• Christophersen Hede posted an update 4 hours, 21 minutes ago

    Increased oxidative stress in the human brain is observed in neurodegenerative diseases such as Parkinson’s disease (PD) and Alzheimer’s disease (AD), and is considered to be a major cause of progression of these disease states. A very long-chain fatty acid, nervonic acid (NA), is the main fatty acid found in various sphingolipid species in the central nervous system. NA plays an important role in forming the plasma membrane’s lipid bilayer and in maintaining normal myelin function. In this study, we examined the neuroprotective effect of NA against rat pheochromocytoma (PC-12) cells stimulated by 6-hydroxydopamine (6-OHDA), which served as a cell model of PD. PC-12 cells were pre-treated with different concentrations of NA for 48 h then subsequently co-treated with NA and 6-OHDA for 48 h to induce cellular oxidative stress. Cell viability was significantly increased by pre-treatment with a very low concentration of NA. The level of malondialdehyde, a marker of lipid peroxidation, was significantly decreased in NA-treated cells. The expression levels of superoxide dismutases (Mn SOD and Cu/Zn SOD) and γ-glutamylcysteine synthetase (GCLC), responsible for the synthesis of glutathione, were significantly increased, indicating that pre-treatment with NA activated the cellular antioxidant defense system. These results suggest that NA may play a role as a neuroprotective mediator in the brain.This study investigates Marula (Sclerocarya birrea) seed oil (SBSO) as a novel feedstock for biodiesel production through the transesterification process catalysed by heterogeneous bio-alkali derived from banana (Musa acuminata) peels. Response surface methodology (RSM) and artificial neural network (ANN) tools were used for the modelling and optimization of the process variables. The reaction process parameters considered were methanol/SBSO molar ratio, catalyst loading levels, reaction time and temperature. Rapamycin Central composite design (CCD) was espoused to generate 30 experimental conditions which were deployed in investigating the individual and synergetic effect of the process input variables on Sclerocarya birrea oil methyl ester (SBOME) yield. Appropriate statistical indices were adopted to investigate the predictive aptitude of the two models. Analysis shows that ANN model obtained for the transesterification process has a higher coefficient of determination (R2) of 0.9846 and lower absolute average deviation (AAD) of 0.07% compared to RSM model with R2 of 0.9482 and AAD of 0.12%. The process modelling outcome also confirmed ANN performance to be more precise than RSM. At methanol/SBSO ratio of 61, catalyst loading level of 2 wt%, process reaction time of 50 min and temperature of 55°C, the experimental maximum SBOME yield was observed to be 96.45 wt % following the ANN predicted yield of 96.45 wt % and RSM predicted yield of 96.65 wt % respectively. The analysed fuel properties of SBOME was found satisfactory within the biodiesel stipulated standard limit(s). The study establishes that SBSO is a good source for biodiesel production and its biodiesel methyl ester is a potential substitute for petroleum diesel and a bioenergy fuel.α-Gels are often used as base materials for cosmetics and hair conditioners. α-Gel-based commercial products typically contain many types of additives, such as polymers, electrolytes, oily components, and other surfactants, in addition to the three basic components. However, few systematic studies have been conducted on the effect of such additives on α-gels. In this study, we chose surfactant as an example to initiate the effect of such additives on the structure and rheological properties of α-gel samples formulated using cetyl alcohol (C16OH) and cetyltrimethylammonium chloride (CTAC). Optical microscopy analysis demonstrated that the size of the vesicles in the α-gel samples in this study was decreased via the addition of hydrogenated soybean lecithin (HSL) and penta(oxyethylene) cetyl ether (C16EO5), a nonionic surfactant, to them. Rheological measurements revealed that at high C16OH/CTAC ratios, the viscosity and yield stress of the α-gel samples decreased owing to the addition of surfactants to them. Conversely, at low C16OH/CTAC ratios, the opposite tendency was observed. Small-angle X-ray scattering analysis indicated that for the α-gel samples with high C16OH/CTAC ratios, the addition of HSL or C16EO5 to them decreased the interlayer spacing of their lamellar bilayer stack, which led to the changes in the rheological properties of the α-gel samples.Quaternary ammonium compounds are widely used as antiseptic and disinfectant. It is been a concern that their widespread use will lead to an increase of environmental problems, therefore the development of biodegradable surfactants is necessary. The present research is aimed at the design of novel amphiphilic molecules with similar properties to those already known but more biodegradable. Based on benzalkonium chloride (BAC), novel carbonate cleavable surfactants (CBAC) were synthesized. The breakable carbonate sites make CBAC compounds more degradable and potentially more biodegradable than their non-cleavable BAC analogues. Natural products such as fatty alcohols (C8-C16) and N,N-dimethyl-2-aminoethanol were used as reagents for the synthesis of CBAC8-16. These amphiphilic compounds were characterized in terms of surface properties and antimicrobial activity against Gram-positive and Gram-negative bacteria, yeasts and moulds. The novel surfactants showed similar surface activities in aqueous solutions when compared to BAC. Also, the surface activity/structure relationship revealed that carbonate cleavable surfactants with n-decyl group (CBAC10) showed the same behaviour as non-cleavable BAC. Furthermore, compounds containing n-octyl (CBAC8), n-decyl (CBAC10) and n-dodecyl (CBAC12) group showed strong antimicrobial activities.In this study, important physicochemical properties, fatty acid and sterol compositions of olive oils from the olives which harvested from Mersin (Buyuk Topak Ulak, Gemlik, Sari Ulak), Adana (Gemlik), Osmaniye (Gemlik) and Hatay (Gemlik, Kargaburun, Hasebi, Halhali) in the Eastern Mediterranean region of Turkey have been investigated. Ripening index and oil yield analysis of the olives and free fatty acids, peroxide value, UV absorbance (K232, K270), fatty acid composition, sterol composition, erythrodiol+uvaol content, and total sterol analysis of the olive oil samples were carried out. The levels of free acidity in the olive oil samples ranged from 0.39% (Hatay Gemlik HG3) to 2.23% (Mersin Gemlik MG). Peroxide value ranged from 8.87 to 18.87 meq O2/kg. As K232 values in the oils fluctuated between 1.4370 and 2.3970, K270 values varied between 0.1270 and 0.1990. The results showed that all ΔK values were lower than the maximum legal limit of 0.01. The main fatty acid in all oil samples was oleic acid, ranging from 58.