Pinostrobin suppresses the Ca2+-signal-dependent growth arrest in yeast by inhibiting the Swe1-mediated G2 cell-cycle regulation

Suppression of SIGMAR1 hinders oral cancer cell growth via modulation of mitochondrial Ca2+ dynamics

BACKGROUND

Oral cancer is the most common malignancy of the oral cavity and facial region, affecting the mucosal and epithelial surfaces in the mouth and lips. Unfortunately, OC is often associated with a high mortality rate and limited treatment options for patients.

METHODS AND RESULTS

Herein, we used in silico analysis and in vitro assays to investigate the impact of the Sigma-1 receptor (SIGMAR1) in OC progression by evaluating mitochondrial function, calcium signaling and clonogenic growth. First, the data from the TCGA pan-cancer analysis revealed that SIGMAR1 was overexpressed in OC versus healthy tissue and related to a worse survival rate. Furthermore, we demonstrated that SIGMAR1 silencing led to an increase in mitochondrial membrane potential, a reduction in cellular ATP levels, inhibition of Ca²⁺ influx, and a significant decrease in the clonogenic growth of OC cells.

CONCLUSIONS

Based on these findings, we suggest that SIGMAR1 may influence mitochondrial membrane potential and energy production by modulating Ca2+ uptake, which is critically important to cellular survival. In addition, SIGMAR1 knockdown may offer a potential strategy to be further explored as treatment for OC.

The Pharmacokinetics, Tissue Distribution, Metabolism, and Excretion of Pinostrobin in Rats: Ultra-High-Performance Liquid Chromatography Coupled With Linear Trap Quadrupole Orbitrap Mass Spectrometry Studies

Pinostrobin is a natural flavonoid found in various plants, well known for its wide range of pharmacological activities. However, there are few reports regarding the pharmacokinetics, tissue distribution, metabolism, and excretion of pinostrobin in rats after oral administration as a single compound. Therefore, we established a method using ultra-high-performance liquid chromatography coupled with linear trap quadrupole orbitrap mass spectrometry (UPLC-LTQ orbitrap-MS/MS) to determine pinostrobin and its metabolites in rat plasma, urine, feces, bile, and tissue homogenates. Pharmacokinetic parameters were measured. The large apparent volume of distribution implied that pinostrobin preferentially bound to tissues and preferably remained within the body. Based on previous pharmacological studies of its antiulcer, anti-HP, anti-inflammatory, and antioxidant activities, pinostrobin is mostly distributed in the gastrointestinal tract, indicating its potential as an effective component of traditional Chinese medicines for the treatment of peptic ulcers. Furthermore, 30 flavonoid metabolites were screened using UPLC-LTQ orbitrap-MS/MS. The metabolism pathways (mainly hydroxylation, demethylation, glucuronidation, and sulfation) of pinostrobin in rats have also been proposed. A small amount of pinostrobin in its parent form is excreted through the urine, feces, and bile, indicating that it is mainly metabolized in vivo. In this study, we systemically investigated the pharmacokinetics, tissue distribution, metabolism, and excretion of pinostrobin in rats. Our results provide a significant basis for the clinical development and application of pinostrobin as well as traditional Chinese medicines containing pinostrobin.