INHIBITORY POTENTIAL OF LEAF AND ROOT BARK EXTRACTS OF TERMINALIA AVICENNIOIDES ON METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS AND CHARACTERIZATION OF THE DISTINCT BIOACTIVE EXTRACT
INHIBITORY POTENTIAL OF LEAF AND ROOT BARK EXTRACTS OF TERMINALIA AVICENNIOIDES ON METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS AND CHARACTERIZATION OF THE DISTINCT BIOACTIVE EXTRACT
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Date
2015-12
Authors
ADIM, EkeneUgochukwu
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Abstract
The increasing concern of antibiotic resistance has lead to search for new antibiotic chemotheraphy. The aim of this study was to investigate the Inhibitory potential of the leaf and root bark extracts of Terminaliaavicennioides against Methicillin resistant Staphylococcus aeurus (MRSA) and characterization of the most distinct bioactive extract.Extraction was done using n-hexane, Chloroform, Ethyl acetate and Methanol. The extracts were graded at concentrations of 60μg/ml, 120μg/ml, 180μg/ml and 240μg/ml. With exception of chloroform, ethyl acetate and n-hexane extract of the leaf at 60μg/ml, every other extracts of the leaf and root bark at all concentrations are inhibitory to the growth of MRSA within the susceptible range ≥ 14mm as defined by Kirby-Bauer standard chart for (Methicillin) antibiotic susceptibility. Chloroform crude extract of the leaf and Ethyl acetate crude extract of the root bark were observed to be the best system for isolation of bioactive principles. A comparison of activity of these two lead to further investigation of Ethyl acetate extract of the root bark. TLC fractionation was done using a mixture of Chloroform: Ethyl acetate: Methanol: Water (15:8:4:1) with a resultant 18 fractions (bands). The organism showed a mean zone inhibitory sensitivity of 14mm at 60μg/ml, 15.76mm at 120μg/ml and 15.33mm at 180μg/ml for fraction TLb4 and 15.33mm at 60μg/ml, 17.33mm at 120μg/ml and 20mm at 180μg/ml for TLb17 (≥ 14mm). The two Fractionswhere subjected to GC-MS and FTIR analysis. Minimum Inhibitory Concentration was 0.6μg/ml for both TLb4 and TLb17 and as well bactericidal at this same concentration. Phytochemical screening of TLb1 to TLb18 fractions from ethyl acetate extract shows that terpenoidswhere present in all fractions. Quantitatively, 42μg of alkaloids, 19.80μg of anthraquinone and 184.25μg of tannins were estimated in 1mg of ethyl acetate root bark extract.Analysis of GC-MS revealed that the most likely
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pharmacological compounds present in both fractions were oleic acid, analogs of palmitic acid (n-Hexadecanoic), methyl ester (11-Octadecenoic acid), stearic acid (Octadecenoic acid ) in association with a possible synergistic effect of 9-Octadecenal, 3,11-Tetradecadien-1-ol, and (9Z)-9-Teradecenal present only in fraction TLb17. FTIR shows the presence of Alkyl Halides: R-Br, R-F, Methyne: ( CH−), Nitro Compounds:R-NO2, Amides: R-C(O)-NH2, R-C(O)-NH-R., Isothiocyanate: (-NCS), Nitril: C≡N, Carboxylic Acids, Saturated Aliphatic (Alkyl):METHYLENE C-H, Alkanes, in both TLb4 and TLb17, and Alkyl Halide: R-I, Allenes, Amines: R-NH2 in TLb17 only as functional groups. These bioactive compounds and functional groups could be effective therapeutic agents for the treatment and management of infections caused by MRSA.
Description
A DESSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTER OF SCIENCE DEGREE IN BIOCHEMISTRY DEPARTMENT OF BIOCHEMISTRY, FACULTY OF SCIENCES AHMADU BELLO UNIVERSITY, ZARIA NIGERIA
Keywords
INHIBITORY POTENTIAL, ROOT BARK EXTRACTS, TERMINALIA AVICENNIOIDES, METHICILLIN RESISTANT STAPHYLOCOCCUS