Rational engineering of a polyvalent aptamer for mitigating Aflatoxin B₁ toxicity by disrupting metabolite Aflatoxin...

Aflatoxin B₁ (AFB₁), a highly toxic and carcinogenic mycotoxin, poses a significant threat to food safety and human health. Herein, a polyvalent aptamer (PA) was rationally engineered for effective neutralization of AFB₁. Molecular docking analysis revealed that the aptamer can cover AFB₁ key toxic sites- 8,9-double bond of the furan ring and O14, O15 positions. The generated steric hindrance effects could block the catalytic oxidation of AFB₁ by the cytochrome P450 (CYP450) enzyme, thereby inhibiting the generation of the active metabolite AFB₁-8,9-epoxide (AFBO) and mitigating its toxicity. Rolling circle amplification (RCA) technology was utilized to construct PA to improve the affinity (2.74 μM), stability (Tm = 60.59 °C), and inhibition efficacy. Compared with monovalent aptamers, PA exhibited significantly enhanced AFB₁ toxicity mitigation effects at both cellular and animal levels by effectively reducing AFB₁-induced cytotoxicity, oxidative stress, and liver tissue damage. Overall, the PA intervention strategy provides a new direction for the development of AFB₁ detoxification and other emerging toxin.