Effect of aqueous extract of olive leaves on some biochemical changes induced by carbon tetrachloride in male rats

Olive tree leaves have been widely used in traditional remedies in European and Mediterranean countries and in the human diet as extracts, herbal teas, and powder, which contain several potential bioactive compounds that may have antihypertensive, antiatherogenic, anti-inflammatory, hypoglycemic, hypocholesterolemic, antidiabetic and antioxidant activities. The present study was carried out to evaluate the role of olive leaves extracts (OLE) in ameliorating the metabolic changes in rats treated with carbon tetrachloride (CCl4). Forty-eight male rats were classified into six groups; the first group was the control which received 1 ml distilled water, the second group was treated daily with oral dose of cold OLE (1 ml/kg) for one month, the third group was treated daily with oral dose of boiled OLE (1 ml/kg) for one month, the fourth group was treated daily with oral dose of CCl4 (1 ml/kg) for one month, the fifth group was treated with both cold OLE and CCl4 (1 ml/kg for each) for one month and the sixth group was treated with both boiled OLE and CCl4 (1 ml/kg for each) for one month. Serum levels of thiobarbituric acid reactive substance (TBARS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), urea, creatinine, insulin and glutathione (GSH), catalase (CAT), albumin, total protein, free triiodothyronine (FT3) , free thyroxin (FT4) were measured in serum.  Histological examination of hepatic tissue was examined. The results showed that administration of CCl4 to rats induced significant increase (P<0.05) in serum levels of thiobarbituric acid reactive substance (TBARS), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma- glutamyl transferase (GGT), lactate dehydrogenase (LDH), urea, creatinine, insulin and significant decrease (P<0.05) in glutathione (GSH), catalase (CAT), albumin, total protein, free triiodothyronine (FT3) and free thyroxin (FT4). The histological examination of hepatic tissue showed some degenerative changes while significant improvement in biochemical and histological changes was observed either in CCl4 + cold OLE or CCl4 + boiled OLE groups. It could be concluded that the protective effect of olive leaves extract either cold or boiling may be attributed to its antioxidant properties. The obtained results indicated that both cold and boiled olive leaves extract has potent effect to restore the antioxidant status, hepato-renal function, insulin and thyroid hormones near to the control levels.