Monosodium glutamate (MSG) consumption is responsible for a wide spectrum of health
hazards including nephrotoxicity. The search for phytochemical strategies having broad
safety profile to counter MSG toxicity is worthwhile. Nigella sativa L. seed (NSS) is very
promising in this regard owing to its antioxidant and cytoprotective nature. Therefore, we
attempted to investigate the potential protective effect of NSS on MSG-induced renal
toxicity in rats. To accomplish this objective, fifteen adult Wistar albino rats were randomly
and equally divided into three groups for 21 days: the control group received no treatment,
MSG group supplemented with MSG at a dose of 30 g/kg feed, and MSG + NSS group
supplemented with MSG at the same previous dose in conjugation with NSS at a dose of
30 g/kg feed. MSG and its combination with NSS failed to cause any significant difference
in the kidney function parameters in comparison with the control. A significant elevation in
lipid peroxides (LPO) level, glutathione-S-transferase activity and total antioxidant capacity
(TAC) and a significant reduction in superoxide dismutase activity were found in MSG
group. LPO level and TAC in MSG intoxicated rats significantly normalized by NSS
ingestion. NO level showed absence of significant difference among all experimental
groups. MSG elicited histopathological lesions such as decreased glycoprotein content
and fibrosis however, NSS succeeded in enhancing all these features. MSG group showed
positive glutathione reductase and superoxide dismutase 2 immuno-expression whereas,
MSG + NSS group showed weak immunostaining. A significant increase in the number of
apoptotic cells was observed in MSG group compared to the control. On the other hand,
MSG + NSS group exhibited a significant decrease in the number of apoptotic cells. NSS
mitigated MSG-induced renal impairments by ameliorating oxidative stress and exerting
anti-apoptotic effect.