Induction of liver monooxygenases by annatto and bixin in female rats

Abstract

Annatto or urucum is an orange-yellow dye obtained from Bixa orellana seeds. It has been used as a natural dye in a variety of food products, drugs and cosmetics, and also in Brazilian cuisine as a condiment (colorau). Bixin, a carotenoid devoid of provitamin A activity, is the main pigment found in annatto. Some carotenoids (canthaxanthin, astaxanthin and ß-Apo-8'-carotenal) are known to be potent inducers of CYP1A1, a property not shared by others (ß-carotene, lycopene and lutein). Little is known, however, about the CYP1A1-inducing properties of bixin and annatto. The present study was performed to determine the effects of an annatto extract (28% bixin) and bixin (95% pure) on rat liver monooxygenases. Adult female Wistar rats were treated by gavage with daily doses of annatto (250 mg/kg body weight, which contains approximately 70 mg bixin/ kg body weight), bixin (250 mg/kg body weight) or the vehicle only (corn oil, 3.75 g/kg body weight) for 5 consecutive days, or were not treated (untreated control). The activities of aniline-4-hydroxylase (A4H), ethoxycoumarin-O-deethylase (ECOD), ethoxy-(EROD), methoxy-(MROD), pentoxy-(PROD) and benzyloxy-(BROD) resorufin-O-dealkylases were measured in liver microsomes. Annatto (250 mg/ kg containing 70 mg bixin/kg) induced EROD (3.8x), MROD (4.2x), BROD (3.3x) and PROD (2.4x). Bixin (250 mg/kg) was a weaker inducer of EROD (2.7x), MROD (2.3x) and BROD (1.9x) and did not alter PROD, A4H or ECOD activities. These results suggest that constituents of the extract other than bixin play an important role in the induction of CYP1A and CYP2B observed with annatto food colorings.

Effect of bixin and norbixin on the expression of cytochrome P450 in HepG2 cell line

“…Exposure of HepG2 to bixin led to an increase in the expression of the CYP1A1 and 1A2 enzymes at a minimum concentration of 0.05 mM (Figure 4). This agrees with De Oliveira et al (2003) and Jewell and O'Brien (1999), who found increased CYP1A activity in rats treated with bixin. The CYP1A1 and CYP1A2 enzymes are regulated by the aryl hydrocarbon receptor (AhR).…”

“…The effect of bixin on rat xenobiotic metabolising enzymes was first reported by Jewell and O'Brien (), who demonstrated that bixin is inducer of rat lung and liver CYP1A1/2 and CYP1B1/2. Increased CYP1A and CYP2B activity bixin induced was also reported by De Oliveira et al ().…”

Effect of an aqueous extract of annatto (Bixa orellana) seeds on lipid profile and biochemical markers of renal and hepatic function in hipercholesterolemic rats

“…The treatment with annatto extract in animals fed with the highlipid diet did not alter these observations. However, De-Oliveira et al (2003) showed that oral annatto intake induced liver cytochrome P450 monooxygenase system, which was a collection of isoenzymes which catalyze different types of oxidation reactions (Jewell and O'Brien, 1999). Liver is the organ responsible for glucose homeostasis, thus observed hepatic injury could explain the glucose levels reduction in high-lipid fed animals.…”

“…The indigenous Amazon people have used "urucum" for body painting for centuries. Seeds and leaves of the annatto tree were used by the Aztecs to prepare remedies for a variety of illnesses such as tonsillitis, asthma, pleurisy, rectal disorders, headache, jaundice, sunstroke, and burns (De Oliveira et al, 2003). Although the plant species originated in northern South America, it is now widely cultivated in tropical areas for commercial production (Hagiwara et al, 2003).…”

Effects of Bixa orellana L. Seeds on Hyperlipidemia

“…Bixa orellana L. ( annatto), ‘urucum ’ aka ‘ urucu ’, family Bixacea, a tropical tree native to the Central and South American rain forests is used in popular medicine to treat various diseases (Paumgartten et al ., ). The indigenous Amazon people have used urucum for body painting for centuries and it is believed that the original Aztec chocolate beverage contained annatto seeds in addition to cocoa (De‐Oliveira et al ., ). In Latin America, urucu has been used as a color additive in drugs, cosmetics and also in food products (Hallagan et al ., ; De‐Oliveira, ).…”