Oxidative stress markers in infectious respiratory diseases: current clinical practice

Cases of some infectious respiratory diseases are on the increase and aetiology of these diseases is associated with assault from exogenous and endogenous oxidants. This requires constant appraisal on current knowledge hence this review looks at current knowledge on oxidative and nitrosative stresses in selected infectious respiratory diseases and the utility of stress biomarkers. A major metabolic or organic stress is oxidative stress; an imbalance between oxidants and anti-oxidants and it is implicated in aetiology of various diseases including respiratory diseases. Physiologically reactive oxygen and nitrogen species are beneficial since they take part in various cellular processes. During infection, the host produces reactive species to defend against invading pathogens but some microorganisms have mechanisms to defend against the reactive oxygen and nitrosative species produced by host. Hence, there is also the oxidative stress ‘pros and cons’ paradox in infectious respiratory disease, which makes careful interpretation of laboratory methods necessary. Although most reactive oxygen and nitrosative species are not very stable and cannot be measured directly, there are indirect assessment methods of oxidative stress or oxidants or anti-oxidants. Various biological samples such as exhaled air, exhaled breath condensate, sputum and blood are used in investigation and management of infectious respiratory diseases. Measurement of oxidative stress can be done using various laboratory methods including, chemical, immunoassays and chromatographic thus allowing oxidative stress assessment to be important in infectious respiratory diseases

Effects of obesity on inflammatory and oxidative stress markers in asthma

Asthma is influenced by environmental factors and obesity, which triggers inflammatory processes that affect airways and give rise to asthmatic condition. Obesity is been associated with low-grade inflammation with the potential of developing several complications including asthma. The origins of asthma and obesity are complex with genetics and environmental factors and among others implicated. The main constituent of obese tissue comprises fat which is chiefly adipocytes. Reactive adipocytes trigger inflammation that has an adverse effect on lung function. Consequently, airways are clogged with inflammatory components leading to asthma. The inflammatory state cause’s macrophages to produce cytokines such as TNF-α which subsequently affect lung function, trigger insulin resistant diabetes and other cardio vascular complications. The mechanism by which the lung changes are characterized by the inflammatory components which triggers oxidative stress markers and pro-inflammatory mediators such as IL-6 and C-reactive protein (CRP). The presence of high oxidative stress markers and pro-inflammatory products exacerbates asthmatic condition. Therefore asthma and obesity result in inflammation that gives rise to oxidative stress, thus these four pathophysiological phenomena are interrelated. This paper reviews the complex relationship between oxidative stress markers and inflammatory markers, especially with regard to evaluation and monitory of respiratory diseases by laboratory methods

A Randomized, Double-Blind, Placebo-Controlled Trial of Lessertia frutescens in Healthy Adults

OBJECTIVES: Indigenous medicines are widely used throughout Africa, despite a lack of scientific evidence for their safety or efficacy. The aims of this study were: (a) to conduct a pilot study of the safety of a common indigenous South African phytotherapy, Lessertia frutescens (Sutherlandia), in healthy adults; and (b) to contribute to establishing procedures for ethical and scientifically rigorous clinical trials of African indigenous medicines. DESIGN: A randomized, double-blind, placebo-controlled trial of Sutherlandia leaf powder in healthy adults. SETTING: Tiervlei Trial Centre, Karl Bremer Hospital, Bellville, South Africa. PARTICIPANTS: 25 adults who provided informed consent and had no known significant diseases or allergic conditions nor clinically abnormal laboratory blood profiles during screening. INTERVENTION: 12 participants randomized to a treatment arm consumed 400 mg capsules of Sutherlandia leaf powder twice daily (800 mg/d). 13 individuals randomized to the control arm consumed a placebo capsule. Each participant received 180 capsules for the trial duration of 3 mo. OUTCOME MEASURES: The primary endpoint was frequency of adverse events; secondary endpoints were changes in physical, vital, blood, and biomarker indices. RESULTS: There were no significant differences in general adverse events or physical, vital, blood, and biomarker indices between the treatment and placebo groups (p > 0.05). However, participants consuming Sutherlandia reported improved appetite compared to those in the placebo group (p = 0.01). Although the treatment group exhibited a lower respiration rate (p < 0.04) and higher platelet count (p = 0.03), MCH (p = 0.01), MCHC (p = 0.02), total protein (p = 0.03), and albumin (p = 0.03), than the placebo group, these differences remained within the normal physiological range, and were not clinically relevant. The Sutherlandia biomarker canavanine was undetectable in participant plasma. CONCLUSION: Consumption of 800 mg/d Sutherlandia leaf powder capsules for 3 mo was tolerated by healthy adults

The apoptosis inducing effects of Sutherlandia spp. extracts on an oesophageal cancer cell line

AIM OF STUDY: Oesophageal cancer is the ninth most common cancer in the world and the second most common cancer among South African men. It also has one of the lowest possibilities of cure, with the 5-year survival rate estimated to be only 10% overall. Sutherlandia frutescens, or the "cancer bush", is a medicinal plant indigenous to southern Africa that is believed to have anti-cancer and anti-proliferative properties. The aim of this study was to investigate the potential apoptosis-inducing effects of two S. frutescens extracts and one Sutherlandia tomentosa extract on the SNO oesophageal cancer cell line. MATERIALS AND METHODS: Cell viability and morphology of SNO cells were evaluated following exposure to the extracts. Apoptotic markers including cytochrome c translocation and phosphatidylserine externalisation were quantified by flow cytometry. The activity of caspases 3 and 7 was evaluated with spectrofluorometry. Apoptosis was evaluated in the presence of the pan-caspase inhibitor, Z-VAD-fmk. The effect of the extracts was compared to non-cancerous peripheral blood mononuclear cells (PBMCs). RESULTS: Time- and dose-response studies were conducted to establish treatment conditions of 2.5 and 5mg/ml of crude plant extracts. Microscopy studies revealed that S. frutescens- and S. tomentosa-treated SNO cells had morphological features characteristic of apoptosis. Annexin V/propidium iodide flow cytometry confirmed that the extracts do, in fact, induce apoptosis in the SNO cells. Caspase inhibition studies seem to indicate that extracts A (S. frutescens (L.) R. Br. subsp. microphylla from Colesberg), B (S. frutescens (L.) R. Br. subsp. microphylla from Platvlei) and C (S. tomentosa Eckl. & Zeyh from Stil Bay) are able to induce caspase-dependent as well as -independent cell death. The S. frutescens and S. tomentosa extracts were found to be more cytotoxic to cancerous SNO cells when compared to the PBMCs. CONCLUSIONS: S. frutescens and S. tomentosa extracts show promise as apoptosis-inducing anti-cancer agents

Poverty, prosperity and faith : An analysis of the prosperity gospel in the neo-Pentecostal church Winners Chapel International in Bamenda, Cameroon

Cameroon has undergone a period of economic crises, which has rendered its citizens extremely poor of which the UN Millennium development goal has its objective to eradicate extreme poverty in Sub Saharan Africa. As a researcher, I wanted to find out how the prosperity gospel preached to the adherents has influenced their views towards poverty and prosperity. Poverty is not predominantly an issue of a certain group of people but an international challenge, it is paradoxical seeing that prosperity gospel is rapidly growing in Cameroon. This dissertation critically reviews the theological interpretation of poverty and prosperity in Winners Chapel International Bamenda. Prosperity theology has been greatly criticized maintaining that it is irresponsible, promotes idolatry, it is contrary to the Bible and that the preachers of this theology quote scriptures in a certain way to argue their claim. A qualitative study with the application of semi-structured interview was conducted in Bamenda. This research discovered that the prosperity gospel has a remarkable influence on the lives of the adherents who view themselves as having observed an economic change because they worship in this church. The adherents believe it is their covenant right to prosper because God wills prosperity for all God’s children. Their belief is that if they play their part God will equally fulfil his part. Poverty is viewed as a combination of wrong mentality and wrong covenant. Their belief is that with faith and the right application of the covenant poverty can be eluded. This research was governed tremendously by the exponential growth of Pentecostalism and the advent of the gospel of prosperity in Cameroon notably in Bamenda an Anglophone region. This research has shown that poverty is not only multidimensional and complex but has several fundamental causes. Urban areas in Cameroon are facing major challenges arising from globalization, demographic changes and migration of the young well-trained people. A conclusion cannot be drawn mainly that poverty is because of wrong covenant and mentality

Christian Cult of Saints : The threat of Rape and the female martyr Saint in the Golden Legend

The hagiographic narration of popular legends by Jacobus Voragine in the Golden Legend has had a wide readership in the 13th century and onwards. The cult of saints was rooted in the Christian tradition. These venerated saints had their feast days celebrated in the liturgical church season. To portray the legends and traditions of the church, Jacobus writes of historical female saints who met the threat of rape. Although he writes about both the male and female saints, the virginity of the female saint is somehow tied to her martyrdom. In Jacobus’ narrative, these virgin martyr saints are of noble birth, beautiful, pious, and desirous. The virginity of these female saints is put online when menaced with rape and their male counterparts never face this horrendous threat. Sexual shaming and physical punishment were related uniquely to the female saint. The sex and gender of the female saint made their martyrdom defer significantly from the male saints though they went through the same magnitude of torture. Particularly only the female saint’s virginity was ardently related to their martyrdom. This research was done using the source-oriented approach and question-oriented approach. It explored Jacobus’ narrative of the male and female saints and attempts to understand how virginity was communicated and propagated. Virginity is articulated as being valuable by the Church Fathers who came up with treatises in the 4th century. Some of these Church Fathers significantly influence Jacobus, who was also a member of the Dominican Order. These Church Fathers regarded Mary as the virgin par excellence, and she epitomized virginity. In conclusion, Jacobus’ narrative promotes the sanctity of the female saints by showcasing their purity. He depicts virginity as having physical and spiritual attributes but overemphasizes that of the female saint

Serotonin receptors and G-protein coupled receptor interacting proteins: potential drug targets in clinical medicine

The experimental approaches from this study have been used to characterize and investigate the function, expression and distribution of the 5-HT4 and 5-HT7 receptor splice variants and G-protein coupled receptor interacting proteins. The results in chapter two provide knowledge of the functional response of the 5-HT4d and 5-HT4g receptor splice variants to different 5-HT receptor agonists. It was found that the ranking order of potency for the various agonists differs. Tegaserod and Y-36912 were reasonably potent similar to 5-HT, MeOT and prucalopride at the (d) and the (g) splice variants. No significant differences regarding response were observed between the 5-HT4d and 5-HT4g receptor splice variants. Indeed it has been suggested previously that, the function of serotonin receptors is enhanced by downstream G-protein coupled receptor interacting proteins (GIPs). This prompted the study of 5-HT4 receptor and GIPs distribution in the guinea pig intestine. In chapter three reverse transcriptase–polymerase chain reaction (RT-PCR) assays and western blot analysis were used to detect the presence of 5-HT4, 5-HT7 receptors and GIPs in different regions of the guinea pig intestine. There is significant evidence to suggest that the guinea pig can be used as a suitable model for biological assays and that a high density of serotonin receptors can be found in the gastrointestinal tract of all mammals. Moreover, functional gastrointestinal disorders such as irritable bowel syndrome (IBS), has been associated with 5-HT receptor function, but there is limited knowledge of GIPs association with IBS. This prompted the introduction of GIPs in chapter three and chapter four. Results showed that 5-HT4 and 5-HT7 receptors and G-protein coupled receptor kinases (GRKs) which are GRK2, GRK3, GRK5, GRK6 and PDZ domain interacting proteins which are Veli-1, Veli-2 and Veli-3 were expressed in the guinea pig intestine. Veli-1 and Veli-2 were expressed in the jejunum, ileum, proximal colon and distal colon of the guinea pig. Veli-3 was not seen in any of the regions studied. The 5-HT4 receptor and the interacting GIPs appeared to co-exist in the same tissue which has been shown in this study for the first time. In chapter four, RT-PCR was used to identify expression patterns of 5-HT4 and 5-HT7 receptor splice variants and GIPs in the human colon. The 5-HT4 and 5-HT7 receptor splice variants, GRK2, GRK3, GRK5 and GRK6 as well as Veli-1, Veli-2 are present in the different regions studied. However, some of the genes are less frequently detected in some of the areas examined. The 5-HT4d and 5-HT4g receptor splice variants were not detected in the ileum and transverse colon respectively. Veli-1 was not detected in the transverse colon while GRK6 was not detected in the ileum, transverse and sigmoid colon. This study suggests that splice variant-specific modulation of 5-HT4 receptor function might be achieved with compounds that affect the interaction of a 5-HT4 receptor with either Velis or GRKs. However, targeting a combination of specific 5-HT4 receptor splice variant and interacting Veli-1, 2 and 3 or a specific 5-HT4 receptor splice variant and interacting GRK2, 3, 5, 6 requires understanding of interactions in the same naturally occurring cell. In chapter five an attempt was made to determine if any of the 5-HT4 receptor splice variants interact with Velis in COS-7 cell lines. Using gateway cloning techniques 5-HT4a, b, d, g and Veli 1, 2 and 3 were expressed and visualized in COS-7 cells. The 5-HT4a receptor splice variant appeared to co-immunoprecipitated with Veli-3 confirming earlier reports that these two proteins are binding partners. It is possible to speculate that, increasing the expression of Veli-3 could potentially up regulate 5-HT4a receptor function towards future therapeutic gain

Oxidative stress markers in infectious respiratory diseases: current clinical practice

Cases of some infectious respiratory diseases are on the increase and aetiology of these diseases is associated with assault from exogenous and endogenous oxidants. This requires constant appraisal on current knowledge hence this review looks at current knowledge on oxidative and nitrosative stresses in selected infectious respiratory diseases and the utility of stress biomarkers. A major metabolic or organic stress is oxidative stress; an imbalance between oxidants and anti-oxidants and it is implicated in aetiology of various diseases including respiratory diseases. Physiologically reactive oxygen and nitrogen species are beneficial since they take part in various cellular processes. During infection, the host produces reactive species to defend against invading pathogens but some microorganisms have mechanisms to defend against the reactive oxygen and nitrosative species produced by host. Hence, there is also the oxidative stress ‘pros and cons’ paradox in infectious respiratory disease, which makes careful interpretation of laboratory methods necessary. Although most reactive oxygen and nitrosative species are not very stable and cannot be measured directly, there are indirect assessment methods of oxidative stress or oxidants or anti-oxidants. Various biological samples such as exhaled air, exhaled breath condensate, sputum and blood are used in investigation and management of infectious respiratory diseases. Measurement of oxidative stress can be done using various laboratory methods including, chemical, immunoassays and chromatographic thus allowing oxidative stress assessment to be important in infectious respiratory diseases

Serotonin receptors and G-protein coupled receptor interacting proteins: potential drug targets in clinical medicine

The experimental approaches from this study have been used to characterize and investigate the function, expression and distribution of the 5-HT4 and 5-HT7 receptor splice variants and G-protein coupled receptor interacting proteins. The results in chapter two provide knowledge of the functional response of the 5-HT4d and 5-HT4g receptor splice variants to different 5-HT receptor agonists. It was found that the ranking order of potency for the various agonists differs. Tegaserod and Y-36912 were reasonably potent similar to 5-HT, MeOT and prucalopride at the (d) and the (g) splice variants. No significant differences regarding response were observed between the 5-HT4d and 5-HT4g receptor splice variants. Indeed it has been suggested previously that, the function of serotonin receptors is enhanced by downstream G-protein coupled receptor interacting proteins (GIPs). This prompted the study of 5-HT4 receptor and GIPs distribution in the guinea pig intestine. In chapter three reverse transcriptase–polymerase chain reaction (RT-PCR) assays and western blot analysis were used to detect the presence of 5-HT4, 5-HT7 receptors and GIPs in different regions of the guinea pig intestine. There is significant evidence to suggest that the guinea pig can be used as a suitable model for biological assays and that a high density of serotonin receptors can be found in the gastrointestinal tract of all mammals. Moreover, functional gastrointestinal disorders such as irritable bowel syndrome (IBS), has been associated with 5-HT receptor function, but there is limited knowledge of GIPs association with IBS. This prompted the introduction of GIPs in chapter three and chapter four. Results showed that 5-HT4 and 5-HT7 receptors and G-protein coupled receptor kinases (GRKs) which are GRK2, GRK3, GRK5, GRK6 and PDZ domain interacting proteins which are Veli-1, Veli-2 and Veli-3 were expressed in the guinea pig intestine. Veli-1 and Veli-2 were expressed in the jejunum, ileum, proximal colon and distal colon of the guinea pig. Veli-3 was not seen in any of the regions studied. The 5-HT4 receptor and the interacting GIPs appeared to co-exist in the same tissue which has been shown in this study for the first time. In chapter four, RT-PCR was used to identify expression patterns of 5-HT4 and 5-HT7 receptor splice variants and GIPs in the human colon. The 5-HT4 and 5-HT7 receptor splice variants, GRK2, GRK3, GRK5 and GRK6 as well as Veli-1, Veli-2 are present in the different regions studied. However, some of the genes are less frequently detected in some of the areas examined. The 5-HT4d and 5-HT4g receptor splice variants were not detected in the ileum and transverse colon respectively. Veli-1 was not detected in the transverse colon while GRK6 was not detected in the ileum, transverse and sigmoid colon. This study suggests that splice variant-specific modulation of 5-HT4 receptor function might be achieved with compounds that affect the interaction of a 5-HT4 receptor with either Velis or GRKs. However, targeting a combination of specific 5-HT4 receptor splice variant and interacting Veli-1, 2 and 3 or a specific 5-HT4 receptor splice variant and interacting GRK2, 3, 5, 6 requires understanding of interactions in the same naturally occurring cell. In chapter five an attempt was made to determine if any of the 5-HT4 receptor splice variants interact with Velis in COS-7 cell lines. Using gateway cloning techniques 5-HT4a, b, d, g and Veli 1, 2 and 3 were expressed and visualized in COS-7 cells. The 5-HT4a receptor splice variant appeared to co-immunoprecipitated with Veli-3 confirming earlier reports that these two proteins are binding partners. It is possible to speculate that, increasing the expression of Veli-3 could potentially up regulate 5-HT4a receptor function towards future therapeutic gain

Polyphenols: Modulators of Platelet Function and Platelet Microparticle Generation?

Platelets and platelet microparticles (PMPs) play a key role in the pathophysiology of vascular disorders such as coronary artery disease and stroke. In atherosclerosis, for example, the disruption of the plaque exposes endogenous agonists such as collagen, which activates platelets. Platelet hyper-activation and the high levels of PMPs generated in such situations pose a thrombotic risk that can lead to strokes or myocardial infarctions. Interestingly, dietary polyphenols are gaining much attention due to their potential to mimic the antiplatelet activity of treatment drugs such as aspirin and clopidogrel that target the glycoprotein VI (GPVI)&ndash;collagen and cyclooxygenease-1 (COX-1)&ndash;thromboxane platelet activation pathways respectively. Platelet function tests such as aggregometry and flow cytometry used to monitor the efficacy of antiplatelet drugs can also be used to assess the antiplatelet potential of dietary polyphenols. Despite the low bioavailability of polyphenols, several in vitro and dietary intervention studies have reported antiplatelet effects of polyphenols. This review presents a summary of platelet function in terms of aggregation, secretion, activation marker expression, and PMP release. Furthermore, the review will critically evaluate studies demonstrating the impact of polyphenols on aggregation and PMP release