Protein Carbonyl as a Biomarker of Oxidative Stress in Severe Leptospirosis, and Its Usefulness in Differentiating Leptospirosis from Dengue Infections

Prolonged exposure to mercuric chloride induces oxidative stress-mediated nephrotoxicity in freshwater food fish Channa punctatus

Mercury (Hg) is regarded as a serious hazard to aquatic life and is particularly prevalent in aquatic ecosystems. However, there is little evidence available regarding the toxicity of mercury chloride (HgCl2) in vital organs of fish. This study was conducted to assess the effects of HgCl2 (0.039 mg/L and 0.078 mg/L) on oxidative stress-mediated genotoxicity, poikilocytosis, apoptosis, and renal fibrosis after 15, 30, and 45 days of the exposure period. According to the findings, HgCl2 intoxication in fish resulted in a significantly (P < 0.05) elevated lipid peroxidation (LPO), protein carbonyls (PC), lactate dehydrogenase (LDH) activity levels in kidney tissues and significantly (P < 0.05) increased reactive oxygen species (ROS), poikilocytosis, DNA tail length, and the frequency of apoptotic cells (AC%) in blood cells. Kidney's ultra-structure and histopathology revealed its fibrosis, which was evident by mRNA expression of targeted genes KIM1, NOX4, TGFβ, and NFϏβ. Different indicators of oxidative stress, apoptosis, and genotoxicity were altered in a dose and time-dependent manner, according to a two-way ANOVA analysis. There was a considerable positive link between oxidative stress and kidney fibrosis in the fish Channa punctatus, and it is evident from regression correlation and PCA data analysis. The kidney's ultra-structure evaluation and histopathology both revealed a noticeable fibrosis state. Additionally, a significant (P < 0.05) downregulation in PPARδ reveals that fish body was unable to combat diseases such as kidney fibrosis induced by HgCl2. This study shed fresh light on the mechanisms underlying nephrotoxicity caused by HgCl2 exposure.

Evaluation of the antioxidant potency of Greek honey from the Taygetos and Pindos mountains using a combination of cellular and molecular methods

Honey is a complex mixture, containing ~180 compounds, produced by the Apis melifera bees, with promising antimicrobial and antioxidant properties. Nevertheless, the mechanisms through which honey exerts its effects remain under investigation. Plant antioxidants are found in honey and other bee products exhibiting a high bioactivity and molecular diversity. The aim of the present study was to estimate the antioxidant capacity of honey collected from areas in Greece by small‑scale producers by i) using in vitro cell free assays; and ii) by investigating the effects of honey varieties on the redox status of a liver cancer cell line (HepG2) using non‑cytotoxic concentrations. The findings of the present study will allow for the identification of Greek honeys with promising antioxidant capacity. For this purpose, six types of honey with various floral origins were examined in cell‑free assays followed by cell‑based techniques using flow cytometric analysis and redox biomarker level determination in order to evaluate the potential alterations in the intracellular redox system. The results indicated various mechanisms of action that are dependent on the honey type, concentration dependency and high antioxidant capacity. The extended findings from the literature confirm the ability of raw honey to influence the redox status of HepG2 cells. Nevertheless additional investigations are required to elucidate their mechanisms of action in cell line models.

The molecular activity of cannabidiol in the regulation of Nrf2 system interacting with NF-κB pathway under oxidative stress

Cannabidiol (CBD), the major non-psychoactive phytocannabinoid of Cannabis sativa L., is one of the most studied compounds in pharmacotherapeutic approaches to treat oxidative stress-related diseases such as cardiovascular, metabolic, neurodegenerative, and neoplastic diseases. The literature data to date indicate the possibility of both antioxidant and pro-oxidative effects of CBD. Thus, the mechanism of action of this natural compound in the regulation of nuclear factor 2 associated with erythroid 2 (Nrf2), which plays the role of the main cytoprotective regulator of redox balance and inflammation under oxidative stress conditions, seems to be particularly important. Moreover, Nrf2 is strongly correlated with the cellular neoplastic profile and malignancy, which in turn is critical in determining the cellular response induced by CBD under pathophysiological conditions. This paper summarizes the CBD-mediated pathways of regulation of the Nrf2 system by altering the expression and modification of both proteins directly involved in Nrf2 transcriptional activity and proteins involved in the relationship between Nrf2 and the nuclear factor kappa B (NF-κB) which is another redox-sensitive transcription factor.

Phytobiotics from Oregano Extracts Enhance the Intestinal Health and Growth Performance of Pigs

This study aimed to investigate the effects of phytobiotics on the intestinal health and growth performance of pigs. Totals of 40 newly-weaned pigs with 6.4 ± 0.3 kg BW (Exp. 1) and 120 growing pigs with 27.9 ± 2.3 kg BW (Exp. 2) were allotted in RCBD in a 2 × 2 factorial arrangement. The factors were: antibiotics as growth promoter (AGP) and phytobiotics (PHY). Pigs were fed experimental diets during 21 d (Exp. 1) and 42 d (Exp. 2). Growth performance, health parameters, and nutrient digestibility were evaluated. In Exp. 1, AGP diet increased (p < 0.05) ADG and G:F compared with a diet without AGP or PHY and a diet with AGP combined with PHY. PHY decreased (p < 0.05) TNF-α and IgG in the jejunum and protein carbonyl in plasma, whereas it increased (p < 0.05) the villus height. In Exp. 2, AGP or PHY diets increased (p < 0.05) ADG, ADFI, and G:F compared with a diet without AGP or PHY and a diet with AGP combined with PHY. PHY decreased (p < 0.05) IgG and PC in plasma. Collectively, AGP and PHY improved growth performance by reducing oxidative stress and enhancing immune status and jejunal morphology. However, the combinational use of phytobiotics with antibiotics suppressed their effect.

The effect of natural infection with different Leptospira interrogans serovars on oxidative stress biomarkers and acute-phase responses in horses and cattle

Leptospirosis is one of the important zoonotic bacterial diseases with a worldwide distribution that is often subclinical. We aimed to investigate the oxidant/antioxidant balance and acute-phase response in naturally infected horses and cattle with Leptospira interrogans. A total of 600 serum samples from horses and cattle were examined for L. interrogans antibodies using the microscopic agglutination test to determine anti-Leptospira IgG antibodies against a panel of eight important Leptospira antigens in Iran. Then, serum total antioxidant capacity, catalase, glutathione peroxidase, and malondialdehyde activities, and nitric oxide, total protein, serum amyloid A, haptoglobin, and albumin concentrations were measured in seropositive and seronegative samples. Serum catalase activities and malondialdehyde, serum amyloid A, and haptoglobin ‌concentrations in seropositive cattle and horses were significantly higher (P < .05) than in those that were seronegative. Antibody titers increased from 1:100 to ≥ 1:200 in cattle with L. interrogans infection, resulting in a decrease in the serum total antioxidant capacity (P < .05), an increase in serum glutathione peroxidase (P < .01) activity and nitric oxide (P < .05) , serum amyloid A (P < .01), and haptoglobin (P < .05) concentrations. Following the increase in the agglutinating antibody titers in horses infected with L. interrogans, the serum total antioxidant capacity (P < .01) decreased, and serum nitric oxide (P < .05), malondialdehyde (P < .05), and serum amyloid A (P < .01) concentrations were increased. In this study, horses and cattle had extensive changes in oxidant/antioxidant equilibrium and acute-phase protein concentrations when infected with L. interrogans. We also demonstrated a direct link between antibody titers and the type of leptospiral serovar using serum oxidative and inflammatory markers.

Resistance to artemisinin in falciparum malaria parasites: A redox-mediated phenomenon

Malaria remains a major public health disease due to its high yearly mortality and morbidity. Resistance to the gold standard drug, artemisinin, is worrisome and needs better understanding in order to be overcome. In this work, we sought to study whether redox processes are involved in artemisinin resistance. As artemisinin is known to act among others via production of reactive species, we first compared the production of reactive oxygen species and concomitant protein oxidation in artemisinin-sensitive and artemisinin-resistant parasites when treated with artemisinin. The results undoubtedly demonstrated, using different original methods, that the level of ROS, including superoxide production, and oxidized protein were lower in the resistant strain. Interestingly, the major in-between strain difference was reported at the earlier ring stages, which are the forms able to enter in a quiescence state according to the ART resistance phenomenon. Moreover, we demonstrated a better homeostasis regulation in relation with higher expression of antioxidants in the artemisinin-resistant parasites than their sensitive counterparts after artemisinin exposure, notably, superoxide dismutase and the glutathione (GSH) system. These findings enrich the body of knowledges about the multifaceted mechanism of artemisinin resistance and will help in the design and development of newer antimalarials strategies active against resistant parasites.

Current Probes for Imaging Carbonylation in Cellular Systems and Their Relevance to Progression of Diseases

Oxidative stress resulted from reactive oxygen or nitrogen species in biological systems has a significant role in the diagnosis/progression of several human diseases. Human diseases associated with oxidative stress include Alzheimer's disease, chronic lung disease, chronic renal failure, cancer, diabetes, and fibrosis. In oxidative stress conditions, carbonylation process can be described as one of the most common modifications in biomolecules that takes place in the presence of carbonyl (C = O) groups which are introduced into molecules by direct metal-catalyzed oxidation of certain amino acids or indirectly by reaction with the oxidation of lipids and sugars. At a molecular cellular level, carbonylation can cause some defective biological consequences or chemical transformations in cells. During this process, specifically, carbonylated proteins can be accumulated in cells and trigger to develop some diseases in human body. The role of the accumulation of carbonylated proteins in the progression of several diseases has also been reported in the literature, such as neurodegenerative diseases, diabetes, obesity, aging, and cancer. Early detection of carbonylation process is, therefore, very critical to monitor these diseases at an early stage. Finding a suitable biomarker or probe is very challenging due to the need for multiple criteria: high fluorescence efficiency, stability, toxicity, and permeability. If they are designed with a good strategy, these probes are highly effective in cell biology applications and they can be used as good diagnostic tools for monitoring oxidative stress-induced carbonylation in relevant diseases. This review highlights the design and use of recent fluorescent probes for visualization of carbonylation in cellular systems and the relationship between oxidative stress and carbonyl species for causing long-term disease complications.

Zingerone Attenuates Methotrexate-Induced Hepatotoxicity in Rats

Background: Methotrexate (MTX) is mainly used for the chemotherapy of different types of malignancy and some autoimmune diseases like rheumatoid arthritis and inflammatory bowel disease. The MTX application is limited by its severe side effects, including several types of hepatic injury. Objectives: In this study, we decided to evaluate if zingerone (the main constituent of ginger) can reduce the hepatic side effects of MTX. Methods: Thirty-five rats were divided into five groups: Control group receiving normal saline (N/S), once daily, by gavage, for 10 days, and N/S intraperitoneally (i.p.), a single dose on the ninth day; Methotrexate (MTX) group receiving N/S, once daily, by gavage, for 10 days, and MTX (i.p.), a single dose (20 mg/kg) on the ninth day; Groups 3 (ZG25), 4 (ZG50), and 5 (ZG100) receiving zingerone (25, 50, and 100 mg/kg, respectively), once daily, by gavage, for 10 days, and MTX (i.p.), a single dose (20 mg/kg) on the ninth day. Results: The results showed a significant decrease in serum AST, ALT, and ALP, as well as the hepatic content of MDA, NO, PC, TNF-α, and IL-1β, in the ZG groups compared with the MTX group. The activity of SOD, CAT, and GPX, as well as the hepatic content of GSH, showed a significant increase in the ZG groups compared with the MTX group. Histopathological improvement in the hepatic tissue of ZG groups compared with the MTX group confirmed all other findings. Conclusions: It is concluded that zingerone can improve hepatic injury induced by MTX in rats regarding the redox system features, inflammation, and histological changes. This can make humans hopeful for using Ginger in the future for attenuating the hepatic side effects of MTX when used chronically.

Reactive Oxygen Species as the Brainbox in Malaria Treatment

Several measures are in place to combat the worldwide spread of malaria, especially in regions of high endemicity. In part, most common antimalarials, such as quinolines and artemisinin and its derivatives, deploy an ROS-mediated approach to kill malaria parasites. Although some antimalarials may share similar targets and mechanisms of action, varying levels of reactive oxygen species (ROS) generation may account for their varying pharmacological activities. Regardless of the numerous approaches employed currently and in development to treat malaria, concerningly, there has been increasing development of resistance by Plasmodium falciparum, which can be connected to the ability of the parasites to manage the oxidative stress from ROS produced under steady or treatment states. ROS generation has remained the mainstay in enforcing the antiparasitic activity of most conventional antimalarials. However, a combination of conventional drugs with ROS-generating ability and newer drugs that exploit vital metabolic pathways, such antioxidant machinery, could be the way forward in effective malaria control.

The relationship between small heat shock proteins and redox homeostasis during acute heat stress in chickens

As heat stress is a major emerging issue in poultry farming, investigations on the molecular mechanisms of the heat-triggered cellular response in chickens are of special importance. In the present study, 32-day-old Ross 308 broiler chickens were subjected to 37 °C environmental temperature combined with 50% relative humidity for 4 or 8 h respectively. Following sampling, redox parameters such as malondialdehyde (MDA), reduced glutathione (GSH), protein carbonyl levels as well as glutathione peroxidase activity were assessed in liver, spleen, and kidney homogenates. The concentrations of small heat shock proteins (sHSP-s) HSP27, αA- and αB-crystallins were also investigated. Among these organs, the liver was found the most susceptible to heat-provoked oxidative stress, indicated by enhanced lipid peroxidation and rapid activation of protective pathways, including the definite increase of glutathione peroxidase activity and the excessive utilization of αA- and αB-crystallin proteins. Heat-associated decline of protein carbonylation and GSH content was observed in the liver in correlation with the increased involvement of αA- and αB-crystallins in cellular defense, resulting supposedly in an overcompensation mechanism. These data highlight the hepatic sensitivity to acute heat shock, potential adaptation mechanisms, and the specific role of sHSP-s in the restoration of physiologic cell function.

Protein oxidation - Formation mechanisms, detection and relevance as biomarkers in human diseases

Generation of reactive oxygen species and related oxidants is an inevitable consequence of life. Proteins are major targets for oxidation reactions, because of their rapid reaction rates with oxidants and their high abundance in cells, extracellular tissues, and body fluids. Additionally, oxidative stress is able to degrade lipids and carbohydrates to highly reactive intermediates, which eventually attack proteins at various functional sites. Consequently, a wide variety of distinct posttranslational protein modifications is formed by protein oxidation, glycoxidation, and lipoxidation. Reversible modifications are relevant in physiological processes and constitute signaling mechanisms ("redox signaling"), while non-reversible modifications may contribute to pathological situations and several diseases. A rising number of publications provide evidence for their involvement in the onset and progression of diseases as well as aging processes. Certain protein oxidation products are chemically stable and formed in large quantity, which makes them promising candidates to become biomarkers of oxidative damage. Moreover, progress in the development of detection and quantification methods facilitates analysis time and effort and contributes to their future applicability in clinical routine. The present review outlines the most important classes and selected examples of oxidative protein modifications, elucidates the chemistry beyond their formation and discusses available methods for detection and analysis. Furthermore, the relevance and potential of protein modifications as biomarkers in the context of disease and aging is summarized.

Evaluation of the Panbio Leptospira IgM ELISA among Outpatients Attending Primary Care in Southeast Asia

Despite estimates suggesting Leptospira spp. being endemic in Southeast Asia, evidence remains limited. Diagnostic accuracy evaluations based on Leptospira ELISA mainly rely on hospitalized and severe patients; therefore, studies measuring the pathogen burden may be inaccurate in the community. We evaluated the Panbio Leptospira ELISA IgM among 656 febrile outpatients attending primary care in Chiangrai, Thailand, and Hlaing Tha Yar, Yangon, Myanmar. ELISA demonstrated limited diagnostic accuracy for the detection of acute leptospiral infection using the manufacturer recommended cutoff, with a sensitivity of 71.4% and specificity of 36.4%, and an area under the receiver operator characteristic curve value of 0.65 (95% CI: 0.41-0.89), compared with our reference test, the PCR assay. ELISA also performed poorly as a screening tool for detecting recent exposure to Leptospira spp. compared with the "gold-standard" microscopic agglutination test, with a specificity of 42.7%. We conclude that the utility of the Leptospira IgM ELISA for both serodiagnosis and seroprevalence is limited in our setting.

Distinguishing bacterial versus non-bacterial causes of febrile illness - A systematic review of host biomarkers

BACKGROUND

Acute febrile illnesses (AFIs) represent a major disease burden globally; however, the paucity of reliable, rapid point-of-care testing makes their diagnosis difficult. A simple tool for distinguishing bacterial versus non-bacterial infections would radically improve patient management and reduce indiscriminate antibiotic use. Diagnostic tests based on host biomarkers can play an important role here, and a target product profile (TPP) was developed to guide development.

OBJECTIVES

To qualitatively evaluate host biomarkers that can distinguish bacterial from non-bacterial causes of AFI.

DATA SOURCES

The PubMed database was systematically searched for relevant studies published between 2015 and 2019.

STUDY ELIGIBILITY CRITERIA

Studies comparing diagnostic performances of host biomarkers in patients with bacterial versus non-bacterial infections were included.

PARTICIPANTS

Studies involving human participants and/or human samples were included.

METHODS

We collected information following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A risk of bias assessment was performed, based on a modified QUADAS-2 (Quality Assessment of Diagnostic Accuracy Score 2).

RESULTS

We identified 1107 publications. Following screening, 55 publications were included, with 265 biomarker entries. Entries mostly comprised protein biomarkers (58.9%), followed by haematological, RNA, and metabolite biomarkers (15.5%, 8.7%, 12.5%). Sensitivity/specificity was reported for 45.7% of biomarker entries. We assessed a high overall risk of bias for most entries (75.8%). In studies with low/medium risk of bias, four biomarker entries tested in blood samples had sensitivity/specificity of more than 0.90/0.80. Only 12 additional biomarker entries were identified with sensitivity/specificity of more than 0.65/0.65.

CONCLUSIONS

Most recently assessed biomarkers represent well-known biomarkers, e.g. C-reactive protein and procalcitonin. Some protein biomarkers with the highest reported performances include a combined biomarker signature (CRP, IP-10, and TRAIL) and human neutrophil lipocalin (HNL). Few new biomarkers are in the pipeline; however, some RNA signatures show promise. Further high-quality studies are needed to confirm these findings.

Biomarkers of disease severity in vivax malaria

Severe complications have been observed and established for Plasmodium falciparum as well as P. vivax infections worldwide. Although P. vivax infection is not fully acknowledged as malignant malaria, recently life-threatening complications have been reported to occur in many studies. The recognition of biomarkers with excellent sensitivity and reliability plays a prime role in disease management. Acute inflammatory response and oxidative stress are observed in malaria due to the production of reactive oxygen species. Lipid and protein oxidative injuries are prospective biomarkers for disease severity owing to the damage caused by the parasite. We have tried to find out whether protein carbonylation (PC), lipid peroxidation (LPO) and superoxide dismutase (SOD) could suffice as a biomarker for severe vivax malaria or not. Blood samples were collected from the individuals attending Jawaharlal Nehru Medical College of Aligarh Muslim University during the wet season of malaria transmission. Microscopy and rapid diagnostic kits were used as a tool for malaria diagnosis. A total of 214 subjects were enrolled for the study: 30 febrile controls and 184 subjects with vivax malaria. Protein carbonylation and lipid peroxidation were found to be directly associated with parasite count and total antioxidant status (TAS). Increase in oxidative stress was also observed in severe vivax malaria patients. Levels of uric acid and bilirubin too were raised in complicated cases. Protein carbonylation was found to be a more reliable indicator of vivax malaria severity than lipid peroxidation.

Tebuconazole induced oxidative stress and histopathological alterations in adult rat heart

TEB belongs to the family of triazole fungicides and it is used to protect agricultural crop plants from fungal pathogens. The information regarding its cardiotoxic effects through different pathways particularly by perturbing the oxidative balance and causing damage to the myocardium is still limited. In the present study, oxidative and histopathologic damages caused by TEB in the cardiac tissue of male adult rats, were evaluated. Rats were exposed orally to TEB at 0.9, 9, 27 and 45 mg/kg b.w. for 28 days. Results showed that following TEB treatment malondialdehyde (MDA), protein carbonyl (PC), advanced oxidation protein product (AOPP), antioxidant enzyme activities (GPx and GR) and GSSG levels increased, while GSH levels and thus the GSH/GSSG ratio decreased. Superoxide dismutase (SOD) and catalase (CAT) initially increased at the doses of 0.9, 9 and 27 mg/kg b.w. and then decreased at the dose of 45 mg/kg b.w. Moreover, western blot analysis showed that TEB increased SOD1, CAT and HSP70 protein levels after 24 h. Furthermore, TEB induced various histological changes in the myocardium, including leucocytic infiltration, hemorrhage congestion of cardiac blood vessels and cytoplasmic vacuolization. Therefore, our investigation revealed, that TEB exhibits cardiotoxic effects by changing oxidative balance and damaging the cardiac tissue.

Effects of Essential Trace Elements and Oxidative Stress on Endemic Arsenism Caused by Coal Burning in PR China

Few studies have investigated the association between essential trace elements and oxidative stress in environmental media and populations with endemic arsenism caused by coal burning. Element contents and oxidative stress indicators were measured. Moreover, the expression of genes related to the nuclear factor E2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)-antioxidant response element (ARE) signaling pathway and Nrf2-ARE binding ability is detected. The results show that the contents of arsenic, copper, iron, and chromium were increased in environmental media from the arsenism area compared with the control area; however, the selenium content decreased. The arsenic, iron, chromium, and copper contents and the copper/zinc ratio were also increased in the arsenic-exposed population; however, the selenium content decreased. The results also show that the concentrations of arsenic, iron, and chromium and the copper/zinc ratio increased gradually with the severity of arsenism. However, selenium concentrations decreased gradually with the severity of arsenism. The contents of malondialdehyde, 8-hydroxyldeoxyguanosine, and protein carbonyl in plasma increased, while the levels of sulfhydryl, thioredoxin reductase (TrxR), glutathione peroxidase (Gpx), and superoxide dismutase 1 (SOD1) decreased. The mRNA expression of Keap1 and TrxR1 decreased in the blood, while the mRNA expression of Nrf2, GPx1, and SOD1 increased. Moreover, the Nrf2 protein content and Nrf2-ARE binding ability increased, and the Keap1 protein content decreased. In conclusion, our data suggest that the increased arsenic content in environmental media and populations was accompanied by abnormal levels of essential trace elements. Insufficient selenium intake, copper, and chromium overload and a high copper/zinc ratio might be some of the causes of arsenism, which might be related to the Nrf2/Keap1-ARE signaling pathway.

Advanced Oxidation Protein Product (AOPP) Levels in Second- and Third-Degree Thermal Burns

Burn is a systemic injury affecting the entire organism according to its etiology and severity. The aim of this study was to investigate plasma AOPP levels before and after treatment of second- and third-degree thermal burn patients and determine the changes in this parameter, and also, to find out the relationship between AOPP level and hospitalization period and total body surface area (TBSA). The study material consisted of pediatric patients with the complaint of second- and third-degree thermal burns aged between 1 and 18 years, with a burn area exceeding 10%. Blood samples were taken twice before and after treatment. AOPP level in blood plasma was measured in ELISA. It was observed that in the second-degree thermal burn group, AOPP level was 25.85 ± 2.82 ng/ml before the treatment decreased to 22.16 ± 3.62 ng/ml after treatment, whereas in the third-degree thermal burn group before the treatment AOPP was 25.96 ± 3.49 ng/ml, and after the treatment dropped to 21.70 ± 3.79 ng/ml, decreases were significantly important (P < .05). There was no statistically significant difference between the two groups in terms of AOPP levels (P > .05). Correlation analyses in the second- and third-degree thermal burn group did not show any correlation between AOPP levels and burn area and length of hospitalization period. As a result, AOPP level has been studied, for the first time, in burn cases. In both groups, the level of AOPP increased due to oxidative stress before treatment and decreased after treatment.

Evaluation of biochemical parameters in Rubus tereticaulis treated rats and its implications in wound healing

We evaluated the effects of Rubus tereticaulis in healing process by determining the total carbonyl content, collagen synthesis, and total protein level on rat wounded tissues. Wounds were performed in the back of 54 Wistar rats, using a biopsy punch instrument with 0.6 mm in diameter. Rats were randomly divided into three groups: (i) un-treatment wounds group served as "controls", (ii) Madecassol® used as "positive control" group, and (iii) the application of topical cream of R. tereticaulis served as "treatment" group of wound healing. The animals were killed at the end of experiment under anesthesia with ketamine, and tissue samples were collected for the evaluation at three times intervals (3rd, 7th, and 14th day). The wounded areas were analyzed for total carbonyl content, collagen, and total protein levels by HPLC, ELISA, and spectrophotometric methods, respectively. Total carbonyl content in the treatment group was significantly lower in comparison with control group on 3rd day (2.839 ± 0.438 vs. 3.216 ± 0.216 nmol carbonyl/mol protein; p < 0.5) and 14th days (4.222 ± 0.128 vs. 4.784 ± 0.077 nmol carbonyl/mol protein; p < 0.05), respectively. New collagen formation on the wound sites after the initial injury was noted in the treated and positive control groups (5.310 ± 0.331 vs. 5.164 ± 0.377 mg collagen/g wet tissue) at the 3rd day than control group (2.180 ± 0.718 mg collagen/g wet tissue, p < 0.01), and in treated and positive control groups at 7th day (9.654 ± 0.201, 9.053 ± 1.062 mg collagen/g wet tissue, p < 0.01); and in treated and positive control groups at 14th day (8.469 ± 0.236, 5.631 ± 0.531 mg collagen/g wet tissue, respectively; p < 0.05) in comparison with the control group. Total protein level of samples did not change significantly between the groups. Thus, application of R. tereticaulis ameliorated the wound healing process in rats as it facilitated collagen formation through healing of the wound. Evaluating total carbonyl content by HPLC could be useful as an advance procedure for quantification of healing.

Differences in serum markers of oxidative stress in well controlled and poorly controlled asthma in Sri Lankan children: a pilot study

Background

Asthma is a disease characterised by hyper responsiveness and bronchoconstriction of airways, and is a major health burden globally. A dysfunction of the oxidant-antioxidant balance, termed oxidative stress, has been implicated in the pathophysiology of asthma. The present study aims to assess the changes in oxidative stress markers, namely nitric oxide metabolites and antioxidant capacity, in children with poorly controlled and well controlled asthma, in comparison to healthy controls.

Methods

The present study enrolled 72 children (ages 5-15 years) classified into three groups: (1) poorly controlled asthma (n = 20), (2) well controlled asthma (n = 24) and (3) healthy controls (n = 27). An interviewer-administered questionnaire was used to record socio-demographic data of the participants. The serum concentrations of the oxidant markers (nitrite, nitrate and total nitric oxide metabolites [NO_x]) were determined using the Griess test, and the total antioxidant capacity (TAOC) was determined using the ABTS decolorisation method. The concentrations of these markers were compared across the three groups.

Results

The three study groups were similar in terms of socio-demographic data. The differences across the three groups were statistically significant for serum concentrations of nitrate and NO_x (but not nitrite) and serum TAOC. Further analyses showed that the disparity for nitrate and NO_x concentrations was greatest between poorly controlled asthma and healthy controls (p = 0.001 and p < 0.001) compared to the well-controlled asthmatics and healthy controls (p = 0.036 and p = 0.049). A significant difference in serum nitrate and NO_x concentrations was not observed between the two asthma groups (p = 0.311 and 0.203). The TAOC were significantly lower in poorly controlled asthmatics as compared to well-controlled asthmatics (p = 0.003) and healthy controls (p < 0.001). However, there was no significant difference in the serum TAOC between healthy controls and well-controlled asthmatics (p = 0.496). These findings may indicate that it is perhaps the higher TAOC that contributes to the well controlled state of asthma.

Conclusions

The present study indicated that an imbalance of oxidants and antioxidants in the serum may have an underlying role in asthma pathophysiology, and how these markers may be effective in asthma management.

Effects of curcumin and yucca extract addition in feed of broilers on microorganism control (anticoccidial and antibacterial), health, performance and meat quality

The aim of this study was to determine whether curcumin and yucca extract addition in broiler feed improves growth, health, and meat quality, and to measure coccidiostatic and antimicrobial activity so as to enable replacement of conventional performance enhancers. We used 240 birds in four treatments: CN, basal feed with antibiotics and coccidiostatic drugs; CU, feed with 100 mg/kg of curcumin; YE, feed with 250 mg/kg of yucca extract; and CU + YE, feed with the combination of 100 mg curcumin/kg and 250 mg yucca extract/kg. A significant reduction in oocysts was observed in birds supplemented with combined additives (CU + YE) at days 37 compared to other treatments and at 42 days in relation to the CU treatment. At 42 days, the total bacterial counts for the CN and CU treatments were lower than the others. Birds fed the additive had lower numbers of leukocytes, lymphocytes, and heterophils than did those in the CN treatment. The highest levels of antioxidants in meat were observed in the treatments with the additives, together with lower levels of lipid peroxidation compared to the CN. The lowest protein oxidation was observed in the CU + YE treatment in relation to the other treatments. Lower total levels of saturated fatty acids (SFA) were observed in the CU treatment than in the CN. There were lower levels of monounsaturated fatty acids (MUFA) in the meat of birds in the YE treatment in relation to the others. Higher levels of total polyunsaturated fatty acids (PUFA) were observed in birds that consumed curcumin, individually and in combination with yucca extract. Taken together, the data suggest that curcumin and yucca extract are additives that can potentially replace conventional growth promoters; they improved bird health. Changes in the fatty acid profile of meat (increase in the percentage of omegas) are beneficial to the health of the consumer.

Therapeutic effect of hydrogen peroxide via altered expression of glutathione S-transferase and peroxiredoxin-2 in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) has a high incidence and mortality that epitomizes one of the prominent causes of cancer-related death globally. Novel therapeutic approaches are therefore required. Reactive oxygen species (ROS) are necessary for maintaining cell cycle. Although ROS is involved in HCC progression, hydrogen peroxide (H₂O₂) has anti-proliferative effect on HCC.

METHOD

HCC Huh-7 cells were cultured and incubated with various concentrations of H₂O₂. Paraoxonase activity, levels of malondialdehyde, glutathione and protein oxidation were measured in treated and untreated Huh-7 cells. Furthermore, untreated and treated Huh-7 cells were subjected to two dimensional gel electrophoresis and identified protein spots which were differentially expressed by LC-MS/MS analysis. qRT-PCR was performed to validate the identified proteins.

RESULTS

H₂O₂ depleted glutathione (GSH) with the concomitant up-regulation of GSTP1 and Prx2. H₂O₂ also increased malondialdehyde and protein oxidation, decreased the activity of paraoxonase in Huh-7 cells.

CONCLUSION

H₂O₂ could be used as a novel therapeutic agent that might be beneficial in inducing cell cytotoxicity and hence suppress HCC proliferation.

Quantitative Estimation of Oxidative Stress in Cancer Tissue Cells Through Gene Expression Data Analyses

Quantitative assessment of the intracellular oxidative stress level is a very important problem since it is the basis for elucidation of the fundamental causes of metabolic changes in diseased human cells, particularly cancer. However, the problem proves to be very challenging to solve in vivo because of the complex nature of the problem. Here a computational method is presented for predicting the quantitative level of the intracellular oxidative stress in cancer tissue cells. The basic premise of the predictor is that the genomic mutation level is strongly associated with the intracellular oxidative stress level. Based on this, a statistical analysis is conducted to identify a set of enzyme-encoding genes, whose combined expression levels can well explain the mutation rates in individual cancer tissues in the TCGA database. We have assessed the validity of the predictor by assessing it against genes that are known to have anti-oxidative functions for specific types of oxidative stressors. Then the applications of the predictor are conducted to illustrate its utility.

Elevated levels of IL-8 in fatal leptospirosis

Leptospirosis causes a wide range of clinical outcomes, including organ failure and death. Early treatment significantly increases the chances of cure. Interleukin-8 (IL-8) is a chemoattractant cytokine for neutrophil and is associated with multiple organ failure. Research has indicated IL-8 to be raised in severe and fatal cases of leptospirosis, but its suitability as a prognostic biomarker has yet to be confirmed. This study aimed to evaluate the significance of IL-8 with the clinical outcomes of leptospirosis patients. Plasma IL-8 was measured in fifty-two samples from hospitalized patients and nineteen healthy controls. The comparisons were made between mild, severe-survived and fatal groups identified by clinical or laboratory findings. IL-8 was significantly higher in fatal (p = 0.01) compared to mild cases. IL-8 was also significantly higher in fatal (p = 0.02) when compared to survived cases of leptospirosis. IL-8 levels in the plasma of fatal leptospirosis cases were significantly elevated compared to survived cases and may serve as a potential prognostic biomarker in determining the possible outcome of leptospirosis patients.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

Oxidative stress response in the pathogenesis of dengue virus virulence, disease prognosis and therapeutics: an update

Dengue virus (DENV) is a mosquito-borne arbovirus that causes febrile illness and can lead to a potentially lethal disease. The mechanism of disease pathogenesis is not completely understood, and there are currently no vaccines or therapeutic drugs available to protect against all four serotypes of DENV. Although many reasons have been suggested for the development of the disease, dengue studies have shown that, during DENV infection, there is an imbalance between oxidants and antioxidants that disrupts homeostasis. An increase in reactive oxygen species (ROS) levels triggers the sudden release of cytokines, which can lead to plasma leakage and other severe symptoms. In the present review, we give an overview of the oxidative stress response and its effect on the progression of dengue disease. We also discuss the role of oxidative-stress-associated molecules in disease prognostic and therapeutics.

Effect of cocoa powder on hypertension and antioxidant status in uninephrectomized hypertensive rats

BACKGROUND AND AIM

High salt diet and uninephrectomy are associated with high blood pressure with attendant cardiovascular disease conditions such as hypertension, renal damage, myocardial infarction, and stroke. The aim of this study was to investigate the beneficial effects of consumption of cocoa and cocoa-containing products in the management of high blood pressure in uninephrectomized hypertensive rats.

MATERIALS AND METHODS

The effect of cocoa powder on blood pressure, markers of inflammation, oxidative stress, and histopathology were investigated in uninephrectomized animals fed with cocoa feed alone or in combination with a high salt diet. Male rats were randomly divided into five groups: Group A was the control group and fed with normal feed alone, Group B was fed with cocoa feed alone, Group C was fed with high salt diet (8% salt), GroupD was fed with cocoa-feed compounded with 8% salt for 4weeks after uninephrectomy, and GroupE was uninephrectomized rats on a normal diet. The left kidneys of animals in GroupsC, D, and E were removed by surgery. After 4weeks of treatment, the systolic, diastolic, and mean arterial blood pressure was measured. The serum markers of renal damage and oxidative stress were determined. Histological examination was also performed on renal and cardiac tissues.

RESULTS

Results showed significant increases in biomarkers of oxidative stress, inflammation, and renal damage with a concomitant decrease in antioxidant status in hypertensive uninephrectomized rats. Cocoa feed, however, significantly improved blood pressure and nitric oxide bioavailability, antioxidant status and reduced markers of inflammation and oxidative stress.

CONCLUSION

These findings show that cocoa powder could be used to maintain blood pressure levels in hypertensive rats through its antioxidant capacity.

Estimating the burden of leptospirosis in Sri Lanka; a systematic review

Background

Although the assessment of disease burden should be a priority for allocating resources, leptospirosis is grossly underestimated despite its true burden in Sri Lanka. This study aimed to assess the morbidity and mortality of leptospirosis based on routine surveillance data, hospital reported data and scientific publications from Sri Lanka.

Method

A systematic review was carried out, and Pub Med, MEDLINE®, BIOSIS Previews, Zoological Record, Web of Science Core Collection, Current Contents Connect, KCI-Korean Journal Database, BIOSIS Citation Index, Data Citation Index, SciELO Citation Index and Google Scholar databases were searched. Quarterly epidemiological bulletin (QEB), indoor morbidity & mortality returns (IMMR) and hand searches of local literature were performed in local libraries. Forty-two relevant full texts, 32 QEBs, and 8 IMMR were included in the full text review. Adjustments were made for under diagnosis, underreporting and chance variability.

Results

The estimated annual caseload of leptospirosis in Sri Lanka from 2008 to 2015, was 10,423, and the cumulative annual incidence of leptospirosis that required hospitalization was 52.1 (95% CI 51.7–52.6) per 100,000 people. The estimated number of annual deaths due to leptospirosis was approximately 730 (95% CI 542–980), with an estimated pooled case fatality ratio of 7.0% (95% CI 5.2–9.4). The most common organs involved were the kidney, liver and heart, with median rates of 48.7, 30, and 14.2%, respectively.

Conclusion

Our systematic review shows gross underestimation of the true leptospirosis burden in the national statistics of Sri Lanka, and the hospitalization rates estimated in our study were compatible with the total burden estimate of 300·6 (95% CI 96·54–604·23) per 100,000 people published previously.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3655-y) contains supplementary material, which is available to authorized users.

Phenelzine reduces the oxidative damage induced by peroxynitrite in plasma lipids and proteins

Peroxynitrite is a reactive nitrogen species produced in the intravascular compartment from superoxide anion and nitric oxide. Peroxynitrite destroys blood plasma proteins and membranes of red blood cells and of platelets. This explains why excessive production of peroxynitrite contributes to diseases and to ageing. Therapeutics that antagonize peroxynitrite may delay ageing and the progression of disease. We developed an in vitro assay that allows the investigation of the oxidative damage caused by peroxynitrite in the intravascular compartment. This assay correlates the damage with the rate of formation of protein carbonyl groups, 3-nitrotyrosine (3-NT) and thiobarbituric acid reactive substances. Using this assay, we evaluated the ability of phenelzine, a scavenger of reactive aldehydes, to antagonize the effects of peroxynitrite. Herein, we showed that phenelzine significantly decreased the lipid peroxidative damage caused by peroxynitirite in blood plasma and platelets. Moreover, it inhibited carbonyl group and 3-NT formation in blood plasma and platelet proteins.

Effect of Antimicrobial Agents on Inflammatory Cytokines in Acute Leptospirosis

The aim of this study was to assess the inflammatory cytokine response and possible association with antimicrobial treatment with penicillin, ceftriaxone, and doxycycline in acute leptospirosis. In the early acute stage, interleukin-10 (IL-10) levels were higher in mild cases than in severe cases (P = 0.01). IL-6 and IL-8 levels were low in patients who received >5 antimicrobial doses (P < 0.01). IL-8 levels were negatively correlated with the number of ceftriaxone doses administered (r = -0.315; P = 0.031). Further studies are needed to evaluate the possible downregulation of proinflammatory cytokines by ceftriaxone in leptospirosis.

Pathogen-specific leptospiral proteins in urine of patients with febrile illness aids in differential diagnosis of leptospirosis from dengue

Leptospirosis and dengue are two commonly seen infectious diseases of the tropics. Differential diagnosis of leptospirosis from dengue fever is often difficult due to overlapping clinical symptoms and lack of economically viable and easy-to-perform laboratory tests. The gold standard for diagnosis is the microscopic agglutination test (MAT). In this study, the diagnostic potential of screening for pathogen-specific leptospiral antigens in urine samples is presented as a non-invasive method of disease diagnosis. In a study group of 40 patients, the serum was tested for anti-leptospiral antibodies by MAT and enzyme-linked immunosorbent assay (ELISA). Urine of these patients was screened for leptospiral antigens by ELISA using specific antibodies against LipL32, LipL41, Fla1, HbpA and sphingomyelinase. Group I patients (n = 23) were classified as leptospirosis-positive based on MAT and high titres of circulating IgM-specific anti-leptospiral antibodies. All of these patients excreted all five leptospiral antigens in the urine. The 17 MAT-negative cases included six patients with pyrexia of unknown origin (PUO; Group II) and 11 confirmed dengue patients (Group III). The latter tested negative for both serum anti-leptospiral antibodies and urinary leptospiral antigens. A salient outcome of this study was highlighting the usefulness of screening for urinary leptospiral antigens in disease diagnosis, as their presence confirmed leptospiral aetiology in two PUO patients. Immunoblots of urinary antigens identified well-defined bands corresponding to LipL32, HbpA and sphingomyelinase; the significance of the 42- and 58-kDa sphingomyelinase bands is discussed.

3D modelling of the pathogenic Leptospira protein LipL32: A bioinformatics approach

Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira species (Leptospiraceae). LipL32 is an abundant lipoprotein from the outer membrane proteins (OMPs) group, highly conserved among pathogenic and intermediate Leptospira species. Several studies used LipL32 as a specific gene to identify the presence of leptospires. This research was aimed to study the characteristics of LipL32 protein gene code, to fill the knowledge gap concerning the most appropriate gene that can be used as antigen to detect the Leptospira. Here, we investigated the features of LipL32 in fourteen Leptospira pathogenic strains based on comparative analyses of their primary, secondary structures and 3D modeling using a bioinformatics approach. Furthermore, the physicochemical properties of LipL32 in different strains were studied, shedding light on the identity of signal peptides, as well as on the secondary and tertiary structure of the LipL32 protein, supported by 3D modelling assays. The results showed that the LipL32 gene was present in all the fourteen pathogenic Leptospira strains used in this study, with limited diversity in terms of sequence conservation, hydrophobic group, hydrophilic group and number of turns (random coil). Overall, these results add basic knowledge to the characteristics of LipL32 protein, contributing to the identification of potential antigen candidates in future research, in order to ensure prompt and reliable detection of pathogenic Leptospira species.

Polymerase Chain Reaction: An Important Tool for Early Diagnosis of Leptospirosis Cases

INTRODUCTION

Various diagnostic methods like Microscopic Agglutination Test (MAT), IgM ELISA, Isolation of Leptospira from the clinical specimen, Rapid leptocheck tests etc., are available for diagnosis of leptospirosis. Polymerase Chain Reaction (PCR) is used for diagnosis of various diseases of infectious origin including leptospirosis but there is paucity of data about comparison of PCR with other available method of diagnosis of leptospirosis.

AIM

The aim of the study was to detect the leptospiral DNA by PCR method and to compare the results of PCR with other available diagnostic methods used for diagnosis of suspected leptospirosis cases in acute phase of illness.

MATERIALS AND METHODS

A total of 207 blood samples were obtained from suspected patients of leptospirosis admitted in New Civil Hospital, a tertiary care hospital in South Gujarat, during the period of July 2008 to November 2008. These blood samples were subjected to Rapid leptocheck, IgM ELISA, MAT test to detect (IgG or IgM) antibody level, Leptospira culture and PCR.

RESULTS

In early phase of the disease, Rapid leptocheck test gave 44% detection, but along with PCR seropositivity reached upto 71%. Detection rate by IgM ELISA was 59% which increased to 80% with PCR. By MAT seropositivity was 57% but combined seropositivity of MAT with PCR was 78%. Sensitivity and specificity of PCR as compared to MAT (Gold standard) was 52% and 79% respectively. Leptospira was not growing in culture.

CONCLUSION

In present study, PCR picked up to 50% of cases which were negative by other serological tests so these finding suggest that PCR should be used routinely in acute phase of disease.