Alireza Jahangiri

Medicinal Chemistry, Analytical Chemistry, Nanotechnology

PhD, PharmD
10.62

Publications

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    ABSTRACT: The key enzyme in the process of melanin biosynthesis is tyrosinase. Skin hyperpigmentation and browning of foods are undesirable phenomena which tyrosinase represents. Therefore, tyrosinase inhibitors have been used increasingly for medicinal and cosmetic products. In this study, inhibitory effects of four plants including: physalis alkekengi L., Alcea rosea L., Bunium persicum B. Fedtsch. and Marrubium vulgare L. on diphenolase activity of mushroom tyrosinase were evaluated. The inhibitory activities of hydroalcoholic extracts of plants against oxidation of L-Dopa (as a substrate) by mushroom tyrosinase were investigated. The hydroalcoholic extract of P. alkekengi showed the most tyrosinase inhibitory effect with IC50 of 0.09 mg/mL vs. 0.38, 0.38 and 2.82 mg/mL of B. persicum, A. rosea and M. vulgare, respectively. M. vulgare exhibited uncompetitive inhibition and other plants showed mixed type inhibition on mushroom tyrosinase. All plants could inhibit mushroom tyrosinase, but more investigations on human tyrosinase and clinical studies are needed.
    02/2015; 10(1):e23356.
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    ABSTRACT: Background:Nowadays, removal of heavy metals from the environment is an important problem due to their toxicity.Objectives:In this study, a modified method was used to synthesize chitosan-coated magnetite nanoparticles (CCMN) to be used as a low cost and nontoxic adsorbent. CCMN was then employed to remove Hg2+ from water solutions.Materials and Methods:To remove the highest percentage of mercury ions, the Box-Behnken model of response surface methodology (RSM) was applied to simultaneously optimize all parameters affecting the adsorption process. Studied parameters of the process were pH (5-8), initial metal concentration (2-8 mg/L), and the amount of damped adsorbent (0.25-0.75 g). A second-order mathematical model was developed using regression analysis of experimental data obtained from 15 batch runs.Results:The optimal conditions predicted by the model were pH = 5, initial concentration of mercury ions = 6.2 mg/L, and the amount of damped adsorbent = 0.67 g. Confirmatory testing was performed and the maximum percentage of Hg2+ removed was found to be 99.91%. Kinetic studies of the adsorption process specified the efficiency of the pseudo second-order kinetic model. The adsorption isotherm was well-fitted to both the Langmuir and Freundlich models.Conclusions:CCMN as an excellent adsorbent could remove the mercury ions from water solutions at low and moderate concentrations, which is the usual amount found in environment.
    05/2014; 9(2):e15913.
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    ABSTRACT: Paraoxonase 1 (PON1) is a high- density lipoprotein (HDL)-associated enzyme, displaying esterase and lactonase activity. The PON1 is involved in a variety of inflammatory diseases, metabolizing toxic oxidized lipids and detoxifying of organophosphorus insecticide compounds and nerve agents. The aim of this study was to investigate the effects of methanolic date seed extract (DSE) on paraoxonase and arylesterase activities in hypercholesterolemic rats. Experiments were conducted in two groups of normal and hypercholesterolemic rats and continued for four weeks. Two weeks after receiving the normal and hypercholesterolemic diet, different dosages of DSE were administered during the last two weeks of the treatment. Blood samples were taken from animals before administration of DSE (at day 14) and at the end of the experimental period (at day 28). Paraoxonase and arylesterase activities of PON1 enzyme were assayed by kit using paraoxone and phenylacetate as the substrates. Relative changes in serum paraoxonase and arylesterase activities and total antioxidant capacity (TAOC) were compared between the two groups during this interval. Administration of DSE significantly increased serum paraoxonase and arylesterase activities in treated hypercholesterolemic groups compared to untreated ones. There was a significant difference in the TAOC of serum between the normal diet and hypercholesterolemic groups. However, DSE did not change the TAOC in hypercholesterolemic groups significantly. DSE increases serum paraoxonase and arylesterase activities. These beneficial effects may be subjected to the presence of natural antioxidants such as phenolic compounds in the date seed. Despite this, DSE did not increase TAOC in treated hypercholesterolemic groups compared to the untreated ones based on ABTS (2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid) radical reduction assay. This indicates that the hypercholesterolemic diet, apart from DSE and atorvastatin effects, may be responsible for the serum TAOC reduction. However, it is concluded that DSE may be useful in decreasing the symptoms of diseases resulting from the low activity of paraoxonase.
    02/2014; 9(1):30-34.
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    ABSTRACT: In this study, soil samples of different places of Khuzestan province were sampled. The sampling positions were registered and determined through GPS. The geostatistics and Geographic Information System (GIS) techniques were applied, and lognormal kriging were used to map the spatial patterns of Pb. Both soil extractable Pb by diethylene triamine penta-acetic acid (Pb-DTPA) and Pb in rice seed were fitted to the Gaussian model with a range of 85 and 89.5 km, respectively. The mean content of extractable soil lead and plant lead in all the sites investigated were 702.88 and 121.82 µg kg-1, respectively. Both Pb-DTPA and Pb in rice seeds had moderate spatial dependence due to the effects of natural factors including parent material, topography and soil type. The statistical survey to determine the possible correlation between some soils characteristics with lead distribution in rice seeds was done through SPSS statistical software. The results showed that close relationships existed between Pb-DTPA with organic matter (OM) (r = 0.376**), Pb in rice seed (r=0. 68**), calcium carbonate equivalent (CCE) (r= 0.084*) and between Pb in rice seed with CCE (r = -0.716**), Pb-DTPA (r = 0. 68**) and pH (r = 0.263*).
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    ABSTRACT: 9 The excessive amounts of cadmium and lead in food chain can cause health problems for humans and ecosystem. 10 Rice is an important food in human diet. Therefore this study was conducted in order to investigate cadmium and 11 Lead concentrations in seed rice (Oryza saliva) of paddy fields in southwest of Iran. A total of 70 rice seed samples 12 were collected from paddy fields in five regions of Khuzestan province, Southwest Iran, during harvesting time. In 13 the samples cadmium and Lead concentrations were measured. To assess the daily intake of Cadmium and Lead 14 by rice, daily consumption of rice was calculated. The results showed that average concentrations of Cadmium and 15 Lead in rice seeds were 273.6 and 121.8 μg/kg, respectively. Less than 72% of rice seed samples had Cadmium 16 concentrations above 200 μg/kg (i.e. Guide value for cadmium); and less than 3% had Lead concentrations above 17 150 μg/kg (i.e. Guide value for Lead). The estimated daily intakes of cadmium by the local population was 18 calculated to 0.59 μg/day kg bw, which corresponds to 59% of the tolerable daily intakes (i.e. 1 μg/day kg bw). 19 Eleven out of 70 samples (15.71%) exceed the tolerable daily intakes. The dietary intakes for Lead in the local 20 population ranged from 0.22 to 0.47 μg/day kg bw. Tolerable daily intakes for Lead is 3.6 μg/day kg bw. As a 21 whole, long term consumption of the local rice may bear high risk of heavy metal exposure to the consumer in the 22 study region. 25 Heavy metals due to poisonous, accumulating traits and 26 long longevity in organism's body are considerably im-27 portant. Many countries were infected to water and soil 28 pollution crisis to heavy metals [1]. Human beings cause 29 this contamination type through different ways. For ex-30 ample, applications of metal-contaminated fertilizers, 31 animal manures, and sewage sludge can result in high 32 concentrations of heavy metals in agricultural soils [2].
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    ABSTRACT: Purpose: To develop and characterize solid lipid nanoparticle (SLN) systems containing dextran sulfate or sodium alginate as anionic polymers for the delivery of clindamycin phosphate as a model hydrophilic cationic drug. Methods: A multi-level factorial design was used for the preparation and optimization of clindamycin SLNs. Polymers (dextran sulfate and sodium alginate), Tween 80, and Pluronic F68 were chosen as the independent variables. The SLNs were prepared using stearic acid as the lipid matrix by an emulsion congealing technique with cold homogenization. Particle size and drug loading were evaluated as the primary responses. The morphology and drug release rate of the selected formulations were also determined. Results: The results revealed that incorporation of anionic polymers increased drug loading of the SLNs. Dextran sulfate had a greater effect on drug loading, increasing it from 1.32 to 18.19 %, compared to the 6.73 % achieved using sodium alginate. Dextran sulfate also reduced drug release rate by half compared with sodium alginate, probably due to the higher charge density, lower molecular weight and lower branching density of the ionic polymer. Conclusion: Incorporation of anionic polymers can increase the loading of clindamycin phosphate into SLNs. Drug release from SLNs is also dependent on the polymer type.
    Tropical Journal of Pharmaceutical Research 08/2013; 12(4):477-482. DOI:10.4314/tjpr.v12i4.5 · 0.50 Impact Factor
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    ABSTRACT: The excessive amounts of cadmium and lead in food chain can cause health problems for humans and ecosystem. Rice is an important food in human diet. Therefore this study was conducted in order to investigate cadmium and Lead concentrations in seed rice (Oryza saliva) of paddy fields in southwest of Iran. A total of 70 rice seed samples were collected from paddy fields in five regions of Khuzestan province, Southwest Iran, during harvesting time. In the samples cadmium and Lead concentrations were measured. To assess the daily intake of Cadmium and Lead by rice, daily consumption of rice was calculated. The results showed that average concentrations of Cadmium and Lead in rice seeds were 273.6 and 121.8 mug/kg, respectively. Less than 72% of rice seed samples had Cadmium concentrations above 200 mug/kg (i.e. Guide value for cadmium); and less than 3% had Lead concentrations above 150 mug/kg (i.e. Guide value for Lead). The estimated daily intakes of cadmium by the local population was calculated to 0.59 mug/day kg bw, which corresponds to 59% of the tolerable daily intakes (i.e. 1 mug/day kg bw). Eleven out of 70 samples (15.71%) exceed the tolerable daily intakes. The dietary intakes for Lead in the local population ranged from 0.22 to 0.47 mug/day kg bw. Tolerable daily intakes for Lead is 3.6 mug/day kg bw. As a whole, long term consumption of the local rice may bear high risk of heavy metal exposure to the consumer in the study region.
    Iranian Journal of Environmental Health Science & Engineering 04/2013; 10(1):28. DOI:10.1186/1735-2746-10-28 · 1.01 Impact Factor
  • GH. Mohebbi · H. Kalantari · MJ. Khodayar · A. Jahangiri
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    ABSTRACT: Background & objectives: Organophosphate (OPs) compounds are widely used in intensive agriculture to improve production, protect crops and to control diseases vectors. The main mechanism of toxicity of OPs is the inhibition of the Cholinesterase enzymes. Methods: In this study the acetylcholinestrase (AChE), butyrylcholinesterase (BChE) and specific acetylcholinestrase (SAChE) activities as potential biomarker of exposure to OPs were evaluated in whole blood and plasma samples of exposed farm workers of Shushtar and Dasht- Azadegan in South west province of Iran based on the Ellman colorimetric method with some modification. Then the comparison of RBCs (Red Blood cell) and plasma cholinesterases, haemoglobin (Hb) and specific activity of acetylcholinestrase in Shushtar and Dasht- Azadegan farm workers with control group were carried out. Results: Results obtained in this study showed that the means of RBC AChE activities in Dasht- Azadegan, the BChE activities in Shushtar as well as the SAChE activities in both of groups were significantly (p < 0.05) lower than their means of activities in their control group. Also, the means of haemoglobin concentration in samples from Shushtar (p: 0.016) and Dasht- Azadegan (p: 3×10-4) were significantly (p < 0.05) higher than control group. conclusions: Data obtained in this study indicated that cholinesterase enzymes inhibition provides a good biomarker of exposure to organophosphate pesticides in field studies in human population. Keywords: cholinesterase, biomarker, organophosphates, farm workers, Khuzestan,
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    ABSTRACT: In this research, soil samples of different places of Khuzestan province were sampled. The sampling position was registered and determined through GPS. The geostatistics and Geographic Information System (GIS) techniques were applied, and the lognormal kriging were used to map the spatial patterns of the cadmium. Cd DTPA was fitted to the spherical model with a range of 105 km, and Cd in rice seeds was fitted to the Gaussian model with a range of 100 km. The extractable soil cadmium and plant cadmium in total places were 273.56 and 81.42 µg/kg respectively. Both Cd DTPA and Cd in rice seeds had moderate spatial dependence due to the effects of natural factors including parent material, topography and soil type. The statistical survey to determine the possible correlation between some soils characteristics with cadmium spread in paddies done through SPSS statistical software (v17). The results showed that existed close relationships between Cd in seed with OM (r = 0.376**), Cd DTPA (r = 0. 271*), pH (r = 0.280*) and between Cd DTPA with TNV (r = 0.277**), Cd in seed with (r = 0.376**) and ECe (r = 0.435**). The geostatistical analyses and the probability calculation were carried out with GS+ software.
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    ABSTRACT: Nanoparticulate drug delivery systems have several opportunities to overcome bioavailability or stability problems of peptide and protein drugs. In this study a 2 3 full factorial design was used for preparation of insulin containing nanoparticles using different concentrations of low, medium and high molecular weight chitosan (CS) and tripolyphosphate (TPP) by ion gelation method. Encapsulation efficiencies (EE) of each formulation were determined by HPLC method. Regression analysis and surface plots were used in order to evaluating the effect of variables on EE and choosing the optimum formulations. The morphology of selected nanoparticles was obtained by transmission electron microscopy (TEM). Particle size, poly dispersity index (PDI) and zeta potential were also measured. Freeze-dried nanoparticles were used for drug release studies in phosphate buffer (pH=6.8). Resulted nanoparticles had mean size of 112-419 nm with PDI< 0.5 and positive zeta potential. Insulin concentration and molecular weight of chitosan had pronounced effect on EE, but chitosan concentration had no considerable effect on EE. The maximum EE of CS nanoparticles with low, medium and high molecular weights were 61.88 %, 70.89 % and 53.73 %, respectively. The in vitro drug release profiles from the low molecular weight chitosan nanoparticles showed an initial burst release followed by a slow release within 3 hours.
    International Journal of Drug Development & Research 05/2012; · 0.18 Impact Factor
  • F Namjooyan · A Jahangiri · E Arkian · M Azemi
    Planta Medica 08/2011; 77(12). DOI:10.1055/s-0031-1282870 · 2.34 Impact Factor
  • F Namjooyan · H Moosavi · A Jahangiri · M Azemi
    Planta Medica 08/2011; 77(12). DOI:10.1055/s-0031-1282880 · 2.34 Impact Factor
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    G.H. Mohebbi · A. Jahangiri · P. Hajeb
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    ABSTRACT: A rapid, sensitive and accurate high-performance liquid chromatographic method with UV detection was developed and validated for the quantification of gabapentin in human plasma. Gabapentin was quantified using pre-column derivatization with 1-fluoro-2,4-dinitrobenzene following protein precipitation of plasma with acetonitrile. Amlodipine was used as internal standard. The chromatographic separation was carried out on a Nova-Pak C(18) column using a mixture of 50 mM NaH(2)PO(4) (pH=2.5)-acetonitrile (30:70, v/v) as mobile phase with UV detection at 360 nm. The flow rate was set at 1.5 ml/min. The method was linear over the range of 0.05-5 microg/ml of gabapentin in plasma (r(2)>0.999). The within-day and between-day precision values were in the range of 2-5%. The limit of quantification of the method was 0.05 microg/ml. The method was successfully used to study the pharmacokinetics of gabapentin in healthy volunteers.
    Journal of Chromatography B 08/2007; 854(1-2):43-7. DOI:10.1016/j.jchromb.2007.03.039 · 2.69 Impact Factor
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    ABSTRACT: There are many evidences that human serum paraoxonase activity modifies plasma lipid profile and paraoxonase has an antiatherogenic property. Non-selective beta-blockers affect plasma lipid profile too, but they have atherogenic property when patients take these drugs in long term. In this study the effect of propranolol, a non-selective beta-blocker, on paraoxonase activity was investigated. Lineweaver-Burk and secondary plots were drawn and showed thatpropranolol is a mixed non-competitive inhibitor of paraoxonase.

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