Browsing by Author "Edirisinghe, E. M. R. K. B."

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Arsenic contamination in Sri Lankan traditional rice varieties in Anuradhapura district and probabilistic assessment of human health risk through rice consumption
(Faculty of Science, University of Kelaniya, Sri Lanka, 2021) Senarathne, E. M. N. S.; Edirisinghe, E. M. R. K. B.
Arsenic (As) is one of major hazardous carcinogen found in foods and identified as a significant public health concern. Diet and lifestyle of Sri Lankans are mainly relied on rice. Nowadays high demand for traditional rice can be distinguished in the market. The study was aimed to determine the As contamination in Sri Lankan traditional rice varieties and to assess the adverse health effect on human through consumption of these varieties. Twenty four rice varieties were collected from local farmers, Anuradhapura district in the North Central province of Sri Lanka. Rice samples were taken without husks and dry weights were considered. Digestion procedure was carried out using microwave digestion system prior to the analysis. Total As levels were detected using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results were verified using a certified reference material (NMIJ 7503b) with 98% recovery. As concentration detected between 39.92 (± 0.10) µg/kg to 543.00 (± 3.10) µg/kg and maximum level was reported in Rathdel while Kuruluthuda showed the lowest concentration. Ten rice varieties including Madathawalu (265.75 ± 4.34) µg/kg , Dik Wee (257.73 ± 2.90) µg/kg, Goda Heenati (249.88 ± 0.50) µg/kg, Rathu Heenati (238.65 ± 3.40) µg/kg, Kiri Murunga (268.04 ± 14.96) µg/kg, Hondaruwal (204.09 ± 6.52) µg/kg, Gurusinghe Wee (251.91 ± 6.03) µg/kg, Gonabaru (274.86 ± 2.50) µg/kg, Al Wee (284.71 ± 7.90) µg/kg and Rathdel (543.40 ± 3.10) µg/kg exceeded the maximum allowable concentration of As in rice (200 µg/kg). There was a significant difference between As amount of Rathdel with that of all the other varieties (P<0.005). Health risk assessment was performed based on the Estimated Daily Intake (EDI) and Hazard Quotient (HQ). EDI for all the rice varieties were within the tolerable daily intake reference limit for As. Noncarcinogenic risk of As was evaluated by HQ value and it was increased in the order, Al Wee < Bada Heenati < Beheth Heenati < Dahanala < Dik Wee < Duru Wee < Goda Heenati < Gonabaru < Gurusinghe Wee < Handiran < Hondaruwal < Kalu Heenati < Kalu Murunga < Kiri Murunga < Kiri Naran < Kurulu Thuda < Madathawalu < Marjuana < Pushparaga < Rath Suwandel < Rathdel < Rathu Heenati < Sudu Heenati < Suwandel. However, all the HQ values were lower than 1 indicating no carcinogenic health risk. Even though ten varieties exceeded the maximum allowable limit, overall health risk assessment confirmed that the consumers are safe to consume rice of these native varieties.
Determination of color characteristics, fatty acid composition and heavy metal in purified shark liver oil.
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Jayakody, J. A. K. S.; Edirisinghe, E. M. R. K. B.; Senevirathne, S. A.; Senarathna, L.
Shark liver oil (SLO) is a promising source of fatty acids (FAs) particularly of Omega-3 polyunsaturated FAs including, Eicosapentaenoic acid (EPA- cis-5, 8, 11, 14, 17- eicosapentaenoic acid) and Docosahexaenoic acid (DHA- cis-4, 7, 10, 13, 16, 19- docosahexaenoic acid). SLO as a dietary supplement is one of the best options to overcome healthrelated problems that arise due to imbalance and insufficient levels of omega-3 FAs. The objectives of this research were to extract and purify omega-3 rich oils from shark livers by traditional method and determine color characteristics, fatty acid composition (FAC), and heavy metals (As, Cd, Pb, and Hg) during purification. SLO was extracted using the conventional heat extraction method. Purification of crude SLO (CSLO) was done using a semi-refining which included, degumming, neutralization, and bleaching to produce purified SLO (PSLO). The color of the SLO was determined using a Chromameter and FAC was determined by Gas Chromatography - Mass Spectrometry. The heavy metals in SLO were determined using Inductively Coupled Plasma-Mass Spectrophotometry after microwave digestion. Both chroma value and hue angle were enhanced during purification, ranging from 15.15 to 35.18 and from 25.17 to 87.68, after each step of purification respectively. Moreover, the total color difference was significantly increased (p < 0.05) in every step of purification, with values of 17.02, 30.78, and 39.17, respectively. During purification, the contents of saturated FAs and monounsaturated FAs significantly increased (p < 0.05) from 117.63 to 141.53 mg g-1 and from 78.91 to 117.53 mg g-1 , respectively w hile, polyunsaturated FAs levels significantly decreased (p < 0.05) from 141.95 mg g-1 in CSLO to 131.09 mg g-1 in PSLO, respectively. The omega-3 fatty acids significantly decreased (p < 0.05) from 96.35 to 83.83 mg g-1 and the EPA+DHA level significantly decreased (p < 0.05) from 85.58 to 72.35 mg g-1 in PSLO compared to CSLO. The As levels decreased during purification from 8.749, 0.348, and 0.006 mg kg-1 , respectively. As was not detected (ND) in PSLO. Cd was ND in any SLO. Pb was recorded only in CSLO with a level of 0.225 mg kg-1 . Hg levels of CSLO and PSLO were found to be 0.292 and 0.135 mgkg-1 , respectively. SLO purification enhanced color characteristics with lowering of heavy metal contents. Moreover, it can be concluded that the purified SLO is a promising rich source of omega-3, enabling the potential for the development of omega-3 dietary supplements.
Profiling of phytochemical composition and potential bioactive compounds in Calotropis gigantea
(Faculty of Humanities, University of Kelaniya, 2023) Kumari, P. K. R. S.; Edirisinghe, E. M. R. K. B.
Phytochemicals derived from medicinal plants are important sources of therapeutic agents in pharmaceutical research and development. Calotropis gigantea is a medicinal herb that belongs to the family Apocynaceae, native to South and Southeast Asia. This latex bearing plant has two varieties: white-flowered and purple-flowered form. The current study was conducted to preliminary screen the phytochemicals and to assess the potential bioactive components found in the methanol fraction of leaves and flowers of Calotropis gigantea by Gas Chromatography-Mass Spectrometry (GC-MS). The dried powder of leaves and flowers of C. gigatea were subjected to cold maceration extraction by methanol. The rotary evaporated crude extract was dissolved in methanol to prepare 100000 ppm extract and it was subjected to GCMS analysis and 10000 ppm extract was used for screening tests. Alkaloids, phenols, tannins, carbohydrates and steroids were found in leaf and flower extracts after conducting a phytochemical screening. While reducing sugars, terpenoids, and flavonoids were only discovered in floral extracts. Both extracts were found to be devoid of saponins, proteins, and other essential amino acids. Fifty eight compounds were identified from the flower extract and fifty nine compounds were identified from the leaf extract by the GC-MS analysis. Most prevalent identified chemical compounds are 9,12,15- Octadecatrienoic acid (Z,Z,Z), 5-hydroxymethylfurfural, n- Hexadecanoic acid, gamma- Sitosterol, Squalene, Phytol, 9-Octadecanoic acid, 4-Hydroxy-2-methyl acetophenone, Ergost-5- ene-3-ol (3-beta), Stigmasterol, Neophytadiene, Squalene, ethyl-9,12,15-octadecatrienoate, Larisiresinol, Stigmasta-5,24-(28)-dien-3-ol (3-beta, 24 Z), Olean-12-en-3-ol acetate (3-beta), Lanosta-8,24-dien-3-ol acetate (3-beta) and Alpha-Amyrin. Most of these chemical compounds are responsible for significant bioactivities. The reported bioactivities of the identified compounds confirm that the C. gigantea comprised mainly of antioxidant, anti-microbial, anti-inflammatory, Anti-cancer, anti-diabetic agents. The findings of the study imply that C. gigantea is a valuable medicinal plant and potential bioactivities of the components need further study.
Quantification and health risk assessment of cadmium and lead content in skin creams sold in the Sri Lankan market.
(Faculty of Science, University of Kelaniya Sri Lanka, 2023) Senarathne, E. M. N. S.; Edirisinghe, E. M. R. K. B.
Across history, humans used diverse personal care products with a rising global demand over time. Mineral pigments, frequently employed in colored cosmetics, represent a prominent origin of heavy metal contamination within cosmetic products. Increased exposure to heavy metals can trigger adverse health effects. This study aims to analyze Cd and Pb concentrations in skin creams in Sri Lankan market, as well as to evaluate the health implications linked to metal exposure. Skin creams were collected from 21 brands, comprising whitening (3), face (8), body lotions (7), and baby creams (3) categories. Identities were anonymized with codes (W1-W3, F1-F8, L1-L7, B1-B3). Samples were digested and subjected to metal analysis via Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Potential health risks were assessed by analyzing Hazard Quotient (HQ), Hazard Index (HI), and incremental lifetime cancer risk (ILCR). Cd concentrations ranged from 0.013 ± 0.001 to 0.085 ± 0.011 mg kg-1 (mean: 0.039 ± 0.002 mg kg-1) and Pb levels varied from below the limit of quantification (ND) to 1.066 ± 0.047 mg kg-1 (mean: 0.146 ± 0.006 mg kg-1). The average Cd levels in whitening creams, face creams, body lotions, and baby creams were found to range from 0.064 ± 0.002 (W3) to 0.085 ± 0.011 (W2), 0.013 ± 0.001 (F6) to 0.047 ± 0.002 (F4), 0.026 ± 0.001 (L7) to 0.051 ± 0.001 (L3) and 0.020 ± 0.001 (B3) to 0.055 ± 0.001 (B1) mg kg-1, respectively. In whitening creams, face creams, body lotions, and baby creams, the average Pb levels ranged from 0.343 ± 0.062 (W2) to 1.066 ± 0.047 (W3), from ND in case of F7 and F8 to 0.108 ± 0.001 (F6) mg kg-1, from ND in L2, L3, L4, and L6 to 0.203 ± 0.002 (L5) and from ND in B1 and B2 to 0.026 ± 0.002 (B3) mg kg-1, respectively. All Cd values met Canadian (3 mg kg-1) and Germany (5 mg kg-1) standards while Pb levels stayed below Canadian (10 mg kg-1) and USFDA (20 mg kg-1) thresholds. For Cd, W2 had the highest HQ (2.826 x 10-9), while W3 obtained the highest HQ (0.042 x 10-9) for Pb. No significant health risk was found for any sample, implying minimal consumer impact. Cumulative HI was below one, indicating no adverse effects. Cd and Pb ILCR values ranged from 1.273 x 10-11 to 8.619 x 10-11 for Cd and ND to 15.030 x 10-11 for Pb, highest in W2 and W3 respectively. The analysis of Cd and Pb concentrations in various brands has shown minimal levels, consistently below the limits set by regulatory authorities. Evaluation of health risk indicates that their presence remains within acceptable parameters. While frequent dermal contact is not expected to pose a cancer risk for the studied heavy metals, excessive use could lead to long-term health issues. However, it is recommended to maintain continuous monitoring and the presence of other heavy metals in cosmetics, while strictly adhering to established safety thresholds