Phytochemical and antimicrobial studies on Detarium microcarpum Guill and Sperr (Caesalpinioceae) seeds coat

Ninety percent aqueous methanol extract of the seeds coat (32.324%, w/w) of Detarium microcarpum was screened against clinical isolates of Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomona aeruginosa, Klebsiella pneumonia, Salmonella paratyphi and Candida albicans. A broad spectrum antimicrobial activity at the test concentration of 10 mg/ml comparable with the control drugs chloramphenicol and penicillin G for bacteria and nystatin for the mould C. albicans was observed. On bio-guided fractionation, the ethyl acetate soluble fraction (ES) retains the observed spectrum of antimicrobial activity. Preparative thin layer  chromatographic separation of the active ESF on silica gel 60G using butan-2-one : chloroform : acetic acid : water (40:40:2:1 v/v/v/v) gave eight constituent bands: B1 (Rf = 0.000), B2 (Rf = 0.079), B3 (Rf =  0.250), B4 (Rf = 0.286), B5 (Rf = 0.500), B6 (Rf = 0.686), B7(Rf = 0.814), and B8 (Rf = 1.000). B1 retained the observed antimicrobial activity spectrum, B2 and B3 showed residual inhibition against B. subtilis and B4 - B8 were inactive. Phytochemical screening indicated the presence steroidal saponins and flavonoids in B1, and flavonoids in B2 and B3. The UV visiblespectrum of B2 and B3 revealed the characteristic benzopyrone maxima (236 – 300 nm). Against the selected bacteria, MIC range of B1 of 1.0488 -2.8887 mg/ml was observed comparable to those of standard control (1.2357 - 3.3420 mg/ml) and chloramphenicol (2.0840 -3.9630 mg/ml) which is suggestive of resistant strains. This study revealed the antimicrobial principles in the seed coat of D. microcarpum to be steroidal saponins and flavonoids with the possibility of synergistic action.Key words: Detarium microcarpum, seed coat, antimicrobial activity, benzopyrone, flavonoids, steroidal saponins, phytoalexins

The association of cold weather and all-cause and cause-specific mortality in the island of Ireland between 1984 and 2007

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.This article has been made available through the Brunel Open Access Publishing Fund.Background This study aimed to assess the relationship between cold temperature and daily mortality in the Republic of Ireland (ROI) and Northern Ireland (NI), and to explore any differences in the population responses between the two jurisdictions. Methods A time-stratified case-crossover approach was used to examine this relationship in two adult national populations, between 1984 and 2007. Daily mortality risk was examined in association with exposure to daily maximum temperatures on the same day and up to 6 weeks preceding death, during the winter (December-February) and cold period (October-March), using distributed lag models. Model stratification by age and gender assessed for modification of the cold weather-mortality relationship. Results In the ROI, the impact of cold weather in winter persisted up to 35 days, with a cumulative mortality increase for all-causes of 6.4% (95%CI=4.8%-7.9%) in relation to every 1oC drop in daily maximum temperature, similar increases for cardiovascular disease (CVD) and stroke, and twice as much for respiratory causes. In NI, these associations were less pronounced for CVD causes, and overall extended up to 28 days. Effects of cold weather on mortality increased with age in both jurisdictions, and some suggestive gender differences were observed. Conclusions The study findings indicated strong cold weather-mortality associations in the island of Ireland; these effects were less persistent, and for CVD mortality, smaller in NI than in the ROI. Together with suggestive differences in associations by age and gender between the two Irish jurisdictions, the findings suggest potential contribution of underlying societal differences, and require further exploration. The evidence provided here will hope to contribute to the current efforts to modify fuel policy and reduce winter mortality in Ireland

Preliminary anti-microbial and phytochemical investigation of the extracts and column fractions of Alchornea Floribunda leaves

The leaves of Alchornea floribunda were collected, identified and reduced to coarse powder. Using various solvent treatments, the powdered drug leaf was fractionated into A1, A2, B, C and D. The fractions were subjected to anti-microbial screening and phytochemical analysis. Phytochemical analysis of the extracts showed the presence of terpenes, sterols, flavonoids, tannins, carbohydrate, glycoside, saponins and alkaloids. Only fraction A2 (the terpenoid fraction) showed promising antimicrobial activity against Pseudomonas aeruginosa (IZD 42 mm) Salmonella keitambii (IZD 34mm) and Bacillus subtilis (IZD 32mm). A2 was further separated into 14 major column chromatographic fractions. The fractions were subjected toanti-microbial and phytochemical investigation. Fraction Af7, Af9, Af12 and Af13 (all terpenoids) showed mild activity against Pseudomonas aeruginosa and Salmonella keitambii. In conclusion, the anti-microbial activity of Alchornea floribunda leaves can be attributed to the presence of the terpenoids which may interact synergistically to causeinhibition of the sensitive bacteria

Daily average temperature and mortality among the elderly: a meta-analysis and systematic review of epidemiological evidence

The impact of climate change on the health of vulnerable groups such as the elderly has been of increasing concern. However, to date there has been no meta-analysis of current literature relating to the effects of temperature fluctuations upon mortality amongst the elderly. We synthesised risk estimates of the overall impact of daily mean temperature on elderly mortality across different continents. A comprehensive literature search was conducted using MEDLINE and PubMed to identify papers published up to December 2010. Selection criteria including suitable temperature indicators, endpoints, study-designs and identification of threshold were used. A two-stage Bayesian hierarchical model was performed to summarise the percent increase in mortality with a 1°C temperature increase (or decrease) with 95% confidence intervals in hot (or cold) days, with lagged effects also measured. Fifteen studies met the eligibility criteria and almost 13 million elderly deaths were included in this meta-analysis. In total, there was a 2-5% increase for a 1°C increment during hot temperature intervals, and a 1-2 % increase in all-cause mortality for a 1°C decrease during cold temperature intervals. Lags of up to 9 days in exposure to cold temperature intervals were substantially associated with all-cause mortality, but no substantial lagged effects were observed for hot intervals. Thus, both hot and cold temperatures substantially increased mortality among the elderly, but the magnitude of heat-related effects seemed to be larger than that of cold effects within a global context