Browsing by Author "Nugara, N.N.R.N."

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    Phenanthrene Degradation Ability of Bacillus sp. Phyllosphere Bacteria Inhabiting the Urban Areas in Sri Lanka
    (Uva Wellassa University of Sri Lanka, 2020) Dharmasiri, R.B.N.; Nilmini, A.H.L.; Undugoda, L.J.S.; Nugara, N.N.R.N.; Udayanga, D.; Pathmalal, M.M.
    Remediation of phenanthrene from the environment is essential since its toxic effect. Out of many remediation methods, bioremediation is the most eco-friendly and effective method which can be used to convert toxic substances to nontoxic. There are many phyllosphere microorganisms which have the capability in phenanthrene like polyaromatic air pollutant degradation. This attempt is to isolate, select, and identify the efficient phenanthrene degrading bacteria. Bacteria were isolated using specific leaf samples collected from Panchikawatta, Orugodawatta, Pettah, Maradana, Colombo Fort, and Sapugaskanda in Sri Lanka. Phenanthrene degradation ability of isolated bacteria was screened using plate assay. Phenanthrene degradation ability of each bacterial species was analysed using the UV-Vis spectrophotometer and HPLC. The selected bacterial isolates were identified up to species level by PCR amplification of a fragment of 16S rRNA gene and sequencing the amplified fragments using the primers 1492R and 27F. Four Bacillus species Bacillus sp. P2B-02, Bacillus velezensis, Bacillus sp.1, and Bacillus megaterium were able to degrade more than 40% of phenanthrene. Out of these bacteria, Bacillus sp.1 (MN190173) was the most efficient bacterial species which was highly capable of degradation of phenanthrene. The Bacillus sp. could be useful as a potential biological agent in bioremediation for polluted environments with phenanthrene like polyaromatic hydrocarbons. Keywords: Phyllosphere, Aromatic hydrocarbon, Bioremediation, Phenanthrene
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    Phytochemical Screening, Quantitative Analysis and In Vitro Cytotoxic Potential of Justicia adhathoda Leaf Extracts
    (Uva Wellassa University of Sri Lanka, 2021) Silva, A.B.W.R.; Nugara, N.N.R.N.; Manage, P.M.; Undugoda, L.J.S.; Udayanga, D.; Nilmini, A.H.L.R.
    Justicia adhathoda L., also known as “Adhathoda” is one of the widely used medicinal plants in indigenous medicinal systems in Sri Lanka and India. Previous studies have found several beneficial effects of different solvent extracts of this plant. However, the best solvent to extract much of the phytoconstituents has not been studied. Therefore, the present study was focused on identification, quantification of phytoconstituents in different crude extracts and in vitro cytotoxic effect of J. adhathoda. Plant leaves were collected from Ambilipitiya, Sri Lanka. Ethanol (EE), hexane (HE) and water (WE) extracts were prepared by adding 1 g of powdered leaf samples to 25 mL of ethanol (99.9%), n-hexane and distilled water, separately in triplicates. Preliminary phytochemical screening was performed according to the Harborne method. Total phenolic content (TPC) was measured spectrophotometrically by Folin-Ciocalteu assay and total flavonoid content (TFC) was determined using aluminum chloride colorimetric assay. To identify the toxicity level of J. adhathoda, different concentration of the WE were exposed to 3T3-L1 cells, a well-established cell culture model that is extensively used to study adipogenesis. The treatment was carried out for 8 days and performed MTS assay to determine the suitability of the WE consumption. Phytochemical screening results showed the availability of flavonoids, terpenoids, steroids, anthocyanins, alkaloids and coumarins in the WE. In contrast, tannin and alkaloids were abundant in the EE. TPC in the WE was 8-fold higher than the EE. The TFC in the EE was 20-fold higher than HE, and marked the highest. Collectively, the best solvent to extract the maximum amount of phytoconstituents was found as distilled water. The WE showed no toxicity below 500 μg/mL against 3T3-L1 adipocytes. The presence of high content of different phytoconstituents in WE of J. adhathoda is a great advantage to gain the health benefits as herbal tea or herbal porridges. These results provide referential information to identify the medicinal value of J. adhathoda and to be utilized in screening novel target compounds to treat various diseases. Keywords: Justicia adhathoda; phytochemical analysis; Medicinal plant; TFC; TPC; 3T3-L1