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- ItemStructure optimization and IR frequency interpretation of Fe6(OH)1s(H20)6 Nano particles by OFT calculations(University of Peradeniya, 2024-11-24) Jayarathna, Lakmal; Bandara, Athula; Vithanaqe, M; Weerasooriya, Ry-Fe203 nanopratciles were syntheised by the co-precipitation method and these particles are in 5-20 nm range in size. Plausible molecular structures (Figure 1) of Y - Fe203 were examined by density functional theory (DFT) using the cluster modelling method. Cluster configurations and IR frequency calculations of Fe6(OH)18(H20)6 were performed using the DFT hybride 83L YP function with 6-31 G (d, p) basic set. The average bond lengths of Fe-Fe and bulk Fe-O entities as 2.93 A and 1.92 A, respectively. The calculated bond lengths are comparable with the crystallographic data. Vibrational frequency calculations and experimental data are in good agreement with the observations in the range of 900 cm' t01024 cm' (Figure 2). However, OH stretching frequencies at (1640), 3000, 3500 crn' of y -Fe203 is significantly different due to H- bonding nature.
- ItemPreparation, characterization and in-vitro release study of Ascorbic acid- Encapsulated liquid Crystal liposomes(University of Peradeniya, 2024-11-24) Hewawarawlta, L. S; Perera, A. D. L. C; Karunaratne, D. NThe use of liquid crystals at the nano level shows some valuable applications in numerous areas. Liposome formulations are used in the medical, food and cosmetic fields after the encapsulation with bioactive ingredients. Generally, liposomes are mainly formed of phospholipids and are used as a store and vehicle for bioactive ingredients. The purpose of the present research was to formulate effective and controlled drug release liquid crystal liposomal formulations. Water soluble ascorbic acid (vitamin C) was used as the model drug and carbohydrate liquid crystal, ETAGP (2,3,4,6-tetra-o- acetyl-epiandrosteronyl-1-0-[l,-D-glucopyranoside) was used as the model liquid crystal. For comparison, conventional liposomes were formulated with phospholipids (egg yolk lecithin) and mixed liposomes with phospholipids and carbohydrate liquid crystals in different compositions. Characterization of the prepared liposomes regarding encapsulation efficiency, pH dependence, particle size analysis and in-vitro release were performed. Carbohydrate liquid crystal liposomes show some characteristics similar to conventional liposomes, such as the drug encapsulation efficiency and pH dependence, whereas the drug release rate is significantly increased in the carbohydrate liquid crystal liposomes. Interestingly, the particle size in the carbohydrate liquid crystal liposomes is in the nano range and the particle size remains the same without forming clusters for several weeks. These novel liquid crystal liposome formulations may have potential applications in encapsulation and delivery of drugs and bioactive ingredients in cosmetic formulations.
- ItemA preliminary study on the Hypoglycaemic effect of Averrhoa Carambola (Star Fruit) in rats(University of Peradeniya, 2024-11-24) Gunasekara, L .C. A; Fernando, P. H. P; Sivakanesan, RDiabetes mellitus (OM) is one of the five leading causes of death in the world. As estimated in 2008, around 24% of the Sri Lankan population suffer from this deadly disease. Maintenance of normoglycaemia is the key issue in managing these patients, and this is achieved by administering exogenous insulin or other hypoglycaemic agents. Averrhoa carambola (star fruit) leaves have been a part of traditional medicine used in Ayurvedic preparations to treat OM in Sri Lanka. Researchers have investigated the hypoglycaemic effects of several insoluble fiber-rich fractions (FRFs) including insoluble dietary fiber, alcohol-insoluble solid and water insoluble solid from the pomace of Acarambola. The objective of the study was to investigate the effect of Acarambola fruit pulp on blood glucose level of healthy rats. Thirty male Sprague Dawley rats weighing between 150-350 g and ten healthy female Sprague Dawley rats of the same age and weight were used in the study. The animals were caged individually at the Animal House, Faculty of Medicine and were provided with 25 g of broiler starter feed per day with ad libitum water. They were allowed to get accustomed to the experimental set up for a period of two weeks and were divided equally into the test groups (male and female), and control groups (male and female). A carambola fruit pulp was prepared by homogenising ripe fruit with a little added water in a warring blender and the resultant pulp was stored at -20°C. The animals in the test groups were then fed with the A carambola fruit pulp at a rate of 1600 mg/kg body weight for 63 days and the fasting blood glucose levels were measured each week, using an enzymatic assay method using glucose oxidase enzyme. Results were compared between A. carambola fruit pulp treated group (1600 mg/kg BW) and control group which received only the basal diet using analyses of variance and Dunnet's t-test. Treatment with A carambola fruit pulp significantly (p = 0.033) decreased blood glucose levels (mean 131.0 ~ 10.2 mg/dl) after a treatment period of 8 weeks and elevated body weight in healthy male Sprague Dawley rats compared to that of normal rats (blood glucose levels mean 153.4 ~ 11.2 mgidl). However, although there was a decrease in blood glucose level of the test group after three weeks of treatment the difference was not statistically Significant up to 7 weeks. Treatment with A carambola fruit pulp non-significantly decreased the blood glucose levels in healthy female rats after treating for 8 weeks, compared to that of control rats which could be due to hormonal changes in the female animals. This study demonstrates that the A carambola fruit pulp has a hypoglycaemic effect on mammalian systems, which need to be investigated further.
- ItemA preliminary study on bioactivities of Agave Vera - cruz leaf extract(University of Peradeniya, 2024-11-24) Karunaratne, K. U; Ranawana, K. B; Wickramasinghe, AAgave vera-cruz is a perennial plant with large, spine-tipped leaves and short thick stems. It belongs to the family Agavaceae. It appears to be well established in Badulla, Nuwara Eliya and Kandy districts. Fibre obtained from this plant is used to make ropes, baskets and cloths. Freshly ground leaves of Agave vera-cruz are currently used as a piscicidal agent in fishing by remote farmers in the Knuckles region. The present study is an attempt to evaluate bioactive properties of Agave vera-cruz. Antioxidant, cytotoxic and phytotoxic properties were investigated. Plant materials were collected from Wattappola in Paranapattiya area. Freeze- dried plant materials were ground into a powder and extracted into methanol (MeOH). Concentrated crude extract was subjected to bioassay. Phytotoxic activity against Lactuca sativa, cytotoxic activity against Artemia salina and antioxidant activity were evaluated. Fractionation involved the use of VLC chromatography using Merck 9385 (40-63 Jim) silica gel, gravity column chromatography using 7734 Merck silica gel (63-200 ,urn) and analytical thin layer chromatography. LD50 value for cytotoxic bioassay was 675 ppm for the MeOH extract. IC50 value for the DPPH radical assay was 62.0 ppm. IC50 value for shoot inhibition was 1000 ppm and that for root inhibition was 1800 ppm. These results show that there are some allelopathic compounds present in Agave vera-cruz.
- ItemA preliminary study on bioactivities of Agave Vera - Cruz leaf extract(University of Peradeniya, 2011-11-24) Karunaratne, K. U; Ranawana, K. B; Wickramasinghe, AAgave vera-cruz is a perennial plant with large, spine-tipped leaves and short thick stems. It belongs to the family Agavaceae. It appears to be well established in Badulla, Nuwara Eliya and Kandy districts. Fibre obtained from this plant is used to make ropes, baskets and cloths. Freshly ground leaves of Agave vera-cruz are currently used as a piscicidal agent in fishing by remote farmers in the Knuckles region. The present study is an attempt to evaluate bioactive properties of Agave vera-cruz. Antioxidant, cytotoxic and phytotoxic properties were investigated. Plant materials were collected from Wattappola in Paranapattiya area. Freeze- dried plant materials were ground into a powder and extracted into methanol (MeOH). Concentrated crude extract was subjected to bioassay. Phytotoxic activity against Lactuca sativa, cytotoxic activity against Artemia salina and antioxidant activity were evaluated. Fractionation involved the use of VLC chromatography using Merck 9385 (40-63 Jim) silica gel, gravity column chromatography using 7734 Merck silica gel (63-200 ,urn) and analytical thin layer chromatography. LD50 value for cytotoxic bioassay was 675 ppm for the MeOH extract. IC50 value for the DPPH radical assay was 62.0 ppm. IC50 value for shoot inhibition was 1000 ppm and that for root inhibition was 1800 ppm. These results show that there are some allelopathic compounds present in Agave vera-cruz.