Single-tree influence of Tectona grandis Linn. f. on plant distribution and soil characteristics in a planted forest

Abstract Background Little is known about the single-tree influence of Tectona grandis Linn. f. on plant distribution and soil characteristics in Benin City, Nigeria. We investigated the possible single-tree effect of T. grandis on understory plants in an 8-year-old teak plantation at the Moist Forest Research Station. An area of 36.57 m by 60.96 m was marked out and divided into 15 equal-sized subplots containing 10 trees per subplot. Marked distances from the base of a randomly selected tree per subplot were made (0–0.5 m, 0.5–1.0 m and 1.0–1.5 m). Results Single-tree influence of T. grandis was observed in the soil total organic carbon, total nitrogen and soluble phosphorus, where concentrations were higher with 1.5-m radius from the tree than beyond. Moreover, the pH of the topsoil within 1.5 m from the base of the tree was lower (pH 4.4) than beyond 1.5 m from the base of the tree (pH 5.4). Species-specific single-tree effect was also observed on the understory plant distribution likely due to diverse ecophysiological interactions. Within 1.5 m from the tree, plant species abundance, especially of Sida garckeana, Reisantia indica, Momordica charantia and Tridax procumbens were negatively affected. However, the distribution of Eleusine indica around the tree was not negatively influenced. Plant abundance was generally suppressed in Cynodon dactylon, Axonopus compressus, Andropogon gayanus, Commelina diffusa and Euphorbia hirta. Generally, there were more plant species beyond the canopy fringes than within the canopy, indicating inhibitory single-tree effects. Conclusion Not all plant species in close proximity to T. grandis are affected. This is important considering that plant-plant associations affect the quality of forest soils. Generally, more plant species were recorded outside the 1.5-m demarcation than within, an increase in soil organic matter may further enhance such plant species abundance. The impact of T. grandis in forest soil quality is possibly a factor of the outcome of its association with neighbouring plant species. Diverse mechanisms at play may be responsible for the observed effects on soil chemistry. However, a reduction in the soil organic matter and variations in other environmental factors also contributed to observed single-tree effect

Effect of Drying Method on Phytochemical Compositions and Inhibition Efficiency of Alchornea Laxiflora and Mucuna Flagellepes Leaves Extracts in Corrosion Prevention

Staff Publication: This study was aimed at investigating the influence of different drying methods on the photochemical composition and inhibition efficiency of Alchornea laxiflora and Muccuna flagellepes leaves extracts in corrosion prevention. The fresh samples of the leaves were collected, sorted, dried using two different drying methods viz; air drying and sun drying methods. The dried plant samples were ground separately sieved using 0.25µm and then extracted with ethanol using maceration method and then concentrated the filtrate in a water bath at 600C to obtained air dried Alchornea laxiflora leaves (AALL), air dried Mucunna flagellepes leaves (AMFL), sun dried Alchornea laxiflora leaves (SALL) and sun dried Muccuna flagellepes leaves (SMFL) extracts. The extract of each sample was analyzed separately for their phytochemical constituents using appropriate methods. From the results, there was variation in the composition in respect of the phytochemical of interest but it could be concluded that the drying methods have little effect on the phytochemical composition of the studied plant but air drying methods could be adopted as it gave highest content (AALL: Sapolin 45.55 mg/g, tannin 10.58mg/g, flavnoid 7.49mg/g, Terpenoid 7.06 mg/g, Alkaloid 35.61mg/g, phytobalatin 2.43mg/g and cardiac glycoside 4.72mg/g; AMFL: Sapolin 28.55mg/g, Tannin 5.39 mg/g, Flavnoid 6.42 mg/g, Terpenoid 5.94 mg/g, Alkaloid 4.53mg/g, Cardiac glycoside 6.33 mg/g; SALL: Saponin 20.00mg/g, Tannin 4.04 mg/g, Flavnoid 1.91 mg/g, Terpenoid 6.03 mg/g, Alkaloid 12.56 mg/g, Phytobalatin 2.57 mg/g, Cardiac glycoside 3.86mg/g: SMFL: Sapolin 15.00 mg/g, Tannin 3.82 mg/g, Terpenoid 4.82 mg/g, Alkaloid 6.25 mg/g and cardiac glycoside 4.93 mg/g. The corrosion inhibition efficiency of the samples extract on mild steel in 1.0M HCl solution was investigated using weight loss measurements. The weight loss measurement indicates an increase in corrosion inhibition efficiencies that reach 90.02% and 84.92% in AALL and AMFL extract and 79.74% and 72.12 in the SALL and SMFL extract respectively. The weight loss data established that the inhibition efficiency on mild steel increases with increase in the concentration of the plant extracts but decreased with increase in temperature. Thermodynamic parameters such as enthalpy change, entropy change, and activation energy were evaluated. Kinetics of the reaction in the presence of the extracts revealed that it follows a first order reaction and the half-life increased as the concentration of the extract increases

Impaired lipid levels and inflammatory response in rats exposed to cadmium

To investigate the subchronic effect of cadmium intoxication on lipid metabolism and the inflammatory responses accompanying it, rats were administered 50 and 100 ppm cadmium through their drinking water for 7 weeks. At both concentrations, cadmium exposure resulted in significant elevation (p < 0.05) of total cholesterol and gave rise to hypertriglyceridemia in the plasma of the animals. The proinflammatory cytokines, IL-2, IL-6 and TNF-α, were highly expressed in the animals. At the 50 ppm dose level, plasma IL-2, IL-6 and TNF-α levels were increased by 20 %, 87 % and 336 % respectively, while the 100 ppm dose yielded 32 %, 57 % and 470 % increases, respectively. A drastic build-up of MDA in the liver elicited by the metal led to an 85 % increase in lipid peroxidation at high dose. A 3-fold increase of lipid hydroperoxidation (LOOH) products was obtained on exposure to cadmium at 100 ppm. Cadmium caused more than a 2-fold increase in oxLDL levels at both doses tested. Paraoxonase activity was also significantly repressed, culminating in a 43 % reduction in activity at 100 ppm dose. Disruption of lipid metabolism, increased lipid peroxidation as well as imbalance in proinflammatory cytokine levels may thus, be means by which cadmium induces its toxicity

Studies on Thermal Stability, Shelf Life and Electrochemical Measurement of Methanol Extract of Air Dried Alchornea Laxiflora Leaves in Corrosion Prevention

Staff PublicationThe aim of this study was to determine the thermal stability and shelf life of the extract together with the influence of extract concentration, temperature and pH variation of the acidic medium on the inhibition efficiency using 1.0 M Sodium hydroxide. The dried plant samples were ground, sieved using 0.25µm and then extracted with methanol using maceration method. The phytochemical constituents were analyzed using appropriate methods. The phytochemicals detected were: Alkaloid, saponin, flavnoid, tannin, terpenoid, steroid and cardiac glycoside. Weight loss experiment was performed to ascertain the stability and shelf life of the extract at different storage temperature and time respectively while polarization experiment was used to study the behaviour of the extract on mild steel corrosion at varying concentration of the extract, pH and temperature of the acidic media. It was found that the stability of the extract inhibition efficiency was affected by the mode of storage and the inhibition efficiency decreases with increase in storage temperature of the extract. The life span of the extract was found to be 60 days from its production stage, after this, there was reduction in the inhibition efficiency of the extract. Moreso, the corrosion rate of the mild steel in 1.0 M HCl, monitored by electrochemical measurement revealed that the corrosion rate decreases with increase in the pH, decrease in temperature and increase in concentration of the extract in the acidic solution

Indikatori oksidacije koreliraju s dislipidemijom i razinama upalnih citokina u štakora izloženih fluoridu

The aim of this study was to establish the effects of fluoride on lipid metabolism and attendant inflammatory response by exposing rats to 50 mg L-1 and 100 mg L-1 of fluoride through drinking water for seven weeks. Both concentrations led to hypercholesterolemia while the 100 mg L-1 concentration induced hypertriglyceridaemia. High density lipoprotein (HDL) cholesterol levels dropped in the exposed rats while interleukin 2 (IL-2) increased more than 1.5-fold (p<0.05) and IL-6 and plasma TNF-α more than 2.5 fold (p<0.05). Fluoride-exposed rats also had significantly higher levels of liver malondialdehyde (MDA) and plasma lipid hydroperoxide (LOOH) but lower plasma paraoxonase (PON1) activity. Oxidative stress indices correlated with pro-inflammatory cytokines and plasma cholesterol. In contrast, pro-inflammatory cytokines inversely correlated with plasma triglyceride, HDL cholesterol and PON1. Our results suggest that the association between fluoride exposure with cardiovascular diseases may be related to its ability to disturb lipid homeostasis, and trigger pro-inflammatory cytokines and oxidative stress.Svrha je ovog istraživanja bila utvrditi djelovanje fluorida na metabolizam lipida i upalni odgovor tako što smo štakore izložili fluoridu u pitkoj vodi u koncentracijama od 50 mg L-1 i 100 mg L-1 sedam tjedana. Obje su koncentracije dovele do hiperkolesterolemije, a viša je koncentracija inducirala i hipertrigliceridemiju. U odnosu na kontrolnu skupinu, u izloženih su se štakora razine lipoproteina visoke gustoće (HDL-a) smanjile, a interleukin 2 (IL-2) se povećao više od 1,5 put (p<0,05), kao i IL-6 i čimbenik tumorske nekroze alfa (TNF-α) u plazmi, i to više od 2,5 puta (p<0,05). Usto su izloženi štakori iskazali značajno više razine malondialdehida (MDA) u jetrima te lipidnog hidroperoksida (LOOH) u plazmi, odnosno sniženu aktivnost paraoksonaze (PON1) u plazmi. Indikatori oksidacijskog stresa korelirali su s upalnim citokinima i kolesterolom u plazmi, a upalni citokini inverzno su korelirali s trigliceridima, HDL kolesterolom i PON1 u plazmi. Rezultati istraživanja upućuju na to da povezanost između izloženosti fluoridu i bolesti srca i krvožilja možda potječe od toga što fluorid remeti lipidnu homeostazu te pokreće upalne citokine i, posljedično, oksidacijski stres

Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation