الفهرس | Only 14 pages are availabe for public view |
Abstract Oral cancer shows lower than 50% long-term survival rate and their prognoses have not greatly improved, despite the development of various treatment methods, TQ is the bioactive phytochemical constituent of the seeds oil of Nigella sativa. Despite its promising results in preclinical settings, its applicability to humans has met with limited success largely due to inefficient systemic delivery and bioavailability. The concept of nanochemoprevention was introduced, which uses nanotechnology for enhancing the outcome of chemopreventive/chemotherapeutic agents. Aim: to evaluate the chemotherapeutic effect of different concentrations of thymoquinone nanoformulation (NTQ) on DMBAinduced epithelial dysplasia in the hamster buccal pouch as compared with the bulk thymoquinone (TQ). Material and methods: The study was carried out on seventyfive male Syrian golden hamsters, divided into four main groups. group A: fifteen animals served as untreated group. group B: Ten animals were painted with 0.5% DMBA three times weekly for six weeks in the left pouch; five of them were sacrificed at the end of 6 th week and the other five were untreated for another 6 weeks. group C: Ten animals were painted with DMBA three times weekly for six weeks in the left pouch then were treated with intraperitoneal injection of whole TQ molecule (0.1 mg/kg), three times per week, for another 6 weeks. group D: forty animals were painted with DMBA three times weekly for six weeks in the left pouch then subdivided into four sub-groups (D1, D2, D3 and D4) treated with intraperitoneal injection of different concentrations of NTQ (0.1, 0.05, 0.025 and 0.01 mg/kg), respectively, three times/week for another 6 weeks. Before animal sacrificing, blood samples were withdrawn from the orbital sinus to evaluate blood parmeters. Right and left Summary 90 buccal pouches were surgically excised, fixed in 10% neutral formalin and processed for H&E stain. Results: White blood cells (WBCs), red blood corpuscles (RBCs), haemoglobin (Hb) were decreased with cancer development (group B) while platelets increased. In TQ and higher concentrations of NTQ (0.1 and 0.05 mg/kg), the blood values improved to near normal values. Histoligically: indicated that topical application of DMBA produced different grades of epithelial dysplasia after six weeks of applications and oral squamous cell carcinoma after another six weeks without further DMBA painting. In contrary, oral carcinogenesis was retarded or regressed by TQ (0.1mg/kg) and NTQ of higher concentrations of (0.1 and 0.05 mg/kg) to mild/moderate dysplastic changes. In conclusion: NTQ (0.1mg/kg) had resulted in regeneration (elongation) of the shortened pouches, through stimulation of myogenesis.NTQ (0.1mg/kg) was more effective than TQ (0.1mg/kg) in that model and could enhance the immune system. |