The dysregulation of autophagy, an evolutionarily conserved lysosomal degradation process, has been implicated in a wide variety of human diseases, and thus, small chemicals that modulate autophagy have therapeutic potential. Here, we assessed the ability of active components isolated from Bupleurum falcatum, a popular Chinese herb, to modulate autophagy. We found that saikosaponin D (SsD) and A (SsA) but not C (SsC) potently and reversibly inhibited the fusion of autophagosomes and lysosomes, resulting in the accumulation of autophagosomes, an increased lysosomal pH, and TFEB nuclear translocation. RAB5A knockdown or the expression of a dominant-negative RAB5 mutant significantly reduced the ability of SsD or SsA to block autophagy. Enterovirus A71 (EV-A71), the cause of hand-foot-mouth disease, has been shown to induce autophagy. We found that SsD potently inhibited EV-A71 RNA replication and subsequent viral protein synthesis, thereby preventing EV-A71-induced cell death. ATG5 knockdown inhibited EV-A71 viral protein synthesis, whereas autophagy induction by rapamycin promoted synthesis. Taken together, our data indicate that SsD and SsA are potent late-stage autophagy inhibitors that can be used to prevent EV-A71 infection.

自噬失调是进化上保守的溶酶体降解过程，已与多种人类疾病有关，因此，调节自噬的小化学物质具有治疗潜力。在这里，我们评估了从柴胡柴胡中分离出的活性成分的能力。，一种流行的中草药，可调节自噬。我们发现赛可皂甙D（SsD）和A（SsA）而非C（SsC）有效且可逆地抑制了自噬小体和溶酶体的融合，导致自噬小体的积累，溶酶体pH值增加和TFEB核易位。RAB5A敲低或显性阴性RAB5突变体的表达显着降低了SsD或SsA阻断自噬的能力。肠病毒A71（EV-A71）是手足口病的病因，已被证明可引起自噬。我们发现SsD有效抑制EV-A71 RNA复制和随后的病毒蛋白合成，从而防止了EV-A71诱导的细胞死亡。ATG5组合式抑制EV-A71病毒蛋白合成，而雷帕霉素自噬诱导促进合成。在一起