Bangladesh Journal of Pharmacology Volume: 18; Number 4; Year 2023 Cite this article as: Segaran G, Hannah CC, Sathiavelu M. Antibacterial activity of Calathea roseopicta. Bangladesh J Pharmacol. 2023; 18: 162-63. Antibacterial activity of Calathea roseopicta Sir, Calathea roseopicta, also known as the rose-painted calathea, is a member of the Marantaceae plant family and is native to northwest Brazil. It is a perennial and grows in bunches. The large, rounded leaves are scarlet below and dark green above. The margins are feathery, and the veins and midrib are beautifully "painted" with cream or pink stripes. C. roseopicta hybrids are distin- guished by their feathery border pattern as well as potentially unique leaf shapes, patterns, and colors. The antibacterial effects of other plants of this family, Calathea anulque (Segaran et al., 2023) and Calathea insignis (Shankar et al., 2023) have been reported. The objective of this study is to assess the antibacterial activity of C. roseopicta utilizing the agar well diffusion method (Shankar and Sathiavelu, 2021). Fresh and healthy leaves from C. roseopicta were collec- ted from the Thota Kalai nursery garden in Chennai, Tamil Nadu, India. To remove dust and unwanted particles, the leaves were washed twice with tap water before being allowed to air dry for two weeks. Using an electric blender, the dried leaves were made into a fine powder. Solvents with different polarities, such as methanol and ethyl acetate, were used to extract the metabolites. About 0.5 g of dry leaf powder was soaked in 100 mL of each solvent in a 250 mL conical flask and kept in a shaker incubator for 48 hours at 120 rpm. After 48 hours, the contents were filtered through a Whatman filter paper No. 1 to obtain concentrated methanolic and ethyl acetate extracts. A rotary vacuum evaporator was employed to collect crude extracts. The agar-well diffusion method was performed to assess the antibacterial activity of the leaf’s crude extracts against pathogenic organisms such as Staphylococcus aureus, Streptococcus pneumonia, Klebsiella pneumonia, and Escherichia coli. The stock culture was prepared with nutrient broth, and the test plates were prepared using Muller-Hinton agar for anti-bacterial assay. The sterile cork borer of 8mm was used to create the wells after the suspended organisms were inoculated into the agar plates. The 100 µL extract was loaded into the wells at various concentrations (100, 50, and 25 µg/mL). Streptomycin disc (antibiotics) was used as a positive control. Then the plates were kept for incubation at 37°C for 24 hours. After the incubation period, the zone of inhibition was measured around the well (Abew et al., 2014). The phytochemical constituents of the C. roseopicta leaf extracts, when analyzed, confirmed the presence of phenol, flavonoids, tannins, terpenoids, and saponins. About 2 mL of a 2% ferric chloride solution was added to the plant extract. The presence of phenol is confirm- ed by the appearance of color changes from blue-green to black (Kancherla et al., 2019). The plant extract was treated with 2 mL of a 2% sodium hydroxide solution. After adding diluted acid, the dramatic color change from yellow to colorless indicates the presence of flavonoids (Hossain et al., 2013). The plant extract was heated in addition to 2 mL of concentrated sulfuric acid. The presence of terpenoids is confirmed by the deve- lopment of gray color. The test tube containing the plant extract with 5 mL of distilled water was shaken vigorously to analyze the presence of saponins (Hossain et al., 2013). This is the first investigation into the phytochemical content and antibacterial activity of C. roseopicta leaves. A qualitative phytochemical analysis was conducted on both crude extracts to determine the existence of the plant's active ingredients. The phytochemical analysis showed the presence of saponins and terpenoids in the leaves, whereas tannins, flavonoids, and phenol showed negative results (Table I). The highest inhibition zone of 25 mm was found for ethyl acetate extract against S. aureus at a 50 µg/mL concentration. A similar inhibition of 25 mm was observed in S. aureus and E. coli for methanol extract at 100 µg/mL (Table II). The growth of K. pneumonia and S. pneumonia was not suppressed by the extracts. Previous reports demonstrated that aqueous and etha- nolic extracts from hibiscus flowers strongly inhibited A Journal of the Bangladesh Pharmacological Society (BDPS) Bangladesh J Pharmacol 2023; 18: 162-163 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.v18i4.68145 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 Table I Phytochemical screening Phytochemicals Methanol Ethyl acetate Tannins - - Terpenoids ++ + Flavonoid - - Phenol - - Saponin + + the development of S. typhimurium and S. aureus at 100 and 50 mg/mL concentrations, respectively (Mak et al., 2012). The study showed that terpenoids were present and that they were effective at killing Bacillus subtilis with a clear zone of inhibition (Gebrewbet et al., 2023). Sym- phonia globulifera and Allophyllus abyssinicus had terpe- noids in all concentrations of water extract and were more effective at killing Gram-positive bacteria (Luku- bye et al., 2022). The ethanolic extract of Acacia nilotica demonstrated antibacterial activity against all test orga- nisms in the presence of terpenoids (Banso, 2009). Ipomoea asarifolia showed positive terpenoids and higher antibacterial activity in an aqueous extract against E. coli (Aliyu et al., 2011). C. analque has potent antibacterial properties against S. aureus. Its methanol and ethyl acetate extracts have terpenoids and saponins (Segaran et al., 2023). C. insignis contains phenols, saponins, and tannins and has effective antibacterial properties against E. coli and S. aureus (Shankar et al., 2023). Similarly, C. roseopicta from the genus Calathea demonstrated prominent antibacterial activity against tested bacterial pathogens. Financial support: Vellore Institute of Technology (SG ID: SG20220100) Ethical issue: The protocol of the study was approved by the Institutional Ethical Committee Conflict of interest: The authors declare that they have no conflict of interest Acknowledgment: The authors thank Vellore Institute of Technology, Vellore for providing a VIT seed grant for carrying out this research Gayathri Segaran, Charlet C. Hannah and Mythili Sathiavelu School of Bioscience and Technology, Vellore Institute of Technology, Tamil Nadu, India. Corresponding author: email: smythili@vit.ac.in References Abew B, Sahile S, Moges F. In vitro antibacterial activity of leaf extracts of Zehneria scabra and Ricinus communis against Escherichia coli and methicillin resistance Staphylococcus aureus. Asian Pac J Trop Biomed. 2014; 4: 816-20. Aliyu MS, Lawal U, Tijjani MB, Doko MHI, Garba I, Kokya HA, Ado S. A, Hanwa UA, Ibrahim MM. Phytochemical and antibacterial properties of leaf extracts of Ipomoea asarifolia. Nig J Basic Appl Sci. 2011; 19: 236-40. Banso AJ. Phytochemical and antibacterial investigation of bark extracts of Acacia nilotica. J Med Plant Res. 2009; 3: 82- 85. Gebrewbet GH, Hndeya AG. Phytochemical screening and antibacterial activity studies of crude leaf extract of Solanum sisymbriifolium: Traditional Ethiopian medicinal plant. Adv Gut Microb Res. 2023; 2023. Hossain MA, Raqmi KA, AL-Mijizy ZH, Weli AM, AlRiyami Q. Study of total phenol, flavonoids contents and phytoche- mical screening of various leaves crude extracts of locally grown Thymus vulgaris. Asian Pac J Trop Biomed. 2013; 3: 705-10. Kancherla N, Dhakshinamoothi A, Chitra K, Komaram RB. Preliminary analysis of phytoconstituents and evaluation of anthelminthic property of Cayratia auriculata (in vitro). Maedica (Bucur). 2019; 14: 350-56. Lukubye B, Ajayi CO, Wangalwa R, Rugunda GK. Phyto- chemical profile and antimicrobial activity of the leaves and bark extract of Symphonia globulifera L.f. and Allophylus abyssinicus (Hochst) Radlk. BMC Complement. Med. 2022; 22: 223. Mak YW, Chuah LO, Ahmad R, Bhat R. Antioxidant and antibacterial activities of hibiscus (Hibiscus rosa-sinensis L.) and Cassia (Senna bicapsularis L.) flower extracts. J King Saud Univ Sci. 2013; 25: 275-82. Segaran G, Srinivasan C, Sathiavelu M. Antibacterial activity of Calathea anulque. Bangladesh J Pharmacol. 2023; 18: 77-78. Shankar S, Ravi ND, Sathiavelu M. Antibacterial activity of Calathea insignis. Bangladesh J Pharmacol. 2023; 18: 75-76. Shankar S, Sathiavelu M. Antibacterial activity of Dracaena lisa. Bangladesh J Pharmacol. 2021; 16: 84-86. Bangladesh J Pharmacol 2023; 18: 162-163 163 Table II Antibacterial activity of Calathea roseopicta leaves extracts Extracts Concentration (µg/mL) Zone of inhibition (mm) Staphylococcus aureus Klebsiella pneumoniae Escherichia coli Streptococcus pneumoniae Methanol 25 - - 15 - 50 20 - 23 - 100 23 - 25 - Ethyl acetate 25 - - - - 50 - - - - 100 25 - - - Streptomycin 10 mg disc 11 28 25 25 mailto:mohanrajupu62@gmail.com mailto:smythili@vit.ac.in