Cytotoxicity of Etlingera pavieana rhizome extract on resistant-cervical cancer cells

Cervical cancer is one of the most common malignancies in women worldwide. Cisplatin-based treatment is most often used in chemotherapy of the disease. However, serious adverse effects and drug-resistant development limit cisplatin in clinical practice. Crude extracts of edible plants can serve as an alternate source of novel anticancer agents that are safe and are able to face chemoresistance. Rhizome of Etlingera pavieana or Raew hawm, an aromatic plant commonly found in Southeast Asia, is a well-known spice and food ingredient used in the Eastern region of Thailand. In the previous studies, E. pavieana rhizome extract exhibited an inhibitory effect on the proliferation of various cancer cells including those resistant to doxorubicin, with much lower toxicity on non-cancer cells. In this ongoing study, the cisplatin-resistant cervical C-33A/R cells were established and were subjected to investigate the cytotoxic effect of the extract. MTT results demonstrated that the viability of C-33A/R cells was significantly reduced after extract treatment in both dose- and time-dependent manners. At 400 μg/mL extract, growth of C-33A/R cells was decreased by 77.32% at 72-hour incubation. The IC50 value against the resistant cells was 269.36 μg/mL which was slightly higher than that of parental cells (230.99 μg/mL). The results suggest E. pavieana rhizome extract as a source of promising anticancer candidates for cervical cancer treatment

Synthesis and characterization of new hydrolytic-resistant dental resin adhesive monomer HMTAF

Hydrolytic and enzymatic degradation of resin adhesives over time has been mainly attributed to secondary caries formation of methacrylate-based tooth-colored resin-based composite restorations. Ability of resin adhesive monomers to infiltrate into demineralized dentin forming stiff polymer matrix and potentially bonding to tooth structure is also a crucial property. The only commercially available antibacterial monomer, 12-methacryloyloxydodecyl pyridinium bromide (MDPB), is a quaternary ammonium methacrylate. This methacrylate monomer undergoes hydrolytic degradation, and could not bond to tooth structure. In this study, a new hydrolytic resistant monomer HMTAF was synthesized. It is methacrylamide-based monomer that, unlike methacrylate, is highly resistant to hydrolysis. Its molecular structure has particular functional groups; quaternary ammonium fluoride salt with potential antibacterial fluoride-releasing activity, hydroxyl and amide group with hydrogen bonding potential to dentin collagen. Hydroxyl group also increases monomer hydrophilicity for better penetration into water-saturated dentin and sufficient resin-dentin bond. The synthesized HMTAF and its polymer showed no hydrolytic degradation in acidic environment, while MDPB and its polymer were partially decomposed under this challenge. The conversion of monomer HMTAF to polymer was illustrated by FT-IR. The results indicated that HMTAF is highly resistant to hydrolysis, polymerizable and non-cytotoxic to Vero cell lines. It is a potential monomer to be incorporated into resin adhesives for improving hydrolytic and enzymatic resistance