Bangladesh Journal of Pharmacology Volume: 13; Number 2; Year 2018 Cite this article as: Mathayan M, Sundar R, Anbarasu S. Antimycobacterial activity of marine Sargassum swartzii extracts against Mycobacterium tuberculosis. Bangladesh J Pharmacol. 2018; 13: 130-31. Antimycobacterial activity of marine Sargassum swartzii extracts against Myco- bacterium tuberculosis Sir, According to World Health Organization report (WHO), about 10.4 million people have fallen ill with tuberculosis out of which around 1.7 million people have died from the disease in the year 2016 (WHO Global Tuberculosis Report, 2017). Tuberculosis possess -es a serious problem around the world by way of increase in the rate of drug-resistant tuberculosis. The increased prevalence of drug-resistant strains and side effects associated with the current anti-tubercular drugs makes the treatment options more complicated. Hence, there is an urgent need to identify novel active compounds with lesser or no toxicity/side effects to fight against the various sub-populations of Myco- bacterium tuberculosis. Marine organisms are now being recognized as a rich source of polyunsaturated fatty acids (PUFA), polysaccharides, natural pigments (NPs), enzymes and bioactive peptides (Senthilkumar and Kim, 2013). Sargassum, a marine brown algae have been reported for its various biological activity (Dore et al., 2013; Song et al., 2016). Numerous studies have been under- taken for purification and characterization of sulfated polysaccharides derived from brown algae Sargassum sp. Such sulfated polysaccharides exhibit anti-viral, immunomodulatory, anti-oxidant, antitumor, anti- inflammatory, anti-angiogenic, anticoagulant and anti- vasculogenic activities (Yende et al., 2014). In India, Sargassum is commonly distributed along the shore of Gulf of Mannar, Pamban, East Coast region and other seashores. Our present study reports the antimycobacterial activity of Sargassum swartzii against the whole cell M. tuberculosis H37Rv by luciferase reporter phage (LRP) assay. Sargassum swartzii was collected from Mandabam (Gulf of Mannar), Tamil Nadu, India and it was cleaned with seawater to remove impurities. Then it was transported to the laboratory in sterile polythene bags. In the laboratory, seaweeds were rinsed thoroughly with tap water followed with distilled water and then shade dried. After drying, seaweeds were cut into small pieces and powdered by using mixer grinder. Different organic solvents such as methanol, ethyl acetate, chloro- form, petroleum ether, hexane and aqueous (distilled water) were used for extraction of active compounds. Briefly, about 100 g of each seaweed powder was soaked in 500 mL of different solvents separately. After 24 hours, the extracts were filtered and concentrated using a rotary evaporator. After evaporation, the crude extracts were weighed and suspended in the 10% dimethyl sulfoxide at a final concentration of 100 mg/ mL. All the extracts were stored at 4°C. The anti- mycobacterial activity of different solvent crude extracts of S. swartzii was tested against M. tuberculosis H37Rv at a concentration of 500 µg/mL by adopting LRP assay (Radhakrishnan et al., 2016). The relative light unit (RLU) was measured immediately at 10 sec integration time in a luminometer (Lumat 9508, Berthold, Germany). Extracts showing more than 50% RLU reduction was considered as inhibition. The percentage of reduction was calculated by using following formula: control RLU – test RLU / control RLU × 100. A Journal of the Bangladesh Pharmacological Society (BDPS) Bangladesh J Pharmacol 2018; 13: 130-31 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, 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.v13i2.35642 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 Antimycobacterial activity of crude extracts against Mycobacterium tuberculosis H37Rv Crude extracts Concentration %Inhibition Result Methanol extract 500 µg/mL 86.8 Inhibition Ethyl acetate extract 500 µg/mL 57.0 Inhibition n-Hexane extract 500 µg/mL 25.5 No inhibition Chloroform extract 500 µg/mL 70.8 Inhibition Water extract 500 µg/mL 67.2 Inhibition Antimycobacterial activities of different solvent crude extracts of S. swartzii were reported in Table I. Among the extracts tested, the methanol extract, ethyl acetate, chloroform extract and aqueous extract showed inhibi- tion at 500 µg/mL concentration against Mycobacterium tuberculosis H37Rv whereas, n-hexane showed no inhibition against the strain tested. In conclusion, the S. swartzi extracts inhibited the whole cell M. tuberculosis H37Rv and findings from this study would pave way for developing a newer antimycobac- terial lead compound. Further studies are required to be carried out with these extracts of S. swartzii to develop a novel anti-tubercular drug in future. The authors thank the management of Sathyabama Institute of Science and Technology, Chennai for support in research activities. Manikannan Mathayan, Revathy Sundar, Siva- raj Anbarasu Center for Drug discovery and Development, Sathyabama Institute of Science and Technology, Jeppiaar Nagar, Rajiv Gandhi Road, Chennai 600 119, Tamil Nadu, India. Corresponding author: email: anbuaras18@gmail.com References Dore CM, das CFAMG, Will LS, Costa TG, Sabr DA, de Souza Rego LA, Accardo CM, Rocha HA, Filgueira LG and Leite EL. A sulfated polysaccharide, fucans, isolated from brown algae Sargassum vulgare with anticoagulant, antithrombotic, antioxidant and anti-inflammatory effects. Carbohydr Polym. 2013; 91: 467-75. Global Tuberculosis Report. 2017. World Health Organization. Radhakrishnan M, Sekar P, Jerrine J, Vanaja K. Anti-tubercular activity of pigment from forest soil Streptomyces sp SFA5. Bangladesh J Pharmacol. 2016; 11: 138-40. Senthilkumar K, Kim SK. Marine invertebrate natural products for anti-inflammatory and chronic diseases. Evid Based Complement Alternat Med. 2013; 2013: 572859. Song L, Chen X, Liu X, Zhang F, Hu L, Yue Y, Li P. Characte- rization and comparison of the structural features, immuno- modulatory and anti-avian influenza virus activities conferred by three algal sulfated polysaccharides. Marine Drugs. 2016; 14: 4. Yende SR, Harle UN, Chaugule BB. Therapeutic potential and health benefits of Sargassum species. Pharmacogn Rev. 2014; 8: 1-7. Bangladesh J Pharmacol 2018; 13: 130-131 131 mailto:anbuaras18@gmail.com DatePrinted: This article was downloaded by you on: Apr 14, 2018