Akademik Veri Yönetim Sistemi
Journal of Fish Biology, 2026 (SCI-Expanded, Scopus)
The aim of this study was to investigate the potential effects of monosodium glutamate (MSG), a known flavour enhancer added to many ready-to-eat foods, as a feed additive in rainbow trout (Oncorhynchus mykiss). Evaluating the effects of MSG on aquatic organisms will fill the knowledge gap in this field by monitoring the haematological indices of O. mykiss with growth parameters and somatic indices, histomap mapping with histopathological observations and determination of antioxidant/cytokine enzyme levels via holistic/multi-biomarker approaches. Accordingly, rainbow trout feed was supplemented with MSG at different concentrations [(control (0% MSG), MSG-I (0.25% MSG), MSG-II (0.5% MSG), MSG-III (0.75% MSG) and MSG-IV (1% MSG)], and a 60-day feeding trial was conducted. Considering the weight gain, MSG-IV group showed an increase of 24.5% compared to the control and was determined as 61%. Exposure to different concentrations of MSG caused a decrease in erythrocyte, leukocyte, hemoglobin (Hg) and hematocrit (Hct) levels in O. mykiss. The effect of the same application on liver tissue, which is the detoxification organ, was determined as inhibition in antioxidant enzyme activities superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and nuclear factor erythroid 2-related factor 2 (NRF-2) level, induction in Reactive oxygen species (ROS) -malondialdehyde (MDA) level, DNA damage, caspase-3, tumour necrosis factor α (TNF-α) and interleukin 6 (IL-6) activities. Histopathological examination of the liver and intestine revealed hydropic degeneration in a very small number of cells and mild hyperaemia of the blood vessels, with inflammation and DNA damage responses. With the reflection of this situation on histomap results, tissue damage profile and toxicity process differed based on dose and marker and manifested itself with mild-to-severe symptoms. These findings revealed that feeding with high concentrations of MSG was effective in NRF-2/ROS pathways of oxidative stress and showed strong haemato/hepatotoxic effects. Although all MSG concentrations applied were successful in terms of biomass measurements in terms of aquaculture, physiologically, the severity of toxic effects caused by MSG exposure was felt at a low level in liver tissues, and such pollutants should be considered in risk assessment.