ผลของสิ่งสกัดแอลกอฮอล์ของ P. palatiferum และ β–sitosterol กับ CYP3A4 ในเซลล์ตับมนุษย์เพาะเลี้ยง HepG2 / กรรัตน์ รัตนวัฒนาธร = Effect of alcoholic extract of pseuderanthemum palatiferum (nees) radlk and β–sitosterol on CYP3A4 in human hepatoma HEPG2 cell / Kornrat Rattanawattanathorn
Pseuderanthemum palatiferum or Hoan-Ngoc is widely used as traditional medicine for treatment of many chronic diseases. Interaction between herbs and drugs used concomitantly is of great interest. As CYP3A4 is responsible for most of drug metabolism, this study was aimed to investigate the quantification of CYP3A4 by investigating its metabolic activity, protein level and mRNA expression. The cytotoxicity of the alcoholic extract of P. palatiferum and β-sitosterol were determined by MTT assay. 0.1-100 µg/ml of the extract and 0.1-1 µM β-sitosterol did not toxic to cells after 24, 48 and 72 hr of incubation. Compared to the solvent group at the same period of incubation, the HepG2 cell treated with the extract or β-sitosterol did not cause a significant difference in CYP3A4 metabolic activity determined by using P450-Glo assay. Expression of CYP3A4 mRNA was determined by real time-PCR with its primer specific and western blot analysis was used to assess the level of CYP3A4 protein. It was shown that incubation of cells in the presence of the extract or β-sitosterol for 12 hr resulted in a significant increase in CYP3A4 mRNA. After 24 hr of incubation, the observed CYP3A4 mRNA of the treated groups were decreased. The results showed that after 24-72 hr of incubation, protein level of CYP3A4 were not differentially expressed between the extract and β-sitosterol treated groups and their control groups. In conclusion, these finding suggested that administration of the extract may result in initial induction CYP3A4 mRNA expression followed by mild inhibition with prolonged administration. At the same time of incubation, the protein level of CYP3A4 was correlated with its metabolic activity. However, there is no correlation between CYP3A4 mRNA expression and its activity as well as the protein level.
