Sarawut Junnu

Protective effect of mangosteen extract against beta-amyloid-induced cytotoxicity, oxidative stress and altered proteome in SK-N-SH cells.

Beta-amyloid (A beta) plays a key role in the pathogenesis of Alzheimers disease (AD) by inducing neurotoxicity and cell death mainly through production of reactive oxygen species (ROS). Garcinia mangostana L. (mangosteen) has been recognized as a major source of natural antioxidants that could decrease ROS. However, its role in protection of A beta-induced cytotoxicity and apoptosis in neuronal cells remains unclear. We therefore examined such a protective effect of mangosteen extract (ME) by evaluating cell viability using MTT test, ROS level, caspase-3 activity, and cellular proteome. Treating SK-N-SH cells with 5-20 microM A beta((1-42)) for 24 h caused morphologically cytotoxic changes, decreased cell viability and increased ROS level, whereas preincubation with 50-400 microg/mL ME 30 min before the induction by A beta((1-42)) successfully prevented such cytotoxic effects in a dose-dependent manner (completely at 400 microg/mL). The A beta-induced increase in caspase-3 activity was also preventable by 400 microg/mL ME. Proteomic analysis using 2-D gel electrophoresis (n = 5 gels/group) followed by mass spectrometry revealed 63 proteins whose levels were significantly altered by A beta((1-42)) induction. Interestingly, changes in 10 proteins were successfully prevented by the ME pretreatment. In summary, we report herein the significant protective effects of ME against A beta-induced cytotoxicity, increased ROS, and increased caspase activity in SK-N-SH cells. Moreover, proteomic analysis revealed some proteins that might be responsible for these protective effects by ME. Further characterizations of these proteins may lead to identification of novel therapeutic targets for successful prevention and/or decreasing the severity of AD.

Protective Effects of Mangosteen Extract on H2O2-Induced Cytotoxicity in SK-N-SH Cells and Scopolamine-Induced Memory Impairment in Mice

Mangosteen extracts (ME) contain high levels of polyphenolic compounds and antioxidant activity. Protective effects of ME against β-amyloid peptide (Aβ), induced cytotoxicity have been reported. Here, we further studied the protective effects of ME against oxidative stress induced by hydrogen peroxide (H2O2) and polychlorinated biphenyls (PCBs), and demonstrated the protection against memory impairment in mice. The cytoprotective effects of ME were measured as cell viability and the reduction in ROS activity. In SK-N-SH cell cultures, 200 μg/ml ME could partially antagonize the effects of 150 or 300 µM H2O2 on cell viability, ROS level and caspase-3 activity. At 200, 400 or 800 µg/ml, ME reduced AChE activity of SK-N-SH cells to about 60% of the control. In vivo study, Morris water maze and passive avoidance tests were used to assess the memory of the animals. ME, especially at 100 mg/kg body weight, could improve the animal’s memory and also antagonize the effect of scopolamine on memory. The increase in ROS level and caspase-3 activity in the brain of scopolamine-treated mice were antagonized by the ME treatment. The study demonstrated cytoprotective effects of ME against H2O2 and PCB-52 toxicity and having AChE inhibitory effect in cell culture. ME treatment in mice could attenuate scopolamine-induced memory deficit and oxidative stress in brain.

The platelet amyloid precursor protein ratio as a diagnostic marker for Alzheimer’s disease in Thai patients

The platelet amyloid precursor protein (APP) ratio has recently been shown to be a promising diagnostic marker for Alzheimers disease (AD). To evaluate its usefulness in Thai patients, platelet APP was analyzed by immunoblotting. The APP ratio was calculated as the ratio of the combined band density of the 120-kD and 130-kD isoforms compared to that of the 110-kD isoform. The mean ages (and ranges) of 27 normal and 13 AD-affected subjects were 68.3 (60-84) and 79.3 (70-97) years, respectively. The Thai Mental State Examination (TMSE) scores demonstrated that the AD patients had significantly poorer cognitive functions than the normal subjects, with mean TMSE scores of 20.3 and 27.6 (maximum score of 30 points), respectively (p<0.05). The platelet APP ratios of the AD patients were significantly lower than those of normal subjects: values (mean ± standard deviation) were 7.32 ± 1.29 and 9.13 ± 3.00, respectively (p<0.05) for AD patients and normal subjects. However, the ranges of the APP ratios from both groups markedly overlapped, which precluded the establishment of a cutoff level to differentiate between the AD and normal subjects. In addition, no significant correlations were observed between the platelet APP ratio and the TMSE score or between the APP ratio and the serum cholesterol in this study, in contrast to previous reports.

Potent antioxidant and anti-apoptotic activity of pre-germinated brown rice extract against hydrogen peroxide in neuronal SK-N-SH cells: A model of Alzheimer's disease

months) participating in a longitudinal study of risk factors for Alzheimer’s disease.The Mini-Mental State Examination (MMSE) was used to measure the rate of cognitive decline. Logistic regression, controlling for age, gender, education and race assessed the relationship between kidney function and cognitive change from baseline to last assessment.Results: The association of GFRwith rate of cognitive declinewas not significant. Since prior studies suggest that cognitive status at baseline might affect the association of a risk factor with rate of cognitive decline, we stratified the sample by the clinical dementia rating scale (CDR). The association remained non-significant in non-demented, questionably demented, or demented subjects. Since there is growing evidence suggesting that effect of cardiovascular risk factors on cognitive decline is stronger in younger elderly, we also stratified the sample by age (<85 or 85) but results remained non-significant in both age groups. Data on presence of hypertension or diabetes was available for 238 subjects. Controlling for these factors in the analysis, did not affect the results.Conclusions: In a sample of very elderly subjects, impaired kidney function is not associated with rate of cognitive decline. Discrepancies between our results and those reported by others may derive from differences in the sample’s age, methodology used for measuring cognitive impairment or the measurement used to capture kidney function.

In vitro Culture and Histological Characterization of Extracted Human Hair Follicles

Background: In vitro-cultured hair, follicles can serve as an excellent model system for exploring the hair follicle biology as well as drug delivery targets. In this study, we aimed to investigate how to maintain whole human hair follicles in vitro and histologically characterize the hair follicles thereof. Methods: Donated hair follicle specimens from hair transplant operation were cultured in vitro using a medium consisting of Williams` medium E, L-glutamine, insulin, hydrocortisone, penicillin, streptomycin, and amphotericin B. The growth of hair follicles was examined daily using a digital microscope. Their histological features were studied at day 0, 7, and 14 to characterize the changes of hair follicles maintained in culture. Results: Cultured hair follicles continued to grow at a rate of about 200 μm/day during the first four days. Then the growth rate declined and stopped after an average (range) of 8.4 (7-11) days in culture. Histological study showed an upward regression of the hair follicles with scattered apoptosis of outer root sheath cells, resembling the follicles in a catagen stage. Conclusion: Human hair follicles can be cultured in vitro for at least 7 days before progressing to catagen.