ABSTRACT

Vegetables are widely used as herbal remedies for combating liver diseases. This study evaluated the phyto contents and in vitro antioxidant capacity of various solvent fraction of the crude extract as well as some biochemical changes following exposure to the hydro-alcohol extract of Amaranthus hybridus in thioacetamide- induced hepatic damage in rats. The plant sample was extracted with 70% ethanol. Preliminary photochemistry and in vitro antioxidant potential of the plant extract was performed using standard methods.  The hepatoprotective effect of HAAH extract was measured in rat model of thioacetamide- induced liver damage for 70 days. Animals were divided into six (6) groups, and were exposed to thioacetamide (300mg/l) in drinking water throughout experimental period, except group that served as control. Liver function status test performed to access the possible effect of HAAH on liver damage. Oxidative stress conditions were measured using malondialdehyde, nitric oxide and glutathione levels. The effects protective activity of HAAH on free radical scavenging were assayed using enzymatic antioxidants. Histology of the liver tissue was performed to access if the extract protected liver architecture from damage. Fractionation of crude plant extract was achieved using solvent partitioning system, and various fractions assayed for antioxidant potential to confirm most potent fraction. The most active fraction was characterised using GC-MS spectrometry. Result showed that the plant extract was rich in phenolic compounds (140.12+0.01 GAEequ.mg/g), flavonoids (3.39+0.02 mgQE/g) and Vitamin C (2.86+0.01mg/100g). Amino acid profiling of the plant extract showed that the extract contained 16 amino acids, which include aromatic amino acids phenylalanine (3.34%), tyrosine (6.08%) and many essential amino acids. In vitro antioxidant studies showed a dose dependent activity for the plant extract that was comparable to standard vitamin c. Results for liver function status assay showed significant (p<0.05) reduction in the liver enzymes, increase in total proteins in the groups administered HAAH compared to negative control. There was significant (p<0.05) increase in enzymatic antioxidant activities in liver homogenates in group administered the plant extract compared to negative control. MDA was significantly (p<0.05) lower in the group treated with plant extract when compared to negative control, while nitric oxide inhibition and GSH concentration were higher in group treated with the plant extract compared to negative control. Histology findings corroborated result obtained from the liver function status assays. Methanol fraction of crude extract showed highest antioxidant potential, and GC-MS profiling of the methanol fraction showed 6 compounds having benzene ring backbone, like those found in most phenolic acids. From the result of this study, it can be concluded that methanol fraction of HAAH contains compounds that may be responsible for the observed hepatoprotective and antioxidant properties.