TY - JOUR T1 - The Effect of Quercetin on Saos2 Osteosarcoma Cell Line TT - بررسی اثر ضد سرطانی کوئرستین بر روی سلول های 2Saos استئوسارکوما JF - RJMS JO - RJMS VL - 29 IS - 11 UR - http://rjms.iums.ac.ir/article-1-7275-en.html Y1 - 2023 SP - 47 EP - 57 KW - SaOS2 KW - Nitric oxide KW - Osteosarcoma KW - Quercetin N2 - Background & Aims: Osteosarcoma (also called osteogenic sarcoma) is the most common type of cancer that starts in the bones. It is a malignant mesenchymal cell tumour, characterized by pleomorphic spindle-shaped cells, capable of producing an osteoid matrix. Tumour cells metastasize primarily via the haematogenous route. This disease is very aggressive and the tumor formed is fixed, hard and irregular. The cancer cells in these tumors look like early forms of bone cells that normally help make new bone tissue, but the bone tissue in an osteosarcoma is not as strong as that in normal bones. Overall, osteosarcoma is a rare disease, however, children and teens are the most commonly affected age group, but osteosarcoma can develop at any age. Although this disease occurs sporadically, approximately 70% of tumor specimens show an abnormality in the chromosome. Moreover, regulation of cell cycle has been reported to demonstrate inherited defects in some cases. The incidence of osteosarcoma is bimodal. The first peak occurs at the ages of puberty, implying the ages of 15 to 19 in boys and the ages of 10 to 14 in girls. The second peak occurs in the elderly with the age of 75 years. Noteworthy, osteosarcoma is rare before the age of 5. With the application of multimodal chemotherapy, disease-free survival of patients with high-grade osteosarcoma has been improved to more than 60% compared to 10–20% which was reachable with the surgery as the only therapeutic approach. At present, treatment of osteosarcoma is a combination of surgery and chemotherapy both before and after the surgery. Additionally, the use of common chemotherapeutic agents such as high-dose methotrexate, cisplatin, doxorubicin and/or etoposide and ifosfamide frequently causes both acute and long-term toxicity. Although several chemotherapy regimens have been applied in the past 20 years, survival rates of patients are still not satisfying and no practical targeted therapy is discovered. Therefore, it is important to investigate different therapeutic methods and anti-tumor agents in order to find an approach that provides a higher survival rate. Flavonoids possess several biological and pharmacological activities. In addition, flavonoids have the advantage of being less toxic and can be prescribed for an extended duration. Therefore, various plant-derived flavonoids use as drugs have been reported as a modulator for chronic inflammation caused by virus infection and other diseases, such as human papillomavirus, hepatitis virus, SARS-CoV-2, autoimmune disease, type 2 diabetes, cardiovascular diseases, Alzheimer’s disease, Parkinson’s disease, and cancer. Quercetin is a naturally occurring polyphenolic flavonoid, whose chemical name is 3,3′,4′,5,7-Pentahydroxyflavone (C15H10O7), can be found in a wide range of daily foods, such as grains, fruits, and vegetables and in higher levels in capers, buckwheat seeds, radish, onions, apples, red leaf lettuce, asparagus, nuts, and teas. It is reported that oral administration of 1 g quercetin per day is safe and is absorbed up to 60%. Quercetin has a high ability to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) molecules; therefore, exhibiting beneficial effects in preventing obesity, diabetes, cardiovascular diseases, and inflammation. Furthermore, quercetin is indicated to exert various anti-tumor effects both in vitro and in vivo against several cancers, such as ovarian cancer, colorectal cancer, lymphoma, gastric cancer, and breast cancer. On the other hand, the high toxic effect of quercetin against cancer cells is accompanied with little or no side effects or harm to normal cells. Its wide accessibility, efficacy, and a broad range of activity, and low toxicity as compared with other examined compounds, make it an attractive chemical in the fight against diseases including cancer. It has been recognized and employed as an alternative drug in treating different cancers alone or in combination with other chemotherapeutic drugs. NO is a free radical that regulates several physiological functions and is formed by the conversion of L-arginine to L-citrulline by nitric oxide synthases (NOS). NO is a dual molecule that can have a tumor-protecting or stimulating effect, depending on its local concentration. Certain reports demonstrated a cytotoxic role of NO; others presented a protective role. Many investigations have shown that quercetin has anti-inflammatory activity that pulls out the nitric oxide, catalase, and cytokines, specifically TNF-α, IL-β, and IL-6, which are inflammatory mediators. Therefore, we tried to elucidate the influence of quercetin in order to suggest a new candidate for the treatment of this cancer, on in vitro NO production from Saos2 osteosarcoma cell line Methods: After 24 hours of culture of Saos2 cells in 96-well plates, different concentrations of quercetin were added to the wells for 72 hours. Cell viability was measured using the colorimetric MTT assay. Briefly, cells were incubated with 0.5mg/mL MTT in DMEM at 37 ºC under 5 % CO2 for 3 h. The blue formazan reduction product, which is generated by the action of the succinate dehydrogenase on the dye only in living cells, was dissolved in 100µL DMSO, and its absorbance was read at 570nm using a Dynex MMX microplate reader. The level of nitrite as an indicator of NO production in the culture medium was measured using modified Griess reagent. In brief, after the experiment, the medium in each well was removed and centrifuged at 10,000 g for 10 min at 20 ºC. Then, 100 µL of the supernatant was mixed with an equal volume of Griess reagent at room temperature for 10 min, and the absorbance was measured at 540 nm using a microplate reader. The nitrite concentration was determined from a sodium nitrite standard curve. The data were analyzed by one-way ANOVA and P < 0.05 was considered statistically significant. Results: The results of this study showed that quercetin can decrease the percentage of cell viability of Saos2 cells compared to the control group. The best effective dose is 120 μM. Also, the data showed that quercetin in all concentrations was able to reduce the production of NO levels in Saos2 cells and the best effective concentration is 120 μM. Conclusion: In this study, it was found that quercetin was able to reduce the viability of Saos2 cells, and part of its effects could be mediated partially by a decrease in NO production. However, further studies are needed on this natural compound. M3 ER -