The effect of cyclopropenoid fatty acids on binding of aflatoxin B₁ to nuclear DNA, RNA and protein of rat hepatocytes

C₁₈ and C₁₉ fatty acids containing a cyclopropene ring (CPFA's) natural compounds in plants of the order Malvales have been shown to augment the cardiogenic effects of aflatoxin B1 (AFB1) and recently identified as a potent mitogen for hepatocytes. Experiments to ascertain whether CPFA's affect the binding of AFB₁ to DNA, RNA and protein of rat liver cells were carried out. 50 gm male Sprague Dawley rats were fed a synthetic diet containing 500 ppm of CPFA's supplied as triglycerides in Sterculia foetida oil ad libitum for 2 wks. Comparable animals fed synthetic diet alone served as controls. Animals were injected I.P. (3μC/100 gm B.W.) with C¹⁴ ring labeled chromatographically pure AFB₁ (Sp. Ac. 5.37 μC/μM) dissolved in N methylformamide and sacrificed 1 hr later. DNA, RNA and protein were extracted; DNA was further purified by treatment with pronase, RNA ase, and by density gradient centrifugation on CsCl₂. These results corroborate earlier work that AFB₁ binds to a greater degree to protein and RNA than to DNA. Ingestion of CPFA enhanced binding of AFB₁ to protein by 39.9%, RNA 35.5% and DNA 37%. This effect of CPFA may be related to its potentiation of AFB₁ induced hepatocarcinoma.