South Asian Research Journal of Natural Products <p style="text-align: justify;"><strong>South Asian Research Journal of Natural&nbsp;Products</strong>&nbsp;aims to publish&nbsp;high-quality&nbsp;papers (<a href="/index.php/SARJNP/general-guideline-for-authors">Click here for Types of paper</a>) covering all aspects of research&nbsp;of naturally occurring compounds or the biology of living systems from which they are obtained.</p> en-US (South Asian Research Journal of Natural Products) (South Asian Research Journal of Natural Products) Sat, 10 Oct 2020 11:37:22 +0000 OJS 60 Investigation of β-Lactamase Enzyme Inhibitory, Anti-Bacterial and Anti-Fungal Bio-Activities of Dillenia retusa Thumb: An Endemic Medicinal Plant to Sri Lanka <p><em>Dillenia retusa</em> (Dilleniacea) is a medicinal plant endemic to Sri Lanka with an immense bioactive potential. To date, no studies are reported on anti-microbial potential of this plant. The present study investigates anti-bacterial, b-lactamase enzyme inhibitory and anti-fungal bio-activities of the ethanol extracts of <em>D. retusa.</em></p> <p>The leaves (DRL), fruits (DRF) and bark (DRB) of <em>D. retusa</em> were extracted with ethanol using cold extraction technique. Anti-bacterial properties of the extracts were investigated against five sensitive bacterial strains namely, <em>Shigella flexneri</em> (ATCC<sup>®</sup>12022), <em>Pseudomonas aeruginosa</em> (ATCC<sup>®</sup> 10145), <em>Escherichia coli</em> (ATCC<sup>®</sup> 25922), <em>Salmonella typhi</em> (ATCC<sup>®</sup> 14028), <em>Staphylococcus aureus</em> (ATCC<sup>®</sup> 6538) and four resistant bacterial strains namely, <em>Klebsiella pneumoniae</em> (MDR ATCC<sup>®</sup> 700603), <em>Escherichia coli</em> (MDR ATCC<sup>®</sup> 35218), <em>Salmonella enterica</em> (MDR ATCC<sup>®</sup> 700408) and <em>Staphylococcus aureus </em>(ATCC<sup>® </sup>MDR MRSA 252) using alamar blue micro-plate based assay. Anti-b-lactamase activity of the extracts were determined using b-lactamase enzyme inhibitory assay. Anti-fungal activity of the extracts was determined against five sensitive fungal strains namely<em>,</em> <em>Candida albicans </em>(ATCC<sup>®</sup> 14053), <em>Candida glabrata</em> (ATCC<sup>®</sup> 2001)<em>, Aspergillus niger </em>(ATCC<sup>®</sup> 1015), <em>Microsporum canis </em>(ATCC<sup>®</sup> 10214) and <em>Trichophyton rubrum</em> (ATCC <sup>®</sup>MYA-4438)) using agar-tube dilution method. Further, polyphenols and flavonoid contents of the extracts were determined. The bio-activities were statistically analyzed at p&lt;0.05.</p> <p>The extracts showed anti-bacterial activity against sensitive bacterial strains within the MIC range of 1.8-2.8 mg/mL and MBC range of 3-4.8 mg/mL and were found to be bactericidal. The extract of DRL showed the highest anti-b-lactamase activity (IC<sub>50</sub>: 226.25 ± 10.53 µg/mL) in a dose-dependent manner. The antifungal activity of the extracts was detected within the range of 1.6-3.2 mg/mL and the highest anti-fungal activity was observed for DRB against <em>C. albicans</em> which may be attributed to the high polyphenol content of DRB.</p> <p>The extracts were identified as novel potential sources of antimicrobial compounds which may impart even higher antimicrobial activities upon bio-activity guided fractionation and purification of extracts.</p> Hettiarachchige Dona Sachindra Melshandi, Jayanetti Koralalage Ramani Radhika Samarasekera, Shiroma Mangalika Handunnetti, Ovitigala Vithanage Don Sisira Jagathpri Weerasena, Rukesh Maharjan, Muhammad Iqbal Choudhary ##submission.copyrightStatement## Sat, 10 Oct 2020 00:00:00 +0000