Abstract
The toxic effects of excess vitamin A (VA) intake deserve increased attention. Nigella sativa (NS) seed possesses physiological and pharmacological actions and protects against toxic agents. This work investigated the availability of NS seed oil as a protective agent against the effects of hypervitaminosis A (HVA) on liver function and immunity.
Fifty adult albino rats were used and divided into five groups: (G1) control; (G2) experimental HVA rats administered extreme doses (10,000 IU/kg body weight) of VA oil orally, daily for 6 weeks; (G3) rats treated with NS seed oil (800 mg/kg) orally, daily for 6 weeks; (G4) HVA rats simultaneously treated with NS seed oil at the same doses and periods; and (G5) HVA recovery group. Liver function, immunoglobulin (IgG and IgM) levels, and lysosome activity were measured in serum.
HVA rats revealed marked elevations in alanine aminotransferase and aspartate aminotransferase activities. This is the first study to demonstrate that NS seed oil possesses significant hepatoprotective activity against HVA. NS seed oil was a potent inducer of IgG and IgM in rat serum either alone or with high doses of VA.
These findings may be considered the initial steps of the physiological and humoral immune responses for NS seed oil against HVA, but further studies examining longer periods are needed prior to recommending the use of NS seed oil as an alternative medicine for hepatic and immune diseases.