28 research outputs found

    Determination of superoxide dismutase mimetic activity in common culinary herbs

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    BACKGROUND: Under conditions of oxidative stress, the removal of superoxide, a free radical associated with chronic inflammation, is catalysed by superoxide dismutase (SOD). Thus in addition to acting as an antioxidant, SOD may also be utilized as an anti-inflammatory agent. Some plant derived foods have been shown to have SOD mimetic (SODm) activity however it is not known if this activity is possessed by culinary herbs which have previously been shown to possess both antioxidant and anti-inflammatory properties. The aim of the study was to ascertain if the culinary herbs rosemary, sage and thyme possess SODm activity, and to investigate the influence of cooking and digestion on this activity. Transition metal ion content was also determined to establish if it could likely contribute to any SODm activity detected. FINDINGS: All extracts of uncooked (U), cooked (C) and cooked and digested (C&D) herbs were shown to possess SODm activity, which was significantly correlated with previously determined antioxidant and anti-inflammatory activities of these herbs. SODm activity was significantly increased following (C) and (C&D) for rosemary and sage only. The impact of (C) and (C&D) on the SODm for thyme may have been influenced by its transition metal ion content. CONCLUSIONS: SODm activity may contribute to the herbs' antioxidant and anti-inflammatory activities however the source and significance of this activity need to be established

    Culinary herbs and spices: their bioactive properties, the contribution of polyphenols and the challenges in deducing their true health benefits

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    Herbs and spices have been used for both culinary and medicinal purposes for centuries. Over the last decade, research into their role as contributors of dietary polyphenols, known to possess a number of properties associated with reducing the risk of developing chronic non-communicable diseases, has increased. However, bearing in mind how these foods are consumed, normally in small quantities and in combination with other foods, it is unclear what their true benefit is from a health perspective. The aim of this review is to use the literature to discuss how preparative and digestive processes, bioavailability and interactions between foods may influence the bioactive properties of these foods, and whether or not polyphenols are responsible for these properties. Furthermore, this review aims to highlight the challenges that need to be addressed so as to determine the true benefits of these foods and the mechanisms of action that underpin their purported efficacy

    Validation of the Abbreviated Socio‑Political Control Scale for Youth (SPCS‑Y) Among Urban Girls of Color

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    This study tested and validated the factor structure of the abbreviated Sociopolitical Control Scale for Youth (SPCS-Y) among a sample of urban girls of color. Participants include (N = 830) urban girls of color from a northeastern United States community. Confirmatory Factor analyses (CFA) were conducted using AMOS Structural Equation Modeling Software. Cluster groups were created using Latent Class Cluster Analysis (LCA) and tested using Multivariate analysis of covariance (MANCOVA) with conceptually related variables. CFA results supported the two-factor structure of the abbreviated SPCS-Y among the sample. Following the creation of cluster groups, MANCOVA analyses revealed significant heterogeneity among cluster groups of participants on neighborhood sense of community, social support, ethnic identity, and lower levels of drug use. Findings support the factor structure of the SPCS-Y and its use to measure empowerment among girls of color. Results contribute significantly to the field of social work and encourages the importance of promoting strengths-based approaches among girls of color. Implications for social work practice with girls of color are conveyed in light of the need for reliable measurement tools for practitioners

    Phytochemical investigations of three Rhodocodon (Hyacinthaceae Sensu APG II) species

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    The genus Rhodocodon (Hyacinthaceae sensu APG II) is endemic to Madagascar and its phytochemistry has not been described previously. The phytochemistry of three species in this genus has been investigated and eight compounds, including three bufadienolides (compounds 1, 4, and 5), a norlignan (2), and four homoisoflavonoids (compounds 3 and 6-8) have been isolated and identified. Compounds 1-3 and 6-8 have not been described previously. The COX-2 inhibitory activity of compound 6 and compound 7 acetate (compound 7A) were investigated on isolated colorectal cancer cells. Compounds 6 and 7A inhibited COX-2 by 10% and 8%, respectively, at a concentration of 12.5 M compared to 12% for 1 mM aspirin (the positive control)

    Melanin production inhibitors from the West African 'Cassipourea congoensis'

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    Cassipourea congoensis (syn. Cassipourea malosana) is used in African countries as a skin-lightening agent. Two previously unreported cycloartane triterpenoids, 26-hydroxy-3-keto-24-methy lenecycloartan-30-oic acid 1 and 24-methylene-cycloartan-3β,26,30-triol 2 along with the known mahuannin B 3, 7-methoxymahuannin B 4, 7-methoxygeranin A 5, methyl-3-(4-hydroxy-3-methoxyphenyl)-2E-propenoate, glycerol-1-alkanoate, (E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enal 6, (-)-syringaresinol 7, and stigmast-5-en-3-O-β-D-glucoside, were isolated from the roots of C. congoensis. The crude extract and compounds 1 and 5 were found to inhibit the production of melanin at 10 μM with low cytotoxicity validating the ethno-medicinal use of this plan

    Randomized Controlled Trials of HIV/AIDS Prevention and Treatment in Africa: Results from the Cochrane HIV/AIDS Specialized Register

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    INTRODUCTION: To effectively address HIV/AIDS in Africa, evidence on preventing new infections and providing effective treatment is needed. Ideally, decisions on which interventions are effective should be based on evidence from randomized controlled trials (RCTs). Our previous research described African RCTs of HIV/AIDS reported between 1987 and 2003. This study updates that analysis with RCTs published between 2004 and 2008. OBJECTIVES: To describe RCTs of HIV/AIDS conducted in Africa and reported between 2004 and 2008. METHODS: We searched the Cochrane HIV/AIDS Specialized Register in September 2009. Two researchers independently evaluated studies for inclusion and extracted data using standardized forms. Details included location of trials, interventions, methodological quality, location of principal investigators and funders. RESULTS: Our search identified 834 RCTs, with 68 conducted in Africa. Forty-three assessed prevention-interventions and 25 treatment-interventions. Fifteen of the 43 prevention RCTs focused on preventing mother-to-child HIV transmission. Thirteen of the 25 treatment trials focused on opportunistic infections. Trials were conducted in 16 countries with most in South Africa (20), Zambia (12) and Zimbabwe (9). The median sample size was 628 (range 33-9645). Methods used for the generation of the allocation sequence and allocation concealment were adequate in 38 and 32 trials, respectively, and 58 reports included a CONSORT recommended flow diagram. Twenty-nine principal investigators resided in the United States of America (USA) and 18 were from African countries. Trials were co-funded by different agencies with most of the funding obtained from USA governmental and non-governmental agencies. Nineteen pharmaceutical companies provided partial funding to 15 RCTs and African agencies co-funded 17 RCTs. Ethical approval was reported in 65 trials and informed consent in 61 trials. CONCLUSION: Prevention trials dominate the trial landscape in Africa. Of note, few principal investigators and funders are from Africa. These findings mirror our previous work and continue to indicate a need for strengthening trial research capacity in Africa

    The effect of isolates from 'Cassipourea flanaganii' (Schinz) alston, a plant used as a skin lightning agent, on melanin production and tyrosinase inhibition

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    Ethnopharmacological relevance The Zulu and Xhosa people of South Africa use the stem bark of Cassipourea flanaganii as a skin-lightning cosmetic. Aim of the study To isolate and identify compounds responsible for the skin lightning properties from the stem bark of Cassipourea flanaganii and to evaluate their cytotoxicity towards skin cells. Materials and methods Extracts from the stem bark of Cassipourea flanaganii were isolated using chromatographic methods and structures were determined using NMR, IR and MS analysis. The tyrosinase inhibitory activity and the ability to inhibit the production of melanin were determined using human primary epidermal melanocyte cells. Cytoxicity was established using the same melanocytes and a neutral red assay. Results One previously undescribed compound, ent-atis-16-en-19-al (1) along with the known ent-atis-16-en-19-oic acid (2), ent-atis-16-en-19-ol (3), ent-kaur-16-en-19-oic acid (4), ent-kaur-16-en-19-al (5), ent-manoyl oxide (6), guinesine A (7), guinesine B (8), guinesine C (9), lichenxanthone (10), 2,4-dihydroxy-3,6-dimethyl benzoic acid methyl ester (11), lynoside (12), lupeol (13), β-amyrin (14), docosyl ferulate (15), stigmasterol, sitosterol and sitosterol-O-glucoside were isolated in this investigation. An impure fraction containing compound 3 was acetylated to obtain 19-acetoxy-ent-atis-16-ene (3a). Compounds 10 and 11 are usually isolated from lichen, hence they are possible contaminants of lichen harvested with the bark. Compounds 1, 3a, 5–14 were not significantly cytotoxic to the primary epidermal melanocyte cells (P > 0.05) when compared to the negative and positive controls (DMSO, 0.1% and hydrogen peroxide, 30 wt% in water). Inhibition of tyrosinase was significantly greater with respect to the negative control (P < 0.001) for compounds 3a, 5–8 and 9–10 at 10 μM and for compounds 5–8 and 9–10 at 100 μM. Compared to hydroquinone (the positive control) at 10 μM, the level of inhibition was comparable or to that of compounds 3a, 5, 6, and 8–10 at 10 μM, with 9 and 10 showing a greater level of inhibition. Inhibition of melanin was both concentration and time dependent for all compounds tested with higher melanin content at 24 h compared to 48 h s and at 10 mM compared to100 mM at both time points; melanin content was significantly lower for hydroquinone at both time points and concentrations. Conclusions Compounds 1, 5–14, isolated from Cassipourea flanaganii and the derivative 3a showed low cytotoxicity. All compounds had a clear time and concentration dependent effect on melanin content which did not appear to be dependent on their inhibition of tyrosinase

    The efficacy and safety of Chinese herbal medicines

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    Studies of glutamine metabolism in skeletal muscle and other tissues

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    Cells of the immune system, both resting and stimulated, utilize glutamine at a high rate (see Ardawi 1983 and Newsholme et al 1985). Skeletal muscle is considered to be an important source of glutamine for cells of the immune system (see Newsholme and Parry-Billings 1990). It is proposed that the process of glutamine release from skeletal muscle is the flux-generating step for the pathway of glutamine utilization by cells of the immune system, and that, control of glutamine release from skeletal muscle influences the rate of glutamine utilization by cells of the immune sytem, and hence the function of these cells. Studies using an in vitro skeletal muscle (soleus) preparation, identifying factors/conditions (e.g. branched chain amino acids, dexamethasone and hyperthyroidism) that modify both the rate of glutamine release from muscle and muscle glutamine concentration, illustrated that glutamine release from muscle is independent of the intracellular glutamine concentration (Parry-Billings 1989). However, the rate of glutamine release from muscle over time was non-linear, which may have lead to misinterpretation of the results reported by Parry- Billings (1989). Investigation of the linearity of the rate of glutamine release from soleus muscle over time, in the present study, using the in vitro muscle preparation, has shown that non-linearity of the rate of glutamine release is due to the presence of an artefact in the muscle incubation medium, rather than the process of muscle glutamine release. With the "correction" of the linearity for muscle glutamine release, a reinvestigation of the effect(s) of factors (e.g. branched chain amino acids) on the rate of glutamine release from muscle (soleus and extensor digitorum longus) and muscle glutamine concentration verified that the process of glutamine release from muscle is independent of the intracellular glutamine concentration. The changes in the concentration of glutamine in muscle caused by these factors suggests that they may affect the process of muscle glutamine synthesis. Quantitative analysis of muscle glutamine release and concentration data plus a study of the effects of factors on the maximal activity of muscle glutamine synthetase confirmed this. Results of the study on the effect(s) of factors on muscle glutamine synthesis, release, and concentration are discussed in relation to a systematic approach used for a study of the control of metabolic pathways (see Newsholme and Crabtree 1979) and are found to be consistent with the predictions made using this systematic approach. The possibility that other tissues, namely rat adipose tissue and immune cells of the rat, are able to provide glutamine, was investigated by determining whether these tissues possess glutamine synthetase activity and thus synthesize glutamine. The present study indicates that, although rat adipose tissue possesses a maximal glutamine synthetase activity that is approximately 6-7 times greater than that of muscle, on a whole body (200g rat) basis, rat adipose tissue may not be a significant contributor of glutamine. In contrast, a study by Frayn et al (1991) suggests that human adipose tissue may be a significant contributor of glutamine. For cells of the immune system, the present study indicates that immune cells possess glutamine synthetase activity and thus can synthesize glutamine. This ability to synthesize glutamine may be of physiological significance since it is suggested that glutamine synthetase in cells of the immune system may provide enough glutamine to maintain some immune cell function during conditions, for example following surgery, injury and during sepsis, in which the plasma glutamine concentration is decreased.</p
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