METHODS: The Trypan blue viability assay used to examine cell death. Immunofluorescence assay, glial fibrillary acidic protein (GFAP) was used to portray the morphology of astrocytes. The hypoxia-inducible factor 1 (HIF-1) staining was performed to confirm hypoxia induced cell death and there was a dramatic expression of HIF-1α displayed in exposed astrocyte cells compared to the control. In molecular level, genes were chosen, such as glyceraldehyde 3-phosphate dehydrogenase (GAPDH), GFAP, HIF-1α and B-cell lymphoma 2 (Bcl-2) and ran the reverse transcription-polymerase chain reaction (RT-PCR).
RESULTS: Microscope revealed a filamentous and clear nucleus appearance in a control whereas the rupture nuclei with no rigid structure of the cell were found in the 3% oxygen. The control and hypoxia cells were also stained with the annexin V-fluorescein isothiocyanate (annexin V-FITC). Fluorescence microscope reveals astrocyte cells after hypoxia showed higher expression of nuclei but not in control. Merging PI and FITC showed the differences of nuclei expression between the control and hypoxia. In the molecular analysis, there were significant changes of GFAP, HIF-1α and Bcl-2 in hypoxia exposed cells when compared to the control group.
CONCLUSION: Cells that were exposed to hypoxia (3% oxygen for 15 min) clearly showed damage. General view of human hippocampal astrocyte genomic response to hypoxia was obtained.
Materials and Methods: The rats were divided into four groups: i) Normoxia treated with sucrose (n=12), ii) Normoxia treated with Tualang honey (n=12), iii) Hypoxia treated with sucrose (n=12), and iv) Hypoxia treated with Tualang honey (n=12). Tualang honey (0.2 g/kg/BW) and sucrose (1 mL of 7.9%) supplementations were administered orally to the rats daily for 14 days. Then the hypoxia groups were exposed to hypoxia (~11%) for 7 days, while the normoxia groups were kept in normal conditions. Following exposure to hypoxia, the rats' memories were analyzed using a novel object recognition task and T-maze test.
Results: The data revealed that rats exposed to hypoxia showed significant impairment in short-term memory (STM), spatial memory (p<0.01), and long-term memory (LTM) when compared to the normoxia group. Hypoxia rats treated with Tualang honey showed significant improvement in STM, LTM, and spatial memory (p<0.05) compared with those treated with sucrose (p<0.05). Tualang honey also reduced neuronal damage in the hippocampus of adult male Sprague Dawley rats exposed to hypoxia.
Conclusion: It is suggested that Tualang honey pretreatment has protective effects against hypoxia-induced memory deficits, possibly through its antioxidant contents.
METHODS: The locomotor activity, learning, and memory were assessed by using open field test and water T-maze test. This study also examined changes in neuronal cell morphology using cresyl violet and apoptosis staining. We also performed immunohistochemical study to analyse the expression of the glutamate AMPA receptor (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) GluA1 subunit and the GABA receptor (γ-Aminobutyric Acid) subtype GABAA α1 subunit in the hippocampus of the same animals.
RESULTS: We found no significant changes in locomotor activity (p > 0.05). The water T-maze data showed that 30 mg/kg dose significantly (p 0.05). Histological data revealed no neuronal morphological changes. Immunohistochemical analysis revealed increased expression of the AMPA GluA1 receptor subunit but there was no effect on GABAA receptor α1 subunit expression in the CA1 and CA2 subregions of the hippocampus.
CONCLUSIONS: The C. asiatica extract therefore improved hippocampus-dependent spatial learning and memory in a dose-dependent manner in rats through the GluA1-containing AMPA receptor in the CA1 and CA2 sub regions of the hippocampus.