Mohammed Torequl Islam - Academia.edu (original) (raw)

Papers by Mohammed Torequl Islam

Extraction is a process of preparation of extracts from biological materials (plant/animal/microo... more Extraction is a process of preparation of extracts from biological materials (plant/animal/microorganism) in the essence of drug discovery and development scienticism. This writing is aimed at proposing a new, rapid, economical and easy extraction method, Maceration-Vortex-Technique (MVT). For this 2-5 g of powdered materials is sucked into 5-10 ml of solvent recommended for extraction. A cleaned, small amber-colored glass bottle of 20-25 ml capacity is needed for this purpose. Powdered materials are mixed with the solvent, then followed by shaking vigorously; shaken for 1.5-2 h and vortexed for 5 min. The extract is collected by immediate filtration through filter paper (Whatmann no. 1) and allowed for concentration and/or solvent partitioning. The MVT allows a 3 h extraction of plant materials. A small amount of extraction material is needed along with a small quantity of solvent which is a marker for the economy of this extraction process. In conclusion, rapidity in the extractio...

$Research paper thumbnail of Antibacterial activity of different fractions of Commelina benghalensis L$

In Bangladesh the herb Commelina benghalensis L. is used for otitis media, suppurative sores, bur... more In Bangladesh the herb Commelina benghalensis L. is used for otitis media, suppurative sores, burns, conjunctivitis and skin diseases (eczema, abscesses, acne, scabies and warts) although the compounds responsible for the medicinal properties have not been identified. In this study the plant was evaluated for antibacterial activity and the extracts (ethanolic, petroleum etheric, diethyl etheric, methanolic and aqueous) were found to possess maximum potency against infectious pathogens Staphylococcus saprophyticus, Staphylococcus aureus, Enterococcus faecalis, Staphylococcus pyogenes, Streptococcus agalactiae, Salmonella typhi, Escherichia coli, Shigella boydii, Shigella dysenteriae and Pseudomonas aeruginosa. The zone of inhibition was observed with almost all bacteria with some exceptions. Minimum inhibitory concentrations of the extracts were found to be significant.

Hypertension, Sep 1, 2012

Angiotensin II (AngII) induces both superoxide (O 2 - ) and nitric oxide (NO) generation forming ... more Angiotensin II (AngII) induces both superoxide (O 2 - ) and nitric oxide (NO) generation forming peroxynitrite (ONOO - ) in biological systems. To determine the role of ONOO - in AngII induced sodium excretory responses, we examined Na + K + ATPase (NKA) activity in cultured HK2 cells (human kidney proximal tubule cell line) incubated for 30 min with a wide range (10 pM to 200 μM) of AngII concentrations (conc) in the presence or absence of a ONOO - scavenger, mercapto-ethyl-guanadine (MEG; 200μM). Post incubation HK2 cellular membrane fractions were used for measurement of NKA activity via colorimetric assay capable of detecting inorganic phosphate (Pi). Baseline value of NKA activity in these HK2 cells was measured as 10.3 ±0.7 μmoles of Pi liberated/mg protein/hr (n=12). AngII exerts dose-dependent differential effects on NKA activity. Compared to the baseline value, NKA activity was increased at lower conc (13.7±1.3% at 10 pM to 19.6±1.5% at 100nM) and decreased at higher conc (-6.0±0.8% at 1 μM to -38±2.1% at 200 μM ) without any significant effect at 500 nM conc (-1.2±0.6%) of AngII. Interestingly, MEG treatment markedly attenuated these AngII induced changes in NKA activity, both at lower conc (activity increased only to 7.8±0.67% at 10 pM and to 8.9±0.57% at 100nM; an average reduction of 33.2±2.4% in stimulatory effects) and at higher conc (activity decreased to -3.0±0.7% at 1 μM and to -20±0.57% at 200 μM; an average reduction of 54.4±4.1% in inhibitory effects). Co-incubation with O 2 - scavenger, tempol (1 mM) or NO synthase inhibitor, nitro-L-arginine methyl ester (100 μM) did not alter these AngII induced responses in HK2 cells indicating that neither O 2 - , nor NO, was directly involved in mediating these responses. AT 1 receptor (AT 1 R) blocker, losartan (10μM) treatment prevented these AngII induced changes on NKA activity confirming the involvement of AT 1 R signaling in these responses. These findings demonstrate a direct contributory role for concomitant ONOO - generation in mediating AngII induced changes in NKA activity in the proximal tubular cells. These data also suggest a reno-protective role for ONOO - in minimizing sodium retaining action of AngII by the renal tubules, particularly in the conditions associated with enhanced renin-angiotensin system.

The FASEB Journal, Apr 1, 2013

American Journal of Physiology-renal Physiology, Jun 15, 2012

Acute administration of tumor necrosis factor-␣ (TNF-␣) resulted in decreases in renal blood flow... more Acute administration of tumor necrosis factor-␣ (TNF-␣) resulted in decreases in renal blood flow (RBF) and glomerular filtration rate (GFR) but induced diuretic and natriuretic responses in mice. To define the receptor subtypes involved in these renal responses, experiments were conducted to assess the responses to human recombinant TNF-␣ (0.3 ng•min Ϫ1 •g body wt Ϫ1 iv infusion for 75 min) in gene knockout (KO) mice for TNF-␣ receptor type 1 (TNF␣R1 KO, n ϭ 5) or type 2 (TNF␣R2 KO, n ϭ 6), and the results were compared with those obtained in corresponding wild-type [WT (C57BL/6), n ϭ 6] mice. Basal levels of RBF (PAH clearance) and GFR (inulin clearance) were similar in TNF␣R1 KO, but were lower in TNF␣R2 KO, than WT mice. TNF-␣ infusion in WT mice decreased RBF and GFR but caused a natriuretic response, as reported previously. In TNF␣R1 KO mice, TNF-␣ infusion failed to cause such vasoconstrictor or natriuretic responses; rather, there was an increase in RBF and a decrease in renal vascular resistance. Similar responses were also observed with infusion of murine recombinant TNF-␣ in TNF␣R1 KO mice (n ϭ 5). However, TNF-␣ infusion in TNF␣R2 KO mice caused changes in renal parameters qualitatively similar to those observed in WT mice. Immunohistochemical analysis in kidney slices from WT mice demonstrated that while both receptor types were generally located in the renal vascular and tubular cells, only TNF␣R1 was located in vascular smooth muscle cells. There was an increase in TNF␣R1 immunoreactivity in TNF␣R2 KO mice, and vice versa, compared with WT mice. Collectively, these functional and immunohistological findings in the present study demonstrate that the activation of TNF␣R1, not TNF␣R2, is mainly involved in mediating the acute renal vasoconstrictor and natriuretic actions of TNF-␣.

The FASEB Journal, Apr 1, 2009

Physiological Reports, Apr 1, 2016

In the normal condition, endogenous formation of peroxynitrite (ONOOˉ) from the interaction of ni... more In the normal condition, endogenous formation of peroxynitrite (ONOOˉ) from the interaction of nitric oxide and superoxide has been suggested to play a renoprotective role. However, the exact mechanism associated with renoprotection by this radical compound is not yet clearly defined. Although ONOOū sually inhibits renal tubular Na + K + ATPase (NKA) activity at high concentrations (micromolar to millimolar range [lM-mM], achieved in pathophysiological conditions), the effects at lower concentrations (nanomolar range [nM], relevant in normal condition) remain unknown. To examine the direct effect of ONOOˉon NKA activity, preparations of cellular membrane fraction from mouse renal tissue and from cultured HK2 cells (human proximal tubular epithelial cell lines) were incubated for 10 and 30 min each with different concentrations of ONOOˉ(10 nmol/L-200 lmol/L). NKA activity in these samples (n = 5 in each case) was measured via a colorimetric assay capable of detecting inorganic phosphate. At high concentrations (1-200 lmol/L), ONOOˉcaused dose-dependent inhibition of NKA activity (À3.0 AE 0.6% and À36.4 AE 1.4%). However, NKA activity remained unchanged at 100 and 500 nmol/L ONOOˉconcentration, but interestingly, at lower concentrations (10 and 50 nmol/L), ONOOˉcaused small but significant increases in the NKA activity (3.3 AE 1.1% and 3.1 AE 0.6%). Pretreatment with a ONOOs cavenger, mercaptoethylguanidine (MEG; 200 lmol/L), prevented these biphasic responses to ONOOˉ. This dose-dependent biphasic action of ONOO À on NKA activity may implicate that this radical compound helps to maintain sodium homeostasis either by enhancing tubular sodium reabsorption under normal conditions or by inhibiting it during oxidative stress conditions.

Hypertension, Oct 1, 2017

IL-10 (interleukin-10) has been suggested to play a protective role in angiotensin II (AngII)-ind... more IL-10 (interleukin-10) has been suggested to play a protective role in angiotensin II (AngII)-induced cardiovascular disorders. This study examined the role of endogenous IL-10 in salt-sensitive hypertension and renal injury induced by AngII. Responses to chronic AngII (400 ng/min per kilogram body weight; osmotic minipump) infusion were evaluated in IL-10 gene knockout mice fed with either normal salt diet (0.3% NaCl) or high salt (HS; 4% NaCl) diet, and these responses were compared with those in wild-type mice. Normal salt diets or HS diets were given alone for the first 2 weeks and then with AngII treatment for an additional 2 weeks (n=6 in each group). Arterial pressure was continuously monitored by implanted radio-telemetry, and a 24-hour urine collection was performed by metabolic cages on the last day of the experimental period. Basal mean arterial pressure was lower in IL-10 gene knockout mice than in wild-type (98±3 versus 113±3 mm Hg) mice. Mean arterial pressure responses to normal salt/HS alone or to the AngII+normal salt treatment were similar in both strains. However, the increase in mean arterial pressure induced by the AngII+HS treatment was significantly lower in IL-10 gene knockout mice (15±5% versus 37±3%) compared with wild-type mice. Renal tissue endothelial nitric oxide synthase expression (≈3-folds) and urinary excretion of nitric oxide metabolites, nitrate/nitrite (1.2±0.1 versus 0.2±0.02 µmol/L/24 hours) were higher in IL-10 gene knockout mice compared with wild-type mice. These results indicate that an increase in nitric oxide production helps to mitigate saltsensitive hypertension induced by AngII and suggest that a compensatory interaction between IL-10 and nitric oxide exists in modulating AngII-induced responses during HS intake.

American Journal of Physiology-cell Physiology, Dec 1, 2015

In this study we characterized ammonia and ammonium (NH3/NH 4 ϩ) transport by the rhesus-associat... more In this study we characterized ammonia and ammonium (NH3/NH 4 ϩ) transport by the rhesus-associated (Rh) glycoproteins RhAG, Rhbg, and Rhcg expressed in Xenopus oocytes. We used ionselective microelectrodes and two-electrode voltage clamp to measure changes in intracellular pH, surface pH, and whole cell currents induced by NH3/NH 4 ϩ and methyl amine/ammonium (MA/ MA ϩ). These measurements allowed us to define signal-specific signatures to distinguish NH3 from NH 4 ϩ transport and to determine how transport of NH3 and NH 4 ϩ differs among RhAG, Rhbg, and Rhcg. Our data indicate that expression of Rh glycoproteins in oocytes generally enhanced NH3/NH 4 ϩ transport and that cellular changes induced by transport of MA/MA ϩ by Rh proteins were different from those induced by transport of NH3/NH 4 ϩ. Our results support the following conclusions: 1) RhAG and Rhbg transport both the ionic NH 4 ϩ and neutral NH3 species; 2

The FASEB Journal, Apr 1, 2011

The FASEB Journal, Apr 1, 2012

The FASEB Journal, Apr 1, 2010

Physiological reports, 2016

In the normal condition, endogenous formation of peroxynitrite (ONOO-) from the interaction of ni... more In the normal condition, endogenous formation of peroxynitrite (ONOO-) from the interaction of nitric oxide and superoxide has been suggested to play a renoprotective role. However, the exact mechanism associated with renoprotection by this radical compound is not yet clearly defined. AlthoughONOO- usually inhibits renal tubular Na(+)K(+)ATPase (NKA) activity at high concentrations (micromolar to millimolar range [μM-mM], achieved in pathophysiological conditions), the effects at lower concentrations (nanomolar range [nM], relevant in normal condition) remain unknown. To examine the direct effect ofONOO- onNKAactivity, preparations of cellular membrane fraction from mouse renal tissue and from culturedHK2 cells (human proximal tubular epithelial cell lines) were incubated for 10 and 30 min each with different concentrations ofONOO- (10 nmol/L-200 μmol/L).NKAactivity in these samples (n = 5 in each case) was measured via a colorimetric assay capable of detecting inorganic phosphate. ...

The Faseb Journal, Apr 1, 2009

Physiological reports, 2015

The calcium-sensing receptor (CaSR), a G-protein-coupled receptor, plays a role in glandular and ... more The calcium-sensing receptor (CaSR), a G-protein-coupled receptor, plays a role in glandular and fluid secretion in the gastrointestinal tract, and regulates differentiation and proliferation of epithelial cells. We examined the expression of CaSR in normal and pathological conditions of human esophagus and investigated the effect of a CaSR agonist, cinacalcet (CCT), and antagonist, calhex (CHX), on cell growth and cell-cell junctional proteins in primary cultures of porcine stratified squamous esophageal epithelium. We used immunohistochemistry and Western analysis to monitor expression of CaSR and cell-cell adhesion molecules, and MTT assay to monitor cell proliferation in cultured esophageal cells. CCT treatment significantly reduced proliferation, changed the cell shape from polygonal to spindle-like, and caused redistribution of E-cadherin and β-catenin from the cell membrane to the cytoplasm. Furthermore, it reduced expression of β-catenin by 35% (P < 0.02) and increased ex...

American journal of hypertension, 2012

Hydrogen sulfide (H(2)S), an endogenous vasoactive agent, is produced by cystathionine γ-lyase (C... more Hydrogen sulfide (H(2)S), an endogenous vasoactive agent, is produced by cystathionine γ-lyase (CGL) and cystathionine β-synthase (CBS) enzymes. This study was conducted to evaluate the relative contribution of these enzymes in regulating systemic arterial pressure. Sprague-Dawley rats were chronically treated with CGL inhibitor, DL-propargylglycine (PAG, 37.5 mg/kg/day; intraperitoneally, i.p.) or CBS inhibitor, aminooxyacetic acid (AOA, 8.75 mg/kg/day; i.p.) or in combination for 4 weeks and the effects on arterial pressure (tail-cuff plethysmography) and renal excretory function (24 h urine collections using metabolic cages) were assessed once in a week. Changes in renal blood flow (RBF; Ultrasonic flowmetry) and glomerular filtration rate (GFR; Inulin clearance) were assessed in acute experiments in anesthetized rats at the end of treatment period. Compared to vehicle treated control group, only the rats with combination therapy showed a decrease in urinary sulfate excretion rat...

Anti-cancer agents in medicinal chemistry, Jan 20, 2018

Phytol have various pharmacological activities such as antimicrobial, cytotoxic, antitumoral, ant... more Phytol have various pharmacological activities such as antimicrobial, cytotoxic, antitumoral, antimutagenic, anti-atherogenic, antidiabetic, lipid-lowering, antispasmodic, antiepileptic, antinociceptive, antioxidant, anti-inflammatory, anxiolytic, antidepressant and immunoadjuvant. Several studies point to an association of phytol with implications for apoptosis and necrosis at cellular levels in cancer, yet no clear conclusions were drawn. To clarify this, we conducted a meta-analysis of non-clinical studies of phytol and its associations with toxicity and cytotoxicity emphasizing the mechanisms of apoptosis and necrosis induction and its importance in tumor therapy. Relevant studies were systematically searched in PubMed and Web of Science. The association between phytol and cyto-/toxicity was assessed by odds ratio (ORs) and 95% confidence intervals (CI). Twenty-three studies were finally included in the meta-analysis. A significant association between phytol and toxicity (OR: 1....

International Journal of Applied Pharmaceutical Sciences and Research, 2016

The term „biomarker‟ is used from 1980. Nowadays, diagnosis/prognosis and research in medical sci... more The term „biomarker‟ is used from 1980. Nowadays, diagnosis/prognosis and research in medical science are more concerned with the discovery and utilization of a number of biomarkers. The information in the library of biomarkers is rising day by day as their major concerns relate diseases, pathogenicity or pharmacology in a variety of hosts. Taking into account, we summarize a number of biomarkers in a number of diseases in human. It includes the name and their up- and/or down expressions in those situations. However, no description was plugged with the individual fact.

International Archives of Medicine, 2016

Cancer is a public health global problem. Cyclophosphamide (CPA) and Doxorubicin (DOX) are used i... more Cancer is a public health global problem. Cyclophosphamide (CPA) and Doxorubicin (DOX) are used in chemotherapy, especially by generating reactive oxygen species. The clinical use of ascorbic acid during chemotherapy also raises several controversies due to its antagonistic effects on antineoplastic agent. In this sense, this study aims to evaluate the effects of ascorbic acid (2 µg/mL) on the modulation of cytogenetic damage induced by CPA (20 µg/mL) and DOX (2 µg/ mL), as well as their interaction (AC protocol) on Sarcoma 180 tumor cells. Cytogenetic damage classified as apoptosis, necrosis, micronuclei, buds and nucleoplasmic bridges were linked to the Cytokinesis-Block Micronucleus Assay application. CPA and DOX induce significant (p<0.05) increases in apoptosis, necrosis and micronuclei in the cell types tested. The damage on Sarcoma 180 cells was modulated by ascorbic acid with percentage modulation in more than 70% of CPA relative to apoptosis and micronuclei, and 32% to necrosis. The damage of DOX has been modulated by 70% to apoptosis, 40% to necrosis, rather than micronuclei, whereas, in AC protocol, modulations were observed by 52% to apoptosis and 32% and 40% to necrosis and micronuclei, respectively. There was no significance in relation to the nuclear buds and nucleoplasmic bridges. In addition, ascorbic acid did not show any effect. These results are other studies, which indicate hazards to chemotherapy effectiveness due to the antioxidant effects