Modelling and optimization of metals (As, Ca, Cd, Cr, Cu, Fe, Mg, and Pb) and Ethylene glycol butyl ether in paints using response surface method

Response surface methodology (RSM) and principal component analyses (PCA) modelling tools have been used in this study to quantitatively describe the interaction effects of more than one factor on system response for the modelling and optimization of experimental data. In Nigeria, there are no stringent policies in place by the government on paint production and this has led to unregulated paint products by producers in the commercial markets. Water-based paints currently available in Nigerian market were sampled. Experimental data of Metals (As, Ca, Cd, Cr, Cu, Fe, Mg, and Pb) and Ethylene glycol butyl ether (Volatile organic compounds (VOC)) measured using Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) and Gas Chromatography-Flame Ionisation Detector (GC-FID), respectively was used to develop a mathematical model. The principal component analyses were explained with a cumulative variance of 82% for the VOC and 76% for metals based on manufacturers. Estimated responses were compared with the experimentally determined responses and prediction capabilities of Response Surface Methodology. In the RSM, the 2 developed model had R value of 0.9569, with optimized value at 0.10 % (1000ppm) of Ethylene glycol butyl ether and concentration (ppm) ranges of As (383.0-1,930.0), Ca (614.0-10,400.0), Cd (98.0-2,000.0), Cr (10.3- 225.0), Cu (133.0-1,840.0), Fe 742.0-2,910.0, Mg (4,000.0-99,510.0), Pb (170.0-3,230.0). The correlation and optimization study employed are applicable for assessing the impact of hazardous air pollutants on indoor air quality and a good applicability in paint industries to produce products within the set limit of international standards. For the purpose of reducing sick building syndrome and protecting public health, it was important to investigate paints and sealers extensively. Keywords: VOCs; Paint; metals; Ethylene glycol butyl ether; Response Surface Method

Effect of methanol extract of Anacardium occidentale stem bark on agonist-induced contraction in rat uterine muscle

Anacardium occidentale (Ao) is widely used in ethnomedicine and the effect on contractility of the gut and heart muscles of laboratory rodents have been established however, its effect on the contractility of uterine muscle has been rarely researched. The present study investigated the effect of stem bark methanolic extract of Anacardium occidentale (AoME) on Isolated Rat Uterus Strips (IRUS). The Anacardium occidentale methanol extract (AoME) was obtained by solvent extraction. The IRUS were suspended in a bath containing 15 ml of De Jalon's solution through a silk connected to a force transducer. A tension of 1.0 g was applied. The strips were allowed to equilibrate for a period of 60–90 min before the commencement of the experiment. The extract (0.025- 0.3mg/ml) added cumulatively did not modify the normal tonus in most of the IRUS used except in one where it feebly contracted it. However, the contractile responses induced by acetylcholine (10-9 -10-5 M) and oxytocin (10-9 -10-5 M) on the IRUS were almost completely blocked by pre-incubated AoME at a concentration of 0.2 mg/ml. Stem bark methanol extract of Anacardium occidentale shifted the log concentration curve of both agonists to the right. The present results report the antagonistic effects of stem bark methanol extract of Anacardium occidentale on oxytocin and acetylcholine-induced contraction in rat uterus strips. Keywords: Anacardium occidentale, Oxytocin, Acetylcholine, Uterus, Smooth muscle

Effect of magnesium on some mechanical properties of 1200 Aluminium alloy

This paper investigated the effect of magnesium as a dispersion strengthening material on some mechanical properties of 1200-Aluminium (Al-Fe-Si) alloy, a typical commercial aluminium alloy used in the production of household utensils. 1200-Aluminium (Al-Fe-Si) alloy containing varying percentages of the dispersion hardening material (i.e. Magnesium) were produced and mechanical tests namely; hardness, tensile strength and impact strength were carried out. Also, the microstructures of the cast materials were studied. The results showed that increase in magnesium content, as dispersion hardening material improved the hardness, tensile strength and caused a slight decrease in impact strength of the 1200-Aluminium alloy. It is inferred from this work that using magnesium as a dispersion hardening material brings about corresponding improvement in some mechanical properties of 1200-Aluminium (Al-Fe-Si) alloy. Keywords: Magnesium, Aluminium alloy, dispersion strengthened, reinforced alloy, crystallographic formation Depth, Geothermal Energy

Antimicrobial activity of Sida acuta, Phyllanthus amarus and Phyllanthus muellerianus against microorganisms implicated in urinary tract infections

Increasing level of antimicrobial resistance among bacterial pathogens causing Urinary Tract Infection (UTI) is one of the most significant public health challenges globally. Hence, the search for alternatives from medicinal plants. This study investigated the efficacy of Phyllanthus amarus (PA), Phyllanthus muellerianus (PM) and Sida acuta (SA) leaf extracts on microorganisms implicated in UTI. Mid-stream urine samples collected from 100 patients clinically diagnosed with UTI were cultured. The microorganisms isolated were identified using their morphological and biochemical characteristics. Methanol leaf extracts of the three plants were obtained by cold maceration in 60% methanol. Crude extract of PM was thereafter purified by solvent partitioning. Antibiotic susceptibility test was determined using the Kirby Bauer disc diffusion. Antimicrobial effects of the extracts and oil was ascertained using agar well diffusion. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentrations (MBC) were also determined. Rate of kill and mechanism of action of the purified extract of PM on isolates were investigated. Cytotoxicity of plant extracts were assayed on brine shrimps while synergism of the purified extract with ciprofloxacin was ascertained using overlay inoculum susceptibility disc method. Antioxidant and phytochemical analyses of the extracts were conducted using standard methods. Phytochemical analysis of the leaf extracts showed the presence of alkaloids, tannins, saponins and steroids. Antioxidant assay also indicated SA had the highest total flavonoids and phenol content of 339.86 mgQUE/g and 27.63 mgGAE/g. Microorganisms isolated include: Escherichia coli (24%), Proteus mirabilis (24%), Staphylococcus aureus (19%), Klebsiella pneumoniae (13%), Candida albicans (11%), Enterobacter sp. (5%) and Citrobacter sp. (4%). The crude extract of PA had zone of inhibition ranging from 16.7 ± 1.53 mm to 24 ± 1.00 mm while SA crude extract had 14.7 ± 1.53 mm to 27 ± 2.00 mm. PM crude extract had inhibition zones of 17 ± 1.00 mm to 22.3 ± 2.12 mm. The MIC and MBC ranged from 6.25 mg/ml to 50 mg/ml and 12.5 mg/ml to 50 mg/ml respectively. Ethyl acetate fraction of PM showed the highest percentage yield and had a zone diameter range from 13.5 ± 1.00 mm to 28 ± 1.53 mm with MIC and MBC ranges of 6.25 mg/ml – 12.5 mg/ml and 25 mg/ml to 50 mg/ml respectively. Synergism with ciprofloxacin was observed at 25% of the microorganisms, 50% antagonism and 25% additively. Toxicity analysis showed lethal dose concentrations of 19.05 mg/ml, 25.12 mg/ml and 130.11 mg/ml for PM, PA and SA respectively. The findings of this study suggest that the methanol extracts of the medicinal plants used in this study does possess a potent lead molecule in combating microorganisms causing UTI. Key words: Antimicrobial activity, Phyllanthus muellerianus, Phytochemicals, Toxicity, UTI,

Effects of sun-drying on the antioxidant potentials of pepper (Capsicum) varieties

The present study investigated the effects of sun-drying on the antioxidant potential of three pepper varieties: Capsicum annuum var, Capsicum chinense and Capsicum annuum. Fresh fruits of the pepper varieties were collected, washed under distilled water and were divided into two parts: one for fresh sample and the other for the dried sample. Dried and fresh samples of the pepper varieties were homogenized and extracted with methanol. The concentrations of total phenolics and flavonoids were evaluated; DPPH-radical scavenging activity and the FRAP potential of the extracts were also determined. The results revealed that sun-drying process significantly reduced the total phenolic content of C. annuum var, C. chinense and C. annuum from 5.91 ± 0.22 mg/g GAE, 6.9 ± 0.23 mg/g GAE, 6.67 ± 0.99 mg/g GAE to 3.31 ± 0.72 mg/g GAE, 3.59 ± 0.89 mg/g GAE, 3.01 ± 0.17 mg/g GAE respectively and flavonoid content from 3.80 ± 0.02 mg/g QE, 3.91 + 0.08 mg/g QE, 3.84 ± 0.08 mg/g QE to 1.26 ± 0.90 mg/g QE, 1.95 ± 0.07 mg/g QE, 1.23 ± 0.04 mg/g QE respectively. The result also revealed that the fresh samples of C. annuum var, C. chinense and C. annuum exhibited higher percentage inhibition of DPPH-radical at 59.4 ± 0.5%, 61.2 ± 0.6%, 58.9 ± 0.2% respectively and were significantly different from the percentage inhibition by the dried samples: 39.2 ± 0.5%, 42.4 ± 0.4%, 38.6 ± 0.6% respectively.The FRAP potential of the fresh samples of C. annuum var, C. chinense and C. annuum: 588.56 ± 29.4 ìmol Fe(II)/g, 691.34 ± 20.46 ìmol Fe(II)/g and 598.9 ± 23. 82 ìmol Fe(II)/g respectively were significantly different from the dried samples: 370.22 ± 14.75 ìmol Fe(II)/g, 392.34 ± 45.74 ìmol Fe(II)/g and 358.6 ± 30.08 ìmol Fe(II)/g respectively. The three Capsicum species are very rich in antioxidants. However, the sun drying method reduced the antioxidant capacities of the peppers, thus further studies should be carried out on the best method for the preservation of Capsicum species. Key Words: Capsicum. annuum var, C. chinense, C. annuum, Antioxidant, Sun-drying, methanolic extract

In-vitro antifungal activity of leaf, stem bark and root extracts of Irvingia gabonensis against fungi associated with its seed deterioration

Irvingia gabonensis (Aubry-Lecomte ex O'Rorke) Baill seeds are often contaminated in storage by postharvest spoilage fungi. This study investigated the nutritional contents of the seeds, phytochemical contents and antioxidant activity of different parts of the plant as well as their antifungal effects against fungi isolated from the deteriorated seeds. Proximate, mineral and phytochemical analyses were carried out using standard laboratory techniques. The antioxidant activity was against DPPH radicals. Ethanol extracts (100 and 200 mg/ml) of the various parts were screened against the isolates using pour plate method in Potato Dextrose Agar (PDA) plates. The plates were examined for growth daily for 10 days. Data were statistically analysed. The healthy seeds contained higher protein (13.73%), fat (58.73%) and fibre (2.50%), whereas, higher content of moisture (10.17%) and carbohydrate (15.47%) were observed in the spoilt seeds. The leaf had highest contents of alkaloids (1228.3 mg/100 g), flavonoids (1345.9 mg/100 g), tannins (1345.9 mg/100 g), saponins (578.3 mg/100 g) and carotenoids (2348.3 μg/100 g). The antioxidant activity of the leaf (50.30%) was the highest. Fungi isolated from the deteriorated seeds were Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus and Curvilaria lunata. The leaf was most effective against A. niger, A. flavus and C. lunata whereas the stem bark extract was most effective against A. fumigatus. The F-values were significant for model, treatment, concentration and number of days for the leaf and root. This study confirmed the antifungal activity of extracts of various parts of the plant against isolates implicated in the deterioration of its seeds. The extracts could be used as preservative to enhance the shelf-life and nutritional quality of the seeds. Keywords: Irvingia gabonensis, Spoilage of seeds, Antifungal activity, Free radical scavengers, Preservatives

Biosynthesis and characterizations of extracellular enzymes of microbial isolates from dairy industrial effluent

Diary effluents are environmental pollutant which could serve as source of substrate for microbial enzymes' synthesis. This research investigated the isolation and screening of bacteria and fungi with potential extracellular proteolytic and amylolytic properties from dairy effluents, and their characteristics for maximum enzyme production. Effluent from a dairy industry located in Ibadan, Nigeria, was collected for isolation and screening of microbial species for enzymatic activities. The Biological Oxygen Demand (BOD), Total Soluble Solid (TTS), and pH of the effluent were determined using standard procedures. The potential isolates were characterized morphologically and by molecular techniques. Proteolytic and amylolytic activities of isolates were investigated on skimmed milk starch agar respectively and optimized with varying pH (6.0 - 9.0), temperature (27 - 60 °C) and incubation period (12 - 72 h). Data were analyzed by Duncan Multiple Range Test. Biological Oxygen Demand, Total Soluble Solid and pH of the effluent were 14.67 mg/L, 13.33% and 7.58 respectively. Eleven isolates were positive for either protease or amylase synthesis, but only two showed both proteolytic and amylolytic activities and were molecularly characterized as Bacillus stratosphericus CM2HG6 and Aspergillus welwitschiae. Optimization showed that enzyme production by B. stratosphericus CM2HG6 was highest at 35 °C, pH 7.0 for 48 h, and that of A. welwitschiae achieved optimum production at 37 °C, pH 8.0 for 72 h. Under optimized conditions, Bacillus stratosphericus CM2HG6 was the highest amylase and protease producer (24.4 and 30.74 U/ml respectively), while A. welwitschiae was the lowest producer (12.58 and 18.8 U/ml respectively). The study successfully showed that these industrially-important enzymes can be produced by microbial strains isolated from dairy effluent, and production can be further optimized

Pedogeochemical survey for uranium mineralization in parts of Igarra Schist belt, Southwestern Nigeria

Pedogeochemical survey for uranium mineralization in Dagbala-Atte district, Igarra schist belt, southwestern Nigeria was carried out. The concentrations of As, Au, Fe, Mn, Mo, Ni, Pb, Se, U and V in the residual soils were subjected to univariate and multivariate analyses and plotted on geochemical distribution maps to delineate possible U-mineralization areas. Histograms and box plots showed the elements are log-normally distributed with threshold values of 9.47 %, 10.8, 1589, 2.98, 45.6, 31.0, 0.68, 8.59, 122 ppm and 10.6 ppb, respectively for Fe, As, Mn, Mo, Ni, Pb, Se, U, V and Au. Correlation matrix revealed a strong correlation between U and each of Fe, Mo and Pb indicating close primary association among these four elements. Factor analysis revealed association of U, Mo and Pb implying possible occurrence of U in the granitic rocks of the area. Geochemical maps showed that the strongest U anomaly occurred in the northeastern part of the district that is underlain by granitic gneisses with numerous unmapable granite-pegmatite veins, which possibly are the host of the U mineralization. Copious geological study of these granite-pegmatite veins is recommended. Keywords: Anomaly, box plots, correlation matrix, geochemical distribution map, uranium mineralization.

Physicochemical characteristics and green microalgae composition of selected rivers in Ogun State, Nigeria

The river system is the most complex of the freshwater bodies in the world and is prone to pollution especially from anthropogenic activities and the quality of water, as partially determined by physicochemical properties, is very crucial for primary productivity in the aquatic environment. This study determined the physicochemical characteristics and green microalgae of water collected from Majopa, Ogunpa and Uren rivers in Ogun State, Nigeria. Surface water samples were collected from three different rivers using direct collection method into the labelled bottles for physicochemical characteristics determination, culturing and ecological studies. Water samples for ecological studies were fixed in 4% unbuffered formalin while sample for culturing were not fixed but growth stimulated using Bold Basal Medium (BBM) and Blue- Green Medium (BG-11). The physicochemical parameters varied widely with the profile of water sample from Ogunpa River being the most favourable for widest diversity of green microalgae of all three. The pH of the water samples were slightly acidic ranging between 6.3 and 6.5 for the rivers, while the lower dissolved oxygen (2.61-3.01 mg/L) recorded pointed to a stressed environment which probably accounted for lower number of microalgae taxa observed, especially in Majopa River. The ecological studies showed the presence of ten taxa from the division Chlorophyta with nine taxa from Ogunpa River and Scenedesmus sp. being dominant genus across the rivers. The microalgae diversity of the river water was Ogunpa River˃Uren River˃Majopa River. BBM supported growth of the microalgae much better. The physicochemical properties portrayed Majopa and Ogunpa River water as unfit for drinking, while that of Uren River is relatively fit for drinking. It is highly recommended that the microalgae reported therein be further characterised for various possible economic benefits. Keywords: Growth, Microalgae, Nutrient, Ogun State, River, WaterDepth, Geothermal Energy

Oral administration of Weissella and Pediococcus sp alleviates formalin induced inflammation in rats by Cytokine Modulation

This study was designed to study the cytokine modulatory activity of three lactic acid bacteria (LAB) strains, Weisella cibaria II-1-59, Weisella confusa JMC 1093, and Pediococcus pentosaceus DSM20336 isolated from a Nigerian locally fermented food condiment; “iru” using paw oedema acute inflammatory model induced with 1% formalin in Wistar rats. Rats were distributed into six groups (A-F). Rats in Groups A were neither administered formalin nor treated with LAB, while Group B received formalin injection only. Rats in Groups C, D, and E were administered formalin and were treated orally with 2 × 107 CFU/ml of Weisella cibaria II-1-59, Weisella confusa JMC 1093, and Pediococcus pentosaceus DSM20336 respectively, while Group F received diclofenac sodium treatment following administration of formalin. The dose of LAB strain used for the oral treatment was 2 × 107 CFU/ml for all the groups while the dose of diclofenac sodium used was 150 mg/kg body weight of the rats. Paw thickness (mm) was checked at t = 0, 1, 4, 8, 24, 72, 168 and 336 h. Cytokine assay for C-reactive protein (CRP), Interleukin (IL-10) and Transforming growth factor (TGF-β) was performed on serum samples of the rats using Enzyme-linked immunosorbent assay (ELISA). Oral administration of W. cibaria II-1-59 showed the best significant decrease in the paw thickness of the rats, which was followed by P. pentosaceus DSM20336 and W. confusa JMC 1093 respectively, and was shown to be statistically significant at P<0.05. There was also a significant decrease (below standard 2000 pg/ml) in the secretion of pro-inflammatory biomarker (CRP) in all LAB treated groups at 1 hour, while there was an increase in the serum levels of anti-inflammatory cytokines IL-10 and TGF- β in Groups C-E rats which was maximally increased in W. confusa JMC 1093 treated rats. This study suggests that W. cibaria II-1-59, W. confusa JMC 1093 and P. pentosaceus DSM20336 possess anti-inflammatory potentials. Keywords: Inflammation, Cytokines, Weisella, Formalin, Oedema, Pediococcus