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ANTIBACTERIAL AND ANTIOXIDANT ACTIVITY OF IMPERATA CYLINDRICA (L.) RAEUSCH

Authors:
  • Bharath institute of higher education and research
  • THIRUTHANGAL NADAR COLLEGE

Abstract and Figures

Medicinal plants constitute an important natural wealth of a country. They play a significant role in providing primary health care services to rural people and serve as therapeutic agents as well as important raw materials for the manufacturing of traditional and modern medicine. Medicinal plants are rich sources of antimicrobial agents. The plant selected for the present study Imperata cylindrica (L.) Raeusche, is a rhizomatous grass and used as traditional medicine in different cultures of Southeast Asia for the treatment of a wide range of infections. The present study aims to determine the antibacterial and antioxidant activities of whole plant extract of I. cylindrica. The aqueous, chloroform, petroleum ether, ethanol and methanol whole plant extracts of I. cylindrica were evaluated against the pathogens (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa and Proteus vulgaris) by disc diffusion method and also their antioxidant potential was studied using ORAC assay. The antibacterial studies revealed that the methanolic extract of I. cylindrica showed high inhibitory effects than the other solvent extracts. In similar way ORAC assay of I. cylindrica showed high radical scavenging activity. A marked antibacterial and antioxidant activity of methanol extracts was observed which may be attributed to the presence of phenolic compounds and other phytochemicals. The plants can be used to control infectious diseases and oxidative damage.
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ANTIBACTERIAL AND ANTIOXIDANT
ACTIVITY OF IMPERATA CYLINDRICA (L.)
RAEUSCH
Sudha Ravi1, Kaleena. P. K1*, Babu. M1, Janaki. A1 and Velu. K1
1Department of Zoology, Presidency College (Autonomous), Chennai-05, Tamilnadu, India.
Abstract
Medicinal plants constitute an important natural wealth of a country. They play a significant role in
providing primary health care services to rural people and serve as therapeutic agents as well as important raw
materials for the manufacturing of traditional and modern medicine. Medicinal plants are rich sources of
antimicrobial agents. The plant selected for the present study Imperata cylindrica (L.) Raeusche, is a
rhizomatous grass and used as traditional medicine in different cultures of Southeast Asia for the treatment of a
wide range of infections. The present study aims to determine the antibacterial and antioxidant activities of whole
plant extract of I. cylindrica. The aqueous, chloroform, petroleum ether, ethanol and methanol whole plant
extracts of I. cylindrica were evaluated against the pathogens (Staphylococcus aureus, Bacillus cereus,
Bacillus subtilis, Pseudomonas aeruginosa and Proteus vulgaris) by disc diffusion method and also their
antioxidant potential was studied using ORAC assay. The antibacterial studies revealed that the methanolic
extract of I. cylindrica showed high inhibitory effects than the other solvent extracts. In similar way ORAC assay
of I. cylindrica showed high radical scavenging activity. A marked antibacterial and antioxidant activity of
methanol extracts was observed which may be attributed to the presence of phenolic compounds and other
phytochemicals. The plants can be used to control infectious diseases and oxidative damage.
Keywords: Imperata cylindrica, disc diffusion method and ORAC assay
INTRODUCTION
Cogon grass, Imperata cylindrica (L.) Raeusche, is a rhizomatous grass native to the Indomalayan and
Australasian realms. The rhizome-root part serves as traditional medicine in different cultures of Southeast Asia
for the treatment of a wide range of infections. The aerial part is a resilient fibre and serves as the most useful
construction material for thatched roofs in traditional houses. The flowers and roots are used for important
medicinal properties such as antibacterial, diuretic, skin softening (emollient), antipyretic (febrifuge), salivating
(sialagogue), anticoagulant (styptic) and soothing (tonic) activities (Townson, 1991). The roots are especially
effective in the treatment of blood urine (haematuria), vomiting of blood (haematemesis), nosebleed (epistaxis),
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dropsy (oedema), and jaundice (MacDonald, 2004). The leaves have been experimentally shown to have neuro-
protective (Yoon et al., 2006) and vasodilative effects (Matsunaga et al., 1994).
This grass is regarded as sacred and widely used in various religious sacrifices and rituals in India. It has
been mentioned in Rig and Atharvaveda (Madhihassan, 1987). The plant is abundant throughout the year in
many states of India. In Mizoram its propagation increases during summer after burning for slash-and-burn
(jhum) cultivation. To the Mizo people, the plant is commonly used as antimicrobial in dermal wound, ring-
worm, cholera, dysentery and diarrhoea. It is traditionally unique to the Mizo people as the roots are known to be
effective anthelmintic agents that can eliminate both tapeworm and roundworms from the intestine. The roots
may be crushed and juiced, or directly consumed for intestinal helminthiasis (Sawmliana, 2013; Lalthanpuii et
al., 2018). Imperata cylindrica is regarded as sthalavriksha (temple trees or sacred plants) in many temples in
Tamil Nadu and the locals used this plant parts for medicinal purpose. The leaves are used as sedative and roots
to treat diarrhoea (Gunasekaran and Balasubramanian, 2012). The pharmacognostical and pharmacological
properties remain unknown. It is therefore imperative to investigate its antibacterial and antioxidant properties.
MATERIALS AND METHODS
Collection of plant samples
Healthy, disease free plants of I. cylindrica were collected from the fields in Nathammedu village in
Tiruvallur district (near Chennai). The plant material was identified and authenticated based on the morphology
characteristics by Prof.P.Jayaraman, Plant Anatomy Research Center (PARC), Tambaram, Tamil Nadu, India.
Washed and air-dried plant were cut into small pieces and pulverized in a domestic blender and used for the
preparation of aqueous and solvent extracts.
Preparation of extracts
Imperata cylindrica were collected and dried under shade at room temperature for about 20 days. The
dried plant was powdered and sieved to get fine powder using an electric blender. 50 g of air-dried powder was
then extracted with 100 ml of solvents viz., petroleum ether, chloroform, methanol, ethanol and aqueous. The
sample was kept in dark for 72 h with intermittent shaking. After incubation, the solution was filtered through
Whatman filter paper No. 1 and the filtrate was collected (crude extracts) and were stored in an air tight container
for the further biological study.
Test Microorganisms
The test microorganisms used for antibacterial analysis were clinical isolates of Staphylococcus aureus,
Bacillus cereus, Bacillus subtilis, Pseudomonas aeruginosa and Proteus vulgaris. The bacterial strains were
maintained on Nutrient Agar at the Department of Bacteriology, King Institute of Preventive Medicine, Guindy,
Chennai and also the above said bacterial cultures were procured from the Department of Microbiology,
Presidency College, Chennai -5. Bacterial inoculums were prepared 24 hours in advance and kept in Mueller-
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Hinton agar. The inoculums were suspended in sterile saline solution using a 0.5 McFarland standard
(108 CFU/mL).
Antibacterial activity
Antibacterial activity of the I. cylindrica solvent extracts was done in vitro adopting Kirby-Bauer disc
diffusion techniques (Bauer et al., 1959). The disc diffusion method is highly effective for rapidly growing
microorganisms and the activities of the test complexes are expressed by measuring the diameter of the zone of
inhibition. The extracts were stored dry at room temperature and dissolved in dimethyl sulfoxide (DMSO, 1%).
Both the Gram-positive (S. aureus, B. cereus and B. subtilis) and Gram-negative (P. aeruginosa and P. vulgaris)
bacteria were grown in nutrient agar medium and incubated at 37°C for 48 h followed by frequent subculture to
fresh medium. Fresh culture discs were inoculated with a loop-full of bacterial culture and spread throughout the
culture discs uniformly using a sterile glass spreader. Different concentration of solvent extract such as 2µg/µl,
4µg/µl, 6µg/µl, 8µg/µl and 10µg/µl were added to each sterile disc and reference standard Norflaxin (20µg/µl)
was added using a sterile micropipette. The plates were then incubated at 35 ± C for 24-48 h for bacteria. The
inhibition was recorded by measuring the diameter of the inhibitory zone after the period of incubation. Methanol
extract alone showed higher activity when compared to other solvent extract and based on the above activity we
have take methanol extract for the further study to find the oxygen radical scavenging capacity (ORAC property).
ORAC radical scavenging activity
The antioxidant potential of I. cylindrica methanol extract was determined by ORAC assay following the
methods of Huang et al. (2002, 2005).To a 96-well plate, 25 μL of the Trolox (Standard) and methanol extract of
I. cylindrica at various concentrations (20, 40, 60, 80 and 100µg/µl) were added in separate wells, followed by
addition of 150 μL of the fluorescein solution to each well. The contents in the wells were mixed thoroughly and
the plate was incubated for 30 min. at 37ºC. Then, 25 μL of AAPH solution was added into each well to initiate
free radical formation. The reaction mixture was thoroughly mixed by pipetting to ensure homogeneity. The
standard and sample wells were read immediately with a fluorescent microplate reader at 37ºC with an excitation
wavelength of 480 nm and an emission wavelength of 520 nM and the results were calculated by the microplate
reader itself as per the formula.
Antioxidant capacity = Sum Sample Sum Blank / Sum Trolox Sum Blank
Statistical Analysis
The antioxidant data with three replicates were subjected to statistical analysis and the mean value along
with its respective standard error was calculated. The per cent change between control and experimental data
were calculated. The data were analyzed statistically using Two Way Analysis of Variance (ANOVA).
RESULTS AND DISCUSSION
The previous studies revealed the presence of various phytocompounds such as tannins, saponins,
flavonoids, alkaloids, anthocyanin, quinines, glycosides, terpenoids, phenols, coumarins and carbohydrates in the
whole plant extracts of I. cylindrica (Sudha et al., 2018).
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Antibacterial activity
The antimicrobial potential of the I. cylindrica was evaluated according to their zone of inhibition against
various pathogens and the results (zone of inhibition) were compared with the activity of the standards, viz.,
Norflaxin (20 μg/μl). The results revealed that the methanol extract alone showed potential activity when
compared to other solvent extracts such as aqueous, chloroform, ethanol and petroleum ether. The ethanol extract
showed activity only against B. cereus at various concentrations and highest inhibition at 10 μg/μl (7.2 mm).
Whereas the methanol extract showed activities against S. aureus, B. cereus, P. aeruginosa and P.vulgaris. The
highest zone of inhibition was shown in concentration 10 μg/μl. Norflaxin showed higher activity than the
methanol extract against S. aureus this may be due to the antibiotic nature of the drug as shown in Table 5 and
Figure 5 Aqueous, chloroform, ethanol and petroleum ether extracts showed no activity as shown in the Tables
1, 2, 3 and 4 and Figures 1, 2, 3 and 4. Similar observations were observed by Shittu et al. (2007) in the
methanolic and ethanolic extracts of Sesame radiatum showed broad spectrum antibacterial activity while the
aqueous extract was ineffective. Indeed, Gram-positive and Gram-negative bacteria are more resistant to
antibiotics because they possess impermeable outer membrane; consequently, the levels of antibiotics in the cell
are reduced (Gebremedhin et al., 2018). Calsamiglia et al. (2007) opined that the cell membrane of Gram-
positive bacteria, which can interact directly with hydrophobic compounds of solvent extracts whereas, the
external cell wall around the cell membrane of Gram-negative bacteria is hydrophilic and blocks the penetration
of extracts and avoids the accumulation of extracts in target cell membrane. The possible reason for highest
antibacterial activities of methanol extract is due to the presence of phytochemicals and their synergistic effects
in I. cylindrica against pathogenic bacteria.
Generally, the antibacterial activities of plant extracts is dependent on various factors; the environmental
and climate conditions under which the plant grew, the solvent that is used for the extraction, the choice of
extraction method, test concentration, the method of determination of antimicrobial activity and the test
microorganisms (Janssen et al., 1987; Cowan, 1999; Valgas et al., 2007). In this study, I. cylindrica was
sequentially extracted with different organic solvents in increasing polarity order. The sequential extraction
method ensures the extraction of active compounds from plant material according to their polarity, and also
reduces the antagonistic effect of compounds in the extract.
ORAC radical scavenging activity
The changes in ORAC radical scavenging activity were significant within various concentrations of I.
cylindrica methanol extract as well as within standard. The results indicated that methanol extract has more
antioxidant potential than standard (Trolox). The calculated IC50 value for methanol extract was 72.754 and for
standard was 69.369. The value pragmatically shows that methanol extract has higher radical scavenging activity
than the standard as shown in the Table 6 and Figure 6. The result showed that methanol extract of I. cylindrica
are more effective as antioxidant compared to Trolox. In this investigation, a promising source of natural
antioxidant compounds in a rather less studied plant I. cylindrica have been identified. In the ORAC assay, the
activities of the studied methanol extract are associated with their reducing properties. This allows them to react
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with certain precursors of peroxides, thus preventing peroxide formation. Overall, the polyphenols contained in
the methanol extract act by donating electrons and reacting with free radicals to convert them into more stable
products and terminate free radical chain reactions. The medicinal properties of this plant could be due to its
antioxidant potentials as evident from this present work. More studies are however needed for investigating its
usefulness in the management and treatment of various diseases.
CONCLUSION
In the study, there is a necessity to introduce new, biologically safe and active drugs. Naturally the plants
possess biologically effective antimicrobial and antioxidant agents. The methanolic extract of I. cylindrica
showed good activity against the Gram-positive and Gram-negative bacteria and good antioxidant potential. It
indicates that the methanol extract of I. cylindrica contains phytochemical (medicinal) compounds for curing the
different human diseases and further investigation should be needed to screen the phytochemicals which are
useful for pharmacological studies.
REFERENCES
1. Bauer, A.W., Perry, D.M., Kirby, W.M.M. 1959. Single-disk antibiotic-sensitivity testing of
Staphylococci; an analysis of technique and results. A.M.A. Arch. Intern. Med, 104(2):208216.
2. Calsamiglia, S., Busquet, M., Cardozo, P.W., Castillejos, L., Ferret, A. 2007. Invited Review: Essential
oils as modifiers of rumen microbial fermentation. J Dairy Sci, 90(6): 2580-2595.
3. Cowan MM. 1999. Plant products as antimicrobial agents. Clin Microbiol Rev., 12(4): 564-582.
4. Gebremedhin, R., Birhanu, A., Tsegaye, H.G., Hailelule, A., Gebreyohans, G. 2018. Antibacterial
activities of five medicinal plants in Ethiopia against some human and animal pathogens. Evidence-Based
Complementary and Alternative Medicine, 10.
5. Gunasekaran, M., Balasubramanian, P. 2012. Ethnomedicinal uses of Sthalavrikshas (temple trees) in
Tamil Nadu, Southern India. Ethnobotany and Research Applications A Journal of Plants, People and
Applied Research, 10:253-268.
6. Harborne, J.B. 1998. Phytochemical methods. Chapman and Hall, London, 6.
7. Huang, D., Ou, B., Hampsch-Woodill, M., Flanagan, J., Prior, R. 2002. High-throughput assay of oxygen
radical absorbance capacity (ORAC) using a multichannel liquid handling system coupled with a
microplate fluorescence reader in 96-well format. J Agric Food Chem, 50:4437-44.
8. Huang, D., Ou, B., Prior, R.L. 2005.The chemistry behind antioxidant capacity assays. J Agric Food
Chem, 53:1841-1856.
9. Janssen, A.M., Scheffer, J.J.C., Baerheim-Svendsen, A. 1987. Antimicrobial activity of essential oils: a
1976-86 literature review. Planta Med, 53:395-398.
© 2019 IJRAR June 2019, Volume 6, Issue 2 www.ijrar.org (E-ISSN 2348-1269, P- ISSN 2349-5138)
IJRAR19K3429
International Journal of Research and Analytical Reviews (IJRAR) www.ijrar.org
26
10. Lalthanpuii, P.B., Zarzokimi, Lalchhandama, K. 2018. Some phytochemical analyses of different extracts
of the cogon grass Imperata cylindrica from Mizoram, India. Sci Vis, 18(4):120-124.
11. MacDonald, G.E. 2004. Cogongrass (Imperata cylindrica)-Biology, ecology, and management. Critical
Reviews in Plant Sciences, 23(5):367380.
12. Madhihassan S. 1987. Three important vedic grasses. Ind J Hist Sci 22: 286 - 291.
13. Matsunaga, K., Shibuya, M., Ohizumi, Y. 1994. Graminone B, a novel lignan with vasodilative activity
from Imperata cylindrica. J Nat Prod, 57(12):17341736.
14. Sawmliana, M. 2013. The Book of Mizoram Plants. Aizawl (India): P. Zakhuma, 143.
15. Shittu, L., Bankole, M.A., Ahmed, T., Bankole, M.N., Shittu, R.K., Saalu, C.L., Ashiru, O.A., 2007.
Iranian J. of Pharmacol. and Therapeut, 6:165.
16. Sudha, R., Kaleena. P. K., Babu. M., Janaki. A., Velu. K., Elumalai. 2018. Phytochemical screening,
antioxidant and anticancer potential of Imperata cylindrica (L.) Raeusch against human breast cancer cell
line (MCF-7) Int. J. Pharm. Biol. Sci., 8(3):938-945.
17. Townson, J.K. 1991. Imperata cylindrica and its control. Weed Abstracts, 40(11):457468.
18. Yoon, J.S., Lee, M.K., Sung, S.H., Kim, Y.C. 2006. Neuroprotective 2-(2-phenylethyl) chromones of
Imperata cylindrica. J Nat Prod, 69(2):290291.
19. Valgas, C., De Souza, S.M., Smânia, E.F.A., Artur Smânia. Jr. 2007. Screening methods to determine
antibacterial activity of natural products. Braz J Microbiol, 38:369-380.
Table 1: Antibacterial activity of I. cylindrica aqueous extract
S.N
o
Name of the
Bacteria
Zone of inhibition in mm
2μg/μl
6 μg/μl
8 μg/μl
10 μg/μl
Norflaxin 20 μg/μl
1
S.aureus
-
-
-
-
7.6 mm
2
B. subtilis
-
-
-
-
6.2 mm
3
B. cereus
-
-
-
-
6.1 mm
4
P.aeruginosa
-
-
-
-
7.1 mm
5
P. vulgaris
-
-
-
-
0 mm
Table 2: Antibacterial activity of I. cylindrica chloroform extract
S.N
o
Name of the
Bacteria
Zone of inhibition in mm
2μg/μl
4 μg/μl
6 μg/μl
8 μg/μl
10 μg/μl
Norflaxin 20 μg/μl
1
S. aureus
-
-
-
-
-
6.3 mm
2
B. subtilis
-
-
-
-
-
0 mm
3
B. cereus
-
-
-
-
-
0 mm
4
P. aeruginosa
-
-
-
-
-
6.2 mm
5
P. vulgaris
-
-
-
-
-
6.4 mm
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Table 3: Antibacterial activity of I. cylindrica ethanol extract
S.No
Name of the
Bacteria
Zone of inhibition in mm
2μg/μl
4 μg/μl
6 μg/μl
8 μg/μl
10 μg/μl
Norflaxin 20 μg/μl
1
S. aureus
-
-
-
-
-
6.3 mm
2
B. subtilis
-
-
-
-
-
0 mm
3
B. cereus
6.1 mm
6.4 mm
6.6 mm
6.9 mm
7.2 mm
7.4 mm
4
P. aeruginosa
-
-
-
-
-
0 mm
5
P. vulgaris
-
-
-
-
-
6.4 mm
Table 4: Antibacterial activity of I. cylindrica petroleum ether extract
S.No
Name of the
Bacteria
Zone of inhibition in mm
2μg/μl
4 μg/μl
6 μg/μl
8 μg/μl
10 μg/μl
Norflaxin 20 μg/μl
1
S. aureus
-
-
-
-
-
6.1 mm
2
B. subtilis
-
-
-
-
-
6.3 mm
3
B. cereus
-
-
-
-
-
0 mm
4
P. aeruginosa
-
-
-
-
-
0 mm
5
P. vulgaris
-
-
-
-
-
6.6 mm
Table 5: Antibacterial activity of I. cylindrica methanol extract
S.N
o
Name of the
Bacteria
Zone of inhibition in mm
2μg/μl
4 μg/μl
6 μg/μl
8 μg/μl
10 μg/μl
Norflaxin 20 μg/μl
1
S.aureus
6.3 mm
6.7 mm
6.9 mm
7.3 mm
7.6 mm
9.5 mm
2
B. subtilis
0 mm
0 mm
0 mm
0 mm
0 mm
6.8 mm
3
B. cereus
6.5 mm
6.6 mm
6.8 mm
7.0 mm
7.6 mm
7.1 mm
4
P.aeruginosa
0 mm
6.1 mm
6.3 mm
6.7 mm
6.9 mm
6.3 mm
5
P.vulgaris
6.1 mm
6.5 mm
6.7 mm
7.2 mm
7.6 mm
7.4 mm
Table 6: ORAC assay of I. cylindrica methanol extract
Samples
Net Relative Fluorescence Unit (NRFU)
IC50 values
μg/μl
Concentration
20 μg/μl
40 μg/μl
60 μg/μl
80 μg/μl
100 μg/μl
Methanol
0.869±0.004*
(-10.065)
0.772±0.004*
(-20.096 )
0.604±0.004*
(-37.469)
0.414±0.005*
(-57.118)
0.225±0.004*
(-76.663)
72.754
Trolax
0.881±0.014*
(-13.679)
0.75±0.007*
( -26.542)
0.604±0.002*
(-40.77)
0.403±0.002*
(-60.463)
0.190±0.007*
(-81.325)
69.369
Values are mean + S.E. of three individual observations. Values in parentheses are percent
change over control.
- Denotes percent decrease over control.
*Values are significant at P<0.01.
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Figure 1: Antibacterial activity of I. cylindrica aqueous extract
Whereas, A- 2 µg/µl, B-4 µg/µl, C-6 µg/µl, D-8 µg/µl, E-10 µg/µl and N (Reference standard Norflaxin)- 20
µg/µl.
Figure 2: Antibacterial activity of I. cylindrica chloroform extract
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Whereas, A- 2 µg/µl, B-4 µg/µl, C-6 µg/µl, D-8 µg/µl, E-10 µg/µl and N (Reference standard Norflaxin)- 20
µg/µl
Figure 3: Antibacterial activity of I. cylindrica ethanol extract
Whereas, A- 2 µg/µl, B-4 µg/µl, C-6 µg/µl, D-8 µg/µl, E-10 µg/µl and N (Reference standard Norflaxin)- 20
µg/µl
Figure 4: Antibacterial activity of I. cylindrica petroleum ether extract
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Whereas, A- 2 µg/µl, B-4 µg/µl, C-6 µg/µl, D-8 µg/µl, E-10 µg/µl and N (Reference standard Norflaxin)- 20
µg/µl
Figure 5: Antibacterial activity of I. cylindrica methanol extract
Whereas, A- 2 µg/µl, B-4 µg/µl, C-6 µg/µl, D-8 µg/µl, E-10 µg/µl and N (Reference standard Norflaxin)- 20
µg/µl
Figure 6: ORAC assay of I. cylindrica methanol extract
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The traditional knowledge on plants when confirmed by phytochemical, antioxidant and anticancer studies can lead to the development of drugs and plant-based medicine. The plant selected for the present study Imperata cylindrica is a rhizomatous grass used for various ailments by traditional healers. The present study aims at phytochemical profiling of whole plant extracts of I. cylindrica and to demonstrate its efficacy as an antioxidant and anticancer agent against human breast cancer cell line (MCF-7). Methanol, ethanol, petroleumether, chloroform and aqueous whole plant extracts of I. cylindrica was screened to identify the bioactive compounds and to evaluate its bioefficacy. Phytochemical (qualitative and quantitative) screening of the whole plant extracts of I. cylindrica revealed the presence of bioactive compounds as tannins, saponins, flavonoids, alkaloids, quinines, glycosides, terpenoids, phenols, coumarin and steroids in all the solvent extracts. Fifty percent inhibition of free radical scavenging activity was observed only in the methanolic extract of I. cylindrica at 59.74µg/ml when compared to the other extracts. The cytotoxicity was evaluated using the changes in cell morphology, cell viability and nuclear staining and the percentage of cell viability was determined by MTT assay. Our results showed that methanolic extract of I. cylindrica inhibited the proliferation of human breast cancer cell line MCF-7 with an IC50value of 83.10µg/ml at 24 h incubation, and was shown to promote apoptosis as seen inpropidium iodide staining. These results suggest that methanolic extract of I.cylindrica has antiproliferative effect against MCF-7 cell by suppressing its growth.
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Cogongrass is considered to be one of the ten most troublesome and problematic weedy species in the world. This species is found throughout tropical and subtropical regions, generally in areas disturbed by human activities. Over 100 common names have been associated with cogongrass, including japgrass, speargrass, alang-alang, and bladygrass. Although this species has several commercial uses, the problems associated with its weediness far outweigh most positive benefits. Cogongrass is a major impediment to reforestation efforts in southeast Asia, the number one weed in agronomic and vegetable production in many parts of Africa, and is responsible for thousands of hectares of lost native habitat in the southeastern U.S. Biologically, cogongrass possesses several features that foster its spread and persistence. Management efforts for cogongrass consist of an integrated approach with several control strategies. In agronomic production, the use of cover crops is widely successful, but incorporation into the overall production scheme is challenging. Success has been achieved with continuous deep tillage or chemical applications, but long-term eradication/suppression must employ sustainable revegetation strategies.
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The data given in the literature published during 1976-1986 concerning antimicrobial activities of essential oils are treated from an experimental point of view and with regard to a possible practical application. Attention is paid to four factors which are important when testing essential oils: the assay technique; the growth medium; the micro-organism; the essential oil.
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Two novel lignans, graminones A [1] and B [2] have been isolated from Imperata cylindrica and their structures have been elucidated on the basis of their spectral data. Graminone B [2] showed inhibitory activity on the contraction of the rabbit aorta.
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The oxygen radical absorbance capacity (ORAC) assay has been widely accepted as a standard tool to measure the antioxidant activity in the nutraceutical, pharmaceutical, and food industries. However, the ORAC assay has been criticized for a lack of accessibility due to the unavailability of the COBAS FARA II analyzer, an instrument discontinued by the manufacturer. In addition, the manual sample preparation is time-consuming and labor-intensive. The objective of this study was to develop a high-throughput instrument platform that can fully automate the ORAC assay procedure. The new instrument platform consists of a robotic eight-channel liquid handling system and a microplate fluorescence reader. By using the high-throughput platform, the efficiency of the assay is improved with at least a 10-fold increase in sample throughput over the current procedure. The mean of intra- and interday CVs was <or=15%, and the limit of detection and limit of quantitation were 5 and 6.25 microM, respectively.
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The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and "leads" which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.