Different extracts (based on the polarity) of Lantana camara were tested against local clinical isolates of bacterial strains using disc diffusion method. All the extracts prepared from the leaves of Lantana camara have been found to inhibit the growth of bacterial strains. Ethanolic extracts of the leaves were moderately active while the other extracts of leaves exhibited little. The good experimental results obtained justify the folk use of this plant species as a bactericidal.
KEYWORDS: Lantana camara ,ethanolic extracts, antibacterial screening
Lantana camara Linn. family Verbenaceae, commonly known as wild sage, is a flowering shrub native of tropical America and is cultivated through out the world as an ornamental (Sharma and Sharma, 1989). Different parts of the plant are used in folklore remedies and traditional systems of medicine for the treatment of various human ailments. Over the last twenty-five years a large number of plant species have been evaluated for their antibacterial activity. One of the plants known for having many medicinal uses in traditional system of medicine is Lantana camara (Juliana et al., 2002). The leaves are used in the treatment of itches, cuts, ulcers, swellings, bilious fever,eczema and rheumatism. Lantana camara has received attention due to its role in economy and ecology. It is serious weed in several countries that causes toxicity in grazing animals and is rapidly disturbing the ecological balance due to its luxuriant growth (Sharma et al., 1988). Many pharmacological investigations indicated that extracts of the leaves of Lantana camara exhibit antibacterial properties. In the light of the medicinal properties attributed to Lantana camara, the present studies were to evaluate the antibacterial screening of several extracts of the leaves of Lantana camara against the local clinical isolated bacterial strains.
MATERIALSAND METHODS
Plant Material
Fresh leaves of Lantana camara were collected in February 2012, near the bank of river Betwa, Vidisha (M. P., India). Voucher specimen of the plant was deposited in the herbarium of Department of Botany, St. Mary's P. G. College, Vidisha, M. P., India.
Preparation of Extracts
The leaves of the plants were air dried at room temperature before grinding them to powdered form with the help of mechanical grinder. Several solvents of different polarity i. e. Benzene, Hexane, Petroleum ether (40-60 [degrees]C), Chloroform, Ethanol and Ethyl acetate were used respectively to get extracts of the previously dried and powered leaves. The powdered leaves were extracted by soxhlet apparatus (Harborne, 1984). Each extract was first filtered through Whatman No. 1 filter paper to clarify and then through a 0.45 [micro]m membrane filter. The filtrate was evaporated under reduced pressure in vacuum evaporator. The dried crude extracts were sterilized overnight by UV radiation and then stored at room temperature in amber color glass vials until used for antibacterial testing.
Preparation of Concentrations
In the study of the antibacterial activity, all the extracts were diluted in dimethylsulfoxide (DMSO). The concentrations corresponding to the extracts given in Table1 are expressed in terms of mg/ml.
Table 1: Antibacterial activity of various extracts of Lantana camara leaves Extract Conc. Diameter of Extract Conc. (mg / zones of (mg / ml) inhibition ml) (mm) (a) 1 (b) 2 3 Benzene extract 80 10 8 7 Chloroform 80 extract 40 9 7 6 40 20 7 5 5 20 10 6 4 4 10 Hexane extract 80 12 8 8 Ethanolic 80 extract 40 10 7 7 40 20 9 6 6 20 10 8 5 5 10 Petroleum ether 80 13 9 11 Ethyl 80 extract acetate extract 40 12 8 10 40 20 11 7 9 20 10 10 5 8 10 Chloramphenicol -- 29 27 30 DMSO -- (c) (d) Extract Diameter of zones of inhibition (mm) (a) 1 (b) 2 3 Benzene extract 15 12 13 14 11 11 12 9 10 12 8 9 Hexane extract 19 15 13 17 13 12 16 12 10 14 10 8 Petroleum ether 17 12 11 extract 16 11 9 15 9 8 13 8 7 Chloramphenicol -- -- -- (a) Each value is mean of three replicates. (b) 1, Staphylococcus aureus; 2. Escherichia coli; 3. Pseudomonas aeruginosa (c )Chloramphenicol (30 [micro]g / disc) (d) -- No zone of inhibition.
Test Bacterial Strains
The following bacterial strains were used as test organisms: Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. All the bacterial strains were obtained from Department of Microbiology, Gandhi Medical College, Bhopal, M. P., India.
Screening of Extracts forAntibacterial Activity
The antibacterial effects were tested by the disc diffusion method (Bauer et al., 1966). Firstly the bacteria to be tested were inoculated into Mueller Hinton broth (HiMedia) and incubated for 3-6 hours at 35 [degrees]C. Petri dishes containing Mueller Hinton Agar (HiMedia) were impregnated with these bacterial suspensions.Discs of 6 mm diameter (Sterile blank, HiMedia) were impregnated with different concentration of each extracts. Blank disc impregnated with DMSO was used as negative control and disc of chloramphenicol (10 [micro]g / disc, HiMedia) as positive control. All test plates were incubated at 37 [degrees]C for 24 hour and the diameter of zones of inhibition were measured.
RESULTS
The inhibitory effects of the different extracts from Lantana camara on the five bacterial strains in Mueller Hinton agar are shown in Table 1. Inhibition zones were measured in mm at 24 hour after incubation. Chloramphenicol and DMSO were used as appropriate controls. The results indicated that the most sensitive organisms were Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli shown in Photoplate No. 1, 2 and 3. DMSO showed no activity against any of the bacterial strains tested, while the Chloramphenicol showed the activity of all the tested strains.
DISCUSSION AND CONCLUSIONS
The antibacterial activity of the Lantana camara extracts varied with the solvents used for the extraction. It is suggested that the Crude preparations of the leaves of the plant containing both the active and non-active components to have higher efficacy than semi-crude or pure plant substances (Kafaru, 1994). The wide variety of activity of the ethanolic extracts over the water extracts is significant because of the leaves of plants are of traditional uses. The antibacterial activity is passively because of the presence of secondary metabolites existed in the plant. Hence, it is difficult to explain the limited spectrum of activity of other extracts compared with the ethanolic extracts since all the extracts had had the secondary metabolites (Begum et al., 1995). Although in unlike proportion provably antithesis may be resolved when the active constituents have been isolated and the activity of the purified component determined. In that phase, the interaction between active and non-active components may expose light onto the various activities of the varied extracts.
ACKNOWLEDGEMENTS
The authors are very thankful to the Principal of St. Mary's P. G. College, Vidisha and Govt. S. N. G. College, Bhopal, M. P., India, for giving laboratory facilities, and Dr. S. P. Garg, Ex. Dean, Department of Chemistry, Jodhpur University, Jodhpur, Rajasthan, India for giving the valuable suggestions.
REFERENCES
Bauer R. W., Kirby M. D. K., Sherris J. C. and Turck M., 1966. Antibiotic susceptibility testing by standard single disc diffusion method. Am. J. Cl. Pathol., 45: 493-496.
Begum S., Raza S. M., Siddiqui B. S. and Siddiqui S., 1995. Triterpenoids from the aerial parts of Lantana camara. Jour. Of Natural Products, 58 (10):1570-1574.
Harborne J. B., 1984. Phytocemical Methods.A Guide to Modern Technique of Plant analysis. II edition, Chapman and Hall, NewYork: 1-228.
Juliania H. R. Jr., Biurrun F., Koroch A. R., Oliva M. M., Demo M. S., Trippi V. S. and Zygadlo J. A., 2002. Chemical constituents and antimicrobial activity of the essential oil of Lantana xenica. Plant Medica, 68:759-762.
Kafaru E., 1994. Immense Help from Nature's workshop. Elikat Health Services, Lagos: 31-210.
Sharma O. P. and Sharma P. D., 1989. Natural products of the Lantana plant: The present and prospects. J. Sci. Ind. Res., 48:471-478.
Sharma O. P., Makkar H. P. and Dawra R. K., 1988. Areview of the noxious plant Lantana camara. Toxicon, 26:975-987.
MILIN K. AGRAWAL (a), (1), ALKA VARMA (b) AND SURENDRA GOYAL (c) (a) Department of Botany, St. Mary's P. G. College, Vidisha, M. P., India E-mail: drmilin_agrawal@yahoo.com
(a) Department of Botany, Govt. Sarojini Naido Girls College, Bhopal, M. P., India E-mail: alok_varma43@yahoo.com
(a) Department of Sericulture, Resham Project, Seronj, Vidisha, M. P., India E-mail: goyal_surendra72@yahoo.com