ZIF-8 and ZIF-67 nanomaterials suppress Nosema bombycis proliferation by mitigating oxidative stress and activating the Toll pathway

ZIF-8 and ZIF-67 are effective against Nosema bombycis infection in silkworms. • ZIF-67 can directly damage spores' structure, showing superior protective efficacy. • ZIF-8 and ZIF-67 can mitigate infection-induced oxidative stress in silkworm. • ZIF-8 and ZIF-67 can activate the host's Toll immune signaling pathway. Pebrine disease, caused by Nosema bombycis , threatens global sericulture due to the lack of green and efficient control agents. Zeolitic imidazolate frameworks (ZIFs) are promising antimicrobial nanomaterials, but their efficacy and mechanism against microsporidia in insects remain unexplored. In this study, we synthesized and characterized ZIF-8 and ZIF-67 nanomaterials to evaluate their protective effects against N. bombycis infection in silkworms and to investigate the underlying mechanisms. Results showed that both materials, administered at 150 μg/g body weight, significantly suppressed the proliferation of N. bombycis and markedly improved the survival rate of infected silkworms, with ZIF-67 showing superior efficacy. Mechanistically, ZIF-67 directly damaged spore structure, while both materials alleviated host oxidative stress by reducing reactive oxygen species levels and upregulating antioxidant enzyme genes ( GSTs1, CAT, Aldh ), and activated the Toll signaling pathway to increase the expression of antimicrobial peptides genes (g loverin2, Attacin1 ). In conclusion, ZIF-8 and ZIF-67, particularly ZIF-67, protect silkworms through a multi-mechanistic strategy involving direct pathogen damage, enhanced host antioxidant capacity, and innate immune activation. Our work not only proposes novel nano-candidates for pebrine control but also provides insights for sustainable agricultural applications.