Effects of humic acid‐metal complexes on hepatic carnitine palmitoyltransferase, carnitine acetyltransferase and catalase activities

Abstract

AbstractA significant increase in activities of hepatic carnitine palmitoyltransferase and carnitine acetyltransferase was observed in male Balb/c mice intraperitoneally injected for 40 d with 0 125 mg/0 1 ml/d humic acid‐metal complexes. Among these complexes, the humic acid‐As complex was relatively effective, whereas humic acid‐25 metal complex was more effective, and humic acid‐26 metal complex was most effective However, humic acid or metal mixtures, or metal such as As alone, was not effective Humic acid‐metal complexes also significantly decreased hepatic catalase activity. A marked decrease of 60‐kDa polypeptide in liver cytoplasm was also observed on SDS‐polyacrylamide gel electrophoresis after the mice had been injected with the complexes. Morphological analysis of a histopathological biopsy of such treated mice revealed several changes in hepatocytes, including focal necrosis and cell infiltration, mild fatty changes, reactive nuclei, and hypertrophy Humic acid‐metal complexes affect activities of metabolic enzymes of fatty acids, and this results in accumulation of hydrogen peroxide and increase of the lipid peroxidation The products of lipid peroxidation may be responsible for liver damage and possible carcino‐genesis. Previous studies in this laboratory had shown that humic acid‐metal complex altered the coagulation system and that humic acid, per se, caused vasculopathy. Therefore, humic acid‐metal complexes may be main causal factors of not only socalled blackfoot disease, but also the liver cancer prevailing on the southwestern coast of Taiwan.