1.N-acetyl-L-cysteine and cysteine increase intracellular calcium concentration in human neutrophils.
Md Ashraful HASAN ; Won Gyun AHN ; Dong Keun SONG
The Korean Journal of Physiology and Pharmacology 2016;20(5):449-457
N-acetyl-L-cysteine (NAC) and cysteine have been implicated in a number of human neutrophils' functional responses. However, though Ca²⁺ signaling is one of the key signalings contributing to the functional responses of human neutrophils, effects of NAC and cysteine on intracellular calcium concentration ([Ca²⁺]ᵢ) in human neutrophils have not been investigated yet. Thus, this study was carried out with an objective to investigate the effects of NAC and cysteine on [Ca²⁺]ᵢ in human neutrophils. We observed that NAC (1 µM ~ 1 mM) and cysteine (10 µM ~ 1 mM) increased [Ca²⁺]ᵢ in human neutrophils in a concentration-dependent manner. In NAC pre-supplmented buffer, an additive effect on N-formyl-methionine-leucine-phenylalanine (fMLP)-induced increase in [Ca²⁺]ᵢ in human neutrophils was observed. In Ca²⁺-free buffer, NAC- and cysteine-induced [Ca²⁺]ᵢ increase in human neutrophils completely disappeared, suggesting that NAC- and cysteine-mediated increase in [Ca²⁺]ᵢ in human neutrophils occur through Ca²⁺ influx. NAC- and cysteine-induced [Ca²⁺]ᵢ increase was effectively inhibited by calcium channel inhibitors SKF96365 (10 µM) and ruthenium red (20 µM). In Na⁺-free HEPES, both NAC and cysteine induced a marked increase in [Ca²⁺]ᵢ in human neutrophils, arguing against the possibility that Na⁺-dependent intracellular uptake of NAC and cysteine is necessary for their [Ca²⁺]ᵢ increasing activity. Our results show that NAC and cysteine induce [Ca²⁺]ᵢ increase through Ca²⁺ influx in human neutrophils via SKF96365- and ruthenium red-dependent way.
Acetylcysteine*
;
Calcium Channels
;
Calcium*
;
Cysteine*
;
HEPES
;
Humans*
;
Neutrophils*
;
Ruthenium
;
Ruthenium Red
2.Scant Extracellular NAD Cleaving Activity of Human Neutrophils is Down-Regulated by fMLP via FPRL1.
Md Ashraful HASAN ; Md Tipu SULTAN ; Won Gyun AHN ; Yeon Ja KIM ; Ji Hye JANG ; Chang Won HONG ; Dong Keun SONG
The Korean Journal of Physiology and Pharmacology 2014;18(6):497-502
Extracellular nicotinamide adenine dinucleotide (NAD) cleaving activity of a particular cell type determines the rate of the degradation of extracellular NAD with formation of metabolites in the vicinity of the plasma membrane, which has important physiological consequences. It is yet to be elucidated whether intact human neutrophils have any extracellular NAD cleaving activity. In this study, with a simple fluorometric assay utilizing 1,N6-ethenoadenine dinucleotide (etheno-NAD) as the substrate, we have shown that intact peripheral human neutrophils have scant extracellular etheno-NAD cleaving activity, which is much less than that of mouse bone marrow neutrophils, mouse peripheral neutrophils, human monocytes and lymphocytes. With high performance liquid chromatography (HPLC), we have identified that ADP-ribose (ADPR) is the major extracellular metabolite of NAD degradation by intact human neutrophils. The scant extracellular etheno-NAD cleaving activity is decreased further by N-formyl-methionine-leucine-phenylalanine (fMLP), a chemoattractant for neutrophils. The fMLP-mediated decrease in the extracellular etheno-NAD cleaving activity is reversed by WRW4, a potent FPRL1 antagonist. These findings show that a much less extracellular etheno-NAD cleaving activity of intact human neutrophils compared to other immune cell types is down-regulated by fMLP via a low affinity fMLP receptor FPRL1.
Adenosine Diphosphate Ribose
;
Animals
;
Bone Marrow
;
Cell Membrane
;
Chromatography, Liquid
;
Humans
;
Lymphocytes
;
Mice
;
Monocytes
;
NAD*
;
Neutrophils*
;
Receptors, Formyl Peptide
3.Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer's disease.
Ji Jing YAN ; Won Gyun AHN ; Jun Sub JUNG ; Hee Sung KIM ; Md Ashraful HASAN ; Dong Keun SONG
Nutrition Research and Practice 2014;8(4):386-390
BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer's disease (AD); intracerebroventricular injection of beta-amyloid peptide (Abeta) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of Abeta1-42 until evaluation) effectively blocked Abeta1-42-induced impairment in passive avoidance performance, and Abeta1-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-1alpha in the hippocampus. In addition, it alleviated the Abeta1-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-1beta in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.
Eleutherococcus*
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Acetylcholine
;
Administration, Oral
;
Alzheimer Disease*
;
Amyloid
;
Animals
;
Brain
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Glial Fibrillary Acidic Protein
;
Hippocampus
;
Interleukins
;
Malondialdehyde
;
Mice*
;
Plaque, Amyloid
4.Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer's disease.
Ji Jing YAN ; Won Gyun AHN ; Jun Sub JUNG ; Hee Sung KIM ; Md Ashraful HASAN ; Dong Keun SONG
Nutrition Research and Practice 2014;8(4):386-390
BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer's disease (AD); intracerebroventricular injection of beta-amyloid peptide (Abeta) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of Abeta1-42 until evaluation) effectively blocked Abeta1-42-induced impairment in passive avoidance performance, and Abeta1-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-1alpha in the hippocampus. In addition, it alleviated the Abeta1-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-1beta in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.
Eleutherococcus*
;
Acetylcholine
;
Administration, Oral
;
Alzheimer Disease*
;
Amyloid
;
Animals
;
Brain
;
Glial Fibrillary Acidic Protein
;
Hippocampus
;
Interleukins
;
Malondialdehyde
;
Mice*
;
Plaque, Amyloid
5. Leonurus sibiricus L. (honeyweed): A review of its phytochemistry and pharmacology
Md. Abu SAYED ; Md. Abu SAYED ; Md. Ashraful ALAM ; Md. Shariful ISLAM ; Abu Zaffar SHIBLY ; Md. Taif ALI ; Md. Emdad ULLAH ; Md. Aslam ALI ; Md. Mahdi HASAN-OLIVE
Asian Pacific Journal of Tropical Biomedicine 2016;6(12):1076-1080
Leonurus sibiricus is a herbaceous plant found in many countries in Asia and America. This plant is widely practiced as a remedy for the treatment of diabetes, menstrual irregularities, and bronchitis. The approval of therapeutic implications of any drugs depends on the well characterized mode of actions of the compounds. The bioactive compounds like diterpenes, triterpenes, flavonoids and phenolic acids in Leonurus sibiricus show analgesic, anti-inflammatory, anti-oxidant, anti-atherogenic and anti-hemorrhagic, anti-diabetic, anti-bacterial and allelopathic potency. Interestingly, the expression level of some genes is altered by the crude extract treatments, which are effective against cancers, diabetes and cardiovascular diseases where the molecular mechanisms are yet to be explored. Intriguingly, the extracts significantly induce nitric oxide production by endothelial nitric oxide synthase, a signaling molecule of vasodilation in combination with interferon-γ indicating positive effect on atherosclerosis. Further investigations are required to unlock the effects of bioactive compounds found in extracts at clinical settings.
6. Characterization, prevalence and antibiogram study of Staphylococcus aureus in poultry
Yeasmeen ALI ; Md. Ashraful ISLAM ; Nazmul Hasan MUZAHID ; Mohd. Omar Faruk SIKDER ; Md. Amzad HOSSAIN ; Lolo Wal MARZAN ; Mohd. Omar Faruk SIKDER
Asian Pacific Journal of Tropical Biomedicine 2017;7(3):253-256
Objective To reveal the presence of methicillin resistant Staphylococcus aureus (S. aureus) (MRSA) in poultry samples and to determine the antibiogram pattern against five antibiotics. Methods Samples from different poultry farm of Chittagong city, Bangladesh were examined for S. aureus by different biochemical tests and confirmed as MRSA by identifying the presence of mecA gene using PCR. Antibiotic resistance pattern in S. aureus was determined by antibiotic disk diffusion method. Results In this study, a total of 60 samples (30 from nasal swabs and 30 from cloacal swabs) were used, of which 54 were confirmed as S. aureus by different biochemical tests. Among these, 12 were confirmed as MRSA by detecting mecA gene using PCR. During antibiogram study, both nasal and cloacal samples showed the highest resistance against penicillin-G and the lowest resistance was observed against neomycin. Conclusions Based on the present study, it can be said that different antibiotics are used extensively in poultry that leads to MRSA and is alarming for human health.