Bangladesh Journal of Pharmacology Volume: 17; Number 4; Year 2022 Cite this article as: Sundar RDV, Arunachalam S. Tradescantia pallida, a natural alternative against vancomycin- resistant Enterococci. Bangladesh J Pharmacol. 2022; 17: 154-156. Tradescantia pallida, a natural alternative against vancomycin-resistant Enterococci Sir, Vancomycin-resistant Enterococcus infection is one of the multidrug-resistant bacteria caused by Enterococcus faecium and E. faecalis. Compared to MRSA, vancomycin -resistant Enterococcus has a lower prevalence and epidemiological impact. Quinupristin and linezolid are two antibiotics often used to treat vancomycin-resistant Enterococcus. Multi- drug-resistant bacteria pose a significant public health risk, as the infections induced by them are difficult to treat and expensive (Sundar and Arunachalam, 2019). The use of medicinal plants may involve an important role in the treatment of drug-resistant microorganisms. For example, hypericin from Hypericum perforatum, is effective against methicillin-resistant and methicillin- sensitive Staphylococcus (Bahmani et al., 2019). Cathor- mion umbellatum extract is effective against antibiotic- resistant E. faecalis (Rattanasuk et al., 2021). Tradescantia pallida (Rose) D. R. Hunt., was well known as purple heart or wandering jew plant. They are commonly grown as ornamental plants and are widely distributed in tropical and subtropical regions. Tradi- tionally, T. pallida have been used to improve blood circulation and as an anti-inflammatory and anti-toxic supplement (Tan et al., 2014). It is also reported to have antibacterial activity against Gram-positive and -nega- tive bacteria (Kamiya et al., 2019). Previous literature reported that chloroform leaf extract from T. pallida purpurea has shown the most promising against the Labeo rohita fish pathogens. The natural colorants deri- ved from T. pallida, anthocyanin and annatto, have also been linked to a wide range of health benefits (Bokhari et al., 2020). Therefore, the present research aimed to investigate the antibacterial efficacy of T. pallida stem and root crude extracts against human pathogens. Healthy, mature and disease-free plant samples (stem and root) were collected from the Vellore district in a sterile polythene bag. The different samples for the antibacterial study were washed, air-dried and using an electric blender it is ground into a fine powder. About 10 to 15 g of powder was soaked in 200 mL of different polarity solvents such as dichloromethane, ethyl acetate and butanol. The flasks were incubated at room tempe- rature in a rotatory shaker for 2 days at 120 rpm. Using Whatman filter paper No. 1, the resultant was filtered and dried. The extracted powder was dissolved in DMSO to a final concentration of 100 mg/mL for fur- ther studies (Bibi et al., 2011). The antibacterial activity of the crude extracts was checked by the disc diffusion method against vancomy- cin-resistant Enterococci (ATCC 51299) and Enterococcus faecalis. The culture was freshly prepared in Brain heart infusion broth and standardized (5 × 107 CFU). The cultures were spread uniformly over the Muller Hinton agar medium. About 100 µL of different concentrations (25, 50, 75, 100 mg/mL) of extracts were introduced into the sterile disc placed over the medium to study their antibacterial property. The inhibition zone diameter was measured after overnight incubation at 37°C. Vancomycin and DMSO have used a positive and negative control respectively (Bibi et al., 2011). The minimum inhibitory concentration of the extracts was checked by micro-broth dilution method using a 96 -well plate. The prepared extracts were diluted serially (two-fold) in Muller Hinton broth making a concentra- tion of 50, 25, 12.5, 6.25, 3.12, 1.56 and 0.78 mg/mL. About 5 µL of inoculum was added and incubated for 18 hours at 37°C. The lowest concentration of the extract with no visible bacterial growth turbidity was recorded as MIC (Praptiwi et al., 2018). From the study, it was noticed that stem crude extracts displayed a strong antibacterial activity compared to that root extracts. However, ethyl acetate extract from both parts of the plant had an antagonistic effect against test pathogens higher than the positive control vancomycin (Figure 1). The maximum inhibition zone diameter of 19 mm was observed in ethyl acetate extract obtained from the stem at 100 mg/mL concentration with a MIC of 6.25 mg/mL, followed by the root (13 mm) with MIC 12.5 mg/mL. The dichloromethane extracts were effective against the test pathogens at a concentration higher than 50 mg/mL. The stem dichlo- romethane extract exhibited an inhibition zone of 12 mm against vancomycin-resistant Enterococci and 18 mm against E. faecalis at 100 mg/mL. The butanol extracts were not active against vancomycin-resistant Enterococci whereas it was active against E. faecalis with a zone of inhibition of 15 and 12 mm of stem and root respectively. There was no zone of inhibition was A Journal of the Bangladesh Pharmacological Society (BDPS) Bangladesh J Pharmacol 2022; 17: 154-156 Journal homepage: www.banglajol.info; www.bdpsjournal.org Abstracted/indexed in Academic Search Complete, Agroforestry Abstracts, Asia Journals Online, Bangladesh Journals Online, Biological Abstracts, BIOSIS Previews, CAB Abstracts, Current Abstracts, Directory of Open Access Journals, EMBASE/Excerpta Medica, Global Health, Google Scholar, HINARI (WHO), International Pharmaceutical Abstracts, Open J-gate, Science Citation Index Expanded, SCOPUS and Social Sciences Citation Index ISSN: 1991-0088; DOI: 10.3329/bjp.v17i4.62162 Letter to the Editor This work is licensed under a Creative Commons Attribution 4.0 International License. You are free to copy, distribute and perform the work. You must attribute the work in the manner specified by the author or licensor observed at 25 mg/mL concentration of all the extracts. Table I and II show the inhibition zone diameter and MIC of the potent crude extracts. To the best of our knowledge, this is the first report on the anti-vancomycin-resistant Enterococci property of T. pallida crude extracts. The present study displayed that crude extracts obtained from the stem and root of T. pallida contain a wide range of phytoconstituents with potential antibacterial activity against the vancomycin- resistant Enterococci pathogen. Further isolation of bioactive compounds from the potent extract can serve as the source of natural products in the treatment of bacterial infections. The authors thank the Vellore Institute of Technology for pro- viding facilities to carry out the present research. Ranjitha Dhevi V. Sundar1 and Sathiavelu Arunachalam2 1School of BioSciences and Technology, Vellore Institute of Technology, Vellore, India; 2VIT School of Agricultural innovations and Advanced Learning, Vellore Institute of Technology, Vellore, India. Corresponding author: Email: asathiavelu@vit.ac.in References Bahmani M, Taherikalani M, Khaksarian M, Rafieian-Kopaei M, Ashrafi B, Nazer M, Soroush S, Abbasi N, Rashidipour M. The synergistic effect of hydroalcoholic extracts of Origanum vulgare, Hypericum perforatum and their active components carvacrol and hypericin against Staphylococcus aureus. Future Sci. 2019; 2019. Bibi Y, Nisa S, Chaudhary FM, Zia M. Antibacterial activity of Bangladesh J Pharmacol 2022; 17: 154-156 155 Figure 1: Antagonistic activity against vancomycin-resistant Enterococcus by dichloromethane (A), ethyl acetate extract of stem (B), and ethyl acetate extract of root (C) Table I Antibacterial efficacy of plant extracts (mg/mL) Extracts Inhibition zone (mm) Vancomycin-resistant Enterococcus E. faecalis Vancomycin (positive control) 50 75 100 50 75 100 (30 mg/disc) Stem 6 Dichloromethane - 10 12 12 15 18 Ethyl acetate 11 14 19 13.5 16 18 Butanol - - - - 11 15 Root Dichloromethane - 6 8.5 6 9 12 Ethyl acetate 10 12 13 15 19 22 Butanol - - - - - 12 Table II MIC of plant crude extracts (mg/mL) Organisms Stem Root Dichloromethane Ethyl acetate Dichloromethane Ethyl acetate Vancomycin-resistant Enterococcus 25 6.25 50 12.5 E. faecalis 3.12 3.12 25 1.56 Vancomycin 50 some selected medicinal plants of Pakistan. BMC Comple- ment Altern Med. 2011; 11: 52. Bokhari SS, Yasmeen R, Manzoor R, Rafi U, Qureshi AW. 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