Introduction: The oral tumor is the sixth most prevalent type of cancer worldwide and the second leading cause of cancer-related mortality. Although chemotherapy and immunotherapy are the main strategies for the treatment of oral cancer, an emergence of inevitable resistance to these treatment modalities is the major drawback that causes recurrence of the disease. Nowadays, probiotics have been suggested as adjunctive and complementary treatment modalities for improving the impacts of chemotherapy and immunotherapy agents. Probiotics, the friendly microflora in our bodies, contribute to the production of useful metabolites with positive effects on the immune system against various diseases such as cancer. Methods: Lactobacillus plantarum is one of the most important bacteria, which commensally live in the human oral system. In the current study, the impacts of L. plantarum on maintaining oral system health were investigated, and the molecular mechanisms of inhibition of oral cancer KB cells mediated by L. plantarum were evaluated using real-time polymerase chain reaction (PCR) and FACS flow cytometry analyses. Results: Our findings showed that L. plantarum is effective in the signal transduction of the oral cancer cells through upregulation and downregulation of PTEN and MAPK pathways, respectively. Conclusion: Based on the biological effects of oral candidate probiotics candidate bacterium L. plantarum on functional expression of PTEN and MAPK pathways, this microorganism seems to play a key role in controlling undesired cancer development in the oral system. Taken all, L. plantarum is proposed as a potential candidate for probiotics cancer therapy.

Abstract. The main aim of the present study was to show the effect of bovineLactoferrin (bLF), an 80 kD iron-binding glycoprotein, its application on antioxidant esterase activities and 8-isoprostane changes in high-cholesterol-diet fed (HCD-Fed) rats. The 44 adult Sprague-Dawley male rats were randomly assigned into four experimental groups. They were randomly assigned into four equivalent groups (n = 11). The groups included the control group which was fed with normal diet, bLF group, the third group which were made hypercholesterolemia by being fed with high cholesterol diet, and the last group which consisted of hypercholesterolemia rats treated with bLF (HCD + bLF) for 4 weeks (200 mg.kg−1 per day wt. dissolved in 0.9% normal saline).After 4 weeks, the serum Paraoxonase1 (PON1), Arylesterase (ARE) activity and 8-isoprostane with lipid profile were measured. Upon treatment with the bLF, the decrease in LDL-Cholesterol (LDL-C), Glucoses, Triglyceride (TG) and Total-Cholesterol (TC) levels and an increase in HDL-Cholesterol (HDL-C) level were observed. The co-administration of bLf for 4 weeks had decreased the 8-isoprostane levels significantly (P < 0.001) (86.36 ± 7.1 vs 117.18 ± 8.62) when compared to hypercholesterolemia-induced rats. Also, the Atherogenic Index (AI) in HCD + bLF group showed a significant decrease as compared to the HCD group (P < 0.001) (0.37 ± 0.07 vs 0.57 ± 0.09). The results indicated that bLF was effective against oxidative stress by its ability to increase PON1 activity and reduce the lipid peroxidation in high-cholesterol-fed rats.