Iranian Journal of Basic Medical Sciences
Year:2017 | Volume:20 | Issue:12|Papers Count:15

Objective(s): To determine the molecular and cellular mechanisms of spinal cord regeneration in zebrafish. Materials and Methods: Medical databases of PubMed and Scopus were searched with following key words: Zebrafish; spinal cord injuries; regeneration; recovery of function. The map of mechanisms was performed using Xmind software. Results: Wnt/ß-catenin signaling, L1. 1, L1. 2, Major vault protein (MVP), contactin-2 and High mobility group box1 (HMGB1) had positive promoting effects on axonal re-growth while Ptena had an inhibitory effect. Neurogenesis is stimulated by Wnt/ß-catenin signaling as well as HMGB1, but inhibited by Notch signaling. Glial cells proliferate in response to fibroblast growth factor (FGF) signaling and Lysophosphatidic acid (LPA). Furthermore, fgf signaling pathway causes glia bridge formation in favor of axonal regeneration. LPA and HMGB1 in acute phase stimulate inflammatory responses around injury and suppress regeneration. LPA also induces microglia activation and neuronal death in addition to glia cell proliferation, but prevents neurite sprouting. Conclusion: This study provides a comprehensive review of the known molecules and mechanisms in the current literature involved in the spinal cord injury (SCI) regeneration in zebrafish, in a time course manner. A better understanding of the whole determining mechanisms for the SCI regeneration should be considered as a main goal for future studies.

Objective(s): Arsenic, a toxic metal in drinking water and butyric acid (BA) is a free fatty acid found in many foods. These two can induce oxidative stress in some tissues. The present study investigated the protective effect of metformin against toxicity induced by Arsenic (As) and BA in isolated mice liver mitochondria and pancreatic islets. Materials and Methods: In this study, liver mitochondria were isolated by adopting different centrifugation methods and pancreatic islets isolated by a collagenase method. Mitochondria were incubated by BA (75 μ M), As (100 μ M) and metformin (0, 0. 5, 1, 3, 10 mM) and the islets also incubated by BA (1000 μ M), As (100 μ M) and metformin (0, 1, 3, 10 mM) for 1 hr. At the end of study, mitochondrial viability (MTT), mitochondrial membrane potential (MMP), reactive oxygen species (ROS), malondial-dehyde (MDA), glutathione (GSH) and islets insulin secretion were measured employing specific relevant methods. Results: As and BA significantly increased ROS, MDA and Δ Ψ m levels and decreased GSH level, succinate dehydrogenase activity and insulin secretion. On the other hand, pretreatment with metformin, returned mitochondrial complex І І activity, reduced ROS, MDA and Δ Ψ m levels and increased GSH level and insulin secretion of pancreatic islets. Conclusion: As and BA in combination or in isolation induce oxidative stress in liver mitochondria and decrease insulin secretion of pancreatic islets. Metformin has a protective effect probably caused by its antioxidant feature. The findings suggest the potential role of metformin in mitochondria therapy and insulin secretion in many diseases.

Objective(s): Bill duct ligation (BDL) is a representative model of biliary cholestasis in animals. Curcumin has a protective effect on the liver; however, its underlying mechanisms are not completely known. This study explored the hepatoprotective activity of curcumin on hepatic damage via measuring the expression of sirtuin3 (SIRT3), AMP-activated protein kinase (AMPK), carnitine palmitoyltransferase 1A (CPT-1A), isocitrate dehydrogenase2 (IDH2) and manganese superoxide dismutase (MnSOD) as well as the level of serum lipid profile in the BDL fibrotic rat model. Materials and Methods: The study consisted of four groups (n=8 for each of Wistar rats): sham group, sham+curcumin (sham+Cur) group (received curcumin 100 mg/kg/day), BDL+Cur group, and BDL group. Transcription levels of SIRT3, AMPK, CPT-1A, IDH2, MnSOD and protein expression level of SIRT3 were measured by real-time PCR and Western blotting, respectively. Results: It was identified that SIRT3, AMPK, CPT-1A, IDH2 and MnSOD expression significantly decreased in BDL rats compared to sham rats; however, in the curcumin treatment of BDL rats, the expression of these factors increased significantly compared to BDL (P<0. 05). It was, moreover, observed that treatment of BDL rats with curcumin reduced liver injury as verified by a reduction in the levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) and increase in high-density lipoprotein (HDL) (P <0. 05). Conclusion: Curcumin reduced liver damage and oxidative stress in the liver tissue of BDL rats through up-regulation of SIRT3, AMPK, CPT-1A, IDH2 and MnSOD as well as changing the level of serum lipid profile.

Objective(s): The role of isoflavones in pulmonary structure and function during menopause is not well studied. Moreover, the important role of estrogen in the physiological function of respiratory system has been revealed. Genistein, as an isoflavone, mimics estrogenic in diabetic and ovariectomized rats. Here, we hypothesized that genistein would reverse changes in the protein expression levels related to estrogen deficiency in the lung of ovariectomized diabetic rats. Materials and Methods: Wistar female rats were assigned to four experimental groups (n=10 in each group): sham, rats underwent laparotomy without removing the ovaries; OVX, rats that underwent ovariectomy; OVX. D, rats underwent bilateral ovariectomy and were fed a high-fat diet (HFD); OVX. D. G, ovariectomized diabetic rats with genistein administration (1 mg/kg /day). After ovariectomy, rats continued to feed HFD for a 4-week period. After 4 weeks of HFD feeding, a single dose of 30 mg/kg of streptozotocin was administered in the diabetic group. Genistein was administered for eight weeks. At the end of the experiment, lung tissue was removed and Western blotting technique and hematoxylin-eosin staining were used for evaluation of the lung. Results: Treatment with genistein significantly decreased inflammatory and apoptotic biomarkers in the ovariectomized diabetic rats compared to non-treated animals (P<0. 05). Also, genistein exerted a protective effect in the lung architecture. Conclusion: Genistein partly reversed ovariectomy-induced changes in apoptotic and inflammatory biomarkers in the lung. Our data suggest that genistein treatment as a natural replacement therapy may prevent the estrogen deficiency effects in the lung of diabetic menopausal women.

Objective(s): Astrodaucus persicus (Apiaceae) is one of the two species of this genus which grows in different parts of Iran. Roots of this plant were rich in benzodioxoles and used as food additive or salad in Iran and near countries. The aim of present study was evaluation of antimalarial and cytotoxic effects of different fractions of A. persicus fruits and roots extracts. Materials and Methods: Ripe fruits and roots of A. persicus were extracted and fractionated by hexane, chloroform, ethyl acetate and methanol, separately. Antimalarial activities of fractions were performed based on Plasmodium berghei suppressive test in mice model and percentage of parasitemia and suppression were determined for each sample. Cytotoxicity of fruits and roots fractions were investigated against human breast adenocarcinoma (MCF-7), colorectal carcinoma (SW480) and normal (L929) cell lines by MTT assay and IC50 of them were measured. Results: Hexane fraction of roots extract (RHE) and ethyl acetate fraction of fruits extract (FEA) of A. persicus demonstrated highest parasite inhibition (73. 3 and 72. 3%, respectively at 500 mg/kg/day) which were significantly different from negative control group (P<0. 05). In addition, RHE showed potent anticancer activities against MCF-7 (IC50 of 0. 01 μ g/ml), SW480 (IC50 of 0. 36 μ g/ml) and L929 (IC50 of 0. 70 μ g/ml) cell lines. Conclusion: According to the results, RHE and FEA fractions of A. persicus could be introduced as excellent choice for antimalarial drug discovery. In addition, cytotoxic activity of RHE was noticeable.

Objective(s): Stroke may cause severe neuronal damage. The sesamin have been demonstrated to possess neuroprotection by its antioxidant and anti-inflammatory properties. One sesamin derivative was artificially composited, 1, 2-bis [(3-methoxyphenyl) methyl] ethane-1, 2-dicaroxylic acid (MMEDA) had been developed to study its antioxidative activity and neuroprotection. Materials and Methods: The infaction of Sprague Dawley (SD) rats and hypoxia models of BV-2 microglia or PC12 cells were investigated for in vivo and in vitro test respectively. Lipid peroxidation and reactive oxygen species (ROS), prostaglandin E2 (PGE2) and related signaling pathways from hypoxic cells were analyzed by ELISA or Western blot assay, respectively. Results: MMEDA showed a protective effect when given 90 min after the focal cerebral ischemia. The neuroprotection of MMEDA was further confirmed by attenuating ROS and PGE2 release from hypoxic BV-2 or PC12 cells. MMEDA significantly reduced hypoxia-induced JNK and caspase-3 (survival and apoptotic pathways) in PC12 cells. Conclusion: The neuroprotective effect of MMEDA on ischemia/hypoxia models was involved with its antioxidative activity and anti-inflammatory effects. These results suggest that MMEDA exert effective neuroprotection against ischemia/hypoxia injury.

Objective(s): Pyocyanin is a blue-greenish redox-active pigment, produced by Pseudomonas aeruginosa, with a wide range of biological and biotechnological applications. Pyocyanin biosynthesis is regulated by the quorum-sensing (QS) system in which the expression of QS genes and QS-controlled virulence genes may be affected by serum as a complex medium. In the current study, effects of adult bovine serum (ABS) and fetal bovine serum (FBS) on the production of pyocyanin were examined in order to develop it. Materials and Methods: The presence of pyocyanin-producing specific genes and proteins in clinical and soil isolates of P. aeruginosa was confirmed using PCR and SDS-PAGE. Isolates were inoculated to media containing different concentrations of complement-active/-inactivated ABS or FBS and pyocyanin concentration was measured by spectrophotometry. Extracted pigment was characterized by using UV-Visible spectrophotometry. Titration of ABS antibodies against studied isolates was performed by the tube agglutination test. Results: Adding ABS to P. aeruginosa culture medium decreased pyocyanin production compared to the control, while its production increased in FBS-containing media (113. 21± 2. 581 vs. 55. 26± 0. 827 μ g. ml-1 and 126. 80± 2. 036 vs. 30. 56± 0. 382 μ g. ml-1 of C11 and E8 pyocyanin concentration in the presence of 10% FBS vs. control, respectively). Conclusion: In this study, due to the presence of inhibitors such as complement proteins and antibodies in ABS samples, the use of FBS devoid of antibodies was effective to increase pyocyanin production in studied isolates.

Objective(s): The aim of this study was to observe the impact of sirolimus on proteinuria in streptozotocin (STZ) induced diabetic rats. Materials and Methods: Rats were given a single injection of STZ to induce diabetic rat model. Rats’ 24 hr urine was collected to test, urinary and the kidney tissues were harvested at the 8th and 20th weeks, respectively. Podocyte morphological changes were examined by electron microscopy and the ZO-1, podocin expressions in kidneys were detected by immunohistochemistry; the protein levels of Raptor and pS6 were measured by Western blot assay. Results: In the early stage of diabetic nephropathy (DN), sirolimus reduced the proteinuria significantly (P<0. 05); but in the advanced stage of DN, sirolimus worsened proteinuria (P<0. 05). Electron microscopy test suggested that sirolimus could reduce the injury of podocyte at the early DN, but increased the injury at the late DN podocyte. Immunohistochemistry results indicated that sirolimus increased the expressions of podocin and ZO-1 at the early DN (P<0. 05), but reduced the expressions of ZO-1 and podocin (P<0. 05) at the advanced DN. In the different periods of DN, the expression levels of Raptor and pS6 in sirolimus-treated groups were significantly lower than in the DN control groups (P<0. 05). Conclusion: Sirolimus can reduce proteinuria and alleviate the early DN podocyte injury in diabetic rat model by inhibiting the activity of mTORC1; but in the advanced stage of DN, sirolimus can increase podocyte injury and urine protein level.

Objective: The role of growth factors, including vascular endothelial growth factor of activated omentum on mitosis is clearly known, though not on all the aspects of in vitro oocyte maturation. This study was designed to assess the effect of activated-omental extract (AOE) on in vitro maturation (IVM) of rat cumulus-oocyte complexes (COCs). Materials and Methods: In this experimental study, the COCs were incubated in Ham’ s F-10 supplemented with either 20% AOE, 20% fetal bovine serum (FBS) or serum-free media. Post-culture COCs were studied according to the cumulus cells (CCs) expansion, nuclear maturation and cytoplasmic maturation. Cumuli expansion was evaluated by inverted microscope without staining; nuclear maturation was assessed by aceto-orcein staining (light microscope) and cytoplasmic maturation was also observed by TEM. Results: Expansion of CCs and nuclear maturation of the oocytes in in vitro for 24 hr was significantly higher in AOE-and FBS-supplemented groups (P=0. 000 and 0. 013) and (P=0. 004 and 0. 014), respectively, compared to serum-free group. At ultra-structural level, after 24 hr, both FBS and AOE-supplemented media showed uniformly wide perivitelline space (PVS). After 12 hr, the cortical granules were found in the oocytes cultured in FBS and AOE-supplemented media. Within 24 hr, both granules and mitochondria were large without any detectable topographic tendency across the ooplasm. In AOE and FBS-supplemented oocytes, the number and size of microvilli were more than those in serum-free one. Conclusion: Although AOE supplementation induced a higher rate of the CCs expansion, and resuming meiosis, it was not as potent as FBS to provide cytoplasmic maturation of rat oocytes.

Objective(s): Apoptotic effect of apoptin has been demonstrated in numerous studies. However, its tumor specificity has been questioned by some reports. The aim of this study was to confine the expression of apoptin in the prostate tumor cells by inducing its gene expression under the control of a chimeric enhancer composing of prostate-specific membrane antigen (PSMA) and prostate-specific antigen (PSA) regulatory elements (PSES). Furthermore, we investigated the effects of apoptin expression on LNCaP prostate carcinoma cell survival and apoptosis using MTT assay and annexin V/7-AAD flow cytometry assay. Materials and Methods: Recombinant plasmids containing apoptin gene under the control of PSES/PSA promoter or Cytomegalovirus (CMV) promoter were constructed. Tumor cell lines including LNCaP cells and HeLa cells, and LX-2 cells (as a normal control) were transfected with the plasmids and the expression of apoptin was evaluated by real time-PCR and western blot analyses. The effects of apoptin expression on cell survival and apoptosis were then investigated using MTT and annexinV/7-AAD flow cytometry assay, respectively. Results: Western blot and real time PCR analyses confirmed the specific expression of apoptin under the control of PSES/PSA regulatory element in the LNCaP cells, while CMV promoter caused apoptin expression in both tumor and normal cell lines. Apoptin expression significantly increased cell death and apoptosis in tumor cells when compared with the normal cells (P<0. 001). Conclusion: These results suggest that PSES/PSA regulatory element may be considered as an efficient approach for specific expression of apoptin gene in prostate tumor cells and treatment of prostate cancer.

Objective(s): Alcohol consumption induces oxidative stress on bone, which in turn increases the risk of osteoporosis. This study determined the effects of vitamin E on bone strength and bone mineral content in alcohol-induced osteoporotic rats. Materials and Methods: Three months old Sprague Dawley male rats were randomly divided into 5 groups: (I) control group; (II) alcohol (3 g/kg) + normal saline; (III) alcohol (3 g/kg) + olive oil; (IV) alcohol (3 g/kg) + alpha-tocopherol (60 mg/kg) and (V) alcohol (3 g/kg) + palm vitamin E (60 mg/kg). The treatment lasted for three months. Following sacrifice, the right tibia was subjected to bone biomechanical test while the lumbar (fourth and fifth lumbar) and left tibia bones were harvested for bone mineral measurement. Results: Alcohol caused reduction in bone biomechanical parameters (maximum force, ultimate stress, yield stress and Young’ s modulus) and bone minerals (bone calcium and magnesium) compared to control group (P<0. 05). Palm vitamin E was able to improve bone biomechanical parameters by increasing the maximum force, ultimate stress and Young’ s modulus (P<0. 05) while alpha-tocopherol was not able to. Both alpha-tocopherol and palm vitamin E were able to significantly increase tibia calcium and magnesium content while only alpha-tocopherol caused significant increase in lumbar calcium content (P<0. 05). Conclusion: Both palm vitamin E and alpha-tocopherol improved bone mineral content which was reduced by alcohol. However, only palm vitamin E was able to improve bone strength in alcohol treated rats.

Objective(s): Cholecystokinin (CCK) has been proposed as a mediator in stress. However, it is still not fully documented what are its effects. We aimed to evaluate the effects of systemic administration of CCK exactly before induction of stress on spatial memory and synaptic plasticity at CA1 in rats. Materials and Methods: Male Wistar rats were divided into 4 groups: the control, the control-CCK, the stress and the stress-CCK. Restraint stress was induced 6 hr per day, for 24 days. Cholecystokinin sulfated octapeptide (CCK-8S) was injected (1. 6 μ g/kg, IP) before each session of stress induction. Spatial memory was evaluated by Morris water maze test. Long-term potentiation (LTP) in Schaffer collateral-CA1 synapses was assessed (by 100 Hz tetanization) in order to investigate synaptic plasticity. Results: Stress impaired spatial memory significantly (P<0. 01). CCK in the control rats improved memory (P<0. 05), and prevented the impairments in the stress group. With respect to the control group, both fEPSP amplitude and slope were significantly (P<0. 05) decreased in the stress group. However, there were no differences between responses of the control– CCK and Stress– CCK groups compared to the control group. Conclusion: The present results suggest that high levels of CCK-8S during induction of stress can modulate the destructive effects of stress on hippocampal synaptic plasticity and memory. Therefore, the mediatory effects of CCK in stress are likely as compensatory responses.

Objective(s): Perovskia abrotanoides Kar., from family Lamiaceae, is a little known medicinal plant growing in various regions of Iran. In the present study, cryptotanshinone (CT), tanshinone 2A (Tan2A), and hydroxycryptotanshinone (HCT) were isolated and purified from the roots of P. abrotanoides. In addition, cytotoxic and apoptotic effects of total root extract (TE) and three purified tanshinones were investigated in human cervical carcinoma (HeLa) and human breast cancer (MCF-7) cell lines. Materials and Methods: Alamar Blue® assay was used to determine cell viability. Cell apoptotic rate was detected using propidium iodide staining of DNA fragmentation by flow cytometry (sub-G1 peak). The PARP cleavage, as the sign of apoptosis, was investigated by Western blotting. Results: The results revealed that CT, Tan2A, HCT, and TE exhibited significant cytotoxicity in cancer cell lines. All of these compounds caused apoptosis in treated cells and induced sub-G1 peak in the related flow cytometry histograms. HCT was found to have the highest anti-proliferative activity on cancer cells. Western blotting analysis showed cleavage of PARP protein in MCF-7 cells treated with purified tanshinones and TE after 48 hr contact with cells. Conclusion: The findings suggest that root extract of P. abrotanoides and purified tanshinones especially Tan2A and HCT have cytotoxic and apoptotic effects against cancer cell lines. So, they may serve as potential cytotoxic agents for future investigations.

Objective(s): Transforming growth factor alpha (TGF-α ) has been shown to modulate the gastric acid secretion. Therefore, the aim of the present study was to investigate the effect of sodium hydrosulfide (NaHS) on TGF-α expression in gastric mucosa in rats. Materials and Methods: Eighteen rats were randomly divided into 3 groups (6 per group). To determine the effect of NaHS on gene and protein expression of TGF-α in gastric mucosa in response to gastric acid, the acid output induced by gastric distension. At the end of experiment, rats were euthanized by anesthetics, and gastric effluents, in addition to mucosa were collected to measure the pH of gastric effluents and to quantify protein and gene expression of TGF-α . Results: The stimulated gastric acid upregulated expression levels of TGF-α in gastric mucosa. These levels were higher in animals pretreated with NaHS. Conclusion: TGF-α upregulatory effect of sodium hydrosulfate implied that TGF-α is involved in the acid inhibitory effect of NaHS.

Objective(s): Diabetes mellitus, a carbohydrate metabolic disorder, occurs due to absolute or relative deficiency of insulin. Current treatment strategies involve either preventing or delaying the intestinal absorption of glucose to lower the levels of postprandial hyperglycemia (PPHG). Herbal remedies have been since ancient times for treating diabetes mellitus. Therefore, identifying novel phytocompounds with α-amylase and α-glucosidase inhibitory activity that would reduce the glucose absorption as well as the rise in postprandial blood glucose level is vital. Consequently, the present study was aimed to investigate the anti-hyperglycemic activity of Croton bonplandianusagainst these pancreatic enzymes. Materials and Methods: The methanol extract of C. bonplandianusleaf was prepared and further fractionation was performed with n-hexane, ethyl acetate and chloroform. The antioxidant activity and anti-hyperglycemic activity of the extracts and its fractions were determined. Further, GC-MS analysis was performed for the leaf extract. Results: The chloroform fraction (ChF) was found to contain highest quantity of polyphenols (114. 28 μ g/ml of GAE), flavonoids (95. 68 μ g/ml of quercetin) and tannins (63. 80 μ g/ml of GAE) and also possessed effective inhibitory activity against α amylase (IC5095. 78 μ g/ml) and α glucosidase (IC50 126. 81 μ g/ml). The antioxidant activity of ChFwas also higher when compared to other fractions. Further, GC-MS analysis of ChF showed the presence of various components that may be responsible for the above mentioned activities. Conclusion: The study findings suggest that the components present in the leaves of C. bonplandianus, may provide a potential therapeutic source in developing treatment forhyperglycemia. Further bioassay guided fractionation procedure is required to identify the active constituents.