Browsing by Author "Perera, W.P.R.T."

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Assessment of the Heavy Metals in Rice Grains Grown in Paddy Soil in CKDu Endemic Area in Eppawala, Anuradhapura
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Perera, W.P.R.T.; Dissanayake, D.M.U.C.; Kannangara, A.T.; Liyanage, J.A.
Global public health attention is being focused on Chronic kidney disease due to significant prevalence and the enormous cost of the treatment process. It was revealed that longterm consumption of bioavailable metals in grains causes CKD in humans. Therefore, the present study was planned to assess the levels of heavy metals in rice grains grown in paddy soil in CKDu endemic area in Eppawala, Anuradhapura. The soil samples (n=30) were collected from paddy fields in Eppawala GN division. Rice plants with rice grains (n=30) were also collected from the same fields. Collected samples (soil, rice roots and rice grains) were digested using the microwave digester (MDS-6G). Concentrations of heavy metals (Cr, Fe, Cu, Zn, As, Cd, Pb) of the paddy soil, rice roots and ride grain samples were analyzed by ICP-MS (Agilent 7800). Based on the analyzed concentrations, Geo acumination indices were calculated to evaluate the heavy metal contamination conditions in the agricultural soil.The results indicated that the average concentrations of Cr, Cd, As and Pb in soil were 49.918 mg/kg, 0.107 mg/kg 5.033 mg/kg and 9.882 mg/kg respectively and they were 1.709 mg/kg, 0.027 mg/kg, 0.217 mg/kg, 0.566 mg/kg respectively in roots. Nevertheless, the lowest levels of metals were observed from rice grains (Cr, Cd, As and Pb were recorded as 0.342 mg/kg, 0.011 mg/kg, 0.035 mg/kg, 0.112 mg/kg respectively). According to the Igeo calculations, agricultural paddy soil in the Eppawala area has been moderately contaminated with Pb, As, Zn, and Cu. (Class 2). Nevertheless, Cd and Cr levels were between near to moderate contamination level. (Class 1). Although the levels of metals in rice grains were low, long term consumption of metal contaminated rice may contribute to chronic failure.
Graphite oxide coated sand composites for efficient removal of calcium ions from hard water: isotherm, kinetics, and adsorption mechanism
(Polish Ministry of Science, 2024) Perera, W.P.R.T.; Premasinghe, Niroshan; Fernando, W.S.K.; Perera, P.L.R.A.; Sandaruwan, Chanaka; Kumarasinghe, A.R.; Liyanage, Janitha A.
Even if granular media filtration effectively reduces the turbidity of water, its limited surface functionalities and physical properties may constrain its ability to effectively remove critical contaminants from water. In our research, we successfully synthesized a new type of porous material – multiple coated GO/sand (M-GO/S) by integrating ordinary river sand with graphite oxide (GO) for the adsorptive removal of calcium ions in terms of water softening. Prior investigations confirmed it could remove water turbidity and fluoride simultaneously. M-GO/S was characterized using microscopic and spectroscopic techniques. The results indicate the presence of an uneven coating of graphite oxide, and the nanocomposite contains oxygencontaining functional groups. Under given conditions, the M-GO/S nanocomposite demonstrated remarkable efficacy in removing 75% of calcium ions (a higher removal percentage than commercial coal powdered activated carbon) from simulated hard water: pH 8, 5.0 g dosage, 50 mg/L calcium ions, and 20 min contact time. The isotherm and kinetic data revealed that the adsorption mechanism primarily comprises multilayer adsorption by means of a chemical sorption process. The mechanism of the proposed M-GO/S nanocomposite for removing calcium ions from hard water is elucidated using (XPS) analysis. The presence of (-O-Ca-O-) chemical bonds on the surface of the nanocomposite after equilibration with calcium ions suggests the occurrence of chemical interactions between the calcium ions and oxygen-containing functional groups of the M-GO/S. Consequently, the synthesized M-GO/S nanocomposite can be identified as a promising candidate for hard water treatment.
Immunomodulatory Efficiency of Tinospora Cordifolia Against Viral Infections
(World Journal of Pharmaceutical and Medical Research, 2020) Dissanayake, K.G.C.; Perera, W.P.R.T.; Premasinghe, N.
Most of the cases, viral infected patients are suffering from secondary infections. Apart from that, due to the exhausted Immune system patients more vulnerable to secondary Infections and various diseases. Dysfunction of the immune system is responsible for multiple illnesses, such as arthritis, ulcerative colitis, asthma, allergies, parasites, cancer, and infectious diseases. So, medicinal plants and their active components are becoming increasingly relevant as a source of immunomodulatory agents. T. cordifolia stem extracts or the isolated compounds of the plant exhibits amazmg immune stimulatory effects in various ways isolated compounds of T. cordifolia such as N-methyl-2-pyrrolidone and Il-hydroxymustakone, Magnoflorme and Tinocordiside shows immunomodulatory effects by enhancing Reactive Oxygen Species (ROS) generation which causes to augment the Immune response. T. cordifoüa extract exhibits a considerable effect of the immunostimulation in HW positive patients and, increases the phagocytosis and intercellular killing capacity by increasing the survival rate and polymorphonuclear leucocyte function. In addition to that, a novel (1,4)-∝-D-glucan from T. Cordifoüa activates the immune system by activatmg macrophages via of TLR6 signaling and NF-kB activation mechanism, leading to cytokine and chemokme production. Immunoductatory protem (Imp) obtained from the dry stem powder of Tinospora cordifoüa is significant for augmenting the various immunological activities in the human body. Hence, more attention should be focused on the phytochemistry and their applications of the Tinospora cordifolta for Immune enhancements as well as reduce secondary infections risks along with the viral infections.
Medicinal importance of Ferula asafetida oligo-gum resins against infective diseases
(Journal of Medicinal Plants Studies 2020, 2020) Dissanayake, K.G.C.; Perera, W.P.R.T.
Ferula foetida oligo-gum resin containing phytochemicals with anti-viral properties. In order to investigate medicinal values of ferula assa-foetida a literature searches were performed through PubMed and PMC academic publications. It contains five sesquiterpene cumarines namely, conferone, badrakemin, feslol, Isosamarcandin and samarcandin with anti-viral properties against Rhinovims (HR V) and Influenza A HINI_ Farnesiferol C and Famesiferol b are novel chemical scaffolds with HR V -2 inhibiting potential at low micromole and mode of inhibition action was prevention of rhinovims adsorption (HR V-2) and/or uncoatmg of the capsid of virus. 5'S-hydroxyumbe11iprenin and 8'-acetoxy- 5'S-hydroxyumbe11iprenin, methyl galbanate, galbanic acid, famesiferol-C, famesiferol-A, conferol showed greater potency against influenza A vims (H IN 1) (IC50 0.26-0.86 pg/mL) than amantadine. Several studies demonstrated that cytotoxic and antitumor activity of Galbanic acid. Additionally, exhibits anti-bacterial effects, anti—diabetic effects, anti- fungal, antiulcer genic effect and hypotensive effects. Asafoetida oligo-gum resin will be beneficial in anti-viral drug productions against disease forming viruses.
Potential of Inhibiting the Receptor Binding Mechanism of SARSCOV-2 Using Phytochemical Extracts of Medicinal Herb; Moleculer Docking Study
(Global Journal of Engineering Science and Research Management, 2020) Rajapaksa, R.M.H.; Perera, B.T.; Nisansala, M.J.; Perera, W.P.R.T.; Dissanayake, K.G.C.
The Corona Viral Infective Disease (COVID-19), which leads to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is caused a pandemic situation globally. World Health Organization (WHO) declared that COVID-19 as a Public Health Emergency of International Concern (PHEIC) on January 30, 2020. Intend of this study is divulge the chemistry behind the phenomenon of viral (SARS-CoV-2) attachment on human epithelial cells as well as evaluate the receptor blocking abilities of selected herbal compounds. Significant anti- viral compounds were identified via review process of medicinal plants and Ferula asafetida, Glycyrrhiza glabra, Curcuma longa, Zingiber officinale etc. are widely used plant species for drugs against viral infectious diseases in Ayurveda medicine. Molecular docking prognosis have been carried out to demonstrate any possible secondary metabolites present in several anti-microbial herbs that could act as blocking agents ofACE2 and GRP78 receptors of epithelial cells to baffle the binding of receptor-binding domain (RBD) sections of SARS-CoV-2. Computational findings reveal that Phyto-chemicals such as Conferone, Samarcadin, Bdrakemin Famesiferol A, Femesiferol C and Galbanic acid isolated from Ferula asafetida have intensive binding energies for ACE2 receptor binding process. Apart from that Hederagenin and Ursolic also shows highest inhibitory potential towards human ACE2.When considering GRP78, almost all isolated compounds in oligo-gum resins ofFeru1a asafetida trot out perfect binding ability towards the active site of GRP78 receptor. Hence, it is worth to pay more attention on natural phytochemicals for mitigating of human infections.
Potential of the Pathogenic Microorganisms Mitigation Using Rhizome Extract of Acorus Calamus as a Medicinal Herb
(World Journal of Pharmacy and Pharmaceutical Sciences, 2020) Dissanayake, K.G.C.; Perera, B.T.; Perera, W.P.R.T.
Acorus calamus exhibits polyploidy and phytochemical coruyosition also depends upon the ploidy. Scented leaves and rhizomes have been traditionally used m Ayurveda medicine for bronchitis, cough, fever, asthma and digestive problems. Pharmacological studies have revealed that Acopus calamus and its major constituents, particularly P-asarone and a-asarone possesses a wide range of amazing pharmacological activities such as anticonvulsant, acetylcholinesterase inhibitory, memory enhancing anti-inflammatory, antioxidant, sedative, CNS depressant, behavioral changes anticancer, cardiovascular, cytoprotective, antidiarrheal, and immunosuppressive activities. In addition to the above-mentioned pharmacological actions, antibacterial, antifungal, antiviral, anthelmintic and insecticidal activities are also reported.
Root/Stem Extracts of Glycyrrhiza glabra; As a Medicinal Plant Against Disease Forming Microorganisms
(International Journal of Sciences: Basic and Applied Research (IJSBAR),, 2020) Dissanayake, K.G.C.; Weerakoon, W.M.T.D.N.; Perera, W.P.R.T.
Nature is one of the major sources of medicines since the beginning of human civilization. Different counties around the globe have been used different plant materials to overcome varieties of ailments from simple cough to hepatitis to more complexes like SARS and most recently Covid 19. This review is an effort to emphasis the phytochemical and chemical constituents of G. glabra and their mechanisms against disease forming microorgamsms. This traditional plant which is well known in Sri Lanka as "Welmi" is belongs to family Leguminosae/ Fabaceae. Chemical constituents of G. glabra like isoliquiritine, isoflavones, glycyrrhetic acid, saponin and their derivatives have been examined for their pharmacological activities. Most critical chemical compounds which isolated from the root/stem extract of the G glabra are Glycyrrhizin and Glycyrrhetic acid. Glycyrrhizin is a prominent triterpenoid contain in Glycyrrhiza glabra which is responsible for the sweet taste of its roots. Glycyrrhizin act as anti-viral compound in tun) ways. It is able to inhibit the replication process of some RNA viruses such as SARS like corona type virus. Another process is acting as an immunostimulator. It has been used to treat patients suffering from chronic hepatitis C virus and HIV-I patients owing to its capability of stimulating endogenous viral defense mechanisms.
Speciation Distribution of Analyzed Drinking Water in a CKDu Endemic Area in the Anuradhapura District
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Weerasinghe, A.A.V.N.; Perera, W.P.R.T.; Liyanage, J.A.
Chronic Kidney Disease of Unknown etiology (CKDu) has been showing a spreading tendency among the agricultural zones in the North Central Province since the mid-1990s. Even though most of the studies have identified that the nephrotoxic heavy metal content in surface and ground water has not exceeded the permissible limits in the CKDu prone areas, long term exposure could influence on renal failures. The present study was attempted to study the chemical speciation of the contaminants in drinking water of CKDu endemic area in the Anuradhapura District. The areas selected for the study were Eppawala Grama-Niladhari division (GND) (8°8′33″N 80°24′10″E) in Anuradhapura District (Endemic site) and Dambethalawa GND (7°17'11.9"N 81°32'04.3"E) in Ampara District (Reference site). Nineteen drinking water samples from each sampling area were randomly collected. Basic physico-chemical parameters such as pH, conductivity, dissolved oxygen and Fluoride content were measured on-site. Concentrations of heavy metals (Cr, Mn, Fe, Cu, Zn, As, Cd, Pb) of the water samples were analyzed by ICP-MS (Agilent 7800) and counter-ion content (F-, Cl-, NO3-, PO43-, SO42-) was analyzed by Ion chromatography (Methorm eco IC). Chemical speciation modeling was performed by using the Visual MINTEQ 3.1 software based on the obtained concentrations. According to the results, the average concentrations of Cr, Cu, Zn, As, Pb were complied with SLS values for drinking water while Mn and Fe concentrations from both areas have exceeded the SLS values which are 100.00 and 300.00 μg/L respectively. The Mn concentration of Eppawala and Ampara were 173.99 (10.39-485.59) μg/L and 129.27 (1.089-239.86) μg/L respectively and for Fe it was recorded as 383.14 (0.18-867.44) μg/L and 526.21 (0.85-897.25) μg/l. Since the samples were collected randomly, the presence of Mn and Fe as heavy contaminants in some sites might be the reason for having a wide concentration range. The mean F- concentration of the Eppawala area was 1.80 (0.10-3.96) mg/L which exceeded the SLS maximum level (1.00 mg/L) while it was 0.45 (0.11-1.00) mg/L in Ampara which was below the SLS maximum limit. According to the speciation results, only species of Cr, Pb, Cd, Cu and Fe, namely Cr(OH)3, CrOH2+, Pb2+, PbOH+, PbCl+, PbSO4, Cd2+, CdCl+, CdSO4, Cu2+, CuOH+, Fe(OH)2+, showed higher variations of percentage distributions under the tested pH range of 4 to 9. Higher percentage distribution values of CdCl+, CdSO4, PbCl+, PbSO4, ZnSO4, MnSO4, CuSO4 were observed from the Eppawala area compared to Ampara area. Manganese, Cadmium, Zinc, Copper, Lead, Fluoride, Nitrate and Chloride species showed more tendency to exist as free ionic species such as Mn2+, Cd2+ , Zn2+, Cu2+, Pb2+, F-, NO3-, Cl- at pH 7 while Chromium, Iron and Arsenic were found as Cr(OH)3, Fe(OH)2+ and H3AsO3 at pH 7. Long-term exposure to different species formed by Cd, Pb, Cr, As and higher F- concentrations may have some significant effects in causing CKDu.
Synthesis of Surface-Modified Graphene-Based Sand for Fluoride Removal from the Drinking Water
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Perera, W.P.R.T.; Fernando, W.S.K.; Premasinghe, N.; Liyanage, J.A.; Kumarasinghe, A.R.
Graphene and graphene-based material such as graphene oxide (GO) are materials of great interest for potential applications in nanoelectronics, nanoelectromechanical systems, sensors, polymer composites, catalysis. As graphene does not possess its native oxide, GO is routinely obtained via the chemical treatment of either graphene or widely available regular graphite. Chemically exfoliated graphene with various oxygenated functional groups bound to sp2 basal plane and edges of graphene sheet is called graphene oxide (GO). The surface sites on commercial sand used in water treatment are dominantly negative (pH = 2.7), and chemically inert. Therefore, they show a low affinity for most of the contaminants present in drinking water. However, conventional sand filters are used in water turbidity removal. Graphene oxide (GO) was synthesized using the modified Hammer’s method and purified sand was coated with GO dispersion to make super sand which can be used for many purposes including water purification. Single GO coated super sand (GO1) and multiple coated super sand (GO2, GO3, GO4, GO5) were prepared. Optimization studies were done for the fluoride removal process by super sand. Multiple coated super sand and fluoride adsorbed super sand were characterized using Scanning Electron Microscopy (SEM), energy dispersive X-ray absorption (EDXA) spectra, Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD). When increasing the coating times, the Enhancement of the GO coatings on the sand surface was clearly depicted by the SEM images and later by later coatings of the GO were observed on the sand surface. Respective EDXA spectra were also taken from both samples which show higher carbon content for sand/GO5 sample than sand/GO1. EDXA spectra of the Fluoride adsorbed five times coated sand show a small percentage of F in addition to the C, O and Si in the spectrum. The FT-IR spectrum for graphite oxide shows major peaks at wavenumbers of 3427, 1744, 1630, 1186, and 875 and 576 cm -1 due to the functional groups such as –OH, C=O, C-O. More or less similar peak patterns were observed on GO coated sand and peak intensities have been decreased when increasing the coatings. A noticeable decrease of the intensity of the peak at 1070 cm -1, which is assigned to be originating from sand, is a clear indication of the formation of layers of GO covering the sand. A noticeable peak of the FT-IR spectrum of Fluoride adsorbed 3 times coated sand observed around 3500 cm-1. It may be due to the Fluoride bond with Hydrogen in the GO. The highest performance of fluoride removal is shown at pH 3.22 and 7.21 for Sand-GO-1 and Sand-GO-5, respectively. In both instances, the fluoride removal efficiency is around 70 % when 3 ppm initial fluoride was used. So finally it can be concluded that five times coated Sand-GO is most suitable for fluoride removal from the contaminated drinking water.