<abstract xmlns="http://www.w3.org/1999/xhtml">

As an abundant source of antioxidants and diet flavor enhancers, the plant essential oils can have positive effects on fish growth, and resistance against environmental stressors. In this study, garden thyme (<italic>Thymus vulgaris</italic>) essential oil (TEO) was used in the diet of rainbow trout, <italic>Oncorhynchus mykiss</italic>, to evaluate its protective effect against malathion pesticide exposure. Tested fish (19.99±0.01 g) were divided into six groups (three replicates), namely: T1: control diet; T2: control diet + 0.025 mg L−1 malathion; T3: control diet + 0.075 mg L−1 malathion; T4: control diet + 1% TEO; T5: control diet + 0.025 mg L−1 malathion + 1% TEO and T6: control diet + 0.075 mg L−1 malathion + 1% TEO. After 21 days, T4 fish had the highest final body weight (FW), weight gain (WG), specific growth rate (SGR), and the lowest feed conversion ratio (FCR) among experimental treatments (P&lt;0.05). The blood parameters including the red blood cells (RBC), white blood cell count (WBC), hematocrit (Hct), and hemoglobin (Hb) values were the highest in T4 treatment, displaying a significant difference with T1 treatment (P&lt;0.05). Fish in the T4 groups had the highest total protein (TP) and albumin (ALB), while fish of T3 showed the lowest levels of these parameters (P&lt;0.05) and also had the highest level of triglycerides (TRG), cholesterol (CHOL), lactate dehydrogenase (LDH), and urea (Ur). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes recorded the lowest levels in T4 treatment, which showed a significant difference with T1 group. The catalase (CAT) and superoxide dismutase (SOD) showed the highest activities in T4 treatment, while the lowest SOD and the highest malondialdehyde (MDA) levels occurred in T3 group (P&lt;0.05). Total immunoglobulin (total Ig) level, alternative complement (ACH50) and lysozyme in the serum and skin mucus of T4 treatment of rainbow trout showed the highest activities with a significant difference from groups (P&lt;0.05). From the results of the present study, it can be concluded that 1% of <italic>T. vulgaris</italic> as a supplement to the diet of rainbow trout can stimulate and improve the immune system of the fish. TEO can have a protective effect against unfavorable effects of malathion and improves the growth of the fish.
</abstract>

As an abundant source of antioxidants and diet flavor enhancers, the plant essential oils can have positive effects on fish growth, and resistance against environmental stressors. In this study, garden thyme (Thymus vulgaris) essential oil (TEO) was used in the diet of rainbow trout, Oncorhynchus mykiss, to evaluate its protective effect against malathion pesticide exposure. Tested fish (19.99±0.01 g) were divided into six groups (three replicates), namely: T1: control diet; T2: control diet + 0.025 mg L−1 malathion; T3: control diet + 0.075 mg L−1 malathion; T4: control diet + 1% TEO; T5: control diet + 0.025 mg L−1 malathion + 1% TEO and T6: control diet + 0.075 mg L−1 malathion + 1% TEO. After 21 days, T4 fish had the highest final body weight (FW), weight gain (WG), specific growth rate (SGR), and the lowest feed conversion ratio (FCR) among experimental treatments (P<0.05). The blood parameters including the red blood cells (RBC), white blood cell count (WBC), hematocrit (Hct), and hemoglobin (Hb) values were the highest in T4 treatment, displaying a significant difference with T1 treatment (P<0.05). Fish in the T4 groups had the highest total protein (TP) and albumin (ALB), while fish of T3 showed the lowest levels of these parameters (P<0.05) and also had the highest level of triglycerides (TRG), cholesterol (CHOL), lactate dehydrogenase (LDH), and urea (Ur). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) enzymes recorded the lowest levels in T4 treatment, which showed a significant difference with T1 group. The catalase (CAT) and superoxide dismutase (SOD) showed the highest activities in T4 treatment, while the lowest SOD and the highest malondialdehyde (MDA) levels occurred in T3 group (P<0.05). Total immunoglobulin (total Ig) level, alternative complement (ACH50) and lysozyme in the serum and skin mucus of T4 treatment of rainbow trout showed the highest activities with a significant difference from groups (P<0.05). From the results of the present study, it can be concluded that 1% of T. vulgaris as a supplement to the diet of rainbow trout can stimulate and improve the immune system of the fish. TEO can have a protective effect against unfavorable effects of malathion and improves the growth of the fish.

Potential protective effects of thyme (<italic>Thymus vulgaris</italic>) essential oil on growth, hematology, immune responses, and antioxidant status of <italic>Oncorhynchus mykiss</italic> exposed to malathion

Agricultural and Natural Resources College, Persian Gulf University

Assistant Professor, Department of Botany

Kuban State Agrarian University named after I.T. Trubilin

Department of Pharmaceutical Chemistry, College of Pharmacy

Annals of Animal Science

This work is licensed under the Creative Commons Attribution 4.0 International License.

Potential protective effects of thyme () essential oil on growth, hematology, immune responses, and antioxidant status of  exposed to malathion

As an abundant source of antioxidants and diet flavor enhancers, the plant essential oils can have positive effects on fish growth, and resistance against...

Potential protective effects of thyme (Thymus vulgaris) essential oil on growth, hematology, immune responses, and antioxidant status of Oncorhynchus mykiss exposed to malathion

Published Online: May 03, 2023

Page range: 481 - 493

Received: Jun 06, 2022

Accepted: Sep 02, 2022

DOI: https://doi.org/10.2478/aoas-2022-0064

Keywords
organophosphate, plant medicine, thyme, welfare, antioxidant, fish

© 2023 Saade Abdalkareem Jasim et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Potential protective effects of thyme (Thymus vulgaris) essential oil on growth, hematology, immune responses, and antioxidant status of Oncorhynchus mykiss exposed to malathion

Published Online: May 03, 2023

Page range: 481 - 493

Received: Jun 06, 2022

Accepted: Sep 02, 2022

DOI: https://doi.org/10.2478/aoas-2022-0064

Keywordsorganophosphate, plant medicine, thyme, welfare, antioxidant, fish

© 2023 Saade Abdalkareem Jasim et al., published by Sciendo

This work is licensed under the Creative Commons Attribution 4.0 International License.

Keywords
organophosphate, plant medicine, thyme, welfare, antioxidant, fish