Monitoring of mitotic index and frequency of micronuclei in evaluation of genotoxic potential of fumagillin (dicyclohexylamine) in vivo

Abstract

Fumagillin (dicyclohexylamine) is a natural antibiotic, secreted by Aspergillus fumigatus. It is used in veterinary medicine against microsporidiosis in bees and fish, as well as in human medicine for the treatment of intestinal amebiasis, microsporidial keratoconjunctivitis and intestinal microsporidiosis due to Enterocytozoon bieneusi in patients with AIDS and other types of immunodeficiency. In this study, the genotoxicity of fumagillin was evaluated in mouse bone marrow cells using the mitotic index (MI) and micronucleus (MN) assay. Fumagillin was administered to BALB/c mice by gavage in doses of 25, 50, 75 mg/kg b.w., repeated for 7 days at 24h intervals, with water-sugar syrup as the negative control and cyclophosphamide as the positive control (40 mg/kg b.w) All experimental doses of fumagillin induced a significant decrease (p lt 0.001) in MI (3.47 ± 0.04%, 3.17 ± 0.01% and 2.27 ± 0.02%, respectively) in comparison with the negative control (6.00 ± 0.01%) and with the positive control (14.78 ± 0.09). Fumagillin significantly (p lt 0.001) increased the frequency of MN (4.98 ± 0.35, 8.45 ± 0.57 and 12.02 ± 0.37, respectively) over the negative control (1.04 ± 0.28). These results suggest that fumagillin (dicyclohexilamine) has an antiproliferative and genotoxic potential in mammal in vivo test.

Fumagilin (dicyclohexylamine) je prirodni antibiotik koga produkuje Aspergillus fumigatus. Upotrebljava se u veterinarskoj medicini protiv mikrosporidioza pčela i riba, ali i u humanoj medicini za tretman intestinalnih amebijaza, microsporidijalnih keratokonjunktivitisa i intestinalnih mikrosporidioza uzrokovanih sa Enterocytozoon bieneusi kod pacijenata obolelih od AIDS-a i drugih tipova imunodeficijencije. U ovom radu procenjivan je genotoksični potencijal fumagilina u ćelijama kostne srži miševa praćenjem mitotskog indeksa i učestalosti pojave mikronukleusa u polihromatofilnim eritrocitima. Fumagilinom su u 7-dnevnom tretmanu tretirani BALB/c miševi intragastrično u dozama 25, 50, 75 mg/kg TM, u intervalima od 24h. Kao negativna kontrola korišćen je vodeno-šećerni sirup dok je ciklofosfamid (40 mg/kg TM) korišćen kao pozitivna kontrola. Sve eksperimentalne doze fumagilina su izazvale signifikantno smanjenje (p lt 0.001) mitotskog indeksa (3.47 ± 0.04%, 3.17 ± 0.01% i 2.27 ± 0.02% respektivno) u poređenju sa negativnom kontrolom (6.00 ± 0.01%), kao i u odnosu na pozitivnu kontrolu (14.78 ± 0.09). Fumagilin je signifikantno (p lt 0.001) povećao frekvenciju pojave mikronukleusa (4.98± 0.35, 8.45 ± 0.57 i 12.02± 0.37, respektivno) u odnosu na negativnu kontrolu (1.04 ± 0.28). Ovi rezultati ukazuju da fumagilin (dicyclohexilamine) ispoljava antiproliferativni (citotoksični) i genotoksični potencijal u sisarskom in vivo testu.