Afshan Kaleem

Dr. Afshan Kaleem


Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 February 2019 in Journal of Nanomaterials
Verified
Journal Article
Open access
ASAsma Shahzad
Asma Shahzad
HSHamid Saeed
Hamid Saeed
MIMehwish Iqtedar
Mehwish Iqtedar
Syed Zajif HussainSyed Zajif Hussain
Syed Zajif Hussain
AKAfshan Kaleem
Afshan Kaleem
ACAsma - Chaudhary
Asma - Chaudhary
The biogenesis of silver nanoparticles by fungi is an ecologically clean and nontoxic method compared to other physical and chemical methods. Thus, we aimed to discuss the mycosynthesis of extracellular size-controlled AgNPs. After comprehensive screening, Aspergillus fumigatus BTCB10 (KY486782) was selected for the synthesis of AgNPs of controlled size. Characterization was performed by UV-Vis spectrophotometer, Zetasizer, X-Ray Diffraction (XRD), FTIR (Fourier-transform infrared), Atomic Force Microscopy (AFM), and Scanning Electron Microscopy (SEM) along with functional assays—antibacterial and MTT assays. Data suggested that under optimized conditions, i.e., temperature 25°C, AgNO3 concentration 1 mM, biomass 7 g, fungal culture age 7 days, pH 6, ratio of cell-free filtrate (CFF)/silver nitrate (3 : 2), NaCl 20%, and under dark light, the smallest size AgNPs of 0.681 nm with 100% monodispersity was obtained as evident by a zeta potential of -23.4 mV, UV-Vis band at 400 nm, and the presence of O-H and C=O groups confirmed by ATR-FTIR; XRD revealed the crystalline nature of AgNPs; additionally, cube-shaped AgNPs were revealed by Scanning Electron Microscopy (SEM). Moreover, synthesized AgNPs exhibited antibacterial activity against multidrug-resistant bacterial strains, notably, Klebsiella pneumoniae BTCB04, Acinetobacter BTCB05, Pseudomonas aeruginosa BTCB01, and Escherichia coli BTCB03, while maximum 7-fold was observed with Acinetobacter BTCB05. AgNPs demonstrated no cytotoxic activity against HepG2 cells; however, in combination with cisplatin, antiproliferative and cytotoxic effects became more evident and significant in comparison to control and as single agent. Taken together, the data suggested that economical and smallest size AgNPs can be biosynthesized from Aspergillus fumigatus BTCB10 and be used as antibacterial and antiproliferative agents in combination with current drugs against clinically relevant multiple drug-resistant bacterial and tumoral cells. Further studies are required to confirm their effects employing in vivo disease models.

13 January 2019 in Preparative Biochemistry & Biotechnology
Verified
Journal Article
Closed access
MIMehwish Iqtedar
Mehwish Iqtedar
MAMehral Aslam
Mehral Aslam
MFMuhammad Akhyar Farrukh
Muhammad Akhyar Farrukh
ASAsma Shehzaad
Asma Shehzaad
RARoheena Abdullah
Roheena Abdullah
AKAfshan Kaleem
Afshan Kaleem
Biosynthesis of metal nanoparticles is an area of interest among researchers because of its eco-friendly approach. Current study focuses at biosynthesis of silver nanoparticles (AgNPs) and optimization of physico-chemical conditions to obtain mono-dispersed and stable AgNPs having antimicrobial activity. Initially Bacillus mojavensis BTCB15 produced silver nanoparticles (AgNPs) of 105 nm. Silver nanoparticles (AgNPs) were characterized by particle size analyzer, UV-Vis Spectroscopy, Fourier transforms infrared spectroscopy (FTIR), Atomic force microscopy (AFM), and X-ray diffraction (XRD). Whereas, under optimal conditions of temperature 55 °C, pH 8, addition of surfactant Tween 20, and metal ion K2SO4, about 104% size reduction was achieved with average size of 2.3nm. Molecular characterization revealed 98% sequence homology with Bacillus mojavensis. AgNPs exhibited antibacterial activity at concentrations ranging from 0.5 to 2.5 µg/µl against Escherichia coli BTCB03, Klebsiella pneumonia BTCB04, Acinetobacter sp. BTCB05, and Pseudomonas aeruginosa BTCB01 but none against Staphylococcus aureus BTCB02. Highest antibacterial activity was observed at 0.27 µg/µl and lowest at 0.05 µg/µl of AgNPs indicated by zone of inhibition. Conclusively, under optimum conditions, Bacillus mojavensis BTCB15 was able to produce AgNPs of 2.3 nm size and had antibacterial activity against multi drug resistant pathogens.

28 January 2024 in Saudi Journal of Biological Sciences
Verified
Journal Article
Open access
RARoheena Abdullah
Roheena Abdullah
QYQamar Younas
Qamar Younas
AKAfshan Kaleem
Afshan Kaleem
MIMehwish Iqtedar
Mehwish Iqtedar
MAMahwish Aftab
Mahwish Aftab
FSFaiza Saleem
Faiza Saleem
In the current study the assessment of the antimicrobial and phytochemical properties of Cassia fistula, Musa paradisiaca, Ficus religiosa and Murraya koenigii plants extracts was carried out. The antibacterial potential of these plants extracts was tested against S. aureus and E. coli. The Cassia fistula and Ficus religiosa leaves showed the larger zone of inhibition in aqueous and butanolic extract respectively against Escherichia coli. Musa paradisiaca and Murraya koenigii leaves showed larger zone of inhibition in ethanolic extract against S. aureus. Qualitative phytochemical analysis showed the presence of alkaloids, flavonoids, phenols, terpenoids, steroids, glycosides, saponins, carbohydrates, proteins and tannins in all extracts while phylobatannins, emodins, anthocyanins and leucoanthocyanins were not present in these extracts. Quantitative phytochemical analysis showed the highest alkaloid content in the Murraya koenigii leaves. Highest tannin content and flavonoid content was found in Ficus religiosa leaves, while highest phenolic content was found in case of Cassia fistula. In addition to this antioxidant potential of all the extracts was determined. Musa paradisiaca leaves showed highest antioxidant potential as compared to other plant extracts. In silico analysis of bioactive components present in plant extracts was performed by molecular docking. The rutin and Glu from Musa paradisiaca and Murraya koenigii respectively, were docked with Glycogen Synthase Kinase 3 beta (1GSK-3beta) protein. Quercetin and rutin from Cassia fistula and Ficus religiosa respectively, were docked with C- reactive protein (CRP). The tested bioactive compounds showed good binding affinity with significant number of hydrogen bonds and can be used as a good alternative of synthetic drugs to treat rheumatism and wounds.

31 October 2022 in Saudi Journal of Biological Sciences
Verified
Journal Article
Open access
KNKinza Nisar
Kinza Nisar
RARoheena Abdullah
Roheena Abdullah
AKAfshan Kaleem
Afshan Kaleem
MIMehwish Iqtedar
Mehwish Iqtedar
MAMahwish Aftab
Mahwish Aftab
FSFaiza Saleem
Faiza Saleem
Cellulases involved in the hydrolysis of cellulose and plays a vital role in different industries like textile, detergent paper and Feed industry. Cellulases have been a prospective target for research by both the academic and industrial sectors because of the intricacy of the enzyme system and the enormous industrial potential. In the present work Thermomyces dupontii, which had previously been isolated and recorded as a promising cellulase producer were used. Both endoglucanases and betaglucosidases were purified to its homogeneity by ammonium sulfate followed by anion exchange and gel filtration chromatography. The recovery and purification fold for endoglucanases and betaglucosidases were 13.7, 10.7 % and 5.9, 2.7, respectively. The molecular weight of endoglucanases and betaglucosidases were estimated as 37 and 66 kDa on SDS-PAGE. Upon kinetic analysis the purified endoglucanases and betaglucosidases showed Km 0.63; 28.56 mg/ml and Vmax 82; 80 U/ml/min, respectively. Characterization revealed that enzyme was found to be acidophilic cellulase having optimal pH of 5.5 and 70 ⁰C. Furthermore, cellulases were accelerated in the presence of Ca2+ and EDTA. The cellulases had activation energy (Ea) of −44.55; −50.02 kJ/mol for carboxy-methyl-cellulose hydrolysis and Enthalpy (ΔH) 42.20; 47.70 kJ/mol and entropy ΔS −5.1 and −5.7 kJ/mol for EG and BGL, respectively. In addition to this the enzyme had a secondary structure of protein as represented by FTIR spectrum The current study suggested that purified cellulases can be used as a detergent additive to improve washing. Furthermore, it shows the biostoning ability when applied on jean fabric.

5 August 2021 in PLOS ONE
Verified
Journal Article
Open access
PDF file
RZRida Zainab
Rida Zainab
AKAfshan Kaleem
Afshan Kaleem
Michał Błażej PonczekMichał Błażej Ponczek
Michał Błażej Ponczek
RARoheena Abdullah
Roheena Abdullah
MIMehwish Iqtedar
Mehwish Iqtedar
DHDaniel C. Hoessli
Daniel C. Hoessli
Proprotein convertase subtilisin/kexin type 9 (PCSK9) is one of the key targets for atherosclerosis drug development as its binding with low-density lipoprotein receptor leads to atherosclerosis. The protein-ligand interaction helps to understand the actual mechanism for the pharmacological action. This research aims to discover the best inhibitory candidates targeting PCSK9. To start with, reported ACE inhibitors were incorporated into pharmacophore designing using PharmaGist to produce pharmacophore models. Selected models were later screened against the ZINC database using ZINCPHARMER to define potential drug candidates that were docked with the target protein to understand their interactions. Molecular docking revealed the top 10 drug candidates against PCSK9, with binding energies ranging from -9.8 kcal·mol-1to -8.2 kcal·mol-1, which were analyzed for their pharmacokinetic properties and oral bioavailability. Some compounds were identified as plant-derived compounds like (S)-canadine, hesperetin or labetalol (an antihypertensive drug). Molecular dynamics results showed that these substances formed stable protein-ligand complexes. (S)-canadine-PCSK9 complex was the most stable with the lowest RMSD. It was concluded that (S)-canadine may act as a potential inhibitor against atherosclerosis for the development of new PCSK9 inhibitory drugs in futurein vitroresearch.

28 October 2018 in Bangladesh Journal of Botany
Verified
Journal Article
Open access
PDF file
RARoheena Abdullah
Roheena Abdullah
IFIqra Farooq
Iqra Farooq
AKAfshan Kaleem
Afshan Kaleem
MIMehwish Iqtedar
Mehwish Iqtedar
TITehreema Iftikhar
Tehreema Iftikhar
Different fungal strains were isolated from the local soil, fruits and vegetables on the basis of pectin hydrolysis. All the isolated strains were identified through microscopic studies and screened for pectinase production using solid state fermentation. The fungal strain identified as Aspergillus niger IBT-7 showed the highest pectinase production. The selected strain was further subjected to optimization through different physical and nutritional parameters to enhance the production of pectinase. Amongst seven different media tested M1 containing rice bran, moistened with Czapek’s nutrient medium showed the highest pectinase production. During optimization maximum pectinase production was achieved after 72 hrs of incubation at 30 ml of moisture content, pH 5.0 and 30°C. Xylose (1.5%) and yeast extract (1%) proved to be best supplemented carbon and nitrogen sources, respectively which gave the highest pectinase production (39.1 U/ml/min).