Polyphyllin D punctures hypertrophic lysosomes to reverse drug resistance of hepatocellular carcinoma by targeting acid sphingomyelinase.

Hypertrophic lysosomes are critical for tumor progression and drug resistance; however, effective and specific lysosome-targeting compounds for cancer therapy are lacking. Here we conducted a lysosomotropic pharmacophore-based in silico screen in a natural product library (2,212 compounds), and identified polyphyllin D (PD) as a novel lysosome-targeted compound. PD treatment was found to cause lysosomal damage, as evidenced by the blockade of autophagic flux, loss of lysophagy, and the release of lysosomal contents, thus exhibiting anticancer effects on hepatocellular carcinoma (HCC) cell both in vitro and in vivo. Closer mechanistic examination revealed that PD suppressed the activity of acid sphingomyelinase (SMPD1), a lysosomal phosphodieserase that catalyzes the hydrolysis of sphingomyelin to produce ceramide and phosphocholine, by directly occupying its surface groove, with Trp148 in SMPD1 acting as a major binding residue; this suppression of SMPD1 activity irreversibly triggers lysosomal injury and initiates lysosome-dependent cell death. Furthermore, PD-enhanced lysosomal membrane permeabilization to release sorafenib, augmenting the anticancer effect of sorafenib both in vivo and in vitro. Overall, our study suggests that PD can potentially be further developed as a novel autophagy inhibitor, and a combination of PD with classical chemotherapeutic anticancer drugs could represent a novel therapeutic strategy for HCC intervention.

Paeoniflorin alleviates lipopolysaccharide-induced disseminated intravascular coagulation by inhibiting inflammation and coagulation activation.

Lipopolysaccharide (LPS) is a toxic component of the outer membrane of gram-negative bacteria that can activate the blood coagulation system, leading to disseminated intravascular coagulation (DIC). DIC is a syndrome characterized by thromboembolism and multiple organ failure. Herein, the beneficial effect of paeoniflorin (PF) on the alleviation of LPS-induced DIC was investigated with an experimental DIC mouse model. Briefly, mice were randomly divided into the following six groups: (1) control; (2) LPS; (3) heparin; (4) low-PF treatment; (5) medium-PF treatment; and (6) high-PF treatment. The histological morphology of the liver and kidney was observed, and the coagulation indicators (such as prothrombin time), function indicators (such as alanine transferase), and inflammatory factors (such as TNF-α) were detected. Additionally, an in vitro cell inflammation model using RAW 264.7 murine macrophages was established. Activation of the nuclear factor kappa B (NF-κB) signaling pathway and tumor necrosis factor-α (TNF-α) were determined by western blotting. Based on our findings, PF could significantly improve the histological morphology of the liver and kidney, indicating that PF protects the liver and kidney against damage induced by LPS. Additionally, PF improved the function and coagulation indicators and reduced the production of inflammatory factors. In vitro, PF inhibited the expression of TNF-α by suppressing NF-κB signaling pathway activation. Collectively, our findings support the hypothesis that PF has anti-inflammatory and anticoagulation effects for the alleviation of LPS-induced DIC. PF is thus a potential co-treatment option for DIC.