Displaying publications 81 - 100 of 2661 in total

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  1. Japarin RA, Harun N, Hassan Z, Shoaib M
    Behav Pharmacol, 2023 Apr 01;34(2-3):123-130.
    PMID: 36752325 DOI: 10.1097/FBP.0000000000000715
    Mitragynine (MG) is a pharmacologically active alkaloid derived from the leaves of Mitragyna speciosa Korth (Kratom). This plant has sparked significant interest as a potential alternative treatment for managing opioid dependence and withdrawal due to its opioid-like pharmacological effects. However, whether MG exposure would trigger opioid-seeking behaviour following abstinence has not been investigated. The present study examined the effects of MG priming on morphine-seeking behaviour in rats. Male Sprague-Dawley rats were initially trained to intravenously self-administer morphine (0.5 mg/kg/infusion) under a fixed ratio-3 schedule of reinforcement. Removal of both morphine infusions and drug-associated cues led to the subsequent extinction of the drug-seeking behaviour. Tests of reinstatement were made following exposure to a randomised order of intraperitoneal injections of MG (3, 10 and 30 mg/kg), morphine (5 mg/kg) and vehicle. Significant levels of drug-seeking behaviour were observed following extended access to morphine self-administration, which was extinguished following removal of morphine and cues indicative of morphine-seeking behaviour, supporting the relapse model. The present finding demonstrated that MG priming in a dose of 10 mg/kg resulted in the reinstatement of morphine-seeking behaviour, whereas the higher MG dose (30 mg/kg) tested suppressed the seeking response. This study indicated that exposure to a low MG dose may increase the likelihood of relapsing to opioids, suggesting that the potential of MG as a treatment for opioid management merits further scientific assessment of its ability to trigger relapse to opioid abuse.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  2. Al Qabbani A, Rani KGA, AlKawas S, Sheikh Abdul Hamid S, Yap Abdullah A, Samsudin AR, et al.
    PLoS One, 2023;18(12):e0294291.
    PMID: 38127838 DOI: 10.1371/journal.pone.0294291
    The aim of this study was to compare the ability of demineralized (DMB) and decellularized (DCC) bovine bone granules to support bone regeneration in rat calvaria critical-size defects. DMB and DCC were prepared using a previously published method. The granule size used ranged between 500 and 750 μm. A total of forty-eight Sprague-Dawley rats were divided into two groups (n = 24). A pair of 5 mm diameter defects were created on the calvaria of the rats in the right and left parietal bone in both groups. Group A animals received DMB granules and Group B received DCC granules in the right parietal defect side while the left parietal untreated defect acted as sham surgery for both groups. Four animals per group were euthanized in a CO2 chamber at day 7, 14 and 21 post-surgery and the calvaria implantation site biopsy harvested was subjected to osteogenic gene expression analysis. Another four animals per group were euthanized at days 15, 30 and 60 post surgery and the calvaria implantation site biopsy harvested was subjected to histological, immunohistochemistry, RAMAN spectroscopy and Micro-CT analysis at the mentioned time points. Statistical analysis was conducted using t-tests and ANOVA. Histomorphometry showed significantly higher new bone formation in the DCC sites (p<0.05) compared to DMB. Both DMB and DCC implantation sites showed distinct staining for osteocalcin and osteopontin proteins compared to their respective sham sites. By day 21 after implantation, DCC sites demonstrated significantly elevated mRNA levels of osteonectin (p<0.001), osteopontin (p<0.001), osteocalcin (p<0.0001), ALP (p<0.01), and BMP-2 (p<0.001) compared to DMB. However, VEGF expression showed no significant differences at this time point between the two groups. Micro-CT analysis also showed enhanced defect closure and higher bone density in DCC implanted sites while RAMAN spectra demonstrated increased abundance of collagen and bone minerals, especially, PO43- ions than DMB. In conclusion, both DMB and DCC granules demonstrated favorable osteogenic potential in critical-sized defects, with DCC exhibited superior osteoconductive, osteoinductive and osteogenesis properties.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  3. Isaeva EV, Kisel AA, Beketov EE, Demyashkin GA, Yakovleva ND, Lagoda TS, et al.
    Sovrem Tekhnologii Med, 2023;15(2):5-16.
    PMID: 37389022 DOI: 10.17691/stm2023.15.2.01
    The aim of the study was to compare type I collagen-based and methacryloyl gelatin-based (GelMA) hydrogels by their ability to form hyaline cartilage in animals after subcutaneous implantation of scaffolds.

    MATERIALS AND METHODS: Chondrocytes were isolated from the costal cartilage of newborn rats using 0.15% collagenase solution in DMEM. The cells was characterized by glycosaminoglycan staining with alcian blue. Chondrocyte scaffolds were obtained from 4% type I porcine atelocollagen and 10% GelMA by micromolding and then implanted subcutaneously into the withers of two groups of Wistar rats. Histological and immunohistochemical studies were performed on days 12 and 26 after implantation. Tissue samples were stained with hematoxylin and eosin, alcian blue; type I and type II collagens were identified by the corresponding antibodies.

    RESULTS: The implanted scaffolds induced a moderate inflammatory response in both groups when implanted in animals. By day 26 after implantation, both collagen and GelMA had almost completely resorbed. Cartilage tissue formation was observed in both animal groups. The newly formed tissue was stained intensively with alcian blue, and the cells were positive for both types of collagen. Cartilage tissue was formed among muscle fibers.

    CONCLUSION: The ability of collagen type I and GelMA hydrogels to form hyaline cartilage in animals after subcutaneous implantation of scaffolds was studied. Both collagen and GelMA contributed to formation of hyaline-like cartilage tissue type in animals, but the chondrocyte phenotype is characterized as mixed. Additional detailed studies of possible mechanisms of chondrogenesis under the influence of each of the hydrogels are needed.

    Matched MeSH terms: Rats, Wistar; Rats
  4. Albaayit SF, Abba Y, Abdullah R, Abdullah N
    PMID: 25610488 DOI: 10.1155/2014/975450
    Clausena excavata (Lour.), locally known as "Kemantu hitam," is a common plant in Malaysian folklore medicine. This study evaluated the antioxidant properties of the solvent extracts of C. excavata leaves and determined the acute toxicity of methanolic extract C. excavata (MECE) leaves in Sprague-Dawley rats. Harvested leaves were dried and subjected to solvent extraction using petroleum ether, chloroform, ethyl acetate and methanol in succession. The antioxidant activity of each extract was determined using the ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl dihydrazyl (DPPH) radical scavenging activity. The total phenolic content (TPC) and total flavonoids content (TFC) were estimated by Folin-Ciocalteu and ethanolic aluminium chloride method, respectively. The chloroform extract was found to be highest in flavonoid content, while the methanolic extract showed the highest TPC and antioxidant activity. There was no mortality in rats treated with MECE leaves even at a high dose of 5000 mg/kg body weight. However, the MECE leaves produced mild to moderate pathological changes in the liver and kidneys, shown by mild degenerative changes and leucocyte infiltration. The extract did not affect the haematological parameters or relative weights of the liver or kidneys. Overall, the MECE leaves have potent antioxidant activity and are presumed safe to be used orally as health-promoting product at low to moderate doses.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  5. Tajul Ariff AS, Soelaiman IN, Pramanik J, Shuid AN
    PMID: 22966245 DOI: 10.1155/2012/818072
    Testosterone replacement is the choice of treatment in androgen-deficient osteoporosis. However, long-term use of testosterone is potentially carcinogenic. Eurycoma longifolia (EL) has been reported to enhance testosterone level and prevent bone calcium loss but there is a paucity of research regarding its effect on the bone structural parameters. This study was conducted to explore the bone structural changes following EL treatment in normal and androgen-deficient osteoporosis rat model. Thirty-six male Sprague-Dawley rats aged 12 months were divided into normal control, normal rat supplemented with EL, sham-operated, orchidectomised-control, orchidectomised with testosterone replacement, and orchidectomised with EL supplementation groups. Testosterone serum was measured both before and after the completion of the treatment. After 6 weeks of the treatment, the femora were processed for bone histomorphometry. Testosterone replacement was able to raise the testosterone level and restore the bone volume of orchidectomised rats. EL supplementation failed to emulate both these testosterone actions. The inability of EL to do so may be related to the absence of testes in the androgen deficient osteoporosis model for EL to stimulate testosterone production.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats
  6. Mazaheri B, Emami F, Moslemi F, Talebi A, Nematbakhsh M
    Malays J Med Sci, 2019 Jul;26(4):39-46.
    PMID: 31496892 DOI: 10.21315/mjms2019.26.4.5
    Backgrounds: Renal ischemia/reperfusion (RIR) is a major cause of kidney dysfunction in clinic. The main objective of this study was to investigate the effect of pre-conditioning ischemia (IPC) and zinc (Zn) supplementation on renal RIR injury.

    Methods: A total of 63 unilateral nephrectomised male and female Wistar rats were divided into five groups. Group 1 (ShOPR): Rats as sham-operated group were subjected to surgical procedure without RIR. Group 2 (Isch): Rats underwent RIR (left kidney ischemia for 30 min followed by 48 h reperfusion). Group 3 (Zn+Isch): Rats were treated as group 2 but they received Zn sulphate (30 mg/kg) 1 h before induction of RIR. Group 4 (IPC+Isch): Rats were treated as group 2 but they underwent 1 min of ischemia followed by 3 min reperfusion as IPC, which was repeated for three times before induction of RIR. Group 5 (Zn+IPC+Isch): Rats were subjected to receive both Zn sulphate and IPC before induction of RIR. Urine samples were collected in the last 6 h of reperfusion, and finally biochemical and histological measurements were performed.

    Results: The serum level of creatinine (Cr), normalised kidney weight (KW) and kidney tissue damage score (KTDS) increased by RIR alone significantly (P < 0.05). These parameters were attenuated statistically by Zn supplementation (P < 0.05). However, IPC alone or co-treatment of Zn and IPC did not improve the biochemical and histological markers altered by RIR injury.

    Conclusion: Zn supplementation had a protective role against RIR while such protective effect was not observed by IPC alone or by co-treatment of Zn and IPC.

    Matched MeSH terms: Rats, Wistar; Rats
  7. Omotoso GO, Kadir RE, Sulaimon FA, Jaji-Sulaimon R, Gbadamosi IT
    Malays J Med Sci, 2018 Sep;25(5):35-47.
    PMID: 30914861 DOI: 10.21315/mjms2018.25.5.4
    Background and aim: This study aimed to determine the effect of gestational nicotine exposure before neurodevelopment on the morphology and histology of the prefrontal cortex (PFC) in rats.

    Methodology: Adult female Wistar rats were time-mated and grouped into three categories: (a) control-given 0.1 mL of normal saline, (b) low-dose nicotine-given 6.88 mg/ kg/d/0.05 mL, and (c) high-dose nicotine-given 13.76 mg/kg/d/0.1 mL in two divided doses. Treatment was given intraperitoneally from gestational days 2 to 6. On postnatal day 15 (P15), the pups were separated from their mothers, anaesthetised and sacrificed, followed by intracardial perfusion with 4% paraformaldehyde. PFC was excised from the brain and processed for tissue histology, histochemistry, and morphology of brain cells.

    Results: Gestational nicotine exposure during the first week of gestation in rats significantly reduced birth weights in nicotine-treated groups compared with control; it, however, accelerated body weights, altered neuronal morphology, and elevated astrocytic count significantly, while oligodendroglial count was slightly increased in the PFC of juvenile rats examined at P15.

    Conclusion: These alterations revealed that gestational nicotine exposure before the commencement of the cellular processes involved in brain development negatively affects neurodevelopment, and this could result in neurological dysfunctions in later life.

    Matched MeSH terms: Rats, Wistar; Rats
  8. Samat S, Nor NA, Nor Hussein F, Ismail WI
    PMID: 24885010 DOI: 10.1186/1472-6882-14-146
    Since ancient times, honey has been used for medicinal purposes in many cultures; it is one of the oldest and most enduring substances used in wound management. Scientific evidence for its efficacy is widely studied, but systemic safety studies are still lacking. It is essential to study the impact of consumption of honey on the health and proper development of the consumer. Therefore, the present study was designed to observe the effects of acute administration (14 days) of Gelam honey (GH), a wild harvesting honey and Acacia honey (AH), a beekeeping honey, on male and female Sprague Dawley (SD) rats.
    Matched MeSH terms: Rats, Sprague-Dawley; Rats/growth & development; Rats/metabolism*
  9. Gilmour CCB
    Malayan Medical Journal, 1934;9:177-81.
    Matched MeSH terms: Rats
  10. Qaid E, Zakaria R, Sulaiman SF, Yusof NM, Shafin N, Othman Z, et al.
    Hum Exp Toxicol, 2017 Dec;36(12):1315-1325.
    PMID: 28111974 DOI: 10.1177/0960327116689714
    Impairment of memory is one of the most frequently reported symptoms during sudden hypoxia exposure in human. Cortical atrophy has been linked to the impaired memory function and is suggested to occur with chronic high-altitude exposure. However, the precise molecular mechanism(s) of hypoxia-induced memory impairment remains an enigma. In this work, we review hypoxia-induced learning and memory deficit in human and rat studies. Based on data from rat studies using different protocols of continuous hypoxia, we try to elicit potential mechanisms of hypobaric hypoxia-induced memory deficit.
    Matched MeSH terms: Rats
  11. Ow Yang CK, Lim BL, Lie Kian Joe
    Med J Malaya, 1965 Sep;20(1):70.
    PMID: 4221428
    Matched MeSH terms: Rats
  12. Yeh LS
    J. Helminthol., 1955;29(1-2):44-8.
    PMID: 13263558 DOI: 10.1017/S0022149X00024214
    A collection of parasitic worms was made from Rattus rattus jarak (Bonhote) from Pulau Jarak, “which lies in the middle of the Malacca Straits between Penang and Port Swettenham and some 85 miles from the Sembilan Islands opposite the Dindings.” (Audy, 1950). It was collected by Dr. J. R. Audy, Senior Research Officer of the Division of Virus Research and Medical Zoology, Institute for Medical Research, Kuala Lumpur while investigating scrub-typhus on the island.
    Matched MeSH terms: Rats
  13. Hana, M., Chen, H.C., Radzi, R.
    Jurnal Veterinar Malaysia, 2017;29(1):28-29.
    MyJurnal
    An innovative assembly to maintain isoflurane anaesthesia in rats is described. This assembly was used successfully in laboratory rats for dental procedures that may last as long as sixty minutes. Repeated exposures to isoflurane anaesthesia, of up to eight times within a 30-day study period in healthy laboratory rats did not result in any observable adverse-effects.
    Matched MeSH terms: Rats
  14. Shidqiyyah Abdul-Hamid, Norliza Muhammad, Isa Naina Mohamed
    Sains Malaysiana, 2016;45(12):1815-1822.
    Postmenopausal osteoporosis is one of the main health problems in aging women. It was due to several factors including oxidative stress, which can be controlled through intake of antioxidants from food sources. Virgin coconut oil (VCO) is one of the natural product rich in antioxidants and has been proven to protect osteoporotic bone. This study was conducted to gain in-depth understanding on virgin coconut oil’s activity on osteoporosis at molecular level. Thirty two female Sprague-Dawley rats were divided into four groups, namely Sham operated group, ovariectomized control group (Ovx+Ctrl), ovariectomized with VCO treatment (Ovx+VCO), and ovariectomized with estrogen treatment (Ovx+E). All treatments were administered orally for ten weeks. Bone samples were obtained to examine changes on expression of superoxide dismutase (SOD), glutathione peroxidase (GPX), osteocalcin and runt-related transcription factor 2 (Runx2) genes. The results indicated that rats receiving VCO treatment had experienced significant increments in SOD, GPX and osteocalcin gene expressions compared to the ovariectomized control group, besides the gene expressions of Runx2 which also showed an increment pattern. In conclusion, VCO helps to protect bone in osteoporotic rat model by increasing the expressions of antioxidant genes and genes which increase the osteoblast acitivities.
    Keywords: Osteoporosis; ovariectomized rat model; postmenopausal; virgin coconut oil
    Matched MeSH terms: Rats, Sprague-Dawley
  15. Ayoub AA, Mahmoud AH, Ribeiro JS, Daghrery A, Xu J, Fenno JC, et al.
    Int J Mol Sci, 2022 Nov 09;23(22).
    PMID: 36430238 DOI: 10.3390/ijms232213761
    This study was aimed at engineering photocrosslinkable azithromycin (AZ)-laden gelatin methacryloyl fibers via electrospinning to serve as a localized and biodegradable drug delivery system for endodontic infection control. AZ at three distinct amounts was mixed with solubilized gelatin methacryloyl and the photoinitiator to obtain the following fibers: GelMA+5%AZ, GelMA+10%AZ, and GelMA+15%AZ. Fiber morphology, diameter, AZ incorporation, mechanical properties, degradation profile, and antimicrobial action against Aggregatibacter actinomycetemcomitans and Actinomyces naeslundii were also studied. In vitro compatibility with human-derived dental pulp stem cells and inflammatory response in vivo using a subcutaneous rat model were also determined. A bead-free fibrous microstructure with interconnected pores was observed for all groups. GelMA and GelMA+10%AZ had the highest fiber diameter means. The tensile strength of the GelMA-based fibers was reduced upon AZ addition. A similar pattern was observed for the degradation profile in vitro. GelMA+15%AZ fibers led to the highest bacterial inhibition. The presence of AZ, regardless of the concentration, did not pose significant toxicity. In vivo findings indicated higher blood vessel formation, mild inflammation, and mature and thick well-oriented collagen fibers interweaving with the engineered fibers. Altogether, AZ-laden photocrosslinkable GelMA fibers had adequate mechanical and degradation properties, with 15%AZ displaying significant antimicrobial activity without compromising biocompatibility.
    Matched MeSH terms: Rats
  16. Sammour RMF, Chatterjee B, Taher M, Saleh MSM, Shahiwala A
    Curr Drug Deliv, 2021;18(9):1272-1279.
    PMID: 33605859 DOI: 10.2174/1567201818666210219105509
    BACKGROUND: Improved bioavailability of Aceclofenac (ACE) may be achieved through proniosomes, which are considered as one of the most effective drug delivery systems and are expected to represent a valuable approach for the development of better oral dosage form as compared to the existing product. However, the carrier in this system plays a vital role in controlling the drug release and modulating drug dissolution. Accordingly, a comparative study on different carriers can give a clear idea about the selection of carriers to prepare ACE proniosomes.

    OBJECTIVE: This study aims to evaluate the role of maltodextrin, glucose, and mannitol as carriers for in vitro and in vivo performance of Aceclofenac (ACE) proniosomes.

    METHODS: Three formulations of proniosomes were prepared by the slurry method using the 100 mg ACE, 500 mg span 60, 250 mg cholesterol with 1300mg of different carriers, i.e., glucose (FN1), maltodextrin (FN2), and mannitol (FN3). In vitro drug release studies were conducted by the USP paddle method, while in vivo studies were performed in albino rats. Pure ACE was used as a reference in all the tests. Lastly, the results were analyzed using the High-Pressure Liquid Chromatography (HPLC) method, and data were evaluated using further kinetic and statistical tools.

    RESULTS: No significant differences (p > 0.05) in entrapment efficiency (%EE) of FN1, FN2, and FN3 (82 ± 0.5%, 84 ± 0.66%, and 84 ± 0.34% respectively) were observed and formulations were used for further in vitro and in vivo evaluations. During in vitro drug release studies, the dissolved drug was found to be 42% for the pure drug, while 70%, 17%, and 30% for FN1, FN2, and FN3, respectively, at 15 min. After 24 hrs, the pure drug showed a maximum of 50% release while 94%, 80%, and 79% drug release were observed after 24 hr for FN1, FN2, and FN3, respectively. The in vivo study conducted on albino rats showed a higher Cmax and AUC of FN1 and FN2 in comparison with the pure ACE. Moreover, the relative oral bioavailability of proniosomes with maltodextrin and glucose as carriers compared to the pure drug was 183% and 112%, respectively. Mannitol- based formulation exhibited low bioavailability (53.7%) that may be attributed to its osmotic behavior.

    CONCLUSION: These findings confirm that a carrier plays a significant role in determining in vitro and in vivo performance of proniosomes and careful selection of carrier is an important aspect of proniosomes optimization.

    Matched MeSH terms: Rats
  17. Johari IS, Harun N, Sofian ZM, Shoaib M
    Psychopharmacology (Berl), 2021 Nov;238(11):3183-3191.
    PMID: 34333672 DOI: 10.1007/s00213-021-05934-4
    RATIONALE: Kratom (Mitragyna speciosa Korth), a native medicinal plant of Southeast Asia, is proposed to exhibit potential therapeutic value as an opioid substitute. However, studies of its negative emotional states resulting from withdrawal particularly of its main psychoactive compound, mitragynine (MG), are limited.

    OBJECTIVES: Using the pentylenetetrazol (PTZ) discrimination assay, this study aims to investigate the effects of MG in responding to the PTZ stimulus and to assess the generalisation effects of withdrawal from MG to the PTZ stimulus.

    METHODS: Rats (n = 20) were trained on a tandem (FR-10, VI-15) schedule of food reinforcement to press one lever after administration of the anxiogenic compound PTZ (16 mg/kg, i.p.) and an alternate lever after vehicle. Following acute tests, training was suspended, and rats were chronically treated with MG or morphine at 8-h intervals for 9 days and withdrawal was precipitated on the tenth day using naloxone (1 mg/kg, i.p.). The rats were tested for generalisation to PTZ at 2, 8 and 24 h after the last dose of MG or morphine administration.

    RESULTS: Unlike morphine that produced dose-related PTZ-like stimulus, MG at 3, 10, 30 and 45 mg/kg doses showed no substitution to the PTZ discriminative stimulus. In contrast to morphine which produced a time-dependent generalisation to the PTZ stimulus, naloxone did not precipitate withdrawal effects in MG-treated rats as they selected the vehicle lever at three withdrawal time points.

    CONCLUSION: These results demonstrate that MG produces a very different response to morphine withdrawal that is not associated with anxiogenic-like subjective symptoms. These characteristics of MG may provide further support for use as a novel pharmacotherapeutic intervention for managing opioid use disorder.

    Matched MeSH terms: Rats
  18. Madzuki IN, Lau SF, Che Ahmad Tantowi NA, Mohd Ishak NI, Mohamed S
    Inflammopharmacology, 2018 Oct;26(5):1207-1217.
    PMID: 29460078 DOI: 10.1007/s10787-018-0452-6
    The tropical herb Labisia pumila is traditionally used in facilitating childbirth and post-partum care. The effects of L. pumila leaf extract (LP) in explant cartilage culture and on postmenopausal osteoarthritis (OA) rat model were assessed. The LP (10, 25 and 50 µg/ml) or diclofenac (10 µg/ml) was added to the cartilage explants containing bovine IL-1β (20 ng/ml), to evaluate their direct effects on cartilage degradation. In the preclinical study, rats were grouped (n = 8) into: non-treated OA; OA + diclofenac (5 mg/kg); OA + LP extract (150 and 300 mg/kg); and healthy control. To induce OA, monosodium iodoacetate was injected into the ovariectomised female rats' intra-articular knee joints and evaluated for OA severity after 8 weeks via physical (radiological, macroscopic and histological observations), biochemical, ELISA and mRNA expression analysis (for inflammation and cartilage degradation biomarkers). The LP reduced the nitric oxide and proteoglycan release from the cartilage explants under IL-1β induction. The radiological, macroscopic, microscopic and histological images showed the OA rats treated with LP and diclofenac had significantly reduced osteophytes and cartilage erosions compared to non-treated OA rats. The extract significantly up-regulated the anti-inflammatory interleukin-10, collagen type II and down-regulated pro-inflammatory PTGS2 (prostaglandin-endoperoxide synthase 2) mRNA expressions compared to non-treated control. The LP treatment significantly reduced serum collagenases (MMP-1 and MMP-3) and collagen type II degradation biomarker (CTX-II) levels in OA rats. The LP containing myricetin and gallic acid suppressed inflammation, collagenases and cartilage degradation, and helped cartilage matrix synthesis, to prevent OA at the dose equivalent to 30-60 mg/kg daily for humans.
    Matched MeSH terms: Rats
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