Black Garlic Extract Modulates Endothelin Expression and Ovulatory Function in Monosodium Glutamate Treated Rats

Monosodium glutamate (MSG), a widely used food additive, has been associated with various health concerns, including potential reproductive toxicity. This study investigated the protective effects of black garlic (BG) ethanol extract against MSG-induced ovarian damage in rats. Thirty-two female rats in estrus were randomly divided into four groups (n = 8 per group): control (saline), BG (250 mg/kg BW), MSG (4 mg/g BW), and BG+MSG (combined treatment). Treatments were administered daily for 14 days. Ovarian tissues were collected for histopathological, immunohistochemical (IHC), and biochemical analyses. Histopathological examination revealed a significant reduction in cystic follicles in the BG+MSG group compared to the MSG group (p < 0.0001). IHC analysis showed decreased immunoreactivity of endothelin-1 and endothelin-2 in the BG+MSG group compared to the MSG group (both p < 0.01). Biochemical assays demonstrated significantly increased follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol levels in the BG+MSG group compared to the MSG group (all p < 0.05), while progesterone levels were significantly lower in the MSG group compared to the BG+MSG group (p < 0.05). These findings suggest that BG ethanol extract may mitigate MSG-induced ovarian dysfunction in rats by alleviating degenerative changes in follicles and modulating hormonal levels. This study provides insights into potential natural interventions for MSG-related reproductive toxicity.