g-Tocotrienol does not substantially protect DS neurons from hydrogen peroxide-induced oxidative ... more g-Tocotrienol does not substantially protect DS neurons from hydrogen peroxide-induced oxidative injury
Experimental and Theoretical NANOTECHNOLOGY, May 15, 2017
Deoxyribonucleic acid (DNA) extraction or sample preparation from biological sample (whole blood)... more Deoxyribonucleic acid (DNA) extraction or sample preparation from biological sample (whole blood) for downstream process on microfluidic platform has been widely studied due to its crucial role in clinical diagnostic and genetic analysis. Sample preparation can be complicated since blood comprises complex matrices and repeated blood pricking from patients can be affected their health. Thus, introduction of solid-phase microextraction (SPME) method would be suitable to isolate, fractionate and concentrate the analyte from complex sample matrices and implemented on microfluidic device with small amount of sample. SPME is an effective sample preparation method by chemical lysis followed by purification mostly by using silica-based platform developed based on direct absorption into silica resins and desorption of analyte from silica resins.
The open conference proceedings journal, Mar 1, 2013
Background: Piper betle (PB) leaves (daun sirih in Malay language) extract has been demonstrated ... more Background: Piper betle (PB) leaves (daun sirih in Malay language) extract has been demonstrated to have anticarcinogenic activities in the experimental systems. It has been found the PB leaves extract could enhance the cytotoxic effect of other anticancer drugs in cancer cells. The aim of this study is to investigate the combination effect of PB and 5-fluorouracil (5-FU) in enhancing the cytotoxic potential using colon cancer cell lines. Methods: We first examined the effect of PB leaves extract on colon cancer cells. Next, we examined whether PB leaves extract could increase the sensitivity of the cells to 5-FU. Isobologram analysis was carried out to elucidate PB-5FU interaction. Apoptotic features of the treated cells were then revealed by Annexin V/ PI stain. HPLC was performed to exclude any possible chemical interaction between the compounds. Result: IC50 of 5-FU treated HT 29 and HCT 116 was 130.0µM and 12.5µM, respectively at 72 hours. IC50 of PB-treated HT 29 (200.0µg/ml) and HCT 116 cells (187.5µg/ml) was observed after 36 hours of treatment. In the presence of PB extract, the cytotoxic effect of 5-FU was observed at a lower dose (12.5µM) and a shorter time (24 hours). HT 29 and HCT 116 cells treated with 5-FU or PB alone induced a greater apoptosis effect compared to the combination treatment. Isobologram analysis indicated PB and 5-FU interacted synergistically in HT 29 cells, but antagonistically in HCT 116 cells. Mixture of 5-FU and PB sample did not show any interaction revealed by HPLC separation. Conclusion: In the presence of PB, a lower dosage of 5-FU is required to achieve the maximum drug effect. PB works synergistically with 5-FU in controlling cancer cell growth. However our current result showed this interaction may not solely contribute to the apoptosis pathway. Further investigation should be performed to elucidate the possible mechanism.
Tocopherols and tocotrienols have been shown in previous studies to protect neurons from oxidativ... more Tocopherols and tocotrienols have been shown in previous studies to protect neurons from oxidative injuries, especially from hydrogen peroxide (H 2 O 2) and buthionine sulfoximine (BSO) induced oxidative stress. In this study, we compared two vitamin E isomers, γ-tocotrienol (GTT) and α-tocopherol (ATF) in their neuroprotective effects against H 2 O 2-induced apoptosis in primary rat cortical neurons and human neuroblastoma cell line SH-SY5Y. Cytotoxicity screening of H 2 O 2 , GTT and ATF was done to determine the IC 50 levels. To screen for neuroprotective effects, cortical neurons and SH-SY5Y cell cultures were pre-incubated with GTT or ATF, respectively at different concentrations for 1 hour before concurrent treatment of H 2 O 2 at IC 50. Results of these treatments were compared to cells treated with H 2 O 2 only and control cells. Cytotoxicology screening showed that IC 50 of H 2 O 2 for cortical neuron is at 50 µM while SH-SY5Y have higher IC 50 of 100 µM. GTT is cytotoxic to cortical neurons at ≥50 µM and SH-SY5Y at ≥100 µM while ATF did not show any toxicity within the range of concentration tested (1-750 µM). Results from neuroprotection screening showed that GTT and ATF were able to protect both cortical neurons and SH-SY5Y from H 2 O 2-induced oxidative stress at concetration of ≤10 µM. Cellular uptake of GTT is higher in both cortical neurons and SH-SY5Y as compared to ATF when both cortical neuron and SH-SY5Y were incubated with 10 µM GTT or ATF, respectively for 24 hour. Although primary rat cortical neurons and human neuroblastoma SH-SY5Y were different culture system, the effects of GTT and ATF are similar in both H 2 O 2-induced culture which strongly suggest that both GTT and ATF act as free radical scavenger to exert their neuroprotective effects.
Tocopherols and tocotrienols have been shown in previous studies to protect neurons from oxidativ... more Tocopherols and tocotrienols have been shown in previous studies to protect neurons from oxidative injuries, especially from hydrogen peroxide (H 2 O 2) and buthionine sulfoximine (BSO) induced oxidative stress. In this study, we compared two vitamin E isomers, γ-tocotrienol (GTT) and α-tocopherol (ATF) in their neuroprotective effects against H 2 O 2-induced apoptosis in primary rat cortical neurons and human neuroblastoma cell line SH-SY5Y. Cytotoxicity screening of H 2 O 2 , GTT and ATF was done to determine the IC 50 levels. To screen for neuroprotective effects, cortical neurons and SH-SY5Y cell cultures were pre-incubated with GTT or ATF, respectively at different concentrations for 1 hour before concurrent treatment of H 2 O 2 at IC 50. Results of these treatments were compared to cells treated with H 2 O 2 only and control cells. Cytotoxicology screening showed that IC 50 of H 2 O 2 for cortical neuron is at 50 µM while SH-SY5Y have higher IC 50 of 100 µM. GTT is cytotoxic to cortical neurons at ≥50 µM and SH-SY5Y at ≥100 µM while ATF did not show any toxicity within the range of concentration tested (1-750 µM). Results from neuroprotection screening showed that GTT and ATF were able to protect both cortical neurons and SH-SY5Y from H 2 O 2-induced oxidative stress at concetration of ≤10 µM. Cellular uptake of GTT is higher in both cortical neurons and SH-SY5Y as compared to ATF when both cortical neuron and SH-SY5Y were incubated with 10 µM GTT or ATF, respectively for 24 hour. Although primary rat cortical neurons and human neuroblastoma SH-SY5Y were different culture system, the effects of GTT and ATF are similar in both H 2 O 2-induced culture which strongly suggest that both GTT and ATF act as free radical scavenger to exert their neuroprotective effects.
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