Carnosic acid from rosemary extracts: a potential chemoprotective agent against aflatoxin B1. An in vitro study.
Since oxidative stress plays an important role in the toxicity mechanism of several mycotoxins such as aflatoxin B1 (AFB1), the use of natural or synthetic free radical scavengers could be a potential chemopreventive strategy. Carnosic acid (CA) is the major polyphenolic compound present in rosemary plants and it can also be found in sage leaves. Its free radical scavenging properties were tested with two chemical methods. It was found that it has good free radical scavenging capacity at pH 7.4. This study also found that a 24 h pre-treatment with 10, 20 and 30 microm CA led to a clear, dose-dependent protective effect on cell toxicity, reducing cell death induced by a 24 h exposure with 10 microm AFB1, respectively, by 16% (P < 0.05), 26% (P < 0.01) and 63% (P < 0.001). It was also found that a 24 h pre-treatment with 20 and 30 microm CA achieved a reduction of ROS levels, respectively, of 146% (P < 0.001) and 173% (P < 0.001) in HepG2 cells exposed to 10 microm AFB1 for 8 h. Moreover, in cells pre-incubated with 30 microm CA for 24 h the concentration of 8-OH-deoxyguanine decreased by 57% (P < 0.001) with respect to the cells exposed for 24 h to 10 microm AFB1 alone. The results obtained with the in vitro and chemical studies support the theory that AFB1 induced oxidative stress plays an important role in the cytotoxic mechanism of this mycotoxin. Furthermore these findings suggest a starting point for developing alimentary strategies in order to counteract the damage caused by AFB1 contamination in feed and food.
Costa
Stefano
S
Department of Pharmacology, University of Bologna, Italy. costa@biocfarm.unibo.it
Utan
Anelì
A
Speroni
Ester
E
Cervellati
Rinaldo
R
Piva
Gianfranco
G
Prandini
Aldo
A
Guerra
Maria Clelia
MC
D000080242:8-Hydroxy-2'-Deoxyguanosine / Q000031:analogs & derivatives; D045784:Abietanes / Q000494:pharmacology*; D016604:Aflatoxin B1 / Q000633:toxicity*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006147:Guanine / Q000031:analogs & derivatives / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008113:Liver Neoplasms; D018384:Oxidative Stress / Q000187:drug effects*; D010936:Plant Extracts / Q000494:pharmacology*; D020011:Protective Agents / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D027542:Rosmarinus / Q000737:chemistry*
D045784:Abietanes; D016166:Free Radical Scavengers; D010936:Plant Extracts; D020011:Protective Agents; D017382:Reactive Oxygen Species; D006147:Guanine; C078307:8-oxo-7,8-dihydrodeoxyguanine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D016604:Aflatoxin B1; C018381:salvin