BIOACTIVITY-GUIDED FRACTIONATION OF AQUEOUS LEAF EXTRACT OFTEPHROSIA VOGELII AND ITS EFFECT ON HYPERLIPIDEMIA IN RATS
BIOACTIVITY-GUIDED FRACTIONATION OF AQUEOUS LEAF EXTRACT OFTEPHROSIA VOGELII AND ITS EFFECT ON HYPERLIPIDEMIA IN RATS
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Date
2017-06
Authors
BAWA, Inalegwu
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Abstract
There are claims by traditional medicine practitioners in Nigeria that the leaves of Tephrosia vogeliihook. f. are used for the treatment of cardiovascular diseases but it appears there is no scientific research and publication or documented work to verify these claims.Thisstudy aimed for bioactivity guided fractionation of aqueous leaves extract ofT. vogeliiand its effect on hyperlipidemic rats. Induction of hyperlipidemia was carried out with high fat diet and Poloxamer 407 (P-407). Partial purification and identification were carried out using Thin Layer Chromatography (TLC), Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography- Mass Spectra (GC-MS). The results of the phytochemical screening of leaves and stem revealed the presence of alkaloids, saponins, phlobatannins and flavonoids in powdered sample of leaves and stem of T. vogelii.Aqueousextract of the leaves has the highest yield (18.21±1.12%) while acetic acid extract of stem has the lowest yield (7.21±1.21%). The cholesterol and triacylglycerol level of rats induced with P-407 was significantly (p<0.05) higher than high fat diet-induced rats. Preliminary antihyperlipidemic study showed aqueous extract at 50mg/kg body weight significantly (p<0.05) lower cholesterol, low density lipoprotein (LDL) and triacylglyceride levels. The LD50of aqueous leaves extractwas found to be 2154mg/kg body weight.Ten fractions (F1-F10) wereobtained from methanol in water leaves extract of T. vogelii significantly (p<0.05) reduced total cholesterol (TC) when compared with normal and hyperlipidemic control.Fraction six (F6) (100mg/kg body weight) significantly (p<0.05) reduced TC, TAG and LDL-c, AST, ALT, MDA, creatinine, total bilirubin and urea and significantly (p>0.05) increase SOD, CAT and GSH when compared with extract treated group and hyperlipidemic group. Lipid profile
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of F6 was significantly (p<0.05) lower than normal rats.There was no significant (p˃0.05) change in the level of TC, HDL at a higher dose. Serum TAG, LDL-c, ratio of LDL-c/HDL and Log TAG/HDL-c were significantly (p<0.05) reduced while ratio of HDL-c/TC was significantly (p<0.05) higher. The TLC separation in solvent system of hexane/ethylacetate in ratio 7:3 gave two fractions (subfraction 1 and 2) with Rf values of 0.22 and 0.60 respectively.Antihyperlipidemic effect of subfraction1 (Rf value 0.22) significantly (p<0.05) reduced triacylglycerol (TAG) when compared to animal treated with other T. vogelii fractions and show no significant change when compared with standard drug and animal in control group. There was no significant (p˃ 0.05) change in the level of total cholesterol (TC), low density lipoprotein (LDL), and high density lipoprotein (HDL) infraction 6, subfraction 1 and 2 when compared with hyperlipidemic control group. The FTIR of subfraction1 showed the presence of phenols, alcohols, alkanes, alkyl halides, carboxylic acids, aromatics, nitro compounds and amines. The prevailing functional groups were alcohol and phenol.The GC-MS analysis of subfraction1shows the presence of fourteen compounds. The prevailing compounds were gamma.-Tocopherol and other compounds that have antihyperlipidemic effect including 4H-pyran-4-one, 3, 5-dihydroxy, 2-Methyl-Z, Z-3, 13-octadecadienol and 9-Octadecenoic acid, (E). The study shows that the aqueous extract ofleaves possess antihyperlipidemic effects and may explains why it has been found to be useful in the management of cardiovascular diseases by traditional medicine practitioners
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES,
AHMADU BELLO UNIVERSITY,ZARIA
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD
OF A
DOCTORAL DEGREE IN BIOCHEMISTRY.
DEPARTMENT OF BIOCHEMISTRY,
FACULTY OF LIFE SCIENCES
AHMADU BELLO UNIVERSITY, ZARIA
NIGERIA
Keywords
BIOACTIVITY-GUIDED FRACTIONATION,, AQUEOUS LEAF EXTRACT,, TEPHROSIA VOGEL II,, EFFECT,, HYPERLIPIDEMIA,, RATS,