Sadegh Khorrami | University of Isfahan (original) (raw)
Papers by Sadegh Khorrami
Journal of Drug Delivery Science and Technology , 2022
The lack of definitive treatment for cancer and the emergence of drug-resistant cancers highlight... more The lack of definitive treatment for cancer and the emergence of drug-resistant cancers highlights the need for alternative therapies and effective anti-cancer agents. Here, we developed and applied a green approach to fabricate Silver nanoparticles (AgNPs) and Graphene oxide-Silver nanocomposite (Ag-GO) using the black peel pomegranate extract. The nanomaterials' physicochemical properties were characterized using UV-Visible, FTIR, TEM-EDX, and Zeta potential analyses. Then, the nanomaterials' biological activities against cancerous (MCF-7) and normal (HUVEC) cells were evaluated via MTT assay, real-time PCR, and ROS/DCFDA assay protocols. Based on the results, synthesized AgNPs were spherical with 35 ± 5 nm diameter and adequate dispersity. However, very small and uniform AgNPs (10 ± 2 nm) with great dispersity were formed on the GO surface. Also, the nanocomposite surface charge (− 41 mV) was substantially lower than that of AgNPs (− 28 mV), indicating higher stability. Both AgNPs and Ag-GO showed much more activity against cancerous cells than normal ones. Yet, AgNPs cytotoxicity was severe, so that 500 μg/ml of this compound, independently of time, reduced the viability of HUVEC and MCF-7 cells to about 41% and 20%, respectively. Ideally, the Ag-GO activity was moderate and time-dependent. 24 h exposure of MCF-7 cells to this compound (500 μg/ml) led to the increase of cell death from 30% to more than 50% after 48 h. Both nanocompounds increased the Bax/Bcl-2 ratio and intracellular ROS, though, AgNPs showed the most activity to increase the Bax/Bcl-2 ratio, while Ag-GO more effectively increased the amount of ROS levels. These findings demonstrated the method's capability of synthesizing nanocomposites with desirable physicochemical and biological properties.
Biotechnology Reports, 2021
Neurology, Psychiatry and Brain Research, 2020
Abstract Background In the etiology of Alzheimer's disease, the free radicals and Brain choli... more Abstract Background In the etiology of Alzheimer's disease, the free radicals and Brain cholinergic system function, play a key role. The antioxidant compounds may well be effective in improving this disease. Hence, this study aimed to investigate the effects of ginseng on the treatment and prevention of Alzheimer’s disease in a rat model. Methods 56 male Wistar rats were randomly divided into four groups: (1) control, (2) Alzheimer’s without treatment, (3) Alzheimer’s under post-treatment (ginseng, 200 mg/kg/day) for three weeks, and (4) Alzheimer's under pre and post-treatment from one week before induction of Alzheimer's to three weeks after that. To induce Alzheimer's disease 1.5 mg/kg of streptozotocin was injected into both lateral ventricles of the brain. Three weeks after induction, the rats' behavioral tests were applied in all groups. Glutathione peroxidase, Glutathione reductase, Total antioxidant capacity, Malondialdehyde, and Brain-derived neurotrophic factor were measured using commercial kits. Data were analyzed using one-way ANOVA and Bonferroni post hoc test. Results Learning and memory, antioxidant defenses, and BDNF showed a significant decrease after the onset of Alzheimer's induction compared with the control group (p Conclusion Based on our results, pre and post-treatment with ginseng have protective effects against Alzheimer -induced learning and memory impairment. The effects of ginseng may be mediated through an increase in BDNF and antioxidants levels in the hippocampus region of the brain.
Food Science & Nutrition, 2020
Biocatalysis and Agricultural Biotechnology, 2020
Biotechnology Reports, 2019
International Journal of Nanomedicine, 2018
Introduction: Silver nanoparticles (AgNPs) are of great interest due to their unique and controll... more Introduction: Silver nanoparticles (AgNPs) are of great interest due to their unique and controllable characteristics. Different synthesis methods have been proposed to produce these nanoparticles, which often require elevated temperatures/pressures or toxic solvents. Thus, green synthesis could be a replacement option as a simple, economically viable and environmentally friendly alternative approach for the synthesis of silver nanoparticles. Methods: Here, the potential of the walnut green husk was investigated in the production of silver nanoparticles. An aqueous solution extracted from walnut green husk was used as a reducing agent as well as a stabilizing agent. Then, the synthesized nanoparticles were characterized with respect of their anticancer, antioxidant, and antimicrobial properties. Results: Results showed that the synthesized nanoparticles possessed an average size of 31.4 nm with a Zeta potential of-33.8 mV, indicating high stability. A significant improvement in the cytotoxicity and antioxidant characteristics of the green synthesized Ag nanoparticles against a cancerous cell line was observed in comparison with the walnut green husk extract and a commercial silver nanoparticle (CSN). This could be due to a synergistic effect of the synthesized silver nanoparticles and their biological coating. AgNPs and the extract exhibited 70% and 40% cytotoxicity against MCF-7 cancerous cells, respectively, while CSN caused 56% cell death (at the concentration of 60 µg/mL). It was observed that AgNPs were much less cytotoxic when tested against a noncancerous cell line (L-929) in comparison with the control material (CSN). The free radical scavenging analysis demonstrated profound anti-oxidant activity for the synthesized nanoparticles in comparison with the extract and CSN. It was also detected that the synthesized AgNPs possess antibacterial activity against nosocomial and standard strains of both Grampositive and Gram-negative bacteria (minimum inhibitory concentration =5-30 µg/mL). Conclusion: These findings imply that the synthesized nanoparticles using green nanotechnology could be an ideal strategy to combat cancer and infectious diseases.
Considering the prevalence of resistance to antibiotics, the discovery of effective agents agains... more Considering the prevalence of resistance to antibiotics, the discovery of effective agents against resistant pathogens is of extreme urgency. Herein, 26 mecA -positive methicillin-resistant S. aureus (MRSA) isolated from clinical samples were identified, and their resistance to 11 antibiotics was investigated. Next, the antibacterial and anti-biofilm activity of the ethanolic extract of M. communis on these strains was evaluated. Furthermore, the effect of this extract on the expression of biofilm-associated genes, icaA , icaD , bap , sarA , and agr , was studied. According to the results, all isolated strains were multidrug-resistant and showed resistance to oxacillin and tetracycline. Also, 96.15 and 88.46 % of them were resistant to gentamicin and erythromycin. However, the extract could effectively combat the strains. The minimum inhibitory concentration (MIC) against different strains ranged from 1.56 to 25 mg/ml and the minimum bactericidal concentration (MBC) was between 3.12...
Researchers believe that food plays an increasingly important role in society with respect to dis... more Researchers believe that food plays an increasingly important role in society with respect to disease prevention and human well-being. For this reason, the microbial aspects of food safety should seriously be taken into consideration (1,2). Due to their essential role in producing flavor and providing food preservation, lactic acid bacteria (LAB, e.g., lactobacilli) are highly important in fermented foods. It is found that the use of these bacteria as probiotic starters leads to the production of stable intestinal flora, competition with potentially harmful bacteria, and the prevention of certain diseases (3-5). In addition, these bacteria are considered as effective means for enhancing food safety and stability due to consumers’ awareness and concern regarding chemical additives (6). Further, LAB can act as an antagonist against some pathogenic bacteria by producing various antimicrobial compounds such as bacteriocins (7), organic acids, hydrogen peroxide, carbon dioxide, and diace...
Biocatalysis and Agricultural Biotechnology
Biofilm formation is one of the major problems associated with pathogenic bacteria besides drug r... more Biofilm formation is one of the major problems associated with pathogenic bacteria besides drug resistance. In this study, the potential of the bacterial strain of mine soil in the biosynthesis of silver nanoparticles with antibacterial and anti-biofilm activities was investigated. The study revealed that the isolated Bacillus thuringiensis is an efficient bacterial strain in the biosynthesis of silver nanoparticles. Based on the results, the spherical biosynthesized silver nanoparticles with a 42 nm average size have good antibacterial properties at low concentrations (MIC = 6.25–12.5 μg/mL). Moreover, these nanoparticles not only inhibited the formation of biofilm, but were also able to interfere in biofilm metabolic activity and its degradation. Besides, with increasing concentrations of nanoparticles, degeneration of bacterial biofilm also increased so that the highest rate of bacterial biofilm degeneration (>90%) was observed at 6 μg/mL concentration.
AMB Express, 2021
Considering the prevalence of resistance to antibiotics, the discovery of effective agents agains... more Considering the prevalence of resistance to antibiotics, the discovery of effective agents against resistant pathogens is of extreme urgency. Herein, 26 mecA-positive methicillin-resistant S. aureus (MRSA) isolated from clinical samples were identified, and their resistance to 11 antibiotics was investigated. Next, the antibacterial and anti-biofilm activity of the ethanolic extract of M. communis on these strains was evaluated. Furthermore, the effect of this extract on the expression of biofilm-associated genes, icaA, icaD, bap, sarA, and agr, was studied. According to the results, all isolated strains were multidrug-resistant and showed resistance to oxacillin and tetracycline. Also, 96.15 and 88.46 % of them were resistant to gentamicin and erythromycin. However, the extract could effectively combat the strains. The minimum inhibitory concentration (MIC) against different strains ranged from 1.56 to 25 mg/ml and the minimum bactericidal concentration (MBC) was between 3.125 and 50 mg/ml. Even though most MRSA (67 %) strongly produced biofilm, the sub-MIC concentration of the extract destroyed the pre-formed biofilm and affected the bacterial cells inside the biofilm. It could also inhibit biofilm development by significantly decreasing the expression of icaA, icaD, sarA and bap genes involved in biofilm formation and development. In conclusion, the extract inhibits biofilm formation, ruins pre-formed biofilm, and kills cells living inside the biofilm. Furthermore, it down-regulates the expression of necessary genes and nips the biofilm formation in the bud.
Biotechnology Reports , 2021
Herein, 18 lactic acid bacteria isolated from 30 samples of traditional dairy products were ident... more Herein, 18 lactic acid bacteria isolated from 30 samples of traditional dairy products were identified, and their probiotic potential was evaluated. According to the results, almost all strains showed the probiotic properties sufficiently, though M1 had better characterise. 16S rRNA gene sequencing revealed that this strain belongs to the Pediococcus sp. (<95 % similarity). This strain had substantial antipathogenic activity and did not show any worrying antibiotic resistance. Also, the strain was resistant to high concentrations of bile salt (1 %), NaCl (6.5 %), and low pH (2). Furthermore, it was revealed that cell-free supernatant (CFS), heat-killed cells and live cells derived from M1 significantly decreased the viability of MCF-7 cells so that the CFS resulted in 85 % cell death. Flow cytometry and western blot analysis determined that this compound induced apoptosis in the cancerous cells through increasing the BAX protein expression and decreasing the Bcl-2 protein expression.
food science & nutrition, 2020
This study was aimed to isolate and partially characterizes the bacteriocin produced by an L. pla... more This study was aimed to isolate and partially characterizes the bacteriocin produced by an L. plantarum sp. isolated from traditional sourdough. The bacteriocin was partially purified, and after treating it with different harsh conditions, its antibacterial activity was evaluated against L. monocytogenes as an indicator. Also, the growth phase during which the bacteriocin is produced, and its mode of action, was examined. Finally, the molecular weight of this compound was evaluated by using SDS-PAGE analysis. According to the results, this bacteriocin had a molecular weight well lower than 10 kDa that was mainly produced at the early stationary phase and reached its highest activity (3,200 AU/ml) at the same stage. It was tolerant toward a wide range of pH (2–10), temperatures (−20 to 120°C), and high concentrations of NaCl. Notably, the bacteriocin-producing strain had proteolytic activity, while the bacteriocin produced by that showed resistance to proteolytic enzymes (pepsin, trypsin, and proteinase K). Also, it was revealed that the bacteriocin activity is mostly bacteriostatic so that it considerably inhibits pathogens’ growth, particularly S. aureus, E. coli, and
L. monocytogenes. These characteristics prove that strain and its bacteriocin can be considered as one of the most promising agents to use in the food industry.
Neurology, Psychiatry and Brain Research, 2020
Background: In the etiology of Alzheimer's disease, the free radicals and Brain cholinergic syste... more Background: In the etiology of Alzheimer's disease, the free radicals and Brain cholinergic system function, play a key role. The antioxidant compounds may well be effective in improving this disease. Hence, this study aimed to investigate the effects of ginseng on the treatment and prevention of Alzheimer's disease in a rat model. Methods: 56 male Wistar rats were randomly divided into four groups: (1) control, (2) Alzheimer's without treatment, (3) Alzheimer's under post-treatment (ginseng, 200 mg/kg/day) for three weeks, and (4) Alzheimer's under pre and post-treatment from one week before induction of Alzheimer's to three weeks after that. To induce Alzheimer's disease 1.5 mg/kg of streptozotocin was injected into both lateral ventricles of the brain. Three weeks after induction, the rats' behavioral tests were applied in all groups. Glutathione peroxidase, Glutathione reductase, Total antioxidant capacity, Malondialdehyde, and Brain-derived neurotrophic factor were measured using commercial kits. Data were analyzed using one-way ANOVA and Bonferroni post hoc test. Results: Learning and memory, antioxidant defenses, and BDNF showed a significant decrease after the onset of Alzheimer's induction compared with the control group (p < 0.05). Pre and post-treatment of the Alzheimer animals with ginseng significantly improved their learning and memory, antioxidant defenses, and BDNF levels (p < 0.05) compared with the Alzheimer animals without treatment. Conclusion: Based on our results, pre and post-treatment with ginseng have protective effects against Alzheimer-induced learning and memory impairment. The effects of ginseng may be mediated through an increase in BDNF and antioxidants levels in the hippocampus region of the brain.
Biocatalysis and Agricultural Biotechnology, 2020
Black peel pomegranate is one of the rarest cultivars of Punica granatum that has not been studie... more Black peel pomegranate is one of the rarest cultivars of Punica granatum that has not been studied precisely. However, selective cytotoxicity and potent antioxidant activity of the fruit peel extract have already been revealed. This study aimed to investigate the antibacterial activity of the extract, and silver nanoparticles synthesized by the extract, against gram-positive and gram-negative bacterial strains. Nanoparticles were characterized by UV–Vis spectroscopy, FE-SEM, and EDS, and their Zeta potential was also evaluated. According to the results, the spherical nanoparticles had an average size of 19 nm and the surface charge of −33 mV. Both extract and silver nanoparticles showed potent antibacterial activity against P. aeruginosa and S. aureus strains, although the gram-negative strain (P. aeruginosa) was less sensitive to these agents. Furthermore, these nanoparticles were able to kill the bacteria at very low concentrations (MBC = 40–65 μg/ml), while no MBC for the extract was determined, confirming it is a bacteriostatic agent. The results determine that “black peel pomegranate” can be considered as a high potential agent to combat infectious diseases due to its significant bacteriostatic activity.
"Black Peel Pomegranate" is a rare pomegranate cultivar that its specific features are still unco... more "Black Peel Pomegranate" is a rare pomegranate cultivar that its specific features are still uncovered particularly in the bio-nano researches. The present study was organized to evaluate this pomegranate's potential in the biosynthesis of silver nanoparticles as well as bio-medical activities. According to the results, the pomegranate peel extract incredibly inhibited 100 % of DPPH free radicals (EC 50 = 5 mg/mL). This extract also induced more than 70 % cell death in the treated breast tumor cell lines, BT-20 and MCF-7. Interestingly, the extract was capable of biosynthesis very stable and small (15.6 nm) silver nanoparticles at ambient temperature in an ultra-fast pace. Likewise, these nanoparticles inhibited 77 % of DPPH free radicals (EC 50 = 9 mg/mL). Although this antioxidant capacity was lower than that of the extract, instead, the anticancer activity of the synthesized nanoparticles was significantly enhanced, so that they led to more than 81 % and 89 % cell death in the breast tumor cell lines BT-20 and MCF-7, respectively. Considerably, neither the extract nor the biosynthesized silver nanoparticles, showed significant toxicity against non-tumor cell lines (L-929) at the same concentrations. These features of the biosynthesized nanoparticles were quite outstanding in comparison with chemical/commercial ones. Overall, the present study introduces black peel pomegranate as a worthy bio-agent in the biosynthesis of silver nanoparticles with unique activities as well as a cancer treatment.
Avicenna Journal of Clinical Microbiology and Infection, 2019
Background: The main purpose of the present study was to identify the qualified probiotic strains... more Background: The main purpose of the present study was to identify the qualified probiotic strains of traditional sourdough and to find stable Lactobacillus strains with enhanced antibacterial/antagonistic activity and without antibiotic resistance.
Methods: Sixteen strains were isolated from traditional sourdough and their susceptibility was evaluated toward a number of different antibiotics. In addition, the isolated strains were assessed with respect to their probiotic properties, antagonistic activity, and resistance to low pH, bile salt, different NaCl concentrations, and low storage temperatures.
Results: Based on the results, although none of the strains had considerable antibiotic resistance, they showed significant antagonistic activity against 6 different pathogens. Among the isolates, H3a and K3b were the most resistant to low pH and bile salt (0.3%) and demonstrated most hydrophobicity, auto-aggregation, and coaggregation characteristics. It was also observed that the strains could produce strong biofilm and were viable at 1%-10% NaCl concentrations, as well as at 4°C and -20°C. Finally, the sequencing results revealed that these
2 strains had the highest homology to Lactobacillus plantarum based on the 16S rRNA gene.
Conclusions: The present data confirmed the safety of Lactobacillus content of the traditional sourdough and the
unique probiotic properties of these strains.
Scientific Reports , 2019
Contrary to popular belief, the results of this investigation shows: o Graphene Oxide (GO) neithe... more Contrary to popular belief, the results of this investigation shows:
o Graphene Oxide (GO) neither show antibacterial nor cytotoxic activities by itself.
o Compounding of silver nanoparticles with GO does not necessarily result in enhanced antibacterial or cytotoxic activities.
o The step of the synthesis process on which reducing/stabilizing agent is added seriously affects the properties of final products.
Journal of Drug Delivery Science and Technology , 2022
The lack of definitive treatment for cancer and the emergence of drug-resistant cancers highlight... more The lack of definitive treatment for cancer and the emergence of drug-resistant cancers highlights the need for alternative therapies and effective anti-cancer agents. Here, we developed and applied a green approach to fabricate Silver nanoparticles (AgNPs) and Graphene oxide-Silver nanocomposite (Ag-GO) using the black peel pomegranate extract. The nanomaterials' physicochemical properties were characterized using UV-Visible, FTIR, TEM-EDX, and Zeta potential analyses. Then, the nanomaterials' biological activities against cancerous (MCF-7) and normal (HUVEC) cells were evaluated via MTT assay, real-time PCR, and ROS/DCFDA assay protocols. Based on the results, synthesized AgNPs were spherical with 35 ± 5 nm diameter and adequate dispersity. However, very small and uniform AgNPs (10 ± 2 nm) with great dispersity were formed on the GO surface. Also, the nanocomposite surface charge (− 41 mV) was substantially lower than that of AgNPs (− 28 mV), indicating higher stability. Both AgNPs and Ag-GO showed much more activity against cancerous cells than normal ones. Yet, AgNPs cytotoxicity was severe, so that 500 μg/ml of this compound, independently of time, reduced the viability of HUVEC and MCF-7 cells to about 41% and 20%, respectively. Ideally, the Ag-GO activity was moderate and time-dependent. 24 h exposure of MCF-7 cells to this compound (500 μg/ml) led to the increase of cell death from 30% to more than 50% after 48 h. Both nanocompounds increased the Bax/Bcl-2 ratio and intracellular ROS, though, AgNPs showed the most activity to increase the Bax/Bcl-2 ratio, while Ag-GO more effectively increased the amount of ROS levels. These findings demonstrated the method's capability of synthesizing nanocomposites with desirable physicochemical and biological properties.
Biotechnology Reports, 2021
Neurology, Psychiatry and Brain Research, 2020
Abstract Background In the etiology of Alzheimer's disease, the free radicals and Brain choli... more Abstract Background In the etiology of Alzheimer's disease, the free radicals and Brain cholinergic system function, play a key role. The antioxidant compounds may well be effective in improving this disease. Hence, this study aimed to investigate the effects of ginseng on the treatment and prevention of Alzheimer’s disease in a rat model. Methods 56 male Wistar rats were randomly divided into four groups: (1) control, (2) Alzheimer’s without treatment, (3) Alzheimer’s under post-treatment (ginseng, 200 mg/kg/day) for three weeks, and (4) Alzheimer's under pre and post-treatment from one week before induction of Alzheimer's to three weeks after that. To induce Alzheimer's disease 1.5 mg/kg of streptozotocin was injected into both lateral ventricles of the brain. Three weeks after induction, the rats' behavioral tests were applied in all groups. Glutathione peroxidase, Glutathione reductase, Total antioxidant capacity, Malondialdehyde, and Brain-derived neurotrophic factor were measured using commercial kits. Data were analyzed using one-way ANOVA and Bonferroni post hoc test. Results Learning and memory, antioxidant defenses, and BDNF showed a significant decrease after the onset of Alzheimer's induction compared with the control group (p Conclusion Based on our results, pre and post-treatment with ginseng have protective effects against Alzheimer -induced learning and memory impairment. The effects of ginseng may be mediated through an increase in BDNF and antioxidants levels in the hippocampus region of the brain.
Food Science & Nutrition, 2020
Biocatalysis and Agricultural Biotechnology, 2020
Biotechnology Reports, 2019
International Journal of Nanomedicine, 2018
Introduction: Silver nanoparticles (AgNPs) are of great interest due to their unique and controll... more Introduction: Silver nanoparticles (AgNPs) are of great interest due to their unique and controllable characteristics. Different synthesis methods have been proposed to produce these nanoparticles, which often require elevated temperatures/pressures or toxic solvents. Thus, green synthesis could be a replacement option as a simple, economically viable and environmentally friendly alternative approach for the synthesis of silver nanoparticles. Methods: Here, the potential of the walnut green husk was investigated in the production of silver nanoparticles. An aqueous solution extracted from walnut green husk was used as a reducing agent as well as a stabilizing agent. Then, the synthesized nanoparticles were characterized with respect of their anticancer, antioxidant, and antimicrobial properties. Results: Results showed that the synthesized nanoparticles possessed an average size of 31.4 nm with a Zeta potential of-33.8 mV, indicating high stability. A significant improvement in the cytotoxicity and antioxidant characteristics of the green synthesized Ag nanoparticles against a cancerous cell line was observed in comparison with the walnut green husk extract and a commercial silver nanoparticle (CSN). This could be due to a synergistic effect of the synthesized silver nanoparticles and their biological coating. AgNPs and the extract exhibited 70% and 40% cytotoxicity against MCF-7 cancerous cells, respectively, while CSN caused 56% cell death (at the concentration of 60 µg/mL). It was observed that AgNPs were much less cytotoxic when tested against a noncancerous cell line (L-929) in comparison with the control material (CSN). The free radical scavenging analysis demonstrated profound anti-oxidant activity for the synthesized nanoparticles in comparison with the extract and CSN. It was also detected that the synthesized AgNPs possess antibacterial activity against nosocomial and standard strains of both Grampositive and Gram-negative bacteria (minimum inhibitory concentration =5-30 µg/mL). Conclusion: These findings imply that the synthesized nanoparticles using green nanotechnology could be an ideal strategy to combat cancer and infectious diseases.
Considering the prevalence of resistance to antibiotics, the discovery of effective agents agains... more Considering the prevalence of resistance to antibiotics, the discovery of effective agents against resistant pathogens is of extreme urgency. Herein, 26 mecA -positive methicillin-resistant S. aureus (MRSA) isolated from clinical samples were identified, and their resistance to 11 antibiotics was investigated. Next, the antibacterial and anti-biofilm activity of the ethanolic extract of M. communis on these strains was evaluated. Furthermore, the effect of this extract on the expression of biofilm-associated genes, icaA , icaD , bap , sarA , and agr , was studied. According to the results, all isolated strains were multidrug-resistant and showed resistance to oxacillin and tetracycline. Also, 96.15 and 88.46 % of them were resistant to gentamicin and erythromycin. However, the extract could effectively combat the strains. The minimum inhibitory concentration (MIC) against different strains ranged from 1.56 to 25 mg/ml and the minimum bactericidal concentration (MBC) was between 3.12...
Researchers believe that food plays an increasingly important role in society with respect to dis... more Researchers believe that food plays an increasingly important role in society with respect to disease prevention and human well-being. For this reason, the microbial aspects of food safety should seriously be taken into consideration (1,2). Due to their essential role in producing flavor and providing food preservation, lactic acid bacteria (LAB, e.g., lactobacilli) are highly important in fermented foods. It is found that the use of these bacteria as probiotic starters leads to the production of stable intestinal flora, competition with potentially harmful bacteria, and the prevention of certain diseases (3-5). In addition, these bacteria are considered as effective means for enhancing food safety and stability due to consumers’ awareness and concern regarding chemical additives (6). Further, LAB can act as an antagonist against some pathogenic bacteria by producing various antimicrobial compounds such as bacteriocins (7), organic acids, hydrogen peroxide, carbon dioxide, and diace...
Biocatalysis and Agricultural Biotechnology
Biofilm formation is one of the major problems associated with pathogenic bacteria besides drug r... more Biofilm formation is one of the major problems associated with pathogenic bacteria besides drug resistance. In this study, the potential of the bacterial strain of mine soil in the biosynthesis of silver nanoparticles with antibacterial and anti-biofilm activities was investigated. The study revealed that the isolated Bacillus thuringiensis is an efficient bacterial strain in the biosynthesis of silver nanoparticles. Based on the results, the spherical biosynthesized silver nanoparticles with a 42 nm average size have good antibacterial properties at low concentrations (MIC = 6.25–12.5 μg/mL). Moreover, these nanoparticles not only inhibited the formation of biofilm, but were also able to interfere in biofilm metabolic activity and its degradation. Besides, with increasing concentrations of nanoparticles, degeneration of bacterial biofilm also increased so that the highest rate of bacterial biofilm degeneration (>90%) was observed at 6 μg/mL concentration.
AMB Express, 2021
Considering the prevalence of resistance to antibiotics, the discovery of effective agents agains... more Considering the prevalence of resistance to antibiotics, the discovery of effective agents against resistant pathogens is of extreme urgency. Herein, 26 mecA-positive methicillin-resistant S. aureus (MRSA) isolated from clinical samples were identified, and their resistance to 11 antibiotics was investigated. Next, the antibacterial and anti-biofilm activity of the ethanolic extract of M. communis on these strains was evaluated. Furthermore, the effect of this extract on the expression of biofilm-associated genes, icaA, icaD, bap, sarA, and agr, was studied. According to the results, all isolated strains were multidrug-resistant and showed resistance to oxacillin and tetracycline. Also, 96.15 and 88.46 % of them were resistant to gentamicin and erythromycin. However, the extract could effectively combat the strains. The minimum inhibitory concentration (MIC) against different strains ranged from 1.56 to 25 mg/ml and the minimum bactericidal concentration (MBC) was between 3.125 and 50 mg/ml. Even though most MRSA (67 %) strongly produced biofilm, the sub-MIC concentration of the extract destroyed the pre-formed biofilm and affected the bacterial cells inside the biofilm. It could also inhibit biofilm development by significantly decreasing the expression of icaA, icaD, sarA and bap genes involved in biofilm formation and development. In conclusion, the extract inhibits biofilm formation, ruins pre-formed biofilm, and kills cells living inside the biofilm. Furthermore, it down-regulates the expression of necessary genes and nips the biofilm formation in the bud.
Biotechnology Reports , 2021
Herein, 18 lactic acid bacteria isolated from 30 samples of traditional dairy products were ident... more Herein, 18 lactic acid bacteria isolated from 30 samples of traditional dairy products were identified, and their probiotic potential was evaluated. According to the results, almost all strains showed the probiotic properties sufficiently, though M1 had better characterise. 16S rRNA gene sequencing revealed that this strain belongs to the Pediococcus sp. (<95 % similarity). This strain had substantial antipathogenic activity and did not show any worrying antibiotic resistance. Also, the strain was resistant to high concentrations of bile salt (1 %), NaCl (6.5 %), and low pH (2). Furthermore, it was revealed that cell-free supernatant (CFS), heat-killed cells and live cells derived from M1 significantly decreased the viability of MCF-7 cells so that the CFS resulted in 85 % cell death. Flow cytometry and western blot analysis determined that this compound induced apoptosis in the cancerous cells through increasing the BAX protein expression and decreasing the Bcl-2 protein expression.
food science & nutrition, 2020
This study was aimed to isolate and partially characterizes the bacteriocin produced by an L. pla... more This study was aimed to isolate and partially characterizes the bacteriocin produced by an L. plantarum sp. isolated from traditional sourdough. The bacteriocin was partially purified, and after treating it with different harsh conditions, its antibacterial activity was evaluated against L. monocytogenes as an indicator. Also, the growth phase during which the bacteriocin is produced, and its mode of action, was examined. Finally, the molecular weight of this compound was evaluated by using SDS-PAGE analysis. According to the results, this bacteriocin had a molecular weight well lower than 10 kDa that was mainly produced at the early stationary phase and reached its highest activity (3,200 AU/ml) at the same stage. It was tolerant toward a wide range of pH (2–10), temperatures (−20 to 120°C), and high concentrations of NaCl. Notably, the bacteriocin-producing strain had proteolytic activity, while the bacteriocin produced by that showed resistance to proteolytic enzymes (pepsin, trypsin, and proteinase K). Also, it was revealed that the bacteriocin activity is mostly bacteriostatic so that it considerably inhibits pathogens’ growth, particularly S. aureus, E. coli, and
L. monocytogenes. These characteristics prove that strain and its bacteriocin can be considered as one of the most promising agents to use in the food industry.
Neurology, Psychiatry and Brain Research, 2020
Background: In the etiology of Alzheimer's disease, the free radicals and Brain cholinergic syste... more Background: In the etiology of Alzheimer's disease, the free radicals and Brain cholinergic system function, play a key role. The antioxidant compounds may well be effective in improving this disease. Hence, this study aimed to investigate the effects of ginseng on the treatment and prevention of Alzheimer's disease in a rat model. Methods: 56 male Wistar rats were randomly divided into four groups: (1) control, (2) Alzheimer's without treatment, (3) Alzheimer's under post-treatment (ginseng, 200 mg/kg/day) for three weeks, and (4) Alzheimer's under pre and post-treatment from one week before induction of Alzheimer's to three weeks after that. To induce Alzheimer's disease 1.5 mg/kg of streptozotocin was injected into both lateral ventricles of the brain. Three weeks after induction, the rats' behavioral tests were applied in all groups. Glutathione peroxidase, Glutathione reductase, Total antioxidant capacity, Malondialdehyde, and Brain-derived neurotrophic factor were measured using commercial kits. Data were analyzed using one-way ANOVA and Bonferroni post hoc test. Results: Learning and memory, antioxidant defenses, and BDNF showed a significant decrease after the onset of Alzheimer's induction compared with the control group (p < 0.05). Pre and post-treatment of the Alzheimer animals with ginseng significantly improved their learning and memory, antioxidant defenses, and BDNF levels (p < 0.05) compared with the Alzheimer animals without treatment. Conclusion: Based on our results, pre and post-treatment with ginseng have protective effects against Alzheimer-induced learning and memory impairment. The effects of ginseng may be mediated through an increase in BDNF and antioxidants levels in the hippocampus region of the brain.
Biocatalysis and Agricultural Biotechnology, 2020
Black peel pomegranate is one of the rarest cultivars of Punica granatum that has not been studie... more Black peel pomegranate is one of the rarest cultivars of Punica granatum that has not been studied precisely. However, selective cytotoxicity and potent antioxidant activity of the fruit peel extract have already been revealed. This study aimed to investigate the antibacterial activity of the extract, and silver nanoparticles synthesized by the extract, against gram-positive and gram-negative bacterial strains. Nanoparticles were characterized by UV–Vis spectroscopy, FE-SEM, and EDS, and their Zeta potential was also evaluated. According to the results, the spherical nanoparticles had an average size of 19 nm and the surface charge of −33 mV. Both extract and silver nanoparticles showed potent antibacterial activity against P. aeruginosa and S. aureus strains, although the gram-negative strain (P. aeruginosa) was less sensitive to these agents. Furthermore, these nanoparticles were able to kill the bacteria at very low concentrations (MBC = 40–65 μg/ml), while no MBC for the extract was determined, confirming it is a bacteriostatic agent. The results determine that “black peel pomegranate” can be considered as a high potential agent to combat infectious diseases due to its significant bacteriostatic activity.
"Black Peel Pomegranate" is a rare pomegranate cultivar that its specific features are still unco... more "Black Peel Pomegranate" is a rare pomegranate cultivar that its specific features are still uncovered particularly in the bio-nano researches. The present study was organized to evaluate this pomegranate's potential in the biosynthesis of silver nanoparticles as well as bio-medical activities. According to the results, the pomegranate peel extract incredibly inhibited 100 % of DPPH free radicals (EC 50 = 5 mg/mL). This extract also induced more than 70 % cell death in the treated breast tumor cell lines, BT-20 and MCF-7. Interestingly, the extract was capable of biosynthesis very stable and small (15.6 nm) silver nanoparticles at ambient temperature in an ultra-fast pace. Likewise, these nanoparticles inhibited 77 % of DPPH free radicals (EC 50 = 9 mg/mL). Although this antioxidant capacity was lower than that of the extract, instead, the anticancer activity of the synthesized nanoparticles was significantly enhanced, so that they led to more than 81 % and 89 % cell death in the breast tumor cell lines BT-20 and MCF-7, respectively. Considerably, neither the extract nor the biosynthesized silver nanoparticles, showed significant toxicity against non-tumor cell lines (L-929) at the same concentrations. These features of the biosynthesized nanoparticles were quite outstanding in comparison with chemical/commercial ones. Overall, the present study introduces black peel pomegranate as a worthy bio-agent in the biosynthesis of silver nanoparticles with unique activities as well as a cancer treatment.
Avicenna Journal of Clinical Microbiology and Infection, 2019
Background: The main purpose of the present study was to identify the qualified probiotic strains... more Background: The main purpose of the present study was to identify the qualified probiotic strains of traditional sourdough and to find stable Lactobacillus strains with enhanced antibacterial/antagonistic activity and without antibiotic resistance.
Methods: Sixteen strains were isolated from traditional sourdough and their susceptibility was evaluated toward a number of different antibiotics. In addition, the isolated strains were assessed with respect to their probiotic properties, antagonistic activity, and resistance to low pH, bile salt, different NaCl concentrations, and low storage temperatures.
Results: Based on the results, although none of the strains had considerable antibiotic resistance, they showed significant antagonistic activity against 6 different pathogens. Among the isolates, H3a and K3b were the most resistant to low pH and bile salt (0.3%) and demonstrated most hydrophobicity, auto-aggregation, and coaggregation characteristics. It was also observed that the strains could produce strong biofilm and were viable at 1%-10% NaCl concentrations, as well as at 4°C and -20°C. Finally, the sequencing results revealed that these
2 strains had the highest homology to Lactobacillus plantarum based on the 16S rRNA gene.
Conclusions: The present data confirmed the safety of Lactobacillus content of the traditional sourdough and the
unique probiotic properties of these strains.
Scientific Reports , 2019
Contrary to popular belief, the results of this investigation shows: o Graphene Oxide (GO) neithe... more Contrary to popular belief, the results of this investigation shows:
o Graphene Oxide (GO) neither show antibacterial nor cytotoxic activities by itself.
o Compounding of silver nanoparticles with GO does not necessarily result in enhanced antibacterial or cytotoxic activities.
o The step of the synthesis process on which reducing/stabilizing agent is added seriously affects the properties of final products.