Pages: (55-66 )
Abstract
Monosodium glutamate (MSG) is a naturally occurring compound widely used as a flavor enhancer. This
study aimed to determine histological and endocrine changes in male Wistar rats following oral
administration of MSG. Thirty (30) male Wistar rats, averaging 120 ± 15 g, were divided into five
experimental groups (A–E) of six rats each. Group A served as control, while Groups B–E received 10,
20, 40, and 80 mg/kg body weight (bwt) of MSG, respectively, via daily oral gavage for 28 days. Rats
were acclimatized for two weeks before treatment. Blood samples were obtained by cardiac puncture for
hormonal analysis, and testes were harvested and fixed in 10% neutral-buffered formalin for histological
evaluation using hematoxylin and eosin staining. Results showed a non-significant decrease in serum
luteinizing hormone (LH) levels (p > 0.05), a significant reduction in testosterone (p < 0.05), and a non-
significant increase in follicle-stimulating hormone (FSH) levels (p > 0.05) across treatment groups
compared to control. Specifically, LH decreased from 3.10 ± 0.14 ng/mL to 1.60 ± 0.28 ng/mL (p =
0.006), testosterone decreased from 3.40 ± 0.28 ng/mL to 0.20 ± 0.28 ng/mL (p = 0.000), and FSH
increased from 1.00 ± 0.00 ng/mL to 2.40 ± 0.28 ng/mL (p = 0.221). Histological assessment revealed
mild hypertrophy and structural alterations in the seminiferous tubules, most pronounced in Group E (80
mg/kg bwt). In conclusion, high-dose MSG administration alters reproductive hormone profiles and
induces testicular histopathological changes in male Wistar rats. These findings suggest a potential risk
of reproductive dysfunction with prolonged high-level MSG exposure.
Keywords: Luteinizing hormone, Testosterone hormone, Follicle-stimulating hormone, Monosodium glutamate, hypertrophy,