Application of SNAP-tag-EGFR cell membrane chromatography model in screening antitumor active components of Silybum marianum (L.) Gaertn.

The SNAP-tag-epidermal growth factor receptor (SNAP-tag-EGFR) cell membrane chromatography (CMC) model is a powerful tool for investigating ligand-receptor interactions and screening active ingredients in traditional Chinese medicine. Most tyrosine kinase inhibitors (TKIs) target epidermal growth factor receptors. However, TKIs associated with significant side effects and drug resistance must be addressed immediately. Therefore, there is an urgent need to develop new TKIs with high efficiency and low toxicity. Because of its low toxicity and side effects, traditional Chinese medicine has been widely employed to treat various diseases, including cancer. Hence, this study aimed to use the SNAP-tag-EGFR/CMC-high-performance liquid chromatography-mass spectrometry (HPLC-MS) two-dimensional system model as the research tool to screen and identify potential EGFR antagonists from the Chinese medicine Silybum marianum (L.) Gaertn. The applicability of the system was verified using the positive control drug osimertinib. Four potential EGFR antagonists were screened from the Chinese medicine Silybum marianum (L.) Gaertn.. They were identified as silydianin, silychristin, silybin, and isosilybin. Additionally, their pharmacological activity was preliminarily verified using a CCK-8 assay. The kinetic parameters of the four active ingredients interacting with EGFR and their binding modes with EGFR were analyzed using nonlinear chromatography (NLC) and molecular docking. This study identified silydianin, silychristin, silybin, and isosilybin from Silybum marianum (L.) Gaertn. and verified their potential antitumor effects on EGFR.

Methylparaben as a preservative in the development of a multi-dose HPV-2 vaccine.

The human papillomavirus (HPV) vaccine is the simplest, most economical, convenient, and effective method of preventing cervical cancer. However, the current HPV vaccine is supplied as a single-dose vial with a relatively high cost per dose, which hinders its supply to low- and middle-income countries (LMICs), where the demand for HPV vaccine is highest. Therefore, it is necessary to develop a multi-dose HPV vaccine to promote large-scale affordable vaccination in LMICs. Moreover, the addition of preservatives is required to reduce the risk of microbial contamination in multi-dose vaccines within a single vial. In this study, we investigated the effects of six preservatives on HPV 16L1 and 18L1 virus-like particles in solution, as well as the aluminum adsorption status, under normal and high-temperature conditions. Multiple methods were employed, including dynamic light scattering, differential scanning calorimetry, an in vitro relative potency assay, and an in vivo potency assay in mice. Based on the above results, four types of selected preservatives were further studied, and an antimicrobial effectiveness test was performed on the HPV-2 vaccine, which was employed as a model HPV vaccine. Finally, three preservatives were selected based on their performance to evaluate the long-term stability of the HPV-2 vaccine. The results indicated that 0.12% methylparaben is the most suitable preservative for the multi-dose HPV-2 vaccine, guaranteeing the shelf life for at least three years and meeting "B" standards for antimicrobial effectiveness. The formula developed in this study can contribute toward combating cervical cancer in LMICs.