Chemical and Biological Evaluation of Myoporum laetum

Myoporum laetum (Myoporaceae) is an evergreen ornamental shrub. Fractionation and isolation of the butanol extract yielded five major flavonoids, luteolin 4-O-rhamnosid, 5-methoxy-lutelin 7-O-arabinoside, 5'-hydroxy-luteolin 7-O-glucoside, luteolin and apigenin. Their structures were determined by spectroscopic methods. The hepatoprotective and antioxidant activities of the butanol extract against liver injury induced by repeated doses of the hepatotoxicant, profenofos, were investigated. Hepatotoxicity of liver tissues was indicated by abnormal liver functions as shown by elevated levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and bilirubin with concomitant decrease in albumin level in relation to normal group. The pesticide induced oxidative hepatopathy ensured by a pronounced decrease in the activities of hepatic antioxidant enzymes namely, catalase (CAT), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G-6-PDH) accompanied by an increase in the oxidative stress marker, malonaldehyde (MDA, index of lipid peroxidation) versus normal ones. Oral supplementation of butanol extract to profenofos treated animals successfully modulated the hepatotoxicant induces deviation in the liver function markers, liver oxidative and antioxidant markers, indicating its potential hepatoprotective and antioxidant abilities.