Browsing by Author "De Silva, K. M. N."

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Beneficial functions of plant materials used in shodhana process of mercury in Ayurveda Rasashastra
(International Conference on Applied and Pure Sciences, 2020, 2020) Gunaratna, T. A. N. R.; De Silva, W. R. M.; Prajapati, P. K.; De Silva, K. M. N.
Shodhana process in rasashastra is a mandatory process for each material prior to use in herbomineral pharmaceutical preparations. Although different types of mercury (Hg) shodhana”processes are described in rasashastra, in Sri Lanka, Ayurveda herbo-mineral manufacturers use a three-step method with Allium sativum extract, Piper betel extract and the decoction using Terminalia chebula, T. bellerica and Phyllanthus emblica. Although this method is well-known within the Ayurveda community, there are no research evidences available to identify the support and the functions given by the plant materials in the mercury shodhana process. Therefore, this research was carried out to analyse the elemental changes that would occur to commercially available mercury during the shodhana process. Shodhana process was carried out as mentioned in the Rasa Jala Nidhi textbook (volume I) of rasashastra literature under the mercury section (eighth process). As the shodhana process involves three steps, there were four samples to be analysed namely, crude mercury, first step completed Hg, second step completed Hg and final step completed Hg. Samples were microwave digested using HNO3: HCl in 3:1 ratio and diluted prior to the Inductive Coupled Plasma Mass Spectroscopy (ICPMS) analysis. These four Hg samples were then, subjected to ICPMS analysis. Standard 2A was performed to check Ag, Al, As, Ba, Be, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Ni, Pb, Rb, Se, Sr, Tl, U, V, Zn elements and standard 2A Hg was performed to check Hg element. Cu, As and V were measured in He gas mode and rest were measured in no gas mode. The analysis was carried out in triplicate. Origin and R software were used for the comparison. According to the results obtained, Mg, Al, Fe, Co, Zn, Cd, Ba and Pb were present in the crude mercury as noticeable elements, but the element levels were changed with each shodhana step. Most importantly, it clearly shows the reduction of Pb level from 2347.25 ± 0.01 ppb to 173.20 ± 0.02 ppb. Furthermore, trace elements such as Li, Ni, Ga and U were completely removed from mercury after the completion of shodhana process. The reason for the reduction of metal ions can be attributed to metal iron chelation, detoxification procedures with plant bioactive compounds such as organic sulphides, polyphenols and flavonoids. Therefore, these results reflect the benefit of shodhana process and clearly explains the use of plant extracts as a removal agent of unwanted metal ions, which are trapped in Hg.
Development of antioxidant encapsulated nano edible sheet using Cocania Grandis (Kowakka): an underutilized wild edible species in Sri Lanka
(Faculty of Science, University of Kelaniya Sri Lanka, 2022) Peduruhewa, P. S.; Jayathunge, K. G. L. R.; Manathunga, D. C.; Liyanage, R.; De Silva, W. R. M.; De Silva, K. M. N.
Recently, food and nutrient security have become crucial concerns around the globe. In that context, using underutilized wild edible plant species become an option way to ensure food supply in acceptable quantity and quality. Referring to nutritional aspects, these plant species are generally recognized as potential sources of micronutrients and bioactive compounds that are essential to human health maintenance and to prevent of malnutrition. Even though they are enriched with a significant amount of nutrients, it does not mean that every ounce of those nutrients can be absorbed. Nano encapsulation technology has become a promising solution to protect food bioactive components against an unfavourable processes and storage conditions, chemical and mechanical barriers. By improving the bioaccessibility, nano encapsulation is able to increase the portion of bioactive compounds released from the food matrix which are available for intestinal absorption. For these reasons, this study was conducted to develop antioxidant encapsulated nano-edible sheet using an underutilized plant species namely Cocania Grandis (Kowakka). Ethanol based plant extracts (0.2%) were encapsulated by electrospinning technique using edible polymer mixture including hydroxypropyl-β-cyclodextrin (70%) and poly (ethylene oxide) (30%) as the wall materials. Fiber mats were then assessed for total polyphenol content using Folin ciocalteu reagent method while the ascorbic acid content was determined using 2, 6 dichlorophenol indophenol visual titration method. Antioxidant capacity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. Antioxidant bioaccessibility of the fiber mats was tested using in vitro digestion model and the final accessibility value was calculated as the bioaccessibility fraction. Furthermore, the fiber mats were characterized for their physical properties using scanning electron microscopy and transmission electron microscopy. The antioxidant activity in Kowakka encapsulated fiber mat was 0.16 mg/mL (IC50) and 333.23 Trolox equivalent antioxidant capacity for DPPH and ABTS assays respectively. The total phenolic content was found to be 280.65 Gallic acid equivalents (GAE) mg/100 and ascorbic acid content was 4.80 mg/mL. According to the antioxidant bioaccessibility assessment, the bioaccessibility level of the encapsulated edible mat containing C. grandis was 63.65% higher than its’ normal bioaccessibility level. C. Grandis encapsulated nano edible fiber mats will be a multifaceted approach for a number of applications in the food industry, as well as for improving human nutrition and health benefits.