Chemistry
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Item Soybean oil and coconut oil enhance the absorption of chlorogenic acid in humans(Journal of Food Biochemistry, 2021) Weerakoon, W. N. M. T. D. N.; Anjali, N. V. P.; Jayathilaka, N.; Seneviratne, K. N.The effect of a mainly polyunsaturated oil (soybean oil) and a mainly medium chain triglyceride oil (coconut oil) on the absorption of the phenolic antioxidant chlorogenic acid (5-caffeoylquinic acid) was investigated using 90 healthy volunteers. Serum concentrations and the absorbed percentages of chlorogenic acid of volunteers who received chlorogenic acid without oils (0.006 ± 0.001 mg/ml, 5.7 ± 0.2%), chlorogenic acid with soybean oil (0.012 ± 0.001 mg/ml, 11.8 ± 1.3%), and chlorogenic acid with coconut oil (0.067 ± 0.014 mg/ml, 65.6 ± 18.1%) were significantly different from each other (p < .05). There was a strong positive correlation between the increase in serum and plasma antioxidant capacity and the absorption of chlorogenic acid. The major fatty acid of each of soybean oil and coconut oil also improved the permeability of chlorogenic acid in Caco-2 cell monolayers. The results suggest that the tested edible oils may improve the nutritional value of chlorogenic acid-containing foods by improving the absorption of chlorogenic acid.Item Phenolic antioxidants in coconut oil: Factors affecting the quantity and quality. A review(Grasas Y Aceites, 2022) Jayathilaka, N.; Seneviratne, K.The total phenol content (TPC) in coconut oil varies with extraction method, variety, nature of coconut kernel components and geographical origin. Commonly reported TPCs of coconut oils extracted by dry methods and wet methods are in the range of 70-300 mg/kg and 250-650 mg/kg, respectively. Based on the commonly reported data, the TPC of coconut oil varies by up to 527 mg/kg oil, 180 mg/kg oil, and 172 mg/kg oil due to the influence of the extraction method, coconut variety and the nature of kernel components, respectively. The identity of the phenolic compounds also varies with the extraction method. Caffeic acid, catechin, p-coumaric acid, ferulic acid, and syringic acid are present in different quantities in coconut oil when extracted by all methods. However, chlorogenic acid, cinnamic acid, epigallocatechin, gallic acid, vanillic and epicatechin are present only in some coconut oils. Many free phenolic compounds present in olive oil are also present in coconut oil.Item Effect of chain length and saturation of the fatty acids in dietary triglycerides on lipid metabolism in Wistar rats(Journal of Food Biochemistry, 2021) Senanayake, C. M.; Hapugaswatta, H.; Samarawickrama, G. R.; Jayathilaka, N.; Seneviratne, K. N.We investigated the effect of the chain length and the degree of saturation of fatty acids in dietary triglycerides on serum lipid profiles and hepatic lipid metabolism in Wistar rats. Fat component of the basal diet (soybean oil) was replaced with fats with fatty acids of different chain lengths and saturation and the serum lipids were monitored for 150 days. Principal component (PC) analysis of serum lipid components was related to chain length and saturation. The combined effect of chain length and saturation on PC 1 scores was evaluated by multiple regression analysis. The results indicated that average chain length of the fatty acids of triglycerides has a higher influence on the quality of serum lipid parameters than the average degree of saturation. Expression of selected genes responsible for lipid metabolism showed similar trends in medium chain saturated and long chain polyunsaturated diet groups. Practical applications Dietary lipids contain a wide range of saturated and unsaturated fatty acids with different chain lengths. Overall contribution of these different fatty acids decides the health effects of the lipids in the diet. Present study shows that the fats with medium chains and higher degree of saturation and fats with long chains and higher degree of unsaturation (lower degree of saturation) affect serum lipid parameters and expression of hepatic genes involved in the lipid metabolism in a similar manner. Such information is important for physicians to plan dietary schemes to improve the nutritional health and manage the noncommunicable diseases.Item Antioxidant and Nutritional Properties of Domestic and Commercial Coconut Milk Preparations(International Journal of Food Science, 2020) Karunasiri, A.N.; Gunawardane, M.; Senanayake, C.M.; Jayathilaka, N.; Senevirathne, K.N.The aqueous extract of scraped coconut kernel is known as coconut milk. Coconut milk preparations are also commercially available in the form of desiccated powders or liquids. While these various coconut milk preparations are heavily used in cooking in the Asian countries as a major source of dietary fat, limited studies have been conducted on their chemical and nutritional composition. In this study, we have determined the chemical composition and nutritional effects of both domestic preparations of coconut milk and the commercially available counterparts. The results indicate that the phenolic compounds of all coconut milk preparations provide protection against oxidative damage on lipids and inhibit oxidative damage of both proteins and DNA. The lipid profiles are not significantly affected by the consumption of the three coconut milk preparations despite their different fat contents.Item Protective Effect of Coconut Oil Meal Phenolic Antioxidants against Macromolecular Damage: In Vitro and In Vivo Study(Journal of Chemistry, 2020) Karunasiri, A.N.; Senanayake, C.M.; Hapugaswatta, H.; Jayathilaka, N.; Seneviratne, K.N.Coconut oil meal, a cheap by-product of coconut oil production, is a rich source of phenolic antioxidants. Many age-related diseases are caused by reactive oxygen species- (ROS-) induced damage to macromolecules such as lipids, proteins, and DNA. In the present study, the protective effect of the phenolic extract of coconut oil meal (CMPE) against macromolecular oxidative damage was evaluated using in vitro and in vivo models. Sunflower oil, bovine serum albumin (BSA), and plasmid DNA were used in the in vitro study, and thiobarbituric acid reactive substances (TBARS), protein carbonyl, and nicked DNA were evaluated as oxidation products. The inhibitory effect of CMPE against H2O2-induced macromolecular damage was evaluated using cultured HEp-2 cells. The results indicate that CMPE inhibits macromolecular damage both in vitro and in vivo. In addition, CMPE regulates redox status of HEp-2 cells under oxidative stress conditions by maintaining higher reduced glutathione levels. There was no significant difference in the expression of glutathione peroxidase in stressed and unstressed cells suggesting that CMPE regulates the cellular oxidative stress responses without affecting the expression of oxidative stress response genes. Oral feeding of Wistar rats with CMPE improves the serum and plasma antioxidant status without causing any toxic effects.Item Phenolic extracts of the leaves of Psidium guineense Sw. improve the shelf life of sunflower oil and baked cake and antioxidant status of Wistar rats(J Food Biochem, 2018) Senanayake, C.M.; Hapugaswatta, H.; Jayathilaka, N.; Seneviratne, K.N.The potential of the ethanolic extract of Psidium guineense Sw. leaves (PGLE) to protect food from oxidation was evaluated using sunflower oil and baked cake as food models. The nutritional quality of PGLE was evaluated by feeding Wistar rats with PGLE for 150 days. Psidium guineense Sw. leaves contain 195.25 ± 9.56 mg g–1 phenolic substances, 51% of which are o‐diphenols. Protection factor, the ability of Psidium guineense Sw. leaves to protect sunflower oil against oxidation (1.82 ± 0.13), was not significantly affected by heat treatment compared to BHT. Formation of oxidation products, peroxide and hexanal in PGLE‐ and BHT‐added cake was significantly lower (<5 ppm over 28 days) compared to control with no added antioxidants. Therefore, addition of PGLE improved the shelf life of sunflower oil and oxidative stability of baked cake. PGLE also improves the serum antioxidant capacity and inhibits lipid and protein oxidation in Wistar rats. Practical applications PGLE is a rich source of phenolic substances. Due to high antioxidant activity, pleasant sensory quality and high thermal stability, PGLE can be used to improve the shelf life of baked cake and edible oils. As PGLE also improves serum and plasma antioxidant properties without causing any toxicity, nutritional food supplements can be developed based on PGLE.Item Host gene expression analysis in Sri Lankan melioidosis patients.(PLoS Negl Trop Dis 11(6), 2017) Krishnananthasivam, S.; Jayathilaka, N.; Sathkumara, H.D.; Corea, E.; Natesan, M.; De Silva, A.D.Melioidosis is a life threatening infectious disease caused by the gram-negative bacillus Burkholderia pseudomallei predominantly found in southeast Asia and northern Australia. Studying the host transcription profiles in response to infection is crucial for understanding disease pathogenesis and correlates of disease severity, which may help improve therapeutic intervention and survival. The aim of this study was to analyze gene expression levels of human host factors in melioidosis patients and establish useful correlation with disease biomarkers, compared to healthy individuals and patients with sepsis caused by other pathogens.Item Comparison of the basic nutritional characteristics of the first extract and second extract of coconut milk(2015) Nadeeshani, R.; Wijayaratna, U.N.; Prasadani, W.C.; Ekanayake, S.; Seneviratne, K.N.; Jayathilaka, N.Item Regulation of MEF2 by a small molecule modulates neuronal synapses(Sri Lanka Association for the Advancement of Science, 2013) Jayathilaka, N.; Balasanyan, V.; Chen, L.