MATERIALS AND METHODS: Adult male Sprague-Dawley rats were divided into 4 groups as control, LPS, CA and LPS + CA. The treatments with LPS (5 mg/kg) were intraperitoneally (i.p) injected on day 4 and CA ethanol extract (200 mg/kg) were given orally for 14 days. Morris Water Maze (MWM) test was performed to assess spatial learning and memory performance. Acute oral toxicity of the extract at the highest dose of 5000 mg/kg was also conducted.
RESULTS: Single administration of LPS was able to significantly elicit learning and memory impairment (p
Methods: A total of 32 Sprague-Dawley male rats were randomly assigned into four groups (n = 8); control healthy, control diabetic (PDN), and PDN rats that received 80 µg or 160 µg intrathecal minocycline respectively. The rats were induced to develop diabetes and allowed to develop into the early phase of PDN for two weeks. Hot-plate and formalin tests were conducted. Intrathecal treatment of minocycline or normal saline was conducted for 7 days. The rats were sacrificed to obtain the lumbar enlargement region of the spinal cord (L4-L5) for immunohistochemistry and western blot analyses to determine the expression of phosphorylated (pNR2B) and total NR2B (NR2B).
Results: PDN rats showed enhanced flinching (phase 1: p
Methods: Thirty Sprague-Dawley rats were randomly assigned to control (non-diabetic), PDN and non-PDN groups (n = 10). The rats were induced with diabetes by streptozotocin injection (60 mg/kg). Tactile allodynia and thermal hyperalgesia were assessed on day 0, 14 (week 2) and 21 (week 3) in the rats. The rats were sacrificed and the spinal cord tissue was collected for the measurement of oxidative stress (malondialdehyde (MDA), superoxide dismutase (SOD) and catalase) and pro-inflammatory markers (interleukin-1β (IL-1β) and tumour necrosis factor-α (TNF-α)).
Results: PDN rats demonstrated a marked tactile allodynia with no thermal hyperalgesia whilst non-PDN rats exhibited a prominent hypo-responsiveness towards non-noxious stimuli and hypoalgesia towards thermal input. The MDA level and pro-inflammatory TNF-α was significantly increased in PDN rats whilst catalase was reduced in these rats. Meanwhile, non-PDN rats demonstrated reduced SOD enzyme activity and TNF-α level and increased MDA and catalase activity.
Conclusion: The changes in oxidative stress parameters and pro-inflammatory factors may contribute to the changes in behavioural responses in both PDN and non-PDN rats.
Methods: The rats were divided into four groups (n = 16): non-diabetic control, diabetic control and diabetic rats receiving minocycline (80 μg/day or 160 μg/day). The diabetic rat model was induced by intraperitoneal injection of streptozotocin (60 mg/kg STZ). Tactile allodynia was assessed on day-0 (baseline), day-14 (pre-intervention) and day-22 (post-intervention). Minocycline at doses of 80 μg and 160 μg were given intrathecally from day-15 until day-21. On day-23, formalin test was conducted to assess nociceptive behaviour response. The spinal expression of OX-42 and level of BDNF and DREAM proteins were detected by immunohistochemistry and western blot analyses.
Results: Diabetes rats showed significant tactile allodynia and nociceptive behaviour. These were accompanied by augmented expression of spinal OX-42, BDNF and DREAM protein levels. Both doses of minocycline attenuated tactile allodynia and nociceptive behaviour and also suppressed the diabetic-induced increase in spinal expressions of OX-42, BDNF and DREAM proteins.
Conclusion: This study revealed that minocycline could attenuate DNP by modulating spinal BDNF and DREAM protein expressions.
METHODS: Thirty-two Sprague-Dawley male rats were randomly allocated into four groups (n=8): control, diabetes mellitus (DM) rats and diabetic rats treated with ifenprodil at a lower dose (0.5 μg/day) (I 0.5) or higher dose (1.0 μg/day) (I 1.0). DM was induced by a single injection of streptozotocin at 60 mg/kg on day 0 of experimentation. Diabetic status was assessed on day 3 of the experimentation. The responses on both tactile and thermal stimuli were assessed on day 0 (baseline), day 14 (pre-intervention), and day 22 (post-intervention). Ifenprodil was given intrathecally for 7 days from day 15 until day 21. On day 23, 5% formalin was injected into the rats' hind paw and the nociceptive responses were recorded for 1 hour. The rats were sacrificed 72 hours post-formalin injection and an analysis of the spinal NR2B expression was performed.
RESULTS: DM rats showed a significant reduction in pain threshold in response to the tactile and thermal stimuli and higher nociceptive response during the formalin test accompanied by the higher expression of phosphorylated spinal NR2B in both sides of the spinal cord. Ifenprodil treatment for both doses showed anti-allodynic and anti-nociceptive effects with lower expression of phosphorylated and total spinal NR2B.
CONCLUSION: We suggest that the pain process in the streptozotocin-induced diabetic rat that has been modulated is associated with the higher phosphorylation of the spinal NR2B expression in the development of PDN, which is similar to other models of neuropathic rats.
METHODS: Fifty adult male Sprague Dawley (SD) rats were randomly allocated to 1 of 5 groups: control, LPS (5 mg/kg), LPS + minocycline (25 mg/kg), LPS + minocycline (50 mg/kg) and LPS + memantine (10 mg/kg). Minocycline and memantine were administered intraperitoneally (i.p) for two weeks, and LPS was injected i.p. once on day 5. ELISA was used to determine the level of phosphorylated tau protein in SD rats' hippocampal tissue. The density and expression of Toll-like receptor-4 (TLR-4), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-кβ), tumour necrosis factor-alpha (TNF-α), and cyclooxygenase (COX)-2 were determined using Western blot and immunohistochemistry.
RESULTS: Minocycline, like memantine, prevented LPS-induced increasein phosphorylated tau protein level suggested via reduced density and expression of TLR-4, NF-кβ, TNF-αand COX-2 proteins in rat hippocampal tissue. Interestingly, higher doses were shown to be more neuroprotective than lower doses.
CONCLUSION: This study suggests that minocycline suppresses the neuroinflammation signalling pathway and decreased phosphorylated tau protein formation induced by LPS in a dose-dependent manner. Minocycline can be used as a preventative and therapeutic drug for neuroinflammatory diseases such as AD.
MATERIALS AND METHODS: Fifty adult Male Sprague Dawley rats were divided into five groups: control, LPS (5 mg/kg), LPS treated with minocycline (25 mg/kg), LPS treated with minocycline (50 mg/kg) and LPS treated with memantine (10 mg/kg). The immunohistochemistry and western blotting were used to analyse the expressions and densities of microglia marker (Iba-1) and astrocyte marker, (GFAP) while enzyme-linked immunosorbent assay (ELISA) was used to measure the protein carbonyl (PCO), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) levels.
RESULTS: In comparison to the control group, the expression and density of Iba-1 and GFAP were significantly enhanced in the LPS group (p