Effect of Alkali Treatment and Fiber Content Variation on the Tensile Properties of Coir Fiber Reinforced Cashew Nut Shell Liquid (CNSL) Composite

The eect of alkali treatment and ber content variation on the tensile properties of coir ber reinforced cashew nut shell liquid (CNSL) composite was studied. Biocomposite consisting of coir bers and cashew nut shell liquid resin was produced using the hand lay-up technique. The bers were treated with 5% NaOH and varied between 0% to 40% weight fractions. Composite laminates with untreated coir bers were also produced with same ber loadings. The results showed that tensile strength and modulus of the CNSL/COIR composite increased as the weight fraction of coir bers was increased up to a ber content of 30%. Also the composites exhibited reduction in elongation at break as ber content was increased. The alkali- treated CNSL/COIR composite laminates showed improved tensile properties and this was attributed to an improvement of interfacial ber-matrix adhesion in the composites

Ethanol extracts of Newbouldia laevis stem and leaves modulate serum liver marker enzymes and antioxidant enzymes activities in diabetic rats

Diabetes is known to involve oxidative stress and changes in antioxidant enzymes. Many plants metabolites have been shown to possess antioxidant activities, improving the effects of oxidative stress complications in diabetic conditions. This study evaluated the effects of extracts from Newbouldia laevis leaves and stem on liver marker enzymes and antioxidant enzymes in rat model. The results confirmed that the untreated diabetic rats were subjected to oxidative stress as indicated by significantly abnormal activities of their scavenging enzymes (low superoxide dismutase, catalase and glutathione activities) to the extent of liver enzymes leakage from the hepatocytes when compared with apparently healthy rats. The ethanol extracts of N. laevis leaves and stem possessed antioxidant activity as shown by increased activities of superoxide dismutase and catalase, and glutathione levels of the diabetic rats after treatment. High levels of alkaline phosphatase (ALP), and alanine aminotransaminase (ALT), which are typical of oxidative stress condition were differentially ameliorated after treatment with the ethanol extracts of N. laevis leaves and stem in a dose dependent manner.Keywords: Diabetes mellitus, oxidative stress, Newbouldia laevis, liver enzymes, antioxidant enzymesAfrican Journal of Biotechnology, Vol 13(22) 2265-227

Physicochemical properties of lignocellulosic biofibres from South Eastern Nigeria: Their suitability for biocomposite technology

Five plant raw materials collected from South Eastern part of Nigeria were used for biofibre extraction and analysis to assess their suitability for biocomposite production. Lignocellulosic biofibres were extracted from young stems of Adenia lobata, Ampelocissus leonensis, Cissus palmatifida, Morinda morindoides and Urena lobata through natural water retting process for a period of 14 - 16 days and the resulting fibres were uniform with almost flat or circular cross sections. Phytochemical contents and extractives were determined on the untreated and treated fibres respectively. The %w/w cellulose contents of the pretreated biofibres were found to be 48.97± 1.33% for A. leonensis and 43.22±0.95% for A. lobata. The cellulose content of M. morindoides and C. palmitifida were found to be 55.76±1.40% and 55.20±1.59%, respectively. In all the plants studied, U. lobata had the greatest %w/w cellulose content of 58.94±1.05% while A. lobata had the least cellulose content of 43.22±0.95%. Estimation of %w/w hemicellulose contents showed A. leonensis to be 21.22±0.89% whilst the hemicelluloses content in A. lobata and U. lobata were observed to be 18.22±2.18% and 12.38±0.33% in that order. Lower hemicelluloses contents were obtained in C. palmitifida and M. morindoides as 10.32±1.27, 9.32±0.58 and 8.62±1.67%, respectively. The klason lignin contents were found to be 31.33±1.05% for C. palmitifida, 31.22±0.97% for M. morindoides, 28.22 ± 1.96% for A. lobata, and 24.91±0.61% for A. leonensis. The lignin content of U. lobata was found to be the least at 22.26±0.55%. Acid soluble lignin (ASL) content was greater in A. lobata (2.17±0.08%) while A. leonensis had the least value of 1.74±0.34%. ASL-derived products (vanillin, p-coumaric acid and ferulic acid) ranged between 0.50±0.12% and 1.41±0.02% for vanillin; 0.03± 0.02% and 0.65±0.14% for p-coumaric acid; and ferulic acid was only detected in A. leonensis as 0.41±0.11%. The mechanical properties of most fibres used in this study are comparable to those of other biofibres already used in manufacturing and can even match those of some synthetic fibres. Results obtained revealed that fibres used in this study had comparable properties with those already established for manufacturing in biofibre industries.Keywords: Biofibre, biocomposite, cellulose, lignin, hemicelluloses.African Journal of Biotechnology, Vol 13(20), 2050-205

Hypoglycaemic and Haematinic properties of ethanol leaf extract of Artocarpus heterophyllus in alloxan induced diabetic rats.

Background: Anaemia is known to be associated with diabetes; moreover, with the increasing cases of diabetes there is need for the use of more affordable alternative herbal medicines for the treatment of diabetes and anaemia. The aim of this work was to evaluate the hypoglycaemic and haematinic properties of Artocarpus heteropyllus on diabetic rats.Materials and Methods: Ethanol leaf extract of Artocarpus heteropyllus was screened for phytochemicals and its acute toxicity was tested on mice. Induction of diabetes was done at a dose of 150 mg/kg body weight (b.w) (with exception of the control group). The extract was administered to rats for a period of 7 days at 100, 300 and 500 mg/kg b.w, respectively, following induction. Blood samples of rats were tested for fasting blood sugar (FBS), packed cell volume (PCV), white blood cell (WBC), red blood cell (RBC), haemoglobin, neutrophil lymphocyte and eosinophil counts.Results: The ethanol leaf extract of A. heterophyllus showed no mortality up to a dose of 5000 mg/kg b.w. Administration of the extract to diabetic rats resulted in a decrease in the FBS of diabetic rat, and significant increases (p< 0.05) in RBC, PCV, WBC and haemoglobin levels.Conclusion: The ethanol leaf extract of A. heterophyllus increased the haematological indices of diabetic rats. Our findings support the use of this plant as an herbal alternative in the treatment of diabetes and anaemia associated diabetes.Key words: Diabetes, Hypoglycaemia, Haematology, Alloxan, Oxidative stress

Potentials of non-edible Abrus precatorius seed oil towards biodiesel production

Abrus precatorius seed oil is not edible and possesses lethal toxicological properties; hence, alternative use as low cost feedstock for biodiesel production was investigated. The n-hexane extracted oil was characterized for its chemical and physical properties, and subsequently transesterified using 1% sodium hydroxide at 60°C to produce biodiesel. The biodiesel produced had acceptable quality following characterization of its fuel properties. The relative density was found to be 0.889 with kinematic viscosity of 3.34 mm2/s within limits of Thailand biodiesel fuel standard. The acid value was 0.281 mg KOH/g, iodine value 52.43 mgI2/g, peroxide value 3.45 mEq/kg, saponification value 227.8 mg KOH/g and 2.87% free fatty acid content. The flash point and the cetane number were 137°C and 58.3, respectively while the heat of combustion was 38.28 MJ/Kg. The low temperature operability properties of A. precatorius seed biodiesel determined by parameters such as cloud point, pour point and cold-filter plugging point were - 2, 1 and - 4°C, respectively. The sulfated ash value and refractive index were found to be 0.09% and 1.457, respectively. GC analysis of the fatty acid methyl esters profile revealed 50.86 and 49.1%, saturated and unsaturated fatty acid methyl esters (FAME), respectively. A percentage FAME yield of 86.1%; with higher content of methyl palmitoleate (31.94%) and a lowest value for methyldecanoate (1.27%) was obtained. Although a n-hexane oil yield was low (2.52% w/w), the results show that Abrus seed oil derived biodiesel has commercially acceptable fuel properties and may be suitable as fuel for internal combustion engine.Keywords: Biodiesel, Abrus precatorius, oil, non-edible oil, fatty acid methyl esterAfrican Journal of Biotechnology, Vol 13(44) 4226-423