Studies on the thoracic stretch receptor organ of Manduca sexta and effects of octopamine and demethylchlordimeform on the activity of the stretch receptor

Call number: LD2668 .T4 1986 J86Master of ScienceBiolog

Effect of tocotrienol rich fraction (TRF) on muscles reinnervation after sciatic nerve crush injury in rats

Introduction: Muscle denervation is a process where muscles lose nerve supply due to neural damage and this may lead to paralysis in human. Muscle denervation is mainly caused by peripheral nerve injuries especially in the lower extremities that resulted in devastating effect on human daily functions and routines. Tocotrienol Rich Fraction (TRF) consist of 75% of tocotrienols have shown potential neuroprotective properties. The objective of this study is to observe motor coordination and histological characteristics on muscles that underwent sciatic nerve crush injury and supplemented with TRF. Methods: A total of 104 Sprague-Dawley rats were divided into four groups; normal group (n=8) with no sciatic nerve crush injury, negative control (n=32) with sciatic nerve crush injury at hindlimb without treatment, positive control (n=32) sciatic nerve crush injury treated with 500 μg/kg/day of methylcobalamin, and experimental group (n=32) of rats that underwent sciatic nerve crush injury and treated with 200 mg/kg/day of TRF. Result: Skeletal muscles which located at hind limb; Soleus Muscle and Extenstor Digitorum Longus Muscle (EDL) muscle have shown an increasing in weight when it is supplemented with TRF 200 mg/kg/day and improved myelin layer of nerve. Conclusion: This study showed that TRF has the potency to improve reinnervation rate and neuron supply in hind muscle

Effects of oil palm tocotrienol rich fraction on the viability and morphology of astrocytes injured with glutamate

Tocotrienol-rich fraction (TRF) is an extract of palm oil that consists of 25% α-tocopherol and 75% tocotrienols. TRF was shown to possess antioxidant, anti-inflammatory, anticancer, neuroprotective and cholesterol-lowering activities. Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. Hence, the efficacy of oil palm TRF and α-tocopherol in protecting astrocytes against glutamate-induced cell death was studied. Specifically, the effectiveness of pre- or post-treatment of TRF and α-tocopherol upon glutamate excitotoxicity was determined by evaluating cell viability and morphology of astrocytes. Cell viability was measured using MTT assay while cell morphology was monitored under fluorescent microscope using the acridine orange/propidium iodide (AO/PI) assay. Exposure to 230 mM glutamate significantly reduced cell viability to 50% in both the pre- and post-treatment studies; however, pre- and post-treatment with TRF and α-tocopherol attenuated the cytotoxic effect of glutamate. Compared to glutamate-injured astrocytes, pre-treatment with 100, 200 and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 86.6%, 86.7% and 93.9%, respectively (p < 0.05). On the contrary, high concentrations of α-tocopherol promote cell death. This study shows that TRF not only provide a better protection against glutamate toxicity (pre-treatment), but was also able to reverse the lipid peroxidation resulting from glutamate insults (post-treatment). The present results demonstrate that TRF, but not α-tocopherol, protected the astrocytes against glutamate-induced cell death, indicating its neuro-protective potential

Neuroprotective potential of Spirulina platensis on lesioned spinal cord corticospinal tract under experimental conditions in rat models

Spinal cord injury (SCI) results from penetrating or compressive traumatic injury to the spine in humans or by the surgical compression of the spinal cord in experimental animals. In this study, the neuroprotective potential of Spirulina platensis was investigated on ultrastructural and functional recovery of the spinal cord following surgical-induced injury. Twenty-four Sprague-Dawley rats were divided into three groups; sham group, control (trauma) group, and experimental (S. platensis) group (180 mg/kg) of eight rats each. For each group, the rats were then subdivided into two groups to allow measurement at two different timepoints (day 14 and 28) for the microscopic analysis. Rats in the control and experimental S. platensis groups were subjected to partial crush injury at the level of T12 with Inox number 2 modified forceps by compressing on the spinal cord for 30 s. Pairwise comparisons of ultrastructural grading mean scores difference between the control and experimental S. platensis groups reveals that there were significant differences on the axonal ultrastructure, myelin sheath and BBB Score on Day 28; these correlate with the functional locomotor recovery at this timepoint. The results suggest that supplementation with S. platensis induces functional recovery and effective preservation of the spinal cord ultrastructure after SCI. These findings will open new potential avenue for further research into the mechanism of S. platensis-mediated spinal cord repair. © 2019, © 2019 Taylor & Francis Group, LLC

The Effect of Camellia sinensis on Wound Healing Potential in an Animal Model

Camellia sinensis (tea) is reported to have health benefits, including the building of healthy skin. This study evaluated the effects of topical application of Camellia sinensis extract on the rate of wound closure and the histology of wound area. A uniform area of 2.00 cm in diameter was excised from the neck of adult male Sprague Dawley rats. The animals were topically treated with 0.2 mL of vehicle (CMC), Intrasite gel (positive control), or 200 and 400 mg/mL of extract. Wounds dressed with the extract and Intrasite gel healed significantly earlier than those with vehicle. Histological analysis of the wound area after 10 days showed that wounds dressed with the extract had less scar width when compared to the control. The tissue contained less inflammatory cells and more collagen and angiogenesis, compared to wounds dressed with vehicle. In this study, Camellia sinensis showed high potential in wound healing activity

Ultrastructural comparison of three stingless bees species of Borneo

Three species of stingless bees were collected from Borneo. The species were Geniotrigona lacteifasciata (4 samples), Tetragonula melanocephala (2 samples) and Tetragonula sirindhornae (4 samples). Several features such as the morphology of mandible, the shape and size of corbiculae, and the hamuli number on both left and right wings were compared. Scanning electron microscopy (SEM) revealed all three species have the same structures of mandibles with two pointed tooth and one large blade, which could be considered as mildly aggressive. G. lacteifasciata showed a wider corbiculae compared to T. melanocephala and T. sirindhornae. The larger corbiculae is assumed to collect and carry heavier pollen load. SEM observation showed clear hamuli on both wings but with asymmetrical number for some. G. lactefasciata showed either 9 hamuli on both wings, or 9 hamuli on the left and 8 on the right wings, or 9 hamuli on the left and 10 hamuli on the right wings. T. melanocephala exhibited a similar number of hamuli, which was 5 hamuli on both wings. T. sirindhornae showed either 4 or 5 hamuli on both side of wings. It could be assumed that the stingless bees with more hamuli will fly further for foraging

Behavioral and Histopathological Study of Changes in Spinal Cord Injured Rats Supplemented with Spirulina platensis

Spinal cord injury (SCI) is a devastating disease that leads to permanent disability and causes great suffering. The resulting neurological dysfunction and paralysis is proportional to the severity of the trauma itself. Spirulina is widely used as a nutritional supplement due to its high protein and antioxidant content. In the present study, the protective effect of the Spirulina treatment on locomotor function and morphological damage after SCI was investigated. Seventy Sprague-Dawley (SD) rats were divided into three groups: Sham (laminectomy alone), Control (laminectomy with SCI), and Experimental (laminectomy with SCI +180 mg/kg per day Spirulina platensis). A laminectomy was performed at T12 and an Inox No.2 modified forceps was used to perform a partial crush injury on the spinal cord. The rats were then perfused at 3, 7, 14, 21, and 28 days after injury for morphological investigations. The injured rat spinal cord indicated a presence of hemorrhage, cavity, and necrosis. Pretreatment with Spirulina significantly improved the locomotor function and showed a significant reduction on the histological changes. The experimental results observed in this study suggest that treatment with Spirulina platensis possesses potential benefits in improving hind limb locomotor function and reducing morphological damage to the spinal cord