Page 1289

www.rsisinternaonal.org

INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,

MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)

ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XV, Issue V, May 2026

"Impact of Sub-Lethal Monosodium Glutamate Exposure on Hepatic

Protein Profiles in Labeo rohita"

Takale A. B

. and Kamble V. S.

1.Research Scholar, School of Life Science, P.A.H. Solapur University, Solapur.

2.Asso.Prof, Department of Zoology Sangola Mahavidyalaya, Sangola

DOI: https://doi.org/10.51583/IJLTEMAS.2026.150500099

Received: 11 May 2026; Accepted: 16 May 2026; Published: 4 June 2026

ABSTRACT

This study evaluated the ecotoxicological impact of Monosodium Glutamate (MSG) on the freshwater fish Labeo

rohita (Rohu). The experiment focused on alterations in liver total protein levels following chronic sub-lethal

exposure. Labeo rohita were exposed to a constant sub-lethal dose of 10 mg/L of MSG across three progressive

temporal intervals: 5, 10, and 15 days. A parallel control group was maintained in chemical-free freshwater.

Quantitative estimation of total liver proteins was conducted using standard spectrophotometric methods.

The results demonstrated a highly significant, time-dependent decline in total liver protein concentration in all

MSG-exposed groups compared to the control group. The baseline liver protein level in the control group was

recorded at 65.4 ± 1.2 mg/g of wet tissue. Upon exposure to 10 mg/L of MSG, liver protein levels dropped to

52.1 ± 1.0 mg/g on Day 5, 41.8 ± 0.9 mg/g on Day 10, and reached a minimum value of 28.5 ± 0.7 mg/g on Day

15. This marked depletion highlights severe physiological stress, metabolic reallocation, and potential cellular

degradation in the hepatic tissue. The study confirms that even low concentrations of agricultural or industrial

MSG runoff pose a threat to aquatic organisms by disrupting essential protein synthesis pathways.

Keywords: Monosodium Glutamate, Labeo rohita, Liver Protein, Ecotoxicity, Metabolic Stress.

INTRODUCTION

The rapid expansion of the food processing industry and food additive production has led to a significant increase

in chemical effluents entering freshwater ecosystems and also in daily diet. Monosodium Glutamate (MSG), the

sodium salt of glutamic acid, is globally utilized as an umami flavour enhancer in household and commercial

food products. While international food regulatory agencies widely classify MSG as safe for human oral

consumption within moderate limits, its continuous release from feed-additive industries and domestic waste

presents an overlooked threat to non-target aquatic organisms.

Fishes serve as excellent biological indicators for ecotoxicological monitoring. They occupy critical positions in

the aquatic food chain and directly mirror the chemical health of their habitat. Labeo rohita (Hamilton, 1822),

commonly known as Rohu, is an economically vital carps species extensively cultivated across South Asia.

Because of its sensitivity to chemical pollutants, it is an ideal candidate for assessing sub-lethal chemical toxicity.

The teleost liver acts as the primary organ for nutrient metabolism, xenobiotic detoxification, and vital plasma

protein synthesis. Cellular disruptions within hepatic tissue directly impair metabolic and homeostatic functions.

Proteins are fundamental biological macromolecules essential for structural architecture, enzymatic biocatalysis,

and cellular defense mechanisms. Exposure to sub-lethal concentrations of environmental toxins alters total

protein profiles due to accelerated protein breakdown or a downregulation in biosynthesis.

While previous research has documented the histopathological impacts of MSG on teleost gills and kidneys,

limited quantitative data exists on its sub-lethal biochemical impact on core metabolic proteins. Therefore, this

investigation was designed to study the time-dependent impact of a sub-lethal MSG concentration (10 mg/L) on

the total liver protein content of Labeo rohita over 5, 10, and 15 days of exposure.

Page 1290

www.rsisinternaonal.org

INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,

MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)

ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XV, Issue V, May 2026

MATERIALS AND METHODS

Healthy Labeo rohita (average weight 90–120 g) were acclimatized in aerated freshwater tanks (temperature

25–28°C, pH 7.0–7.5, for 15 days. Fish were fed a commercial diet and divided into control and treatment groups.

The treatment group received a 5 mg dose of MSG through diet. Liver samples were collected after 5, 10, and

15 days of exposure.

Liver protein was quantified using a Lowry Method (Colorimetric). Results are expressed as mg of protein/100

mg of wet liver tissue weight.

RESULTS

No fish mortality was observed during the 15 days of sub-lethal MSG exposure. However, fish exposed to 10

mg/L of MSG exhibited mild behavioral changes, including transient hyper-locomotion and altered feeding

patterns.

Biochemical analysis of the hepatic tissue revealed a clear, time-dependent decrease in total protein levels in the

MSG-treated groups compared to the control group. The baseline liver protein level of the control group

remained stable at 65.4 ± 1.2 mg/g. In the MSG exposure groups, protein levels dropped steadily across the test

intervals. On Day 5, liver protein decreased to 52.1 ± 1.0 mg/g, representing a 20.3% reduction. By Day 10, the

level fell to 41.8 ± 0.9 mg/g, a 36.1% reduction.

The maximum depletion occurred on Day 15, where the protein level fell to 28.5 ± 0.7 mg/g, a 56.4% decrease

compared to the control group. One-way ANOVA confirmed that the reduction in total liver protein across all

exposure intervals was statistically highly significant (\(p < 0.05\)).

Table No. 1: Liver Protein Content (mg/100 mg tissue) in Labeo rohita under 10 mg MSG Exposure for

15 days-

Exposure

Period of

MSG

Total Liver

Protein

(mg/g of wet

tissue)

Percentage

Change

(%)

Statistical

Significance (\ (p <

0.05\))

Control

65.4

Baseline

Non-Significant

5 Days

52.1

20.34%

Significant

10 Days

41.8

36.08%

Highly Significant

15 Days

28.5

56.42%

Extremely Significant

Graph No.1: Liver Protein Content (mg/100 mg tissue) in Labeo rohita under 10 mg MSG Exposure for

15 days-

Control 5 Days 10 Days 15 Days

Liver Protein Content (mg/100 mg tissue) in

Labeo rohita under 10 mg MSG Exposure for 15

days

Total Liver Protein (mg/g of wet tissue) Percentage Change (%)

Page 1291

www.rsisinternaonal.org

INTERNATIONAL JOURNAL OF LATEST TECHNOLOGY IN ENGINEERING,

MANAGEMENT & APPLIED SCIENCE (IJLTEMAS)

ISSN 2278-2540 | DOI: 10.51583/IJLTEMAS | Volume XV, Issue V, May 2026

DISCUSSION

The quantitative results demonstrate that a sub-lethal dose of 10 mg/L of MSG induces a severe, time-dependent

reduction in the total liver protein content of Labeo rohita. Proteins serve as vital cellular structural components

and are actively involved in physiological compensation during chemical-induced stress. The steady decline in

liver protein content indicates that chronic exposure to MSG compromises basic metabolic and cellular

functionality in teleost models.

This depletion can be attributed to several interacting physiological mechanisms. First, exposure to sub-lethal

concentrations of xenobiotics accelerates protein catabolism. Under chemical stress, organisms require extra

energy to maintain cellular homeostasis and activate detoxification pathways. Consequently, the fish metabolizes

its own structural and functional proteins via proteolysis to supply free amino acids to the tricarboxylic acid

(TCA) cycle, helping meet this elevated energy demand. This compensatory strategy is common in freshwater

teleosts facing chemical stress.

Second, excess accumulation of exogenous glutamate in the aquatic medium can lead to systemic oxido-nitrergic

stress within hepatic tissues. Intracellular accumulation of MSG triggers the overproduction of Reactive Oxygen

Species (ROS). This induces lipid peroxidation of hepatocyte organelle membranes, particularly the rough

endoplasmic reticulum. Structural damage to the endoplasmic reticulum directly disrupts ribonuclear protein

translation machinery, leading to as down-regulation of new protein synthesis. This pathway aligns with previous

findings where high doses of MSG caused cellular toxicity, mitochondrial membrane alterations, and damaged

hepatocytes in animal models.

CONCLUSION

This investigation confirms that a sub-lethal concentration of Monosodium Glutamate (10 mg/L) causes a

significant, time-dependent reduction in the total liver protein content of Labeo rohita. The maximum depletion

(56.42%) occurred at the 15-day mark, demonstrating that prolonged exposure risks severe metabolic

impairment. This reduction points to accelerated proteolysis to meet energy demands and a breakdown in protein

synthesis driven by oxidative stress. These findings underscore that low-level MSG contamination in natural

water bodies can destabilize health profiles in non-target carps. Further studies are needed to assess recovery

potential in clean water and the broader impact of this metabolic stress on the aquatic food chain.

REFERENCES

1. Ataseven, H., et al. (2025). Evaluation of the Effects of Monosodium Glutamate on Hepatic and Renal

Oxidative Stress. MDPI Toxics, 15(3), 64.

2. Diniz, Y. S., et al. (2021). Toxicity of monosodium glutamate intake on different tissues and metabolic

profiles. Journal of Metabolic and Animal Sciences, 26(3), 45-58.

3. Eweka, A. O., & Om'Iniabohs, F. A. E. (2020). Histochemical Studies of the Effects of Monosodium

Glutamate on the Liver of Adult Wistar Rats. Internet Journal of Gastroenterology, 12(2).

4. Niaz, K., et al. (2020). Monosodium glutamate induces memory and hepatic challenges in test models:

Defensive role of herbal intervention. PMC Pharmacology, 11(4), 215-227.

5. Perumalsamy, K., et al. (2024). Histopathological alterations in the vital organs of Indian major carp

Labeo rohita exposed to sub-lethal concentration of MSG. Journal of Basic and Applied Zoology, 85(10),

1-12.

6. Sharma, A. (2021). Changes in the plasma electrolytes of fresh water teleost fish Labeo rohita exposed

to sublethal concentration of monosodium glutamate. ResearchGate Publication, 352041990.

7. Thomas, M., et al. (2023). The excitotoxic effect of monosodium glutamate on Zebra Fish (Danio rerio).

International Journal of Biosciences, 23(6), 112-120.

8. Zanfirescu, A., et al. (2019). A review of the alleged health hazards of monosodium glutamate.

Comprehensive Reviews in Food Science and Food Safety, 18(4), 1111-1134.