioxidant status, was 35.27 +/- 15.37 in the HLD group and 20.63 +/- 11.52 nmol/ml in the OLE group. The level of CHO, TG and LDL-C were 104.46 +/- 30.34, 2.48 +/- 1.11, 82.83 +/- 28.44 mmol/l in the HLD group versus 83.03 +/- 27.23, 1.84 +/- 0.44, 59.51 +/- 23.72 mmol/l in the OLE group. Down-regulated expressions of MCP-1, VCAM-1, NF-kappaB and TNF-alpha at both protein and mRNA level (P < 0.05) were also found with the administration of OLE. This study proved the effect of OLE on inhibition of atherosclerosis, which is related to the suppressed inflammatory response.
    European Journal of Nutrition 08/2008; 47(5):235-43. · 3.13 Impact Factor
  • Lili Guan, Dezheng Gong, Nan Tian, Yuan Zou
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    ABSTRACT: Glucagon-like peptide 2 (GLP-2) is an intestinal epithelium-specific growth factor. However, its protective effects and related mechanism on the small intestine injured by ischemia-reperfusion (I/R) in mice remain unclear. This study aimed to reveal the effects of GLP-2 and its functional relationship with uncoupling protein 2 (UCP2) on the small intestine after I/R injury in mice. Male Balb/c mice were given GLP-2 (250 microg/kg/day, ip) for 3 days and underwent 30 min of superior mesenteric artery occlusion followed by 1 hr of reperfusion on day 4. Histological damage, bacterial translocation, diamine oxidase, and malondialdehyde level were assessed, and UCP2 expression was measured by immunohistochemistry and Western blot. GLP-2 attenuated the intestinal histological damage caused by I/R and increased the villous height by 28% and the crypt depth by 10%, respectively. Compared to the I/R group, diamine oxidase activity was increased, the incidence of bacterial translocation and malondialdehyde level were decreased, and UCP2 expression was increased in GLP-2-treated mice. GLP-2 protected the small intestine from I/R injury and increased UCP2 expression. These results suggested that effects of GLP-2 should be related to the upregulation of mitochondrial UCP2, which antagonized reactive oxygen species production.
    Digestive Diseases and Sciences 04/2005; 50(3):554-60. · 2.26 Impact Factor
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    ABSTRACT: Rats i.p. injected once with 10 mg/kg kainic acid exhibited clear seizure behavior (“wet-dog shakes,” rearing on the hindlimbs, and bilateral clonus). Pretreatment with L-arginine (L-Arg twice a day for 5 days) significantly decreased these manifestations. The medium dose of L-Arg (40 mg/kg) was found to be close to optimum; 10 and 160 mg/kg L-Arg provided much smaller positive effects. In KA-treated rats, a much higher density of GFAP-positive astrocytes was found in the hilus of the dorsal hippocampus, while 40 mg/kg L-Arg+KA-treated rats demonstrated noticeably weaker GFAP overexpression. The results of Western blotting analysis were fully comparable with those obtained in the immunostaining experiments.
    Neurophysiology 45(1). · 0.38 Impact Factor