Evaluation of Different Doses of <i>Tanacetum parthenium</i> Extract (TPE) on Blood Biochemical Parameters and Oxidative Stress Liver Biomarkers of Fish

Although medicinal plants can be used to reduce stress caused by transportation and handling and to prevent and treat certain diseases in fish, evaluating their safety for fish is essential before their use. This study aimed to evaluate the pharmacological effects and determine the safe dose of the Tanacetum parthenium (known as feverfew) extract (TPE) on blood biochemical parameters and the oxidative stress liver biomarker of common carp ( Cyprinus carpio ). In this study, fish were fed with doses of 0.0%, 0.5%, 1%, 2%, 5%, and 10% TPE per kg feed for 28 days. Next, blood biochemical parameters and hepatic oxidative biomarkers were measured to determine safe doses of the extract. The activities of aspartate aminotransferase (AST) and gamma‐glutamyl transpeptidase significantly increased ( p &lt; 0.05) after feeding fish with 10% TPE. Conversely, there was a notable decrease ( p &lt; 0.05) in alanine aminotransferase activity in the plasma of fish given 10% TPE. Furthermore, lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activities in the plasma were significantly higher ( p &lt; 0.05) in fish fed with either 5% or 10% TPE compared to the control group. Increasing doses of the extract significantly elevated plasma cholesterol, triglycerides, creatinine, and glucose levels; however, it did not significantly affect total protein, albumin, and globulin levels. Oxidative stress biomarkers indicated that 0.5%, 1%, and 2% doses were safe, while 5% and 10% extracts induced oxidative stress in fish. In conclusion, lower doses (0.5%–2%) of TPE are recommended for evaluating its therapeutic properties, as they offer safe and effective treatment for common carp without causing oxidative stress.