In vitro antimicrobial activity of ethanolic fractions of Cryptolepis sanguinolenta
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Date
2012-12-01
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Publisher
BioMed Central Ltd.
Abstract
Background: Following claims that some plants have antimicrobial activities against infectious microbes, the
in vitro antimicrobial activities of different solvent fractions of ethanolic extract of Cryptolepis sanguinolenta were
evaluated against eight standard bacteria and clinical isolates.
Methods: The solvent partitioning protocol involving ethanol, petroleum ether, chloroform, ethyl acetate and
water, was used to extract various fractions of dried pulverized Cryptolepis sanguinolenta roots. Qualitative
phyto-constituents screening was performed on the ethanol extract, chloroform fraction and the water fraction. The
Kirby Bauer disk diffusion method was employed to ascertain the antibiogram of the test organisms while the agar
diffusion method was used to investigate the antimicrobial properties of the crude plant extracts. The microplate
dilution method aided in finding the MICs while the MBCs were obtained by the method of Nester and friends. The
SPSS 16.0 version was used to analyze the percentages of inhibitions and bactericidal activities.
Results: The phytochemical screening revealed the presence of alkaloids, reducing sugars, polyuronides,
anthocyanosides and triterpenes. The ethanol extract inhibited 5 out of 8 (62.5%) of the standard organisms and 6
out of 8 (75%) clinical isolates. The petroleum ether fraction inhibited 4 out of 8 (50%) of the standard microbes
and 1 out of 8 (12.5%) clinical isolates. It was also observed that the chloroform fraction inhibited the growth of all
the organisms (100%). Average inhibition zones of 14.0 ± 1.0 mm to 24.67 ± 0.58 mm was seen in the ethyl acetate
fraction which halted the growth of 3 (37.5%) of the standard organisms. Inhibition of 7 (87.5%) of standard strains
and 6 (75%) of clinical isolates were observed in the water fraction. The chloroform fraction exhibited bactericidal
activity against all the test organisms while the remaining fractions showed varying degrees of bacteriostatic
activity.
Conclusion: The study confirmed that fractions of Cryptolepis sanguinolenta have antimicrobial activity. The
chloroform fraction had the highest activity, followed by water, ethanol, petroleum ether and ethyl acetate
respectively. Only the chloroform fraction exhibited bactericidal activity and further investigations are needed to
ascertain its safety and prospects of drug development.
Description
An article published by BioMed Central Ltd. and also available at doi:10.1186/1476-0711-11-16
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Citation
Mills-Robertson et al.: In vitro antimicrobial activity of ethanolic fractions of Cryptolepis sanguinolenta. Annals of Clinical Microbiology and Antimicrobials 2012 11:16. doi:10.1186/1476-0711-11-16