Research - Lung Disease
Antimycobacterial activity against different pathogens and selectivity index of fourteen medicinal plants used in southern Africa to treat tuberculosis and respiratory ailments
J.P. Dzoyem, A.O. Aro, L.J. McGaw, J.N. Eloff
Many plants are used in traditional medicine to treat tuberculosis and other respiratory disorders in Africa. The emergence of multiple drug resistance has become a major threat and thus calls for an urgent need to search for new effective and safe anti-TB agents. The aim was to determine the antimycobacterial activity and the safety of the acetone leaf extracts of 14 plant species used in southern Africa to treat tuberculosis and pulmonary ailments.
The antimycobacterial activity was evaluated by a tetrazolium violet based broth microdilution method against three fast-growing mycobacteria species (Mycobacterium smegmatis,Mycobacterium aurum and M. fortuitum) and one pathogenic M. tuberculosis field strain. The in vitro cellular toxicity was determined using the MTT assay on Vero monkey kidney cells. The extraction yield, the LC50 and MIC values were used to determine the total activity (TA) and the selectivity index (SI) of the extracts.
Extracts had moderate to weak activity with the MIC values ranging from 0.039 to > 2.5 mg/mL. M. fortuitum appeared to be better predictor of activity against pathogenic M. tuberculosis than M. smegmatis and M. aurum. Extracts from Heteropyxis natalensis (3.3) and Hexalobus monopetalus (2.47) had the highest selectivity index.
The results substantiate the safety and in some cases the potential efficacy of the traditional use of these species against tuberculosis and pulmonary ailments.
Source : South African Journal of Botany
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Circulating 25-hydroxyvitamin D and risk of lung cancer: a dose–response meta-analysis
- Guo-Chong Chen
- , Zeng-Li Zhang
- , Zhongxiao Wan
- , Ling Wang
- , Peter Weber
- , Manfred Eggersdorfer
- ,Li-Qiang Qin
- , Weiguo Zhang
Mounting experimental evidence supports a protective effect of high 25-hydroxyvitamin D (25[OH]D), a good indicator of vitamin D status, on risk of various cancers including lung cancer. However, prospective observational studies examining the 25(OH)D–lung cancer association reported inconsistent findings. A dose–response meta-analysis was carried out to elucidate the subject.
Potentially eligible studies were identified by searching PubMed and EMBASE databases, and by carefully reviewing the bibliographies of retrieved publications. The summary relative risks (RRs) with 95 % confidence intervals (CIs) were calculated using the random-effects model.
Thirteen reports from ten prospective studies were included, totaling 2,227 lung cancer events. Results of the meta-analysis showed a significant 5 % (RR 0.95, 95 % CI 0.91–0.99) reduction in the risk of lung cancer for each 10 nmol/L increment in 25(OH)D concentrations. This inverse association was not significantly modified by area, study duration, sex, methods for 25(OH)D measurement, baseline 25(OH)D levels, or quality score of included studies. There was evidence of a nonlinear relationship between 25(OH)D and risk of lung cancer (p-nonlinearity = 0.02), with the greatest reductions in risk observed at 25(OH)D of nearly 53 nmol/L, and remained protective until approximately 90 nmol/L. Further increases showed no significant association with cancer risk, but scanty data were included in the analyses of high-level 25(OH)D. There was no evidence of publication bias.
This dose–response meta-analysis of prospective studies suggests that 25(OH)D may be associated with reduced risk of lung cancer, in particular among subjects with vitamin D deficiencies.
Source : Journal Cancer Causes and Control
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Protective effect of polyphenols in an inflammatory process associated with experimental pulmonary fibrosis in mice
Polyphenols have been described to have a wide range of biological activities, and many reports, published during recent years, have highlighted the beneficial effects of phenolic compounds, illustrating their promising role as therapeutic tools in several acute and chronic disorders. The purpose of study was to evaluate, in an already-assessed model of lung injury caused by bleomycin (BLM) administration, the role of resveratrol and quercetin, as well as to explore the potential beneficial properties of a mango leaf extract, rich in mangiferin, and a grape leaf extract, rich in dihydroquercetin (DHQ), on the same model. Mice were subjected to intra-tracheal administration of BLM, and polyphenols were administered by oral route immediately after BLM instillation and daily for 7 d. Treatment with resveratrol, mangiferin, quercetin and DHQ inhibited oedema formation and body weight loss, as well as ameliorated polymorphonuclear infiltration into the lung tissue and reduced the number of inflammatory cells in bronchoalveolar lavage fluid. Moreover, polyphenols suppressed inducible nitric oxide synthase expression, and prevented oxidative and nitroxidative lung injury, as shown by the reduced nitrotyrosine and poly (ADP-ribose) polymerase levels. The degree of apoptosis, as evaluated by Bid and Bcl-2 balance, was also suppressed after polyphenol treatment. Finally, these natural products down-regulated cyclo-oxygenase-2, extracellular signal-regulated kinase phosphorylated expression and reduced NF-κBp65 translocation. Our findings confirmed the anti-inflammatory effects of resveratrol and quercetin in BLM-induced lung damage, and highlight, for the first time, the protective properties of exogenous administration of mangiferin and DHQ on experimental pulmonary fibrosis.
Source : British Journal of Nutrition
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The Effects of Regular Yoga Practice on Pulmonary Function in Healthy Individuals: A Literature Review
Allison N. Abel, BEd, Lisa K. Lloyd, PhD, and James S. Williams, PhD
Department of Health and Human Performance, Texas State University–San Marcos, San Marcos, TX.
Objectives: Yoga is a popular form of exercise in the Western world, and yoga's effects on pulmonary function have been investigated previously. The purpose of this article is to review this research systematically and determine if regular yoga training improves pulmonary function in apparently healthy individuals.
Methods: Using the Alternative Health Watch, the Physical Education Index, Medline,® and the SPORTdiscus databases; and the keywords yoga, respiration, and pulmonary function, a comprehensive search was conducted that yielded 57 studies. Of these studies selections were made to include only experimental studies written in English, published in peer-reviewed journals after 1980, and investigating the effects of regular yoga practice on pulmonary function in healthy individuals participating in the studies.
Results: Yoga improved pulmonary function, as measured by maximum inspiratory pressure, maximum expiratory pressure, maximum voluntary ventilation, forced vital capacity, forced expiratory volume in 1 second, and peak expiratory flow rate, in all (N=9), but 1, study.
Conclusions: Overall, pulmonary function appears to improve with a minimum of 10 weeks of regular yoga practice, and the magnitude of this improvement is related to fitness level and/or the length of time the subjects spend practicing pranayama (i.e., breathing exercises). In other words, greater improvements in pulmonary function are more likely to be seen in less-fit individuals and/or those that engage in longer periods of pranayama. Additional studies examining various yoga practices are warranted to gain a more comprehensive understanding of the effects of yoga techniques on pulmonary functions.
Source : the Journal of Alternative and Complementary Medicine
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