In vivo antileishmanial activity and chemical profile of polar extract from Selaginella sellowii

The polar hydroethanolic extract from Selaginella sellowii(SSPHE) has been previously proven active on intracellular amastigotes (in vitro test) and now was tested on hamsters infected with Leishmania (Leishmania) amazonensis (in vivo test). SSPHE suppressed a 100% of the parasite load in the infection site and draining lymph nodes at an intralesional dose of 50 mg/kg/day × 5, which was similar to the results observed in hamsters treated with N-methylglucamine antimonate (Sb) (28 mg/Kg/day × 5). When orally administered, SSPHE (50 mg/kg/day × 20) suppressed 99.2% of the parasite load in infected footpads, while Sb suppressed 98.5%. SSPHE also enhanced the release of nitric oxide through the intralesional route in comparison to Sb. The chemical fingerprint of SSPHE by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry showed the presence of biflavonoids and high molecular weight phenylpropanoid glycosides. These compounds may have a synergistic action in vivo. Histopathological study revealed that the intralesional treatment with SSPHE induced an intense inflammatory infiltrate, composed mainly of mononuclear cells. The present findings reinforce the potential of this natural product as a source of future drug candidates for American cutaneous leishmaniasis.     

Comparison of Classical Models for Evaluating the Heat Requirements of Olive （Olea europeae L.） in Portugal

The aim of the present study was to compare the accuracy and reproducibility of six statistical models for the calculation of olive （Olea europeae L.） heat requirements to trigger the onset of flowering in three Portuguese regions： Reguengos de Monsaraz, Valenga do Douro, and Braga. Other alms were to ascertain the date on which the heat-accumulation period started and the threshold temperatures above which the development of reproductive structures starts in olives. The starting and peak dates for the regional O. europeae flowering season were estimated by monitoring airborne pollen from 1998 to 2004 using ＂Cour＂- type samplers. The threshold temperature values calculated for the three regions were very similar （9.0 ℃ for Valenca do Douro, 9.2 ℃ for Reguengos de Monsaraz, and 9.7 ℃ for Braga）. The accumulated daily mean temperature model had less interannual and inter-regional variation, showing best predictive results for 2004, with absolute differences between the observed and predicted dates of 4 d in Reguengos de Monsaraz and 2 d In Valenca do Douro and Braga for the onset of flowering date and of 2 d In Reguengos de Monsaraz, 7 d in Valenca do Douro, and 4 d in Braga for peak flowering dates. This model was the most accurate, reproducible, and operational to calculate heat requirements for olives to flower, with an average mean temperature accumulation of 1 446 ℃ In Reguengos, 1 642 ℃ in Valenga do Douro, and 1 703℃ In Braga to reach the onset of flowering. The best initial date for this accumulation was 1 January.     

Litter accumulation and biomass dynamics in riparian zones in tropical South America of the Asian invasive plant Hedychium coronarium J. König (Zingiberaceae)

ABSTRACT

Background: Promoting changes in abiotic conditions and ecosystem processes, such as decomposition, is a mechanism by which some exotic plant species displace native plants and become invasive.

Aims: We monitored ramets of Hedychium coronarium over 30 months to estimate the litter decay rate, biomass dynamics and litter accumulation over time in riparian sites invaded by the species in southeastern Brazil.

Methods: We measured the number, height, emergence and mortality of ramets in three environments invaded by H. coronarium (natural, rural and urban). We also measured litter decay in situ and in in vitro experiments. We used sinusoidal models to describe height fluctuation and exponential models to simulate litter decay and litter accumulation.

Results: Ramets of H. coronarium showed high seasonal variation in terms of height and emergence, as well as low litter decay. Accordingly, our models predicted high litter production and a seasonal pattern of litter accumulation in invaded sites.

Conclusions: H. coronarium produces a great amount of litter, which shows slow decay and hence seems to affect decomposition processes. Investigating seasonal variation on the effects of invasive species on ecosystem functioning shed light on the factors driving the success and impact of invasive plants.     

Effects of physical exercise training in DNA damage and repair activity in humans with different genetic polymorphisms of hOGG1 (Ser326Cys)

The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8‐oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty‐two healthy Caucasian men (40–74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild‐type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG‐sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG‐sensitive sites) and repair activity (OGG1) between genotype groups (in the pre‐training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG‐sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism. Copyright © 2015 John Wiley & Sons, Ltd.     

Olive crop-yield forecasting based on airborne pollen in a region where the olive groves acreage and crop system changed drastically

Olive trees are one of the most economically important perennial crops in Portugal. During the last decade, the Alentejo olive-growing region has suffered a significantly change in the crop production system, with the regional pollen index (RPI) and olive fruit production registering a significant growth. The aim of this study was to ascertain the utility of this highly variable production and pollen data in crop forecasting modeling. Airborne pollen was sampled using a Cour-type trap from 1999 to 2015. A linear regression model fitted with the regional pollen index as the independent variable showed an accuracy of 87% in estimating olives fruit production in Alentejo. However, the average deviation between observed and modeled production was 32% with half of the tested years presenting deviations between 36 and 66%. The low accuracy of this model is a consequence of the great overall variation and significant upward trend observed in both the production and the RPI dataset that conceal the true association between these variables. In order to overcome this problem, a detrend procedure was applied to both time series to remove the trend observed. The regression model fitted with the fruit production and the RPI detrended data showed a lowest forecasting accuracy of 63% but the average deviation between observed and modeled production decrease to 14% with a maximum deviation value of 33%. This procedure allows focusing the analysis on the production fluctuations related to the biological response of the trees rather than with the changes in the production system.