Recovery of neurosurgical high-frequency electroporation injury in the canine brain can be accelerated by 7,8-dihydroxyflavone.

BACKGROUND: Although traumatic brain injury (TBI) occurs in a very short time, the biological consequence of a TBI, such as Alzheimer's disease, may last a lifetime. To date, effective interventions are not available to improve recovery from a TBI. Herein we aimed to ascertain whether recovery of neurosurgical high-frequency irreversible electroporation (HFIRE) injury in brain tissues can be accelerated by 7,8-dihydroxyflavone (7,8-DHF). METHODS: The HFIRE injury was induced in the right parietal cortex of 8 adult healthy and neurologically intact male dogs. Two weeks before HFIRE injury, each dog was administered orally with or without 7,8-DHF (30 mg/kg) once daily for consecutive 2 weeks (n = 4 for each group). The values of blood-brain barrier (BBB) disruption, brain edema, and cerebral infarction volumes were measured. The concentrations of beta-amyloid, interleukin-1ß, interleukin-6 and tumor necrosis factor-α in the cerebrospinal fluid were measured biochemically. RESULTS: The BBB disruption, brain edema, infarction volumes, and maximal cross-section area caused by HFIRE injury in canine brain were significantly attenuated by 7,8-DHF therapy (P < 0.0001). Additionally, 7,8-DHF significantly reduced the HFIRE-induced cerebral overproduction of beta-amyloid and proinflammatory cytokines in the cerebrospinal fluid (P < 0.0001) in dogs with HFIRE. CONCLUSIONS: Recovery of neurosurgical HFIRE injury in canine brain tissues can be accelerated by 7,8-DHT via ameliorating BBB disruption as well as cerebral overproduction of both beta-amyloid and proinflammatory cytokines.

7,8-Dihydroxyflavone accelerates recovery of Brown-Sequard syndrome in adult female rats with spinal cord lateral hemisection.

BACKGROUND: 7,8-Dihydroxyflavone (DHF) mimicks the physiological action of brain-derived neurotrophic factor (BDNF). Since local BDNF delivery to the injured spinal cord enhanced diaphragmatic respiratory function, we aimed to ascertain whether DHF might have similar beneficial effects after Brown-Sequard Syndrome in a rat model of spinal cord lateral hemisection (HX) at the 9th thoracic (T9) vertebral level. METHODS: Three sets of adult female rats were included: sham+vehicle group, T9HX+vehicle group and T9HX+DHF group. On the day of surgery, HX+DHF group received DHF (5 mg/kg) while HX+vehicle group received vehicle. Neurobehavioral function, morphology of motor neurons innervating the tibialis anterior muscle and the transmission in descending motor pathways were evaluated. RESULTS: Adult female rats received T9 HX had paralysis and loss of proprioception on the same side as the injury and loss of pain and temperature on the opposite side. We found that, in this model of Brown-Sequard syndrome, reduced cord dendritic arbor complexity, reduced cord motoneuron numbers, enlarged cord lesion volumes, reduced motor evoked potentials, and cord astrogliosis and microgliosis were noted after T9HX. All of the above-mentioned disorders showed recovery by Day 28 after surgery. Therapy with DHF significantly accelerated the electrophysiological, histological and functional recovery in these T9HX animals. CONCLUSIONS: Our data provide a biological basis for DHF as a neurotherapeutic agent to improve recovery after a Brown-Sequard syndrome. Such an effect may be mediated by synaptic plasticity and glia-mediated inflammation in the spared lumbar motoneuron pools to a T9HX.

[Ruifuping pectin protects against intestinal mucosal injury in the rat exertional heat stroke model].

OBJECTIVE: To evaluate the intestinal function in rats with exertional heat stroke (EHS) and explore the protective role of Ruifuping pectin (RFP) against heat related intestinal mucosal injury. METHODS: One hundred and twenty healthy special pathogen free (SPF) male Sprague-Dawley (SD) rats were randomly divided into normothermic control group, EHS model group, hyperthermic plus drinking water group (H2O+EHS group) and hyperthermic plus pectin group (RFP+EHS group) with 30 rats in each group. The rats in the H2O+EHS group and RFP+EHS group were given water 20 mL/kg or RFP 20 mL/kg orally for 5 days during adaptive training period. After 1 week, the temperature control range was adjusted to (37±1) centigrade using the temperature control treadmill, and the rat model of EHS was reproduced by one-time high temperature exhaustive exercise. No rehydration intervention was given during the training adaptation period in the EHS model group. The rats in the normothermic control group were maintained to room temperature (25±2) centigrade and humidity (55±5)% without other treatment. Behavior tests including withdraw response, righting, and muscle strength were performed immediately after onset of EHS. Blood of inferior vena cava was collected, and the serum inflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-1ß, IL-10)] and activity of diamine oxidase (DAO) were detected by enzyme linked immunosorbent assay (ELISA). The intestinal mucosa was collected, after hematoxylin-eosin (HE) staining, and Chiu score was performed to assess EHS induced pathological changes under light microscope. RESULTS: The rats in the EHS model group had behavioral, inflammatory and pathological changes, such as delayed withdraw response and righting, decreased forelimb pulling, increased inflammatory index, and obvious intestinal mucosal injury, which indicated that the reproduction of the EHS model was successful. There was no significant difference in above parameters between the H2O+EHS group and the EHS model group except that the inflammatory index in the RFP+EHS group was improved. Compared with the EHS model group, the withdraw reflex to pain and righting after RFP pretreatment in the RFP+EHS group were significantly improved (righting score: 1.4±0.2 vs. 0.3±0.2, withdraw reflex to pain score: 1.0±0.1 vs. 0.2±0.1, both P < 0.05), the muscle strength was significantly increased (N: 13.0±0.5 vs. 8.2±0.6, P < 0.01). The levels of pro-inflammatory factors in the RFP+EHS group were significantly lower than those in the EHS model group [TNF-α (ng/L): 67.5±9.2 vs. 194.3±13.7, IL-6 (ng/L): 360.0±54.1 vs. 981.2±84.4, IL-1ß (ng/L): 33.7±9.0 vs. 88.7±6.1, all P < 0.01], while the level of anti-inflammatory factor IL-10 was higher than that in the EHS model group (ng/L: 208.7±10.5 vs. 103.7±7.0, P < 0.01). The degree of intestinal mucosal injury in the RFP+EHS group was less severe than that in the EHS model group, and the Chiu score and DAO were significantly lower than those in the EHS model group [Chiu score: 1.5±0.2 vs. 3.8±0.0, DAO (U/L): 83.7±6.7 vs. 128.7±10.5, both P < 0.05]. CONCLUSIONS: High temperature training can damage the intestinal barrier function, and induce endotoxemia and systemic inflammatory response syndrome (SIRS) in rats. Oral prophylactic RFP can protect the intestinal barrier function, alleviate SIRS, and promote the recovery of basic nerve reflex and muscle strength after the occurrence of EHS in rats.