Abstract
We studied the protective effect of bee honey and Nigella grains as nutraceuticals on the oxidative stress and carcinogenesis induced by methylnitrosourea (MNU) in Sprague Dawely rats. Four groups of animals were used and fed ad-libitum. The first group was a control (n=8), the second (n=8), the third (n=15) and the fourth groups (n=12) were injected MNU (single i.v. dose 50 mg/kg body weight). After one week the third and fourth groups were given orally 0.2g ground Nigella grains and 0.2g Nigella with 5g honey/rat/day, respectively. After six. months all animals were sacrificed except two from the second group (MNU-injected rats) that died one-week before the end of the experiment. We observed that MNU injected in the second group produced a variety of oxidative stresses ranging from severe inflammatory reaction in lung and skin to colon adenocarcinoma in four out of six animals. There was an associated elevation of malondialdehyde (MDA) and nitric oxide (NO) in sera obtained from animals of this group compared to the control one. Nigella sativa grains given orally protected against MNU-induced oxidative stress and carcinogenesis by 80% (12/15) and combated this effect by lowering MDA and NO. Whereas honey from bees and Nigella sativa together protected 100% (12/12) against MNU-induced oxidative stress, carcinogenesis and abolished the NO and MDA elevations shown in sera of animals who did not receive these nutrients. These results showed that supplementation of diet with honey and Nigella sativa has a protective effect against MNU-induced oxidative stress, inflammatory response and carcinogenesis.