scholarly journals Antimicrobial Activity and Nutraceutical Potential of Tuscan Bee-Pollens on Oxidative and Endoplasmic Reticulum Stress in Different Cell-Based Models

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 108
Author(s):  
Morena Gabriele ◽  
Stefania Frassinetti ◽  
Laura Pucci

Bee-pollen is an apiary product of great interest owing to its high nutritional and therapeutic properties. This study aimed to assess the cellular antioxidant activity and the antihemolytic effects of Castanea, Rubus, and Cistus bee-pollens on oxidized human erythrocytes. In addition, the antimicrobial potential of each sample was tested on three Gram-negative and two Gram-positive bacteria. Finally, the effect of Castanea bee-pollen, showing better phytochemical content, was analyzed on human microvascular endothelial cells (HMEC-1) exposed to thapsigargin, used to induce endoplasmic reticulum stress (ER-stress). Our results showed good biological activities of all bee-pollen samples, which, under oxidative conditions, significantly improved the erythrocytes’ antioxidant activity and limited cell lyses. Moreover, all samples exerted antimicrobial activity with different selectivity among the tested microorganisms, with minimal inhibitory concentration values ranging from 5 to 10 mg/mL. Finally, thapsigargin treatment increased intracellular ROS (reactive oxygen species) production and up-regulated the expression of factors involved in the ER-stress and inflammatory pathways. Conversely, Castanea bee-pollen was effective in reducing gene overexpression, as well as the oxidation process arising from thapsigargin treatment, with a maximum protective effect at 10 µg/mL. In conclusion, bee-pollens, mainly Castanea species, represent good natural antibacterial and potential nutraceutical products useful in the prevention of free radical and ER-stress associated diseases.

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1422
Author(s):  
Morena Gabriele ◽  
Stefania Frassinetti ◽  
Laura Pucci

Bee pollen is an apiary product of great interest owing to its high nutritional and therapeutic properties. This study aimed to assess the cellular antioxidant activity and the antihemolytic effect of Castanea, Rubus, and Cistus bee pollens on human erythrocytes. We also tested the antimicrobial potential of each sample on selected Gram-negative and Gram-positive bacteria. Finally, the effect of Castanea bee pollen, showing the best phytochemical profile, was analyzed on human microvascular endothelial cells exposed to thapsigargin, used as endoplasmic reticulum (ER) stressor. Our results showed good biological activities of all bee pollen samples that, under oxidative conditions, significantly improved the erythrocytes’ antioxidant activity and limited cell lyses. Castanea and Cistus showed comparable antihemolytic activities, with higher % hemolysis inhibition than Rubus. All samples exerted antimicrobial activity with different selectivity among all the tested microorganisms with minimal inhibitory concentration values ranging from 5 to 10 mg/mL. Finally, Castanea bee pollen was effective in reducing gene over-expression and oxidation process arising from thapsigargin treatment, with a maximum protective effect at 10 µg/mL. In conclusion, bee pollen represents a potential natural antibacterial and a good nutraceutical product useful in the prevention of free radical and ER stress-associated diseases.


2021 ◽  
Vol 33 (3) ◽  
pp. 545-550
Author(s):  
P. Siripipatthana ◽  
P. Srihanam ◽  
A. Sangdee

A hydromethanolic root extract of Ampelocissus martinii Planch. (A. martinii) was analyzed by standard methods for its phytochemical content, antioxidant activity, α-amylase and α-glucosidase inhibitions and antibacterial activities. The root extract exhibited the highest content of saponins, followed by phenols, proanthocyanidin and flavonoids, respectively. It showed high antioxidant activity in FRAP and CUPRAC assays. The root extract and standard Trolox had similar antioxidant activities in the DPPH and ABTS assay. It also showed much higher α-amylase and α-glucosidase inhibitory activity compared to standard acarbose. Moreover, the root extract inhibited all tested Gram-positive bacteria with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 6.25 mg/mL. These results indicate that A. martinii root can be pharmaceutically used as active ingredients to prevent bacterial infection and radical-related diseases especially diabetes.


2021 ◽  
Vol 39 (No. 4) ◽  
pp. 273-280
Author(s):  
Saban Keskin ◽  
Semiramis Karlidag ◽  
Nazlı Mayda ◽  
Asli Ozkok

Honey, a natural healing agent and a sweet food, has been used since ancient times. A honey sample could possess many biological activities depending on its chemical composition. The amount and the diversity of these minor components of honey mainly depend on the floral sources. That is why the biological activity of the honey sample obtained in a region should be determined. In this study, total phenolic and flavonoid content, antioxidant activity, melissopalynological analyses and antimicrobial activity of twenty honey samples obtained from Doganyol, Malatya, Turkey were examined. In order to determine the in vitro antibacterial activity of honey samples, the agar well diffusion (AWD) method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were used. For this purpose, ten Gram-positive bacteria and eight Gram-negative bacteria were used. Total phenolic content was found in the range from 9.68 ± 0.72 to 29.40 ± 1.03 mg GAE g<sup>–1</sup> sample. Antioxidant activity of honey samples varied from 2.21 ± 0.46 to 6.03 ± 1.11 µmol FeSO<sub>4</sub> 7H<sub>2</sub>O g<sup>–1</sup>. Honey samples showed moderate antimicrobial activity against tested microorganisms, especially against Gram-positive bacteria. It could be concluded from our findings that there is a good correlation between total phenolic content and the biological activity of honey samples.


2019 ◽  
Vol 19 (5) ◽  
pp. 665-675 ◽  
Author(s):  
Wenjiao Shi ◽  
Zhixin Guo ◽  
Ruixia Yuan

Background and Objective: This study investigated whether rapamycin has a protective effect on the testis of diabetic rats by regulating autophagy, endoplasmic reticulum stress, and oxidative stress. Methods: Thirty male Sprague-Dawley rats were randomly divided into three groups: control, diabetic, and diabetic treated with rapamycin, which received gavage of rapamycin (2mg.kg-1.d-1) after induction of diabetes. Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65mg.Kg-1). All rats were sacrificed at the termination after 8 weeks of rapamycin treatment. The testicular pathological changes were determined by hematoxylin and eosin staining. The protein or mRNA expression of autophagy-related proteins (Beclin1, microtubule-associated protein light chain 3 (LC3), p62), ER stress marked proteins (CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), caspase-12), oxidative stress-related proteins (p22phox, nuclear factor erythroid2-related factor 2 (Nrf2)) and apoptosis-related proteins (Bax, B cell lymphoma-2 (Bcl-2)) were assayed by western blot or real-time fluorescence quantitative PCR. Results: There were significant pathological changes in the testes of diabetic rats. The expression of Beclin1, LC3, Nrf2, Bcl-2 were significantly decreased and p62, CHOP, caspase12, p22phox, and Bax were notably increased in the testis of diabetic rats (P <0.05). However, rapamycin treatment for 8 weeks significantly reversed the above changes in the testis of diabetic rats (P <0.05). Conclusion: Rapamycin appears to produce a protective effect on the testes of diabetic rats by inducing the expression of autophagy and inhibiting the expression of ER-stress, oxidative stress, and apoptosis.


2021 ◽  
Vol 22 (9) ◽  
pp. 4538
Author(s):  
Helena Kratochvílová ◽  
Miloš Mráz ◽  
Barbora J. Kasperová ◽  
Daniel Hlaváček ◽  
Jakub Mahrík ◽  
...  

The aim of our study was to analyze mitochondrial and endoplasmic reticulum (ER) gene expression profiles in subcutaneous (SAT) and epicardial (EAT) adipose tissue, skeletal muscle, and myocardium in patients with and without CAD undergoing elective cardiac surgery. Thirty-eight patients, 27 with (CAD group) and 11 without CAD (noCAD group), undergoing coronary artery bypass grafting and/or valvular surgery were included in the study. EAT, SAT, intercostal skeletal muscle, and right atrium tissue and blood samples were collected at the start and end of surgery; mRNA expression of selected mitochondrial and ER stress genes was assessed using qRT-PCR. The presence of CAD was associated with decreased mRNA expression of most of the investigated mitochondrial respiratory chain genes in EAT, while no such changes were seen in SAT or other tissues. In contrast, the expression of ER stress genes did not differ between the CAD and noCAD groups in almost any tissue. Cardiac surgery further augmented mitochondrial dysfunction in EAT. In our study, CAD was associated with decreased expression of mitochondrial, but not endoplasmic reticulum stress genes in EAT. These changes may contribute to the acceleration of coronary atherosclerosis.


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Eti Nurwening Sholikhah ◽  
Maulina Diah ◽  
Mustofa ◽  
Masriani ◽  
Susi Iravati ◽  
...  

Pycnarrhena cauliflora (Miers.) Diels., local name sengkubak, is one of indigenous plants from West Kalimantan that has been used as natural flavor. Pycnorrhena cauliflora is one of species of Menispermaceae family which is rich in bisbenzylisoquinoline alkaloids. This alkaloids are known to have various biological activities including antiprotozoal, antiplasmodial, antifungal and antibacterial activities. This study aimed to investigate antimicrobial activity of  the P. cauliflora (Miers.) Diels. methanolic extracts against gram-positive and gram-negative bacteria. The methanolic extract of P. cauliflora (Miers.) Diels., root, leaf and stem were prepared by maceration. The disk-diffusion method was then used to determine the antimicrobial activity of the extracts against Streptococcus pyogenes, S. mutants, Staphylococcus aureus, S. epidermidis, Salmonella typhi, Shigella flexneri, Pseudomonas aeruginosa and Escherichia coli after 18-24 h incubation at 37 oC. Amoxicillin was used as positive control for gram-positive bacteria and ciprofloxacin was used as gram-negative bacteria. The inhibition zones were then measured in mm. Analysis were conducted in duplicates. The results showed in general the methanolic extracts of P. cauliflora (Miers.) Diels. root (inhibition zone diameter= 10-23 mm) were more active than that leaf (0-15 mm) and stem (0-17 mm) extracts against gram-positive bacteria. The zone inhibition diameter of amoxicillin as positive control was 8-42 mm. In addition, the methanolic extracts of P. cauliflora (Miers.) Diels. root (12-17 mm) were also more active than that leaf (0-12 mm) and stem (0-12 mm) extracts against gram-negative bacteria. The zone inhibition diameter of ciprofloxacin as positive control was 33-36 mm. In conclusion, the methanolic extract of P. caulifloria (Miers.) Diels. root is the most extract active against both gram-positive and gram-negative bacteria. Further study will be focused to isolate active compounds in the methanolic extract of the root.


Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2669
Author(s):  
Michaela Barkociová ◽  
Jaroslav Tóth ◽  
Katarzyna Sutor ◽  
Natalia Drobnicka ◽  
Slawomir Wybraniec ◽  
...  

Epiphyllum, Hylocereus, and Opuntia plants belong to the Cactaceae family. They are mostly known as ornamental plants but also for their edible fruits, which can potentially be sources of betalains, such as betanin, a natural pigment used in the food industry, e.g., under the European label code E 162. The aim of this work was the identification of betalains (using LC-MS/MS), evaluation of total betalain content (spectrophotometrically), analysis of functional groups (using FT-IR), evaluation of antioxidant activity (using DPPH, ABTS, FRAP, DCFH-DA, and reducing power methods) and evaluation of antimicrobial activity (S. aureus, E. coli, and C. albicans) in fruits of Epiphyllum, Hylocereus, and Opuntia taxa. A total of 20 betalains were identified in the studied Cactaceae fruits. The Epiphyllum pink hybrid had the highest values of total betalains amongst all samples. The highest antioxidant activity was observed in the Epiphyllum pink hybrid, in Opuntia zacuapanensis and O. humifusa fruits. The antimicrobial activity assay showed that cacti fruits were not able to effectively inhibit the growth of E. coli, S. aureus, or C. albicans. Our results prove that these fruits are good sources of natural pigments—betalains. They do not contain toxic compounds in significant amounts and they exhibit antioxidant activity.


2021 ◽  
Author(s):  
Viorica Liebe Lastun ◽  
Matthew Freeman

In metazoans, the architecture of the endoplasmic reticulum (ER) differs between cell types, and undergoes major changes through the cell cycle and according to physiological needs. Although much is known about how the different ER morphologies are generated and maintained, especially the ER tubules, how context dependent changes in ER shape and distribution are regulated and the factors involved are less characterized. Here, we show that RHBDL4, an ER-resident rhomboid protease, modulates the shape and distribution of the ER, especially under conditions that require rapid changes in the ER sheet distribution, including ER stress. RHBDL4 interacts with CLIMP-63, a protein involved in ER sheet stabilisation, and with the cytoskeleton. Mice lacking RHBDL4 are sensitive to ER stress and develop liver steatosis, a phenotype associated with unresolved ER stress. Our data introduce a new physiological role of RHBDL4 and also imply that this function does not require its enzymatic activity.


mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Oanh H. Pham ◽  
Bokyung Lee ◽  
Jasmine Labuda ◽  
A. Marijke Keestra-Gounder ◽  
Mariana X. Byndloss ◽  
...  

ABSTRACT The inflammatory response to Chlamydia infection is likely to be multifactorial and involve a variety of ligand-dependent and -independent recognition pathways. We previously reported the presence of NOD1/NOD2-dependent endoplasmic reticulum (ER) stress-induced inflammation during Chlamydia muridarum infection in vitro, but the relevance of this finding to an in vivo context is unclear. Here, we examined the ER stress response to in vivo Chlamydia infection. The induction of interleukin 6 (IL-6) production after systemic Chlamydia infection correlated with expression of ER stress response genes. Furthermore, when tauroursodeoxycholate (TUDCA) was used to inhibit the ER stress response, an increased bacterial burden was detected, suggesting that ER stress-driven inflammation can contribute to systemic bacterial clearance. Mice lacking both NOD1 and NOD2 or RIP2 exhibited slightly higher systemic bacterial burdens after infection with Chlamydia. Overall, these data suggest a model where RIP2 and NOD1/NOD2 proteins link ER stress responses with the induction of Chlamydia-specific inflammatory responses. IMPORTANCE Understanding the initiation of the inflammatory response during Chlamydia infection is of public health importance given the impact of this disease on young women in the United States. Many young women are chronically infected with Chlamydia but are asymptomatic and therefore do not seek treatment, leaving them at risk of long-term reproductive harm due to inflammation in response to infection. Our manuscript explores the role of the endoplasmic reticulum stress response pathway initiated by an innate receptor in the development of this inflammation.


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