Publications by authors named "Mohammadreza Taheri"

6 Publications

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The anti-cancer properties of neem () through its antioxidant activity in the liver; its pharmaceutics and toxic dosage forms; a literature review.

J Complement Integr Med 2021 May 10. Epub 2021 May 10.

Department of Physiology and Medical Physics, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran.

Objectives: The neem () have been used in herbal medicine for the treatment of multiple diseases, particularly cancer. The mechanism of anti-cancer properties of neem are far from clear. However, it is well accepted that anti-cancer effects of neem is mediated via its hepatic anti-oxidant activity. In the present review, we are going to classify and studies about anti-cancer activity of neem via its hepatic anti-oxidant activity. We also summarize its active ingredients and some therapeutic and toxic dosage forms.

Methods: A systematic search in the literature was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, as well as Google Scholar pre-print database using all available MeSH terms for neem, , anti-cancer, anti-tumor, carcinogen, liver, antioxidant activity, neem ingredients, and glutathione. Electronic database searches combined and duplicates were removed.

Results: The neem plant have been used in herbal medicine for the treatment of various diseases, particularly cancer. The mechanisms of anti-cancer effects of neem are far from clear. Cancerous cells growth can induce imbalance the oxidant and anti-oxidant activity in various organs particularly in the liver. Therefore, it seems that neem have anti-cancer effects via restore of the antioxidant disturbances close to the control ones in the liver. Additionally, administration of neem extract can induce oncostatic potential via several mechanism including; suppression of the NF-κβ pathway, increased expression of tumor suppressor (such as p53 and pTEN), decreased expression of oncogenes (such as c-Myc), and increased apoptosis in cancerous cells. The median lethal dose (LD50) value for extracts of neem was higher than 2,500 mg/kg.

Conclusions: It is suggested that neem plays pivotal role in the prevention and treatment of cancer via its hepatic antioxidant activity. Indeed, application of neem extract can decreased tumor growth via restore of the antioxidant disturbances close to the control ones in the liver.
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http://dx.doi.org/10.1515/jcim-2021-0009DOI Listing
May 2021

Optimization of throughput in semipreparative chiral liquid chromatography using stacked injection.

Chirality 2017 10 27;29(10):579-588. Epub 2017 Jul 27.

Phytochemistry Department, Medicinal Plants and Drugs Research Institute, Shahid Beheshti UniversityEvin, Tehran, Iran.

An interesting mode of chromatography for preparation of pure enantiomers from pure samples is the method of stacked injection as a pseudocontinuous procedure. Maximum throughput and minimal production costs can be achieved by the use of total chiral column length in this mode of chromatography. To maximize sample loading, often touching bands of the two enantiomers is automatically achieved. Conventional equations show direct correlation between touching-band loadability and the selectivity factor of two enantiomers. The important question for one who wants to obtain the highest throughput is "How to optimize different factors including selectivity, resolution, run time, and loading of the sample in order to save time without missing the touching-band resolution?" To answer this question, tramadol and propranolol were separated on cellulose 3,5-dimethyl phenyl carbamate, as two pure racemic mixtures with low and high solubilities in mobile phase, respectively. The mobile phase composition consisted of n-hexane solvent with alcohol modifier and diethylamine as the additive. A response surface methodology based on central composite design was used to optimize separation factors against the main responses. According to the stacked injection properties, two processes were investigated for maximizing throughput: one with a poorly soluble and another with a highly soluble racemic mixture. For each case, different optimization possibilities were inspected. It was revealed that resolution is a crucial response for separations of this kind. Peak area and run time are two critical parameters in optimization of stacked injection for binary mixtures which have low solubility in the mobile phase.
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http://dx.doi.org/10.1002/chir.22727DOI Listing
October 2017

Response surface methodology based on central composite design accompanied by multivariate curve resolution to model gradient hydrophilic interaction liquid chromatography: Prediction of separation for five major opium alkaloids.

J Sep Sci 2017 Sep 28;40(18):3602-3611. Epub 2017 Aug 28.

Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran.

Hydrophilic interaction liquid chromatography on bare silica presents some benefits for analysis and purification of ionizable basic alkaloids. This mode was used to separate five major opium alkaloids: morphine, codeine, thebaine, papaverine, and noscapine. Central composite design based on response surface methodology was applied for experimental design, modeling, and optimization in a single-step gradient method. The main effects and their interactions (initial percentage of modifier, changing range of modifier in run time, pH of buffer, and its concentration) were investigated in 30 experiments. Multivariate curve resolution-alternating least squares, by resolving overlapped curves, helped in the accurate calculation of baseline resolution factors to be modeled and optimized more accurately. Then three crucial resolution factors besides elution time were modeled in quadratic and cubic equations and optimized. In addition to the four factors, five extra logarithmic, and nonlogarithmic factors extracted from the four factors to give nine factors overall were inspected on mechanism of retention. It was shown that a linear combination consist of four independence variables successfully describes morphinans retentivity in a single-step gradient method.
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http://dx.doi.org/10.1002/jssc.201700416DOI Listing
September 2017

Evaluation of hydrophilic interaction liquid chromatography stationary phases for analysis of opium alkaloids.

J Chromatogr A 2017 Aug 30;1511:77-84. Epub 2017 Jun 30.

Pharmaceutical and Medicinal Chemistry Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, Dokki, Giza 12622, Egypt. Electronic address:

The separation of a mixture containing five major opium alkaloids, namely morphine, codeine, thebaine, noscapine and papaverine has been investigated in hydrophilic interaction liquid chromatography (HILIC) mode using five different stationary phases: bare silica, zwitterion, aminopropyl, diol and cyanopropyl. In order to propose the appropriate column for separation and purification, retention behaviors of the five natural opioids have been studied on mentioned HILIC stationary phases. The mechanism of separation in diverse HILIC media, based on the formation of water-rich layer on surface of the HILIC stationary phases and the physicochemical properties of opium alkaloids, such as pKa (acidic pK) and the octanol-water distribution coefficient (log Do/w) are discussed. Chromatographic responses including modified limit of detection LOD, signal to noise ratio (S/N), and defined modified R have considered for suggestion of the suitable column for quantitative/qualitative and preparative purposes. According to the obtained results, diol stationary phase is best suited for analytical chromatography, whereas bare silica and zwitterionic stationary phases are appropriate for preparative applications.
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http://dx.doi.org/10.1016/j.chroma.2017.06.072DOI Listing
August 2017

Central composite design with the help of multivariate curve resolution in loadability optimization of RP-HPLC to scale-up a binary mixture.

J Sep Sci 2016 Mar 16;39(6):1031-40. Epub 2016 Feb 16.

Medicinal Plants and Drug Research Institute, Shahid Beheshti University, Tehran, Iran.

Chromatographic method development for preparative targets is a time-consuming and subjective process. This can be particularly problematic because of the use of valuable samples for isolation and the large consumption of solvents in preparative scale. These processes could be improved by using statistical computations to save time, solvent and experimental efforts. Thus, contributed by ESI-MS, after applying DryLab software to gain an overview of the most effective parameters in separation of synthesized celecoxib and its co-eluted compounds, design of experiment software that relies on multivariate modeling as a chemometric approach was used to predict the optimized touching-band overloading conditions by objective functions according to the relationship between selectivity and stationary phase properties. The loadability of the method was investigated on the analytical and semi-preparative scales, and the performance of this chemometric approach was approved by peak shapes beside recovery and purity of products.
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http://dx.doi.org/10.1002/jssc.201500526DOI Listing
March 2016

Inhibition and structural changes of liver alkaline phosphatase by tramadol.

Drug Metab Lett 2014 ;8(2):129-34

BioResearch Lab, Faculty of Biological Sciences, Shahid Beheshti University,G.C. Iran.

Tramadol is a potent analgesic drug which interacts with mu-opioid and has low effect on other opioid receptors. Unlike other opioids, it has no clinically significant effect on respiratory or cardiovascular parameters. Alakaline phosphatase is a hydrolase enzyme that prefers alkaline condition and removes phosphate group from different substrates. In this study, the interaction between tramadol and calf liver alkaline phosphatase was investigated. The results showed that tramadol can bind to alakaline phosphatase and inhibit the enzyme in an un-competitive manner. Ki and IC50 values of tramadol were determined as about 91 and 92 μM, respectively. After enzyme purification, structural changes on alakaline phosphatase-drug interaction were studied by circular dichroism and fluorescence measurement. These data revealed the alteration in the content of secondary structures and also conformational changes in enzyme occurred when the drug bound to enzyme-substrate complex.
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http://dx.doi.org/10.2174/1872312808666140506093756DOI Listing
October 2015