ผลของสารสกัดเหง้าไพลต่อการยับยั้งการแสดงออกของยีนทีเอซีวันที่ควบคุมการสร้างซับสแตนพี ในเนื้อเยื่อในฟันมนุษย์ (INHIBITORY ACTIVITY OF Zingiber cassumunar Roxb. RHIZOME EXTRACT ON TAC-1 SUBSTANCE P GENE IN HUMAN DENTAL PULP CELLS)

Abstract

              การลดการอักเสบ  Inflammation of dental pulp tissue is the major cause of tooth pain. Contamination from caries is one of most common cause of pulpal infection and inflammation. When inflammation occurs in restricted area of the tooth, it may cause necrotic pulp tissue. Substance P, be controlled by TAC-1 gene, is a neurotransmitter which is increasingly in the dental pulp inflammation. It can stimulate neuroreceptor to generate pain and vasodilatation. Zingiber cassumunar Roxb. (Phlai) is an important medicinal plant to reduce inflammation. However, the effect of Phlai on substance P has not been studied before. Thus, the study attended on the inhibitory effect of Phlai extract on substance P gene expression (TAC-1). The dental pulp cells, from 3 donated human teeth, were cultured in the laboratory by explant technique. All substances were investigated the cytotoxicity before used by MTT assay. The experiments started by cell culturing in culture medium supplemented with 100 µg/ml Phlai extract, or 1 µM of dexamethasone for two hours. Lipopolysaccharide (LPS) was added at the concentration 100 µg/ml and further cultured for twenty four hours. The cells were harvested and RNA was the samples to determine the expression of TAC-1 gene using reatime PCR technique. The results revealed that the concentration of Phlai extract from 250 µg/ml and higher, dexamethasone 5 µM and higher had significant cytotoxicity when were compared with the control group with IC₅₀ 543.40 and 3.95, respectively. The Phlai extract and dexamethasone groups similarly expressed of TAC-1 gene to the control group which were fed with only culture medium. Phlai extract and dexamethasone could inhibit TAC-1 gene expression in dental pulp cells when they were stimulated by LPS. The TAC-1 gene expression was lower than 4 times that of the LPS alone. The results suggested that Phlai extract and dexamethasone were likely to reduce neurogenic inflammation by inhibiting TAC-1 gene expression in LPS-stimulated dental pulp cells.