Gold nanoparticles attenuate the interferon-γ induced SOCS1 expression and activation of NF-κB p65/50 activity via modulation of microRNA-155-5p in triple-negative breast cancer cells

Objective

Triple-negative breast cancer (TNBC) is a very aggressive form of cancer that grows and spreads very fast and generally relapses. Therapeutic options of TNBC are limited and still need to be explored completely. Gold nanoparticles conjugated with citrate (citrate-AuNPs) are reported to have anticancer potential; however, their role in regulating microRNAs (miRNAs) in TNBC has never been investigated. This study investigated the potential of citrate-AuNPs against tumorigenic inflammation via modulation of miRNAs in TNBC cells.

Methods

Gold nanoparticles were chemically synthesized using the trisodium-citrate method and were characterized by UV-Vis spectrophotometry and dynamic light scattering studies. Targetscan bioinformatics was used to analyze miRNA target genes. Levels of miRNA and mRNA were quantified using TaqMan assays. The pairing of miRNA in 3'untranslated region (3'UTR) of mRNA was validated by luciferase reporter clone, containing the entire 3'UTR of mRNA, and findings were further re-validated via transfection with miRNA inhibitors.

Results

Newly synthesized citrate-AuNPs were highly stable, with a mean size was 28.3 nm. The data determined that hsa-miR155-5p is a direct regulator of SOCS1 (suppressor-of-cytokine-signaling) expression and citrate-AuNPs inhibits SOCS1 mRNA/protein expression via modulating hsa-miR155-5p expression. Transfection of TNBC MDA-MB-231 cells with anti-miR155-5p markedly increased SOCS1 expression (p<0.001), while citrate-AuNPs treatment significantly inhibited anti-miR155-5p transfection-induced SOCS1 expression (p<0.05). These findings were validated by IFN-γ-stimulated MDA-MB-231 cells. Moreover, the data also determined that citrate-AuNPs also inhibit IFN-γ-induced NF-κB p65/p50 activation in MDA-MB-231 cells transfected with anti-hsa-miR155-5p.

Conclusion

Newly generated citrate-AuNPs were stable and non-toxic to TNBC cells. Citrate-AuNPs inhibit IFN-γ-induced SOCS1 mRNA/protein expression and deactivate NF-κB p65/50 activity via negative regulation of hsa-miR155-5p. These novel pharmacological actions of citrate-AuNPs on IFN-γ-stimulated TNBC cells provide insights that AuNPs inhibit IFN-γ induced inflammation in TNBC cells by modulating the expression of microRNAs.

An Updated Analysis on the Risk Factors Associated with COVID-19 Transmission

BACKGROUND: The coronavirus disease 2019 (COVID-19) is a global public health disaster and knowledge of its associated risk factors provides protection/slowdown against its transmission. AIM: This study was undertaken to investigate all major risk factors associated with transmission of the COVID-19 infection. METHODS: The data on the risk associated factors for the COVID-19 transmission were collected from the Texas Medical Association, Center for Disease Prevention and Control, World Health Organization, and Health and Safety Executive. The collected data were combined, analyzed, and presented as percentage mean ± SD. RESULTS: The collective data showed that among games such as playing football and basketball are highly risky followed by swimming in public pool and playing at the beach. Whereas, playing golf and tennis are not risky (p < 0.05). Moreover, the carryout food from the restaurants is much safer as compared with eating at buffet, in restaurants (p < 0.01). The data on social gathering showed that religious places, sports stadium, music concert, cinema halls, amusement parks, attending funerals, and wedding showed a higher risk of spreading COVID-19. The data on general outing showed that going to gymnasium, traveling by bus or plane, and visiting in salon are highly risky (p < 0.01) for COVID-19 infection. Moreover, hugging, shaking hands, and kissing are also highly risky for the COVID-19 infection. CONCLUSIONS: This study provides the collective information on the risk factors associated with the COVID-19 transmission. The findings can contribute to the concerned authorities to formulate the preventive measures to limit spread of the COVID-19 infection.

Honey polyphenolic fraction inhibits cyclooxygenase-2 expression via upregulation of microRNA-26a-5p expression in pancreatic islets

Objectives

Honey total polyphenolic fraction (HTPF) is reported to have anti-disease potential, however the role of HTPF in the regulation of microRNAs (miRNAs) has never been investigated. This study was undertaken to investigate the potential of HTPF against inflammation via regulation of miRNAs in pancreatic islets of Langerhans.

Methods

Pancreatic islets were isolated from C57BL/6 mice and HTPF was purified from honey. Bioinformatics algorithms were used to determine miRNA target genes. Expression of miRNA and mRNA was determined using their specific taqman assays. Pairing between miRNA and 3′ untranslated region (3′UTR) of mRNA was confirmed using luciferase reporter clone containing the 3′UTR of mRNA sequences and results were verified by transfection of mouse pancreatic β-cell line Min6 with miRNA inhibitors.

Results

The data showed that mmu-miR-26a-5p is a direct regulator of cyclooxygenase-2 (COX-2) expression and HTPF inhibits COX-2 expression or prostaglandin E2 (PGE2) production via up-regulating mmu-miR-26a-5p expression. Transfection of islets with anti-miR-26a-5p significantly enhanced COX-2 expression and PGE2 production ( p < .01), while HTPF treatment significantly inhibited anti-miR-26a-5p transfection-induced COX-2 expression or PGE2 production ( p < .05). These findings were further verified in pancreatic β-cells Min6. Moreover, the data also determined that HTPF also inhibits glucose-induced nuclear transcription factor (NF)-κB activity.

Conclusion

HTPF suppresses glucose-induced PGE2 production and activation of NF-κB via negative regulation of COX-2 and mmu-miR26a-5p. These novel pharmacological actions of HTPF on glucose-stimulated pancreatic islets provide new suggestions that HTPF or HTPF-derived compounds inhibit glucose induced inflammation in pancreas by up-regulating the expression of microRNAs.

Thymoquinone provides structural protection of human hemoglobin against oxidative damage: Biochemical studies

Hydroxyl radicals (OH^.) are one of the most active reactive oxidants recognized for their deleterious effects to cause protein oxidative damage. Thymoquinone, a monoterpene molecule abundantly present in black cumin and known for its pharmacological activities, but its activity against the OH^.-induced protein oxidative damage has never been explored. This study determined the therapeutic potential of thymoquinone against OH^.-induced oxidative human hemoglobin damage. Novel data demonstrated that thymoquinone provides structural protection of hemoglobin against oxidative damage. Treatment of hemoglobin with OH^. induces hypochromicity at 280 and 405 nm, whereas thymoquinone reversed these hypochromic effects. In addition, OH^. cause significant reduction in tryptophan fluorescence, however thymoquinone also reversed these damaging effects. Thymoquinone also reduces OH^.-induced hydrophobicity and also reduces OH^.-induced carbonylation. Moreover, it also inhibits thermal stabilization of OH^.-hemoglobin complex. SDS-PAGE of unmodified hemoglobin showed four bands, which disappeared upon OH^. treatment and these changes were also retained by thymoquinone. In conclusion, this is the first study that shows the therapeutic potential of thymoquinone against OH^.-induced oxidative damage in human hemoglobin.

Dietary Patterns of Females with Cholecystolithiasis: A Comprehensive Study from Central Region of Saudi Arabia

BACKGROUND: Cholecystolithiasis is a worldwide gastrointestinal disorder and dietary pattern is one of the major risk factors involved in formation of cholelithiasis. AIM: This study was undertaken to determine the dietary patterns of female patients with cholecystolithiasis in the central region of Saudi Arabia. METHODS: A total of 332 females respondents were included, among them 157 were cholecystolithiasis cases, whereas 175 were healthy female subjects. All respondents were from central region of Saudi Arabia. Data were collected from a self-administered questionnaire and dietary patterns of studied population samples were compared by Chi-square test using SPSS software. RESULTS: The data showed that the consumption of meat from beef, lamb or goat, butter, ghee, pizza, cereals, legumes, coffee, tea, kabsa rice, tomatoes, and eggs was found to be positively associated with the risk of cholelithiasis. Interestingly, the data also demonstrated that consumption of cakes, chocolates, cookies, ice cream, doughnuts, chicken, fish or other sea foods, French fries, and hot dogs showed no relation with the risk of cholelithiasis. CONCLUSIONS: This study provides a comprehensive description of the dietary patterns of females from central region of Saudi Arabia and their association with the risk of onset of cholelithiasis. Specifically, the majority of non-vegetarian food stuffs showed positive association with the risk of development of cholelithiasis. These findings strongly recommended that the Health Ministry of Saudi Arabia should initiate the specific intervention public health programs on the dietary pattern in relation with the risk of cholelithiasis.

Experience of Cancer Patients for the Usage of Complementary and Alternative Medicine Therapy

BACKGROUND: Cancer patients have always been reported to have multiple complications and the treatment has always seemed challenging. The complementary and alternative medicine (CAM) therapy has widely accepted by the patients with various disorders. AIM: This study evaluated the experience of cancer patients for the usage of CAM therapy. MATERIALS AND METHODS: This is a cross-sectional study designed to determine the experience of cancer patients for the usage of CAM therapy. RESULTS: Out of 232 cancer patients, 94% were urban residents and were non-smokers. Importantly, 66.4% of cancer patients experienced that the combination of CAM with conventional chemotherapy was effective for their treatment. Among all CAM therapies, 31.5% cancer patients experienced that herbal medicines/herbs were good. Among herbal therapies, green tea and black seeds were most effective for cancer patients. In contrast, 12.5% patients experienced that homeopathic medicines were good for their treatment. CONCLUSIONS: To the best of our knowledge, this is the first comprehensive study from Saudi Arabia to show the experience of cancer patients toward the usage of CAM therapy. Most of the cancer patients experienced that CAM therapies with the convention chemotherapy were effective for their treatment. Among all studied CAM therapies, green tea and black seeds were suggested by most of the cancer patients for their treatment.

Absence of CD74 Isoform at 41kDa Prevents the Heterotypic Associations between CD74 and CD44 in Human Lung Adenocarcinoma-derived Cells

Lung cancer is a leading cause of cancer-associated death in all over the globe. This study was undertaken to determine the expression and interaction of membrane-bound receptors CD74 and CD44 in human lung adenocarcinoma cells and their associated signaling was also attempted. Levels of CD74 and CD44 were studied in human lung adenocarcinoma-evolved cells A549 and H460. CD74-mediated downstream signaling was studied by the nuclear-transcription-factor NF-κB and prostaglandin E₂ (PGE₂) production. Flow-cytometric analysis showed that both CD74 and CD44 were perfectly expressed in A549 cells. Importantly, Western immunoblotting showed that A549 cells expressed only two isoforms of CD74 at 33 and 35 kDa but isoform at 41 kDa was absent. These results were verified in H460 cells. Confocal microscopy showed CD74 and CD44 was colocalized but heterotypic interaction between them was missing in both A549 and H460 cells. Activation of NF-κB and production of PGE₂ in human lung cancer cells were comparable with other cancer cells. In conclusion, this is the first study that shows A549 and H460 cells expressed two distinctive isoforms of CD74 but isoform at 41 kDa was absent. Due to the absence of this isoform, the direct physical interaction between them CD74 and CD44 was lacking. Furthermore, the data also demonstrated that lacking of direct physical interaction between CD74 and CD44 had no effect on NF-κB activation and PGE₂ production indicating that CD74-mediated downstream signaling occurs either through coreceptors or indirect interaction with CD44 in human lung cancer cells.

ABBREVIATION

CD: cluster of differentiation; SCLC: small cell lung cancer; NSCLC: nonsmall cell lung cancer; SCC: squamous cell carcinoma; ADC: adenocarcinoma; LCC: large cell carcinoma.

Stress Associated Alterations in Dietary Behaviours of Undergraduate Students of Qassim University, Saudi Arabia

BACKGROUND:

Psychological stress associated eating habits among public health have now become a global concern.

AIM:

This study was undertaken to investigate the levels of psychological stress among undergraduate students of Qassim University and to explore the stress associated alterations in their eating habits.

METHODS:

This is a cross-sectional survey conducted on 614 undergraduate students of Qassim University, Saudi Arabia. A self-administered questionnaire was used, which included questions on socio-demography and eating habits. Level of stress was measured by a standardised questionnaire highlights the levels of non-chronic stimulation through difficulty relaxing, nervous arousal and being easily upset/agitated, irritable / over-reactive and impatient.

RESULTS:

Our results show that 28.2% of total participants suffered from some extent of stress. Among stressed participants, 17.3%, 49.1%, 24.8% and 8.7% of participants suffered from mild, moderate, severe and extremely severe stress, respectively. Stressed participants were more preferred to eat junk foods such as fast foods, snacks and beverages as compared with unstressed participants (p < 0.05) and the junk food preference was increased with the increase of stress levels. Moreover, non-stressed participants preferred more healthy foods such as vegetarian food, fresh fruits as compared with stressed participants (p < 0.05). Taste and easy to access were the main reasons for the preference of junk foods by the stressed participants.

CONCLUSIONS:

This is the first comprehensive study from Saudi Arabia to show stress associated dietary alterations in undergraduates of Qassim University. Data concluded that most of the young adults followed a healthy eating pattern, but a significant number from them were affected by stress. Therefore, specific intervention programs are strongly recommended for the reduction of stress and to improve their quality of life.

MicroRNA-125b-5p regulates IL-1β induced inflammatory genes via targeting TRAF6-mediated MAPKs and NF-κB signaling in human osteoarthritic chondrocytes

Abnormal post-transcriptional modulations in inflammatory genes by microRNAs (miRNAs) play a crucial role in human disorders including arthritis. In this study, we determined the effect of hsa-miR-125b-5p on interleukin (IL)-1β induced inflammatory genes in human osteoarthritic (OA) chondrocytes. Bioinformatics algorithms showed 3′untranslated region (3′UTR) of TRAF6 mRNA (NM_004620.3) has perfectly matched ‘seed-sequence’ for hsa-miR-125b-5p. Treatment of cells with IL-1β up-regulates TRAF6 mRNA and down-regulates hsa-miR-125b-5p expression. This negative correlation between TRAF6 and hsa-miR-125b-5p was verified by transfection with miR-125b mimic (pre-miR-125b). Moreover, transfection with miR-125b mimic caused marked inhibition of IL-1β-induced phosphorylation of p38-MAPK, JNK-MAPKs and ERK-MAPKs and also suppressed the nuclear levels of NF-κBp50, NF-κBp65 and inhibited the activation of IκBα. Furthermore, transfected chondrocytes with miR-125b mimic in the presence of IL-1β also showed marked inhibition in the secretion of several proinflammatory cytokines, chemokines and growth factors including IL-6, IL-8, INF-γ, TGF-β1, IGFBP-1 and PGDF-BB. Importantly, this transfection also significantly inhibited IL-1β- induced MMP-13 expression/production. In short, this study concludes that hsa-miR-125b-5p acts as a negative co-regulator of inflammatory genes including MMP-13 via targeting TRAF6/MAPKs/NF-κB pathway in human OA chondrocytes.

Elevated Levels of Protein Carbonylation in Patients With Diabetic Nephropathy: Therapeutic and Diagnostic Prospects

BACKGROUND

Oxidative stress-induced protein oxidation has been reported in diabetes mellitus; however a relationship between protein carbonylation and diabetic nephropathy remains to be determined. This study was undertaken to investigate a correlation between protein carbonylation and diabetic nephropathy.

METHODS

Sera from 153 patients with diabetic nephropathy and 142 healthy humans were selected and protein carbonylation was compared. The glycated hemoglobin (Hb_A1C), postprandial blood glucose (PPBG), disease duration (DD) and serum creatinine were analyzed and were correlated with the levels of protein oxidation.

RESULTS

Protein carbonylation was more pronounced in patients with diabetic nephropathy as compared with healthy humans (P < 0.001). The data showed a positive correlation between protein oxidation and Hb_A1C (P < 0.001, r = 0.752); the carbonylation was high in those patients with high Hb_A1C (P < 0.01). The data also showed an important correlation between protein oxidation and PPBG (P < 0.0001, r = 0.680); the carbonyl contents were higher in those patients with higher PPBG (P < 0.001). Results also pointed out a positive correlation of protein oxidation with patients DD (P < 0.001, r = 0.769). Importantly, elevated levels of carbonylation in patients with diabetic nephropathy were also correlated with the elevated levels of serum creatinine.

CONCLUSIONS

This is the first study that shows a positive correlation between protein carbonylation and diabetic nephropathy. The higher carbonylation in patients with higher Hb_A1C, blood glucose, DD or serum creatinine indicate that oxidative modifications in proteins play a key role in the progression of diabetic nephropathy.

Protein Mediated Oxidative Stress in Patients with Diabetes and its Associated Neuropathy: Correlation with Protein Carbonylation and Disease Activity Markers

INTRODUCTION

Free radicals have been implicated as Diabetes Mellitus (DM) contributors in type 2 DM and its associated Diabetes Mellitus Neuropathy (DMN). However, the potential for protein mediated oxidative stress to contribute disease pathogenesis remains largely unexplored.

AIM

To investigate the status and contribution of protein mediated oxidative stress in patients with DM or DMN and to explore whether oxidative protein modification has a role in DM progression to DM associated neuropathy.

MATERIALS AND METHODS

Sera from 42 DM and 37 DMN patients with varying levels of disease activities biomarkers (HbA1C, patients' age or disease duration) and 21 age- and sex-matched healthy controls were evaluated for serum levels of protein mediated oxidative stress.

RESULTS

Serum analysis showed significantly higher levels of protein carbonyl contents in both DM and DMN patients compared with healthy controls. Importantly, not only was there an increased number of subjects positive for protein carbonylation, but also the levels of protein carbonyl contents were significantly higher among DM and DMN patients, whose HbA1C were ≥8.8 as compared with patients with lower HbA1C (HbA1C<8.8). Similar pattern of protein carbonyls formation was also observed with patients' ages or with patient's disease durations, suggesting a possible relationship between protein oxidation and disease progression. Furthermore, sera from DMN patients had higher levels of protein carbonylation compared with non-neuropathic DM patients' sera, suggesting an involvement of protein oxidation in the progression of diabetes to diabetes neuropathy.

CONCLUSION

These findings support an association between protein oxidation and DM or DMN progression. The stronger response observed in patients with higher HbA1C or patients' ages or disease durations suggests, that protein mediated oxidative stress may be useful in evaluating the progression of DM and its associated DMN and in elucidating the mechanisms of these disorders pathogenesis.

Epigallocatechin-3-O-gallate modulates global microRNA expression in interleukin-1β-stimulated human osteoarthritis chondrocytes: potential role of EGCG on negative co-regulation of microRNA-140-3p and ADAMTS5

PURPOSE

MicroRNAs (miRNAs) are short, non-coding RNAs involved in almost all cellular processes. Epigallocatechin-3-O-gallate (EGCG) is a green tea polyphenol and is known to exert anti-arthritic effects by inhibiting genes associated with osteoarthritis (OA). This study was undertaken to investigate the global effect of EGCG on interleukin-1β (IL-1β)-induced expression of miRNAs in human chondrocytes.

METHODS

Human chondrocytes were derived from OA cartilage and then treated with EGCG and IL-1β. Human miRNA microarray technology was used to determine the expression profile of 1347 miRNAs. Microarray results were verified by taqman assays and transfection of chondrocytes with miRNA inhibitors.

RESULTS

Out of 1347 miRNAs, EGCG up-regulated expression of 19 miRNAs and down-regulated expression of 17 miRNAs, whereas expression of 1311 miRNAs remains unchanged in IL-1β-stimulated human OA chondrocytes. Bioinformatics approach showed that 3`UTR of ADAMTS5 mRNA contains the 'seed-matched-sequence' for hsa-miR-140-3p. IL-1β-induced expression of ADAMTS5 correlated with down-regulation of hsa-miR-140-3p. Importantly, EGCG inhibited IL-1β-induced ADAMTS5 expression and up-regulated the expression of hsa-miR-140-3p. This EGCG-induced co-regulation between ADAMTS5 and hsa-miR-140-3p becomes reversed in OA chondrocytes transfected with anti-miR-140-3p.

CONCLUSIONS

This study provides an important insight into the molecular basis of the reported anti-arthritic effects of EGCG. Our data indicate that the potential of EGCG in OA chondrocytes may be related to its ability to globally inhibit inflammatory response via modulation of miRNAs expressions.

Epigallocatechin-3-O-gallate up-regulates microRNA-199a-3p expression by down-regulating the expression of cyclooxygenase-2 in stimulated human osteoarthritis chondrocytes

Osteoarthritis (OA) is a most common form of arthritis worldwide leading to significant disability. MicroRNAs (miRNAs) are non‐coding RNAs involved in various aspects of cartilage development, homoeostasis and pathology. Several miRNAs have been identified which have shown to regulate expression of target genes relevant to OA pathogenesis such as matrix metalloproteinase (MMP)‐13, cyclooxygenase (COX)‐2, etc. Epigallocatechin‐3‐O‐gallate (EGCG), the most abundant and active polyphenol in green tea, has been reported to have anti‐arthritic effects, however, the role of EGCG in the regulation of miRNAs has not been investigated in OA. Here, we showed that EGCG inhibits COX‐2 mRNA/protein expression or prostaglandin E₂ (PGE₂) production via up‐regulating microRNA hsa‐miR‐199a‐3p expression in interleukin (IL)‐1β‐stimulated human OA chondrocytes. This negative co‐regulation of hsa‐miR‐199a‐3p and COX‐2 by EGCG was confirmed by transfection of OA chondrocytes with anti‐miR‐199a‐3p. Transfection of OA chondrocytes with anti‐miR‐199a‐3p significantly enhanced COX‐2 expression and PGE₂ production (P < 0.001), while EGCG treatment significantly inhibited anti‐miR‐199a‐3p transfection‐induced COX‐2 expression or PGE₂ production in a dose‐dependent manner. These results were further re‐validated by co‐treatment of these transfection OA chondrocytes with IL‐1β and EGCG. EGCG treatment consistently up‐regulated the IL‐1β‐decreased hsa‐miR‐199a‐3p expression (P < 0.05) and significantly inhibited the IL‐1β‐induced COX‐2 expression/PGE₂ production (P < 0.05) in OA chondrocytes transfected with anti‐hsa‐miR‐199a‐3p. Taken together, these results clearly indicate that EGCG inhibits COX‐2 expression/PGE₂ production via up‐regulation of hsa‐miR‐199a‐3p expression. These novel pharmacological actions of EGCG on IL‐1β‐stimulated human OA chondrocytes provide new suggestions that EGCG or EGCG‐derived compounds inhibit cartilage breakdown or pain by up‐regulating the expression of microRNAs in human chondrocytes.

Integrated Study of Globally Expressed microRNAs in IL-1β-stimulated Human Osteoarthritis Chondrocytes and Osteoarthritis Relevant Genes: A Microarray and Bioinformatics Analysis

This study was undertaken to identify and characterize the globally expressed microRNAs (miRNAs) involved in interleukin-1β (IL-1β)-induced joint damage and to predict whether miRNAs can regulate the catabolic effects in osteoarthritis (OA) chondrocytes. Out of 1347 miRNAs analyzed by microarrays in IL-1β-stimulated OA chondrocytes, 35 miRNAs were down-regulated, 1 miRNA was up-regulated, and the expression of 1311 miRNAs remained unchanged. Bioinformatics analysis showed the key inflammatory mediators and key molecular pathways are targeted by differentially expressed miRNAs. Novel miRNAs identified could have important diagnostic and therapeutic potentials in the development of novel therapeutic strategies for pain managements in OA.

Lactoferrin from Camelus dromedarius Inhibits Nuclear Transcription Factor-kappa B Activation, Cyclooxygenase-2 Expression and Prostaglandin E2 Production in Stimulated Human Chondrocytes

Background:

Osteoarthritis (OA) is a progressive joint disorder, which remains the leading cause of chronic disability in aged people. Nuclear factor-kappa B (NF)-κB is a major cellular event in OA and its activation by interleukin-1β (IL-1β) plays a critical role in cartilage breakdown in these patients.

Objective:

In this study, we examined the effect of lactoferrin on NF-κB activation, cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE₂) production in stimulated human articular chondrocytes.

Materials and Methods:

Human chondrocytes were derived from OA articular cartilage and treated with camel lactoferrin and then stimulated with IL-1β. Gene expression was determined by TaqMan assays and protein expression was studied by Western immunoblotting. NF-κB activity and PGE₂ levels were determined by ELISA based assays. NF-κB activity was also determined by treatment of chondrocytes with NF-κB specific inhibitor Bay 11–7082.

Results:

Lactoferrin inhibited IL-1β-induced activation and nuclear translocation of NF-κB p65 in human OA chondrocytes. Lactoferrin also inhibited mRNA/protein expression of COX-2 and production of PGE₂. Moreover, Bay 11–7082 also inhibited IL-1β-induced expression of COX-2 and production of PGE₂. The inhibitory effect of lactoferrin on the IL-1β induced expression of COX-2 or production of PGE₂ was mediated at least in part via suppression of NF-κB activation.

Conclusions:

Our data determine camel lactoferrin as a novel inhibitor of IL-1β-induced activation of NF-κB signaling events and production of cartilage-degrading molecule PGE₂ via inhibition of COX-2 expressions. These results may have important implications for the development of novel therapeutic strategies for the prevention/treatment of OA and other degenerative/inflammatory diseases.

SUMMARY

Lactoferrin shows anti-arthritic activity in IL-1β stimulated primary human chondrocytes.

Lactoferrin inhibits IL-1β-induced NF-κB activation.

Lactoferrin inhibits production of cartilage degrading PGE2 via inhibition of COX-2 expression.

Abbreviations Used: OA: Osteoarthritis IL-1β: Interleukin-1 beta NF-κB: Nuclear factor-kappa B COX-2: cyclooxygenase-2 PGE₂: prostaglandin E₂

Stress-mediated modulations in dopaminergic system and their subsequent impact on behavioral and oxidative alterations: an update

CONTEXT

Stress-induced changes in the dopaminergic system and subsequent enhancement of oxidative load and behavior are associated with a wide range of central and peripheral nervous disorders. Dopamine acts as a key neurotransmitter in the brain plays an important role in the regulation of motor and limbic functions.

OBJECTIVE

This article reviews the effect of stress on central dopaminergic system and its subsequent impact on the alterations in behavior and oxidative stress.

METHODS

A literature survey in PubMed (Bethesda, MD), Scopus (Philadelphia, PA), SciFinder (Columbus, OH) and Google Scholar (PMV, CA) was performed to gather information regarding the role of stress on central dopaminergic system and its associated behavioral and oxidative alterations.

RESULTS

Our collective data on behavioral studies and oxidative distress in stressful conditions show the functional reduction in dopaminergic neuronal system that could be one of the factors for the development of stress-induced motor suppression. Collectively, stress caused significant behavioral and oxidative alterations via suppression of neuronal functions of the central dopaminergic system.

CONCLUSIONS

This study provides an insight into the overall pathophysiological alterations in neuronal functions of the central dopaminergic system caused by acute and chronic unpredictable stress that, in our opinion, represent optimal utility as future therapeutic targets for neurodegenerative disorders.

Novel Ocimumoside A and B as anti-stress agents: modulation of brain monoamines and antioxidant systems in chronic unpredictable stress model in rats

Therapies targeting central stress mechanisms are fundamental for the development of successful treatment strategies. Ocimum sanctum (OS) is an Indian medicinal plant traditionally used for the treatment of various stress-related conditions. Previously, we have isolated and characterized three OS compounds; Ocimarin, Ocimumoside A and Ocimumoside B. However, their role in modulating chronic stress-induced central changes is unexplored. Thus, in the present study the efficacy of these OS compounds have been evaluated on the chronic unpredictable stress (CUS)-induced alterations in the monoaminergic and antioxidant systems in the frontal cortex, striatum and hippocampus, along with the changes in the plasma corticosterone levels. CUS (two different types of stressors daily for seven days) resulted in a significant elevation of plasma corticosterone level, which was reversed to control levels by pretreatment with Ocimumoside A and B (40 mg/kg p.o.), while Ocimarin showed no effect. The levels of NA, DA and 5-HT were significantly decreased in all the three brain regions by CUS, with a selective increase of DA metabolites. A significant decrease in the glutathione (GSH) content, the activities of superoxide dismutase and catalase with a significant increase in the glutathione peroxidase activity and lipid peroxidation was observed in all the three regions of the brain by CUS. The OS compounds alone did not cause any significant change in the baseline values of these parameters. However, Ocimumoside A and B (40 mg/kg body p.o.) attenuated these CUS-induced alterations with an efficacy similar to that of standard anti-stress (Panax quinquefolium; 100 mg/kg p.o.) and antioxidant (Melatonin; 20 mg/kg i.p.) drugs. While, Ocimarin failed to modulate these CUS-induced alterations. Therefore, this is the first report which identified the anti-stress activity of novel Ocimumoside A and B at the level of central monoamines and antioxidant properties, implicating their therapeutic importance in the prevention of stress-related disorders.

Restraint stress-induced central monoaminergic & oxidative changes in rats & their prevention by novel Ocimum sanctum compounds

BACKGROUND & OBJECTIVES

Ocimum sanctum (OS) is known to possess various therapeutic properties. We have earlier isolated and characterized three OS compounds; Ocimarin, Ocimumoside A and Ocimumoside B. However, their role in modulating stress-induced central changes is unexplored. Thus, the present study was aimed to investigate the effect of these OS compounds on restraint stress (RS)-induced changes in the monoaminergic and antioxidant systems in the frontal cortex, striatum and hippocampus of rats.

METHODS

RS was produced by immobilizing (restraining) the Sprague Dawley rats for a period of 2.5 h inside cylindrical steel tubes. The monoamine levels and the in vivo antioxidant status in brain regions were evaluated by HPLC-EC and spectrophotometric assays, respectively.

RESULTS

RS significantly increased the dopamine levels in the frontal cortex and decreased in the striatum and hippocampus, and accompanied with selective increase of dopamine metabolites compared to the NS control group. The serotonin and its metabolite levels were significantly increased, while noradrenaline levels were decreased by RS in the three brain regions studied. The activities of superoxide dismutase and glutathione peroxidase in the frontal cortex and striatum were significantly increased by RS with decreased glutathione levels and increased lipid peroxidation. Pre-treatment with Ocimumoside A and B (40 mg/kg po) for a period of 3 days prevented the RS-induced changes with an efficacy similar to that of standard anti-stress (Panax quinquefolium; 100 mg/kg po) and antioxidant (Melatonin; 20 mg/kg ip) drugs, while, Ocimarin failed to modulate these changes. OS compounds per se had no effect on these parameters.

INTERPRETATION & CONCLUSIONS

The present findings showed the anti-stress potential of Ocimumoside A and B in relation to their simultaneous modulatory effects on the central monoaminergic and antioxidant systems implicating their therapeutic importance in stress-related disorders. Further studies are required to understand the mechanism of action of these compounds.

Immunological functions of oxidized human immunoglobulin G in type 1diabetes mellitus: its potential role in diabetic smokers as a biomarker of elevated oxidative stress

The role of oxidized immunoglobulin G in type 1 diabetic smokers has been investigated in the present study. Human immunoglobulin G (IgG) was modified by reactive oxygen species (ROS). The binding characteristics of circulating autoantibodies in type 1 diabetes patients against native and modified IgG were assessed by direct binding ELISA. High degree of specific binding by 68.5% of patients sera towards ROS-modified IgG was observed in comparison to its native analogue (p < 0.05). In addition, diabetic smokers (n = 28) were examined and the results were compared with diabetic non-smokers (n = 26). Circulating antibodies of diabetic smokers showed substantially stronger binding to modified IgG as compared with the antibodies present in diabetic non-smokers (p < 0.05). Normal human sera (n = 53) showed negligible binding with either antigen. Competitive inhibition ELISA reiterates the direct binding results. The increase in total serum protein carbonyl levels in the diabetic smokers was largely due to an increase in oxidized IgG. Diabetic smokers showed substantially higher carbonyl contents in sera as well as in purified IgG as compared with sera and IgG of diabetic non-smokers. Collectively, the oxidation of plasma proteins, especially IgG, might enhance oxidative stress in type 1 diabetes smokers.

Neuroprotective and anti-stress effect of A68930 in acute and chronic unpredictable stress model in rats

The neurorescuing effect of A68930 (a potent selective D(1) agonist) and its role on the regulation of hypothalamus-pituitary-adrenal (HPA)-axis have been investigated. Acute (AS) and chronic unpredictable (CUS) stress models were used to evaluate the effect of A68930 on HPA-axis regulation in relation to the change in the fiber density and number of immunoreactive (ir) neurons of tyrosine hydroxylase (TH) and glucocorticoid receptor (GR) in the dopamine (DA) and GR rich brain regions in rats. CUS caused a significant decrease in the number of TH ir neurons in the striatum, medial forebrain bundle, ventral tegmental area and substansia nigra and GR in the cortex, striatum and hippocampus as compared to the non-stress controls (NS). Administration of A68930 (0.25mg/kg i.p.) significantly normalized these CUS-induced alterations. We also examined the role of A68930 on stress-induced brain oxidative status. AS enhanced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the cortex and striatum, while CUS reduced the activities of SOD and catalase (CAT) in the cortex, striatum and hippocampus, when compared with NS. Increased GSH-Px activity, with reduced glutathione and increased lipid peroxidation was observed in both AS and CUS in selected brain regions as compared to NS. Administration of A68930 normalized the antioxidant enzyme activities, replenished GSH and decreased the extent of lipid peroxidation. In conclusion, present findings suggest that the stress-induced immunoreactivity of TH and GR in distinct brain regions are modulated by A68930 leading to the normalization of HPA-axis response. Ours results show the therapeutic importance of DA D(1) agonist in stress-induced dopaminergic-related neurological disorders. A68930 also influenced the brain antioxidant machinery probably through the restoration of stress-induced changes in the dopaminergic system and its crosstalk with GR.

Alterations in monoamine levels and oxidative systems in frontal cortex, striatum, and hippocampus of the rat brain during chronic unpredictable stress

Stress plays a key role in the induction of various clinical disorders by altering monoaminergic response and antioxidant defenses. In the present study, alterations in the concentrations of dopamine (DA), serotonin (5-HT) and their metabolites, and simultaneous changes in the antioxidant defense system and lipid peroxidation in different brain regions (frontal cortex, striatum, and hippocampus) were investigated immediately and 24 h after exposure to chronic unpredictable stress (CUS). CUS involved subjecting Sprague-Dawley rats to two different types of stressors varying from mild to severe intensity every day in an unpredictable manner, over a period of 7 days. CUS significantly decreased DA and 5-HT concentrations, with increased DA turnover ratios in the selected brain regions. In the frontal cortex and striatum, DA metabolite concentrations were increased; however, in the hippocampus they remained unaltered. Further, a decrease of 5-hydroxyindoleacetic acid content was observed in the frontal cortex and striatum, with no significant alteration in the hippocampus. CUS also reduced the activities of superoxide dismutase and catalase, with increased lipid peroxidation and decreased glutathione levels in the selected brain regions. Glutathione peroxidase activity was increased in the frontal cortex and hippocampus only. The pattern of CUS-induced monoamine and oxidative changes immediately after the last stressor and 24 h later were similar when compared with the control group, indicating that the observed changes were due to the chronic exposure to the various stressors and were not merely acute effects of the last stressor. The altered redox state in the striatum and frontal cortex might be related to the perturbed DA and/or 5HT levels, while the hippocampus seems to be less influenced by CUS in terms of monoamine metabolite changes. These results suggest that the perturbed monoamine levels could interact with the oxidative load during CUS. Hence, the current study has implications for pharmacological interventions targeting both central monoamines and cellular antioxidants as a potential stress management strategy for protecting against central stress-induced disorders.

Antioxidant flavonoid glycosides from Evolvulus alsinoides

Oxidative damage is an established outcome of chronic stress. Thus, the present study was designed to investigate the modulatory role of ethanolic extract of Evolvulus alsinoides (EA) in terms of oxidative alterations at peripheral and central level in rats subjected to chronic unpredictable stress (CUS). CUS exposure for 7 days reduced Cu, Zn superoxide dismutase and catalase activity with increase in glutathione peroxidase activity and lipid peroxidation, while decrease in reduced glutathione level in blood plasma, frontal cortex and hippocampus regions of brain. Oral administration of EA extract at 200mg/kg p.o. normalized these stress induced oxidative alterations with an efficacy similar to that of melatonin. Further, EA extract was taken up for detailed chemical investigation. Two new flavonol-4'-glycoside, kaempferol 4'-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside (3) and kaempferol 4'-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (5) were isolated, along with eight known compounds (1, 2, 4 and 6-10). The structures of new compounds were established by detailed spectroscopic studies, while known compounds were characterized by direct comparison of their reported NMR data. All these compounds were evaluated for their in vitro antioxidant activity. Compounds 3, 5, 9 and 10 at 100 and 200 microg/ml showed significant in vitro antioxidant activity. Therefore, EA may hold great potential in preventing clinical deterioration in stress induced oxidative load and related disorders.

Differential response of central dopaminergic system in acute and chronic unpredictable stress models in rats

We aimed to evaluate the response of dopaminergic system in acute stress (AS) and chronic unpredictable stress (CUS) by measuring dopamine (DA) levels, its receptor densities in the frontal cortex, striatum, hippocampus, amygdala and orbito-frontal cortex regions of rat brain, and investigated the corresponding behavioral locomotor changes. Involvement of D(1) receptor was also examined during AS and CUS using A 68930, a D(1) selective agonist. Rats were exposed to AS (single immobilization for 150 min) and CUS (two different stressors for 7 days). AS significantly decreased the DA levels in the striatum and hippocampus, and A 68930 pretreatment significantly reverted these changes. However, in the frontal cortex significantly increased DA levels were remain unchanged following A 68930. CUS led to a decrease of DA levels in the frontal cortex, striatum and hippocampus, which were normalized by A 68930. Saturation radioligand binding assays revealed a significant decrease in the number of D(1)-like receptors in the frontal cortex during CUS, which were further decreased by A 68930 pretreatment. However, in the striatum and hippocampus, A 68930 pretreatment reduced the CUS induced increase in the number of D(1)-like receptors. No significant changes were observed in the amygdala and orbito-frontal cortex during AS and CUS, while D(2)-like receptors were unchanged in all the brain regions studied. Locomotor activity was significantly decreased in both the stress models, A 68930 pretreatment significantly increased stereotypic counts and horizontal activity. Thus, present investigation provide insights into the differential regional response of dopaminergic system during AS and CUS. Further, neurochemical and behavioral effects of D(1) agonist pretreatment suggest specific modulatory role of D(1) receptor under such stressful episodes.

Melatonin protects against experimental reflux esophagitis

Reflux esophagitis (RE), a major gastrointestinal disorder results from excess exposure of the esophageal mucosa to acidic gastric juice or bile-containing duodenal contents refluxed via an incompetent lower esophageal sphincter. Recent studies implicated oxygen derived free radicals in RE induced esophageal mucosal damage resulting in mucosal inflammation. Thus, control over free radical generation and modulation of inflammatory responses might offer better therapeutic effects to counteract the severity of RE. In this context we investigated the effect of melatonin against experimental RE in rats. Melatonin pretreatment significantly reduced the haemorrhagic lesions and decreased esophageal lipid peroxidation aggravated by RE. Moreover, the depleted levels of superoxide dismutase and glutathione observed in RE were replenished by melatonin signifying its free radical scavenging properties and antioxidant effects resulting in the improvement of esophageal defense mechanism. Further melatonin repressed the upregulated levels of expression of proinflammatory cytokines like, TNF-alpha, IL-1beta and IL-6 in RE. However, increased levels of the anti-inflammatory cytokine IL-10 remained unaltered after melatonin administration signifying its immunomodulatory effect through suppression of Th1-mediated immune responses. The involvement of receptor dependent actions of melatonin against RE were also investigated with MT2 receptor antagonist, luzindole (LUZ). LUZ failed to antagonize melatonin's protective effects against RE indicating that melatonin mediated these beneficial effects in a receptor-independent fashion. Thus, esophageal mucosal protection elicited by melatonin against experimental RE is not only dependent on its free radical scavenging activity but also mediated in part through its effect on the associated inflammatory events in a receptor-independent manner.

Involvement of monoamines and proinflammatory cytokines in mediating the anti-stress effects of Panax quinquefolium

Panax quinquefolium (PQ) is well acclaimed in literature for its effects on central and peripheral nervous system. The present study explores the effects of PQ on stress induced changes of corticosterone level in plasma, monoamines (NA, DA and 5-HT) and interleukin (IL-2 and IL-6) levels in cortex and hippocampus regions of brain and also indicate their possible roles in modulating stress. Mice subjected to chronic unpredictable stress (CUS, for 7 days) showed significant increase in plasma corticosterone level and depletion of noradrenaline (NA), dopamine (DA) and 5-hydroxytryptamine (5-HT) levels in cortex and hippocampal regions along with an increased level of IL-2 and IL-6 in the same areas. Aqueous suspension of PQ was administered daily at a dose of 100 and 200mg/kg p.o. prior to the stress regimen and its effects on selected stress markers in plasma and brain was evaluated. PQ at a dose of 200mg/kg p.o. was found to be effective in normalizing the CUS induced elevation of plasma corticosterone and IL-2, IL-6 levels in brain. Moreover, it was significantly effective in reinstating the CUS induced depletion of NA, DA and 5-HT in hippocampus, while NA and 5-HT in cortex of brain. However, PQ at a dose of 100mg/kg p.o. was found ineffective in regulating any of these CUS induced changes. Present study provides an insight into the possible role of PQ on hyperactive HPA axis in the regulation of immediate stress effectors like corticosterone, cytokines and brain monoamines. In this study, PQ has emerged as a potential therapeutic in the cure of stress related disorders and needs to be evaluated in clinical studies to ascertain its efficacy.

Enhanced recognition of reactive oxygen species damaged human serum albumin by circulating systemic lupus erythematosus autoantibodies

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with autoantibodies as a near universal feature of the disease. Earlier investigations from our laboratory revealed increased oxidative damage in SLE patients. Therefore, we hypothesized that oxidative by-products, such as hydroxyl radical (*OH), could lead to neoantigens like *OH damaged human serum albumin (HSA), which could in turn initiate autoimmunity in SLE. In the present study, the binding characteristics of SLE autoantibodies with native and *OH damaged HSA were assessed. SLE patients (n = 74) were examined by direct binding ELISA and the results were compared with healthy age- and sex-matched controls (n = 44). High degree of specific binding by 52.7% of patients sera towards *OH damaged HSA, in comparison to its native analogue (p < 0.05) was observed. Normal human sera showed negligible binding with either antigen. Competitive ELISA and gel retardation assays reiterate the direct binding results. The increase in total serum protein carbonyl levels in the SLE patients was largely due to an increase in oxidized albumin. HSA of SLE patients (SLE-HSA) and normal subjects (normal-HSA) were purified. Spectroscopic analysis confirmed that the SLE-HSA samples contained higher levels of carbonyls than normal-HSA (p < 0.01). SLE-HSA was conformationally altered, with more exposure of its hydrophobic regions. Collectively, the oxidation of plasma proteins, especially HSA, might enhance oxidative stress in SLE patients.

Reactive oxygen species damaged human serum albumin in patients with hepatocellular carcinoma

The role of reactive oxygen species (ROS) damaged human serum albumin (HSA) in hepatocellular carcinoma (HCC) has been investigated in the present study. HSA was modified by hydroxyl radical. Modification occurred in HSA was characterized by physico-chemical techniques. ROS modified HSA was found to be highly immunogenic in rabbits. The binding characteristics of circulating antibodies in HCC patients against native and ROS-modified HSA were assessed. HCC patients (n = 31) were examined by direct binding ELISA and their results were compared with healthy age-matched controls (n = 22). High degree of specific binding by 77.4% of HCC sera towards ROS-HSA, in comparison to its native analogue (p < 0.05) was observed. Competitive ELISA reiterates the direct binding results. Gel retardation assay further substantiated the enhanced recognition of ROS-HSA by circulating antibodies in HCC patients. The increase in total serum protein carbonyl levels in the HCC patients was largely due to an increase in oxidized albumin. Purified HSA of HCC patients (HCC-HSA) contained higher levels of carbonyls than HSA of normal subjects (normal-HSA) (p < 0.01). HCC-HSA was conformationally altered, with more exposure of its hydrophobic regions. Collectively, the oxidation of plasma proteins, especially HSA, might enhance oxidative stress in HCC patients.