The Role of Quercetin in Mitigating the Oxidative Stress and Hepatotoxicity Induced by Monosodium Glutamate (MSG) in Male Albino Rats

Objective: Monosodium glutamate (MSG) is a widely used food additive, but high-dose exposure has been linked to liver toxicity. This study assessed the protective effects of quercetin on MSG-induced hepatotoxicity in male albino rats. Methods: Twenty male Sprague Dawley rats (200–250 g) were divided into four groups (n = 5/group). Group 1 received distilled water (control); Group 2 received quercetin (100 mg/kg/day) for three months; Group 3 received MSG (15 mg/kg/day) for three months; Group 4 received MSG for one month, followed by a 48-hour washout, then quercetin (100 mg/kg/day) for one month. Serum levels of malondialdehyde (MDA), total antioxidant capacity (T-AOC), tumour necrosis factor-alpha (TNF-α), and liver enzymes (ALT, AST, ALP, GGT) were evaluated. Results: MSG significantly increased MDA (3.65 ± 0.26 nmol/mL), TNF-α (3.71 ± 0.98 pg/mL), ALT (56.86 ± 3.64 U/L), AST (65.26 ± 3.65 U/L), ALP (146.10 ± 8.32 U/L), and GGT (5.84 ± 0.36 U/L), while decreasing T-AOC (2.76 ± 0.32 U/L) (p ≤ 0.05). Group 4 showed marked improvement: reduced MDA (2.78 ± 0.31 U/L), TNF-α (2.78 ± 0.37 pg/mL), ALT (21.75 ± 2.33 U/L), AST (31.54 ± 3.78 U/L), ALP (65.73 ± 6.42 U/L), GGT (2.99 ± 0.35 U/L), and increased T-AOC (2.78 ± 0.48 µmol/mL). Conclusion: Quercetin significantly reduced MSG-induced oxidative stress, inflammation, and liver enzyme elevation. These findings support its potential as a natural hepatoprotective agent.