CLOVE (SYZYGIUM AROMATICUM L.) AND THEIR EFFECT ON THE FORMATION OF HETEROCYCLIC AMINES

Abstract

Heterocyclic amines (HCAs) are a group of toxic chemicals, play an important role in the etiology of human cancer which formed at high temperature during cooking meat and fish. Antioxidants have proved to inhibit the formation of HCAs due to different mechanisms scavenging free radical, inhibits oxidative enzymes like cyochrome P450 and chelates metal ions like Fe⁺² as well as protecting lipids against oxidation. Clove has potent antioxidants and antimicrobial activities standing out among the other species. Therefore current study done to show efficiency of 0.5% clove at preventing the formation of two most common HCAs: 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) through seasoning of beef steaks before grilling and estimate antioxidant status of animals fed on the experimental diets. HCAs levels in food and blood samples were analyzed by HPLC.  The results showed that content of MeIQx and PhIP in grilled beef meat steak were 23.0 ±2.87 and 15.0±2.14 ng/g, respectively. While the content of MeIQx and PhIP in seasoning grilled steak were degraded to 1.9 ± 0.31 and 1.6 ± 0.23 ng/g, respectively. On the other hand the results showed that the percentages of reduction of MeIQx and PhIP were 91.7 and 89.3% in seasoning grilled steak, respectively comparing with un- seasoning grilled steak. The levels of tested HCAs also showed significant differences among rat groups fed on the experimental diets. The highest MeIQx and PhIP concentrate in serum rats group fed on untreated grilled meat diet (positive control) were11.1±1.85  and 8.77±8.77 ng/ml, respectively, while seasoning with 0.5% clove before grilling led to decrease in MeIQx and PhIP concentrate to 0.82±0.16 and 0.51±0.09  ng/ml respectively with decreasing percent reached  92.6 % and   94.2%  respectively. In addition, the results revealed that fed rats on un-seasoning grilled steak (positive control) caused high significant increased in lipid peroxide (malonaldhyde, MDA) accompanied by significant decreased in the levels of reduced glutathione content (GSH)  and activities of antioxidant defense enzymes glutathione peroxidase (GHPx) and catalase (CAT),  compared with basal diet group (negative control). However, clove treatment group lowered the level of lipid peroxidation and enhanced the antioxidant status of animals. Seasoning beef meat steaks before grilling with potent antioxidant clove species inhibit HCAs formation and their potential hazards to human health. This might be due to the powerful antioxidant activity of clove as strong hydrogen donating, metal chelating and scavenging of free radicals, hydrogen peroxide and superoxide.

Keywords: Heterocyclic amines (HCAs), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) , 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), clove, grilled beef meat, antioxidant plants, lipid peroxide, antioxidant defense enzymes.