International Research Journal of Environment Sciences________________________________ ISSN 2319–1414Vol. 2(4), 48-49, April (2013) Int. Res. J. Environment Sci. International Science Congress Association 48 Short Communication Antimicrobial and Cytotoxic Activities of the Crude Extracts of Callistemon linearis available in South East region of Bangladesh Khan M. Shaiful Islam, Chowdhury Mahedy Hasan, Saha Partha**, Haque S.M. Estiar Department of Applied Chemistry and Chemical Engineering, University of Dhaka, Dhaka-1000, BANGLADESHAvailable online at: www.isca.in Received 27th February 2013, revised 3rd March 2013, accepted 11th April 2013 AbstractThe extracts (n-hexane and chloroform crude extracts) of Callistemon linearis (Family-Myrtaceae) were subjected to antimicrobial screening and brine shrimp lethality bioassay. In case of antimicrobial screening, the n-hexane, and chloroform crude extracts exhibited very prominent antimicrobial activity against most of the test organisms while from the results of the brine shrimp lethality bioassay, it can be well predicted that the n-hexane extract showed highly cytotoxic potency due to 100% mortality over whole concentration range in which cytotoxicity screening was done whereas chloroform crude extract showed moderate cytotoxic potency with LC90 of 30.90 g/mL. Keywords: Antimicrobial activity, Callistemon linearis, Disk diffusion technique, n-hexane extract.Introduction Callistemon linearis (Bengali name- Brushful; Family- Myrtaceae) is a beautiful evergreen shrubs and small trees with 34 species. They are commonly known as bottle brushes because of their cylindrical brush like flowers resembling a traditional bottle brush. They are found in the more temperate regions of Australia and seven species of callistemon have been introduced in India as an ornamental tree1. Previous Phytochemical studies of different callistemon species revealed that the presence of different monoterpenes, sesquiterpenes, flavonoids. There are several reports of the oil exhibiting fungi toxicity, inhibiting the growth of cowpea mosaic virus, mungbean mosaic virus2. The leaf extracts of plant contain carbohydrate, glycoside, flavonoids, saponin, phytosterol, phenolic compounds and volatile oil of leaf contains 4 component namely n-Dec-3-ene,3-carene,1,8-cineol,gamaterpinine3. Material and Methods Collection and preparation of plant material: Fresh leaves of Callistemon linearis was collected from Chittagong B.C.S.I.R. A voucher specimen has been deposited in the Bangladesh National Herbarium, Dhaka (DACB -33560) for the collection. The air-dried and powdered leaves were successively extracted with n-hexane (15 days) and chloroform (15 days) through cold extraction process accompanying occasional shaking and stirring. After filtration of the extracts through fresh Whatman No.1 filter paper, the filtrates were then concentrated at 50 C by a rotary evaporator and afforded n-hexane extract (16.11g), and chloroform extracts (22.56g). Anti Microbial and cytotoxicity screening: The antimicrobial activity of the crude extracts was determined by the disc diffusion method4-6 against the microbial strains listed in table 1. These were collected as pure cultures from the Institute of Nutrition and Food Science (INFS), University of Dhaka, Bangladesh. Here, Kanamycin (30 g/disc) was used as the standard. The n-hexane and chloroform extracts were dissolved separately in chloroform and applied to sterile discs at a concentration of 500g/disc and carefully dried to evaporate the residual solvent. The zone of inhibition (mm) and LC90 (µg/mL) were calculated for the antimicrobial screening and brine shrimp lethality bioassay respectively. For cytotoxicity screening, DMSO solutions of the n-hexane and chloroform extracts were applied against Artemia salina 7in a 1-day in vivo assay. For the experiment, 4 mg of each of the n-hexane and chloroform extracts were dissolved in DMSO and solutions of varying concentrations (400, 200, 100, 50, 25, 12.50, 6.25, 3.125, 1.563, 0.781 g/mL) were obtained by serial dilution technique for each extract. Following the procedure of Meyer7-9 the lethality of the n-hexane and chloroform extracts to brine shrimp were evaluated on A. salina after 24 hours of exposure the samples and the positive control, vincristine sulphate (VS). Results and Discussion The zones of inhibition produced by n-hexane and chloroform extracts were found to be 28 – 34 mm and 24-28 mm respectively at a concentration of 500g/disc. The n-hexane extract was screened against 8 test bacteria and 2 fungi. This extract showed high activity against the test bacteria International Research Journal of Environment Sciences______________________________________________ ISSN 2319–1414 Vol. 2(4), 48-49, April (2013) Int. Res. J. Environment Sci. International Science Congress Association 49 Bacillus subtilis, Bacillus cereus, s.aureus, E.coli, Salmonella typhi, Shigella boydii, Vibrio mimicus and thefungi C. albicans, Aspergillus niger. The chloroform extract was also screened against 8 test bacteria and 2 fungi. This fraction showed high activity against the test bacteria Bacillus subtilis,Bacillus cereus, Bacillus megaterium, S.aureus, E.coli, Salmonella typhi, Shigella boydii, Vibrio mimicus and the fungi C. albicans, Aspergillus niger. Table-1 Antimicrobial activity of C.linearis extracts (500 µg/disc) and Kanamycin (30 µg/disc) Test microorganisms Diameter of zone of inhibition (mm) HE CE KAN Gram Positive Bacillus cereus B. megaterium B. subtilis Staphylococcus aureus 33 30 28 28 26 24 26 24 39 32 20 22 Gram Negative Escherichia coli S. typhi Shigella boydii Vibrio mimicus 31 31 31 30 28 24 25 28 23 20 26 24 Fungi Candida albicans Aspergillus niger34 31 25 24 24 32 HE: Hexane extract; CE: Chloroform extract; KAN: kanamycin. The LC50 could not be found for n-hexane (HE) and chloroform (CE) extracts from the graph of log of concentration of extracts versus percent mortality. Moreover even the LC90 could not be found for n-hexane (HE) due to 100% mortality over whole concentration range in which cytotoxicity screening was done. Comparison with positive control, vincristine sulfate (VS) signifies that cytotoxicity exhibited by the n-hexane is very much significant and it might have antitumor or pesticidal compounds. Conclusion Historically, medicinal plants have provided a source of inspiration for novel drug compounds, as plant derived medicines have made large contributions to human health and well being. On the basis of the result obtained in this present investigation and conclude that the n-hexane extract of Callistemon linearis had significant in vitro microbial activity and the most active extracts can be further subjected to isolation and identify therapeutic antimicrobials and undergo further pharmacological evaluation. Table-2 LC90 and LC50 data of C. linearis extracts and vincristine sulfate Samples LC 50 (µg/mL) VS 0.33 Samples LC 90 (µg/mL) CE 30.90 AcknowledgementsThe authors wish to thank the Bangladesh Council of Scientific and Industrial Research under Ministry of Science and Information and Communication Technology, Government of the Peoples' Republic of Bangladesh. References1.Kanjilal and Das, Flora of Assam, Omsons Publications, (2), 287 (1992)2.Aburjaj Talal and Hudaib Mohammad, Antiplatelet, antibacterial and antifungal activities of Achilleafalcata extracts and evaluation of volatile oil composition, Phcog. Mag: Research Article, (2), 191-198 (2006)3.Das Anudwipa, Zaman K. and Singh Akhilesh V., Phytochemical and Chemical composition evaluation of Volatile Oil of Callistemon linearis DC Leaf, Advances in Natural and Applied Sciences, 3(1), 56-59 (2009)4.Bauer A.W., Kirby W.M.M., Sherris J.C. and Turck M., Antibiotic susceptibility testing by a standardized single disc method, Am. J. Clin. Pathol. 45), 493-496 (1966)5.Gazi H.R., Kabir S, Rahman M.S., Chowdhury A.M.S., Begum B., and Rashid M.A., Antimicrobial and cytotoxic activities of the crude extracts of Hopea scaphula, Dhaka Univ. J. Pharm. Sci., 6(2), 131-133 (2007)6.Nahar K., Khan M.G.U., Rahman M.S., Begum B. and Rashid M.A., Antimicrobial and cytotoxic activities of Bryophyllum daigremontianum,Dhaka Univ. J. Pharm. Sci., 7(1), 99-101 (2008)7.Meyer B.N., Ferringni N.R., Puam J.E., Lacobsen L.B., Nichols D.E. and McLaughlin J.L., Brine shrimp: a convenient general bioassay for active constituents, Planta Medica., (45), 31-32 (1982)8.Kabir Humayun, Siddiqi M.M.A., Al-Mansur M.A., Sohrab M.H., Chowdhury A.M., Sarwaruddin and Choudhury M. Hasan, Phytochemical and Biological Investigations of Casuarina equisetifolia,The Dhaka University Journal of Science, 58(2),191-193 (2010)9.Mostafa Md. Faisal Kabir, Siddiqi M.M.A., Al-Mansur, Sohrab M.A., M.H., Chowdhury A.M., Sarwaruddin and Choudhury M. Hasan, Antimicrobial and Cytotoxic Activities of the Crude Extracts of Abroma augusta, The Dhaka University Journal of Science, 58(2), 199-200 (2010)10.Alagammal M., Paulpriya K. and Mohan V.R., Anticancer activity of Ethanol extract of Polygala javana DC whole Plant against Dalton Ascites Lymphoma, Res.J.Recent Sci., 2(2), 18-22 (2013)