摘要Background Aflatoxin B1(AFB1)risks animal and human health,and the liver is considered the most crucial detoxifi-cation organ.Phlorotannin(PT)is a polyhydroxy phenol that has a wide range of biological activities,including anti-oxidation and hepatoprotection,which can promote the ability of liver detoxification.This study aimed to elucidate the protective effect of PT on AFB1-induced liver damage in broilers.Results In vivo experiment showed that the PT reduced AFB1 content and AFB1-exo-8,9-epoxide DNA(AFBO-DNA)concentration in serum and liver(P＜0.05),improved the histomorphology of liver and hepatic mitochon-dria,and activated nuclear factor erythroid 2-related factor 2(Nrf2)-related antioxidant and detoxification pathway by upregulating the activities of antioxidant enzymes(catalase[CAT],glutathione S-transferase[GST])and total antioxidant capacity(T-AOC)level(P＜0.05),and inhibited the mRNA expression of CYP1A1(cytochrome P450 fam-ily 1 subfamily A member 1)and phase Ⅱ detoxification enzyme related genes(GPX1,GSTT1,and NQO1)of broilers exposed to AFB,(P＜0.05).Meanwhile,PT upregulated the Nrf1 pathway-related mitochondrial biosynthetic genes(Nrf1,mitochondrial transcription factor A[TFAM],mitofusin 1[MFN1])in broilers fed AFB1 contaminated diet(P＜0.05).In vitro verification study suggested that the use of Nrf2/Nrf1 inhibitors suppressed the ameliorative role of PT on AFB1-induced liver injury of broilers,which was manifested in the mRNA expression of Nrf2,NQO1,GSTT3,Nrf1,TFAM,and other genes decreasing(P＜0.05),and down-regulation of the protein expression of Nrf2,total and nucleus p-Nrf2,and total and nucleus p-Nrf1(P＜0.05).Conclusion The PT ameliorates oxidative stress and hepatotoxicity by activating the Nrf2-mediated phase Ⅱ detoxifi-cation enzymes pathway and maintains mitochondrial homeostasis by activating the Nrf1 signaling pathway in broil-ers exposed to AFB1.