Bangladesh Journal of Pharmacology Volume: 11; Number 4; Year 2016 Cite this article as: Chander MP, Vijayachari P. In vitro antibacterial and anti-oxidant potentials of selected sea- weeds of Andaman and Nicobar Islands, India. Bangladesh J Pharmacol. 2016; 11: 874-875. In vitro antibacterial and anti-oxidant potentials of selected seaweeds of Andaman and Nicobar Islands, India Sir, Seaweeds are primitive non-flowering plants without true root, stem and leaves. Seaweeds have been used as food stuff in Asian countries from centuries as it contains carotenoids, dietary fibers, proteins, vitamins and minerals. Red and brown algae are mainly used as human food sources (Chander et al., 2014). Seaweeds have some valuable medicinal components such as anticoagulants, anti-angiogenic and anti-adhesive acti- vities (Cumashi et al., 2007). Seaweeds have recently been received significant attention for their potential as natural anti-oxidants, anti-bacterial and cytotoxic properties (Patra et al., 2016, Rani et al., 2013). The prevention and treatment of infectious diseases by marine seaweeds appears to be a possible alternative resource. Andaman Islands marine ecosystem is unique, isolated and understudied compared to other marine eco- systems, may have potential of rich source of anti- microbial compounds. Therefore, it was worthwhile to investigate the antibacterial and anti-oxidant properties of seaweeds against human pathogenic bacteria that often cause of infectious diseases in human beings. The seaweeds were separately dried under shade, pulverized by a mechanical grinder. Hundred grams of coarsely powdered dry leaves were extracted by cold percolation method, by using 1000 mL 95% methanol as a solvent and keeping it for 72 hours at room temperature. The whole seaweed extract was collected in a conical flask, filtered, and the solvent was evapora- ted to dryness under reduced pressure in an evaporator at 40-45°C. Resulted residues were stored at 4°C for further use (Chander et al., 2014). The seaweed extracts were screened for their ability to scavenging 2,2-diphenyl-1-picrylhydrazyl stable radi- cals (DPPH) by using the method described previously (Singh et al., 2015). The seaweed extracts were screened for antibacterial activity using the agar well diffusion method (Chander et al., 2016). The effect of anti-oxidant on DPPH radical scavenging was thought to be due to their hydrogen donating ability or radical scavenging activity. The free radical scavenging activity depends upon the chemical composition of extracts (Nilgun et al., 2007). The DPPH radical scavenging results showed that S. swartzi exhibited highest activity having IC50 value 73.2 ± 0.6 µg/mL followed by T. ornate and H. opuntia (Table I). The antimicrobial activities of the investigated extracts against human pathogens used by agar well diffusion method were shown in Table II. Results obtained in the current study relieved that selected seaweed extracts were found to possess potential antimicrobial activity against tested organisms. The G. corticata extract showed activity against seven pathogens tested followed by S. natans and P. tetrastromatica while the highest activity (22.7 ± 1.5) was shown by G. corticata against S. aureus. In the present study, seaweeds were found to possess antibacterial and anti-oxidant properties against human pathogens. The species G. corticata, S. natans and P. tetrastromatica were found to be very effective. These A Journal of the Bangladesh Pharmacological Society (BDPS) Bangladesh J Pharmacol 2016; 11: 874-875 Journal homepage: www.banglajol.info Abstracted/indexed in Academic Search Complete, Agroforestry Abstracts, Asia Journals Online, Bangladesh Journals Online, Biological Abstracts, BIOSIS Previews, CAB Abstracts, Current Abstracts, EMBASE/Excerpta Medica, 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.v11i4.29094 Letter to the Editor Table I Details of seaweeds and their anti-oxidant properties Name of the seaweed Family Place of collection (GPS Location) Anti-oxidant IC50 (µg/mL) Gracilaria corticata Gracilariaceae Wandoor N 11°36'0.83" E 92°36'45.39" 276.8 ± 6.3 Halimeda opuntia Halimedaceae Wandoor N 11°36'8.04" E 92°36'41.76" 99.8 ± 0.4 Padina tetrastromatica Dictyotaceae Little Andaman N 10°34'8.45" E 92°33'43.29" 349.8 ± 5.8 Sargassum natans Sargassaceae Pongibalu N 11°37'15.20" E 92°36'45.79" 357.3 ± 7.8 Sargassum swartzii Sargassaceae Little Andaman N 10°39'8.25" E 92°34'9.78" 73.2 ± 0.6 Turbinaria ornate Sargassaceae Pongibalu N 11°37'7.20" E 92°37'15.92" 99.7 ± 2.0 http://www.bioxbio.com/if/html/BANGL-J-PHARMACOL.html organisms need to investigate in detail, in order to isolate biologically active molecules and thus paving the way to search for novel compounds. Furthermore, the encouraging biological activity observed in this study show that the Andaman and Nicobar Islands are potential source of variety of marine organisms worthy of further investigation. The authors acknowledge to the Indian Council of Medical Research, New Delhi, India for providing financial grant for the study (Project No. Tribal/43/2008-ECD-II). Authors are also thankful to the Department of Ocean Studies and Marine Biology, Port Blair and Zoological Survey of India, Port Blair for their help in collection and identification of seaweed specimens M. Punnam Chander and P. Vijayachari Department of Medical Microbiology and Molecular Biology, Regional Medical Research Centre (Indian Council of Medical Research), Port Blair 744-101, Andaman and Nicobar Islands, India. Corresponding author: email: pblicmr@sancharnet.in References Chander MP, Pillai CR, Sunish IP, Vijayachari P. Antimicrobial and antimalarial properties of medicinal plants used by the indigenous tribes of Andaman and Nicobar Islands. Microb Pathog. 2016; 96: 85-88. Chander MP, Sachithanandam V, Vijayachari. Antimicrobial and haemolytic activity of seaweed Padina gymnospora from South Andaman, Andaman and Nicobar Islands of India. Int J Curr Microbiol Appl Sci. 2014; 3: 364-69. Cumashi A, Ushakova NA, Preobrazhenskaya ME, et al. A comparative study of the anti-inflammatory, anticoagulant, antiangiogenic, and antiadhesive activities of nine different fucoidans from brown seaweeds. Glycobiology 2007; 17: 541 -52. Nilgun GB, Gulcin O, Samin Y. Evaluation of the antiradical and anti-oxidant potential of grape extracts. Food Control. 2007; 18: 1131–36. Patra JK, Lee SW, Park JG, Baek KH. Anti-oxidant and anti- bacterial properties of essential oil extracted from an edible seaweed Undaria pinnatifida. J Food Biochem. 2016; doi: 10.1111/jfbc.12278 Rani RJ, Sundar SK, Parthipan B, Antonisamy JM. In vitro cytotoxicity studies on selected seaweeds from South East Coast of India. Indo-Am J Pharm Res. 2013; 3: 3183-91. Rattaya S, Benjakul S, Prodpran T. Extraction, antioxidative, and antimicrobial activities of brown seaweed extracts, Turbinaria ornate and Sargassum polycystum, grown in Thailand. Int Aquat Res. 2015; 7: 1–16. Singh R, Muftah AMS, Asma B. Antibacterial and anti-oxidant activity of Mentha piperita L. Arabian J Chem. 2015; 8: 322-28. 875 Bangladesh J Pharmacol 2016; 11: 874-875 Table II Antibacterial activity of methanol crude extracts of seaweeds Microorganisms G. corticata H. opuntia P. tetrastromatica S. natans S. swartzi T. ornate S. aureus 22.7 ± 1.5 - 12.7 ± 0.6 - - - B. cereus 18.3 ± 0.6 10.7 ± 0.6 13.3 ± 1.5 21.3 ± 0.6 - 10.7 ± 0.6 P. aeruginosa - - - 13.3 ± 1.5 - - K. pneumonia 14.0 ± 1.0 10.7 ± 0.6 - - 13.7 ± 1.2 - E. coli 13.7 ± 2.1 - 11.3 ± 1.5 14.7 ± 1.2 15.7 ± 1.2 - S. flexeneri 12.3 ± 0.6 - 11.3 ± 1.5 13.3 ± 2.1 - 13.7 ± 0.6 S. typhi 10.3 ± 1.5 - - - 13.7 ± 1.2 - S. epidermidis 16.7 ± 1.2 11.7 ± 0.6 - - - - P. mirabilis - - - - - - mailto:pblicmr@sancharnet.in Table I: Microorganisms G corticata H opuntia P tetrastromatica S natans S swartzi T ornate: DatePrinted: This article was downloaded by you on: Oct 24, 2016