The leaves of Mitragyna speciosa Korth (M. speciosa), commonly known as ketum in Malaysia, have b... more The leaves of Mitragyna speciosa Korth (M. speciosa), commonly known as ketum in Malaysia, have been widely used to treat common illnesses such as intestinal infections, muscle pain, cough, diarrhea, diabetes, hypertension and to improve blood circulation. Nevertheless, there are growing concerns about the safety and abuse or misuse potentials of the plant which exhibits addictive effects. The safety profile of the plant is not fully elucidated. The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit underlying cardiac rapidly delayed rectifier potassium current (IKr)
International Journal of Environmental Research and Public Health, 2021
Malaysia implemented its first Movement Control Order (MCO) during the early phase of the COVID-1... more Malaysia implemented its first Movement Control Order (MCO) during the early phase of the COVID-19 pandemic to slow the transmission of the virus. This study aimed to explore the public perception of the MCO implementation and people’s experiences during this period. The study employed qualitative explorative in-depth interviews conducted with 23 Malaysian adults from various demographic backgrounds. Thematic analysis was performed using NVivo 12. Three main themes were identified: a period of information surge, heterogeneous emotional response, and attempts to adapt. During the MCO, the participants obtained information from multiple platforms. They suggested the need for clear and repeated instructions to avoid confusion and misinformation. They also acknowledged the importance of the MCO in breaking the chain of transmission and safeguarding high-risk groups; however, they also expressed that stricter enforcement from the authorities was warranted. The changes in the participants...
Background Combating viral outbreaks extends beyond biomedical and clinical approaches; thus, pub... more Background Combating viral outbreaks extends beyond biomedical and clinical approaches; thus, public health prevention measures are equally important. Public engagement in preventive efforts can be viewed as the social responsibility of individuals in controlling an infectious disease and are subjected to change due to human behaviour. Understanding individuals’ perception of social responsibility is crucial and is not yet explored extensively in the academic literature. We adopted the grounded theory method to develop an explanatory substantive theory to illustrate the process of how individual responded to the outbreak from a social responsibility perspective. Methods In-depth interviews were conducted among 23 Malaysians either through telephone or face-to-face depending on the participant’s preference. Both purposive and theoretical sampling were used. Participants were invited to share their understanding, perceptions and activities during the COVID-19 pandemic. They were furth...
Background Home visiting services for older adults have been offered for decades to maintain and ... more Background Home visiting services for older adults have been offered for decades to maintain and promote health and independent functioning, thus enhancing quality of life. Previous systematic reviews have provided a mixed picture of the benefits of home visiting programmes in older adults, primarily because of heterogeneity in study designs, targeted populations, and intervention strategies. These reviews may also become out of date; thus, an updated synthesis of relevant studies is warranted. Our objective is to perform a systematic review of recently published primary studies on the effectiveness of multi-professional home visits on quality of life among older adults. Methods We will perform a comprehensive search for studies investigating the effect of a multi-professional home visit approach on quality of life among older adults. We will conduct the literature search in selected electronic databases and relevant research websites from January 2010 onwards. We will include rando...
Mitragyna speciosa Korth (M. speciosa) has been widely used as a recreational product, however, t... more Mitragyna speciosa Korth (M. speciosa) has been widely used as a recreational product, however, there are growing concerns on the abuse potentials and toxicity of the plant. Several poisoning and fatal cases involving kratom and mitragynine have been reported but the underlying causes remain unclear. The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit underlying cardiac rapidly delayed rectifier potassium current (IKr). Pharmacological blockade of the IKr can cause acquired long QT syndrome, leading to lethal cardiac arrhythmias. This study aims to elucidate the mechanisms of mitragynine-induced inhibition on hERG1a/1b current. Electrophysiology experiments were carried out using Port-a-Patch system. Quantitative RT-PCR, Western blot analysis, immunofluorescence and co-immunoprecipitation methods were used to determine the effects of mitragynine on hERG1a/1b expression and hERG1-cytosolic chaperones interaction. Mitragynine was found to inhibit the IKr cu...
Mitragyna speciosa Korth is known for its euphoric properties and is frequently used for recreati... more Mitragyna speciosa Korth is known for its euphoric properties and is frequently used for recreational purposes. Several poisoning and fatal cases involving mitragynine have been reported but the underlying causes remain unclear. Human ether-a-go-go-related gene (hERG) encodes the cardiac IKr current which is a determinant of the duration of ventricular action potentials and QT interval. On the other hand, IK1, a Kir current mediated by Kir2.1 channel and IKACh, a receptor-activated Kir current mediated by GIRK channel are also known to be important in maintaining the cardiac function. This study investigated the effects of mitragynine on the current, mRNA and protein expression of hERG channel in hERG-transfected HEK293 cells and Xenopus oocytes. The effects on Kir2.1 and GIRK channels currents were also determined in the oocytes. The hERG tail currents following depolarization pulses were inhibited by mitragynine with an IC50 value of 1.62μM and 1.15μM in the transfected cell line ...
A cell-based assay to measure cytochrome P450 3A4 (CYP3A4) induction was developed to screen for ... more A cell-based assay to measure cytochrome P450 3A4 (CYP3A4) induction was developed to screen for potential CYP3A4 inducers. This 96-well format assay utilizes HepG2 cells transfected with a gene construct of CYP3A4 proximal promoter linked to green fluorescence protein (GFP) gene, and the expression of the GFP is then measured quantitatively. Bergamottin at 5 to 25 µmol/L produced low induction relative to the positive control. Both curcumin and lycopene were not found to affect the expression of GFP, suggesting no induction properties toward CYP3A4. Interestingly, resveratrol produced significant induction from 25 µmol/L onward, which was similar to omeprazole and may warrant further studies. In conclusion, the present study demonstrated that this cell-based assay can be used as a tool to evaluate the potential CYP3A4 induction properties of compounds. However, molecular docking data have not provided satisfactory pointers to differentiate between CYP3A4 inducers from noninducers o...
The leaves of Mitragyna speciosa Korth (M. speciosa), commonly known as ketum in Malaysia, have b... more The leaves of Mitragyna speciosa Korth (M. speciosa), commonly known as ketum in Malaysia, have been widely used to treat common illnesses such as intestinal infections, muscle pain, cough, diarrhea, diabetes, hypertension and to improve blood circulation. Nevertheless, there are growing concerns about the safety and abuse or misuse potentials of the plant which exhibits addictive effects. The safety profile of the plant is not fully elucidated. The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit underlying cardiac rapidly delayed rectifier potassium current (IKr)
International Journal of Environmental Research and Public Health, 2021
Malaysia implemented its first Movement Control Order (MCO) during the early phase of the COVID-1... more Malaysia implemented its first Movement Control Order (MCO) during the early phase of the COVID-19 pandemic to slow the transmission of the virus. This study aimed to explore the public perception of the MCO implementation and people’s experiences during this period. The study employed qualitative explorative in-depth interviews conducted with 23 Malaysian adults from various demographic backgrounds. Thematic analysis was performed using NVivo 12. Three main themes were identified: a period of information surge, heterogeneous emotional response, and attempts to adapt. During the MCO, the participants obtained information from multiple platforms. They suggested the need for clear and repeated instructions to avoid confusion and misinformation. They also acknowledged the importance of the MCO in breaking the chain of transmission and safeguarding high-risk groups; however, they also expressed that stricter enforcement from the authorities was warranted. The changes in the participants...
Background Combating viral outbreaks extends beyond biomedical and clinical approaches; thus, pub... more Background Combating viral outbreaks extends beyond biomedical and clinical approaches; thus, public health prevention measures are equally important. Public engagement in preventive efforts can be viewed as the social responsibility of individuals in controlling an infectious disease and are subjected to change due to human behaviour. Understanding individuals’ perception of social responsibility is crucial and is not yet explored extensively in the academic literature. We adopted the grounded theory method to develop an explanatory substantive theory to illustrate the process of how individual responded to the outbreak from a social responsibility perspective. Methods In-depth interviews were conducted among 23 Malaysians either through telephone or face-to-face depending on the participant’s preference. Both purposive and theoretical sampling were used. Participants were invited to share their understanding, perceptions and activities during the COVID-19 pandemic. They were furth...
Background Home visiting services for older adults have been offered for decades to maintain and ... more Background Home visiting services for older adults have been offered for decades to maintain and promote health and independent functioning, thus enhancing quality of life. Previous systematic reviews have provided a mixed picture of the benefits of home visiting programmes in older adults, primarily because of heterogeneity in study designs, targeted populations, and intervention strategies. These reviews may also become out of date; thus, an updated synthesis of relevant studies is warranted. Our objective is to perform a systematic review of recently published primary studies on the effectiveness of multi-professional home visits on quality of life among older adults. Methods We will perform a comprehensive search for studies investigating the effect of a multi-professional home visit approach on quality of life among older adults. We will conduct the literature search in selected electronic databases and relevant research websites from January 2010 onwards. We will include rando...
Mitragyna speciosa Korth (M. speciosa) has been widely used as a recreational product, however, t... more Mitragyna speciosa Korth (M. speciosa) has been widely used as a recreational product, however, there are growing concerns on the abuse potentials and toxicity of the plant. Several poisoning and fatal cases involving kratom and mitragynine have been reported but the underlying causes remain unclear. The human ether-a-go-go-related gene 1 (hERG1) encodes the pore-forming subunit underlying cardiac rapidly delayed rectifier potassium current (IKr). Pharmacological blockade of the IKr can cause acquired long QT syndrome, leading to lethal cardiac arrhythmias. This study aims to elucidate the mechanisms of mitragynine-induced inhibition on hERG1a/1b current. Electrophysiology experiments were carried out using Port-a-Patch system. Quantitative RT-PCR, Western blot analysis, immunofluorescence and co-immunoprecipitation methods were used to determine the effects of mitragynine on hERG1a/1b expression and hERG1-cytosolic chaperones interaction. Mitragynine was found to inhibit the IKr cu...
Mitragyna speciosa Korth is known for its euphoric properties and is frequently used for recreati... more Mitragyna speciosa Korth is known for its euphoric properties and is frequently used for recreational purposes. Several poisoning and fatal cases involving mitragynine have been reported but the underlying causes remain unclear. Human ether-a-go-go-related gene (hERG) encodes the cardiac IKr current which is a determinant of the duration of ventricular action potentials and QT interval. On the other hand, IK1, a Kir current mediated by Kir2.1 channel and IKACh, a receptor-activated Kir current mediated by GIRK channel are also known to be important in maintaining the cardiac function. This study investigated the effects of mitragynine on the current, mRNA and protein expression of hERG channel in hERG-transfected HEK293 cells and Xenopus oocytes. The effects on Kir2.1 and GIRK channels currents were also determined in the oocytes. The hERG tail currents following depolarization pulses were inhibited by mitragynine with an IC50 value of 1.62μM and 1.15μM in the transfected cell line ...
A cell-based assay to measure cytochrome P450 3A4 (CYP3A4) induction was developed to screen for ... more A cell-based assay to measure cytochrome P450 3A4 (CYP3A4) induction was developed to screen for potential CYP3A4 inducers. This 96-well format assay utilizes HepG2 cells transfected with a gene construct of CYP3A4 proximal promoter linked to green fluorescence protein (GFP) gene, and the expression of the GFP is then measured quantitatively. Bergamottin at 5 to 25 µmol/L produced low induction relative to the positive control. Both curcumin and lycopene were not found to affect the expression of GFP, suggesting no induction properties toward CYP3A4. Interestingly, resveratrol produced significant induction from 25 µmol/L onward, which was similar to omeprazole and may warrant further studies. In conclusion, the present study demonstrated that this cell-based assay can be used as a tool to evaluate the potential CYP3A4 induction properties of compounds. However, molecular docking data have not provided satisfactory pointers to differentiate between CYP3A4 inducers from noninducers o...
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