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Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions

E. coli 0157:H7 is a newly emerging pathogen that cause bloody diarrhoea to severe abdominal cramps, haemolytic uremic syndrome (HUS), thrombotic thrombocytopenic purpura and even death. There are reports that antibiotic treatment increases the risk of patients developing fatal HUS. Therefore plant...

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Main Author: Ismail, Nur Sharafina
Format: Thesis
Language:English
Published: 2014
Subjects:
QH1 Natural history (General - Including nature conservation, geographical distribution)
Online Access:http://eprints.usm.my/43590/1/NUR%20SHARAFINA%20ISMAIL_HJ.pdf
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spelling my.usm.eprints.43590 http://eprints.usm.my/43590/ Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions Ismail, Nur Sharafina QH1 Natural history (General - Including nature conservation, geographical distribution) E. coli 0157:H7 is a newly emerging pathogen that cause bloody diarrhoea to severe abdominal cramps, haemolytic uremic syndrome (HUS), thrombotic thrombocytopenic purpura and even death. There are reports that antibiotic treatment increases the risk of patients developing fatal HUS. Therefore plant products could be an alternative source for prevention of transmission and hence infection of the pathogen among the general populations. By disc diffusion assay, out of twenty four extracts from eight Malaysian plants, acetone extract of P. betle inhibited E. coli 0157:H7 strongly giving the largest inhibition zone at 20.56 ± 0.19 mm. This correlates strongly with its total phenolic content (TPC) which was the highest among those tested at 430.69 ± 47.50 μg GAE/ mg as determined by Folin-Ciocalteu method. By microdilution assay, acetone extract of P. betle gave the lowest MIC at 500 μg/ ml and MBC at 2000 μg/ ml against E. coli O157:H7. Bio-assay guided fractionation of acetone extract was done using a solvent system of chloroform: methanol at a ratio of 19:1. Fractionation was done by preparative TLC and the fractions collected were all assessed for antibacterial activity, TPC and AOA. Fraction 5 gave the lowest MIC against E. coli 0157:H7 at 500 μg/ ml, high TPC (398.25 ± 7.74) as well as high anti-oxidant activity as assessed by DPPH (80.43 ± 0. 71 %). Upon storage, the antibacterial activity of fraction 5 was reduced. It was subsequently mixed with fraction 6 and 7 (now known as Fraction A) which was more stable. The MIC for fraction A against E. coli O157:H7 was much lower at 250 μg/ml but its MBC increased to >2000 μg/ ml. Acetone extract of P. betle and fraction A were also tested for induction of morphological and ultrastructural changes of E. coli O157:H7 at exponential phase in a batch culture. Based on observation by SEM and TEM, cellular damage by fraction A was not as severe as that given by acetone extract, both at 2000 μg/ml. Toxicity assay using brine shrimp (Artemia salina) showed LC50 of acetone extract was 500 μg/ ml and fraction A was >1000 μg/ ml. Gas chromatography- mass spectrometry (GC-MS) of the fraction revealed three major phenolic compounds, Chavicol, Hydroxychavicol and Chavibetol which may contribute to the antibacterial activity. From this study, it can be concluded that fraction A at 250 μg/ ml to 2000 μg/ ml and acetone extract up to 500 μg/ ml were only bacteriostatic towards E. coli O157:H7 meanwhile acetone extract was bactericidal at 2000 μg/ ml. Acetone extract was toxic at bactericidal concentration, while fraction A though bacteriostatic was non-toxic. 2014-02 Thesis NonPeerReviewed application/pdf en http://eprints.usm.my/43590/1/NUR%20SHARAFINA%20ISMAIL_HJ.pdf Ismail, Nur Sharafina (2014) Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions. Masters thesis, Universiti Sains Malaysia.
institution Universiti Sains Malaysia
building Hamzah Sendut Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Sains Malaysia
content_source USM Institutional Repository
url_provider http://eprints.usm.my/
language English
topic QH1 Natural history (General - Including nature conservation, geographical distribution)
spellingShingle QH1 Natural history (General - Including nature conservation, geographical distribution)
Ismail, Nur Sharafina
Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions
description E. coli 0157:H7 is a newly emerging pathogen that cause bloody diarrhoea to severe abdominal cramps, haemolytic uremic syndrome (HUS), thrombotic thrombocytopenic purpura and even death. There are reports that antibiotic treatment increases the risk of patients developing fatal HUS. Therefore plant products could be an alternative source for prevention of transmission and hence infection of the pathogen among the general populations. By disc diffusion assay, out of twenty four extracts from eight Malaysian plants, acetone extract of P. betle inhibited E. coli 0157:H7 strongly giving the largest inhibition zone at 20.56 ± 0.19 mm. This correlates strongly with its total phenolic content (TPC) which was the highest among those tested at 430.69 ± 47.50 μg GAE/ mg as determined by Folin-Ciocalteu method. By microdilution assay, acetone extract of P. betle gave the lowest MIC at 500 μg/ ml and MBC at 2000 μg/ ml against E. coli O157:H7. Bio-assay guided fractionation of acetone extract was done using a solvent system of chloroform: methanol at a ratio of 19:1. Fractionation was done by preparative TLC and the fractions collected were all assessed for antibacterial activity, TPC and AOA. Fraction 5 gave the lowest MIC against E. coli 0157:H7 at 500 μg/ ml, high TPC (398.25 ± 7.74) as well as high anti-oxidant activity as assessed by DPPH (80.43 ± 0. 71 %). Upon storage, the antibacterial activity of fraction 5 was reduced. It was subsequently mixed with fraction 6 and 7 (now known as Fraction A) which was more stable. The MIC for fraction A against E. coli O157:H7 was much lower at 250 μg/ml but its MBC increased to >2000 μg/ ml. Acetone extract of P. betle and fraction A were also tested for induction of morphological and ultrastructural changes of E. coli O157:H7 at exponential phase in a batch culture. Based on observation by SEM and TEM, cellular damage by fraction A was not as severe as that given by acetone extract, both at 2000 μg/ml. Toxicity assay using brine shrimp (Artemia salina) showed LC50 of acetone extract was 500 μg/ ml and fraction A was >1000 μg/ ml. Gas chromatography- mass spectrometry (GC-MS) of the fraction revealed three major phenolic compounds, Chavicol, Hydroxychavicol and Chavibetol which may contribute to the antibacterial activity. From this study, it can be concluded that fraction A at 250 μg/ ml to 2000 μg/ ml and acetone extract up to 500 μg/ ml were only bacteriostatic towards E. coli O157:H7 meanwhile acetone extract was bactericidal at 2000 μg/ ml. Acetone extract was toxic at bactericidal concentration, while fraction A though bacteriostatic was non-toxic.
format Thesis
author Ismail, Nur Sharafina
author_facet Ismail, Nur Sharafina
author_sort Ismail, Nur Sharafina
title Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions
title_short Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions
title_full Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions
title_fullStr Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions
title_full_unstemmed Anti-Escherichia Coli 0157 : H7 And Anti-Oxidant Activities Of Acetone Extract Of Piper Betle L. And Its Fractions
title_sort anti-escherichia coli 0157 : h7 and anti-oxidant activities of acetone extract of piper betle l. and its fractions
publishDate 2014
url http://eprints.usm.my/43590/1/NUR%20SHARAFINA%20ISMAIL_HJ.pdf
http://eprints.usm.my/43590/
_version_ 1643710783032393728
score 13.211869

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