[Show abstract][Hide abstract] ABSTRACT: Logistic response of antioxidants to lipid peroxide concentration in carbon tetrachloride
toxicity in rabbit liver was evaluated. Carbon tetrachloride (CCl4), ethanol extracts of
Chromolaena odorata (ETECO), sylimarin (a known hepatoprotective agent) and water,
were used to induce variations in the oxidant/antioxidant balance in the test and control
animals. This was used as a model to study the delicate balance between the activities and/or the intracellular concentrations of these antioxidants and lipid peroxide. Concentrations of lipid peroxidation product (malondialdehyde) were estimated to access the degree of oxidation of the polyunsaturated fatty acids in the liver tissue. Glutathione (GSH) concentration was estimated to capture the non-enzymatic antioxidant concentration, while glutathione-s-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities were assayed in the liver to assess the enzymatic antioxidant activities. Results obtained from this study showed that the concentrations of lipid peroxidation product (malondialdehyde) varied in a logistic fashion with the nonenzymatic antioxidant (glutathione) and the enzymatic antioxidants (glutathione-s-transferase, superoxide dismutase, and catalase). The concentration of the peroxidation product and the concentration/activity of the antioxidants were inversely related, maintaining a highly logistic relationship (R2 = 0.99). The non-enzymatic antioxidant (GSH) concentration and the enzymatic antioxidant (GST, SOD, and CAT) activities were found to be directly related in a sigmoidal manner (R2 = 0.98). These observations indicated that oxidant/antioxidant concentrations and activities in a rabbit liver tissue is tightly related and mathematically associated.
[Show abstract][Hide abstract] ABSTRACT: The ethanol extract of the leaf of Chromolaena odorata (Linn) was assessed for free-radical-scavenging and antioxidant potentials. Ability of the extract to scavenge reactive intermediates (superoxide ion O2·-, hydrogen peroxide H2O2, nitric oxide NO˙, hydroxyl radical OH˙) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, were used to assess its free radical scavenging potentials. Antioxidant potential was studied by assessing in-vitro inhibition of lipid peroxidation in both the brain (Neuro-protective potentials) and liver homogenates of Fenton-oxidant stressed rabbits. Inhibition of protein oxidation was assessed in-vitro by loss of protein thiol (P-SH), while assessment of the reducing power of the extract was further used to assess antioxidant capacity. Results obtained showed the ability of the extract to scavenge free radicals and reactive intermediates in a dose-response manner. The plant also had good antioxidant capacity. The secondary plant metabolites found earlier in the extract may explain reasons for the bio-efficacy of the plant. These findings are of great importance in view of the availability of the plant and its observed possible diverse applications in medicine and nutrition.
[Show abstract][Hide abstract] ABSTRACT: Carbon tetrachloride and its toxic metabolites consistently produce liver injury in many
species including man. The hepatoprotective potential of Chromolaena odorata Linn. (C.
odorata) was evaluated in male rabbits against carbon tetrachloride-induced liver
damage. Carbon tetrachloride intoxicated control (CCl4) and ethanol extract of C. odoratatreated
rabbits (ETECO TEST) received a single dose of CCl4 (0.2 ml/kg bw in liquid
paraffin 1:1). Pre-treated rabbits received ethanol extract of C. odorata at 400 mg/kg/day
in two divided doses of 200 mg/kg in morning and at night for 6 days prior to CCl4
administration. Sylimarin control received 50 mg/kg bw as a replacement for ETECO prior
to CCl4 intoxication. Normal animals received only extract in the above stated dose and
served as extract controls (ETECO CTRL). Pre-treatment with C. odorata significantly (p<0.05) prevented the elevation of serum aspartate aminotransferase (AST), alanineaminotransferase (ALT), lactate dehydrogenase (LDH), gamma glutamyl transferase ( ץ-GT), total bilirubin and malondialdehyde (MDA) resulting from carbon tetrachloride intoxication. C. odorata extract also significantly (p<0.05) prevented a decrease in serum total protein, albumin, and glutathione (GSH) concentrations. The extract also significantly (p<0.05) prevented a decrease in superoxide dismutase (SOD), catalase (CAT) and glutathione-s-transferase (GST) activities. The presence of secondary plant metabolites like alkaloids, saponins, phenolic compouds, flavonoids and tannins found in C. odorata extract could beresponsible for its hepatoprotective action.
[Show abstract][Hide abstract] ABSTRACT: Protection against hydroxyl radical-induced oxidative damage, reduction in glucose concentration and inhibition
of dehydrogenase enzymes as possible mechanisms of wound healing using ethanol extracts of Chromolaena
odorata-Linn were studied. Hydroxyl radical (OH˙)-scavenging activity was measured by studying the competition
between deoxyribose degradation and C. odorata for hydroxyl radicals generated via the Fe3+ / ascorbate /
EDTA / H2O2 system. Hypoglycaemic potential was assessed by the glucose tolerance test in white New Zealand
rabbits. Inhibition of dehydrogenase activity (DHA) in menacing wound pathogenic bacteria was investigated
via dehydrogenase assay using 2,3,5-triphenyl tetrazolium chloride (TTC) as the artificial electron acceptor. Pure
cultures of the organisms (Escherichia sp., Staphylococcus sp., and Pseudomonas sp.) were exposed to graded
concentrations of ethanol extracts of C. odorata (ETECO 0-2000μg/ml). Our results reveal the potential of the
extract to protect against hydroxyl radical-induced damage as demonstrated by its ability to scavenge hydroxyl
radical in-vitro. The ethanol extract of C. odorata was shown to be hypoglycaemic in the glucose tolerance test.
C. odorata exhibited a concentration-dependent response against dehydrogenase activity in the tested organisms.
Dehydrogenase activity (mg Formazan/mg cell dry weight /h) was inhibited in a manner that obeyed a logistic
dose response model (abcd). Inhibitory concentrations (IC20, IC50, IC70, and IC100) of ETECO showed that the
plant C.odorata is a good inhibitor of dehydrogenase activity in the tested pathogens. %Inhibition of hydroxyl
radicals: followed a logistic dose response model (abcd) similar to percentage inhibition of DHA.