Evaluation of Myrcia bella in murine osteosarcoma cells: effect of the crude extract and fractions of ellagitannins and flavonoids

Author(s)

Vanessa Svizzero Fakhoury

• Document type: Master's Dissertation
• Press: Bauru.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB)
• Defense date: 2020-06-19

Examining board members

Rodrigo Cardoso de Oliveira; Adriana Arruda Matos; Luiz Leonardo Saldanha; André Luis Shinohara

• Advisor: Rodrigo Cardoso de Oliveira

Abstract

Osteosarcoma (OS) is the most common type of cancer that develops in bone tissue, characterized by the formation of abnormal osteocytes. Natural products are consistently emerging in the medical health field with promising therapeutic implications, due to drug resistance in the cure rate for chemotherapy in osteosarcoma. Medicinal plants make up part of biodiversity and have been used extensively throughout the existence of mankind. Among the medicinal species of note in the Cerrado is Myrcia bella Cambess, from the Myrtaceae family. Studies show that species of the genre Myrcia have been used in folk medicine as astringents, diuretics, in stopping bleeding, treating hypertension and Diabetes mellitus and also against gastric tumor cells. Phytochemical studies of the hydroalcoholic extract of the leaves of Myrcia bella (MB), revealed of acetylated flavonoid heterosides derived from quercetin and myricetin, in addition to tannins derived from ellagic acid and gallic acid. Thus, MB has demonstrated a promising potential against several pathological alterations, requiring the understanding of its action and confirmation of safe concentrations. This study evaluated the effects of MB on UMR-106 osteosarcoma tumor cells (in vitro). Cell viability tests were carried out at different concentrations of crude extract (CE) of MB leaves and ellagitannin (ELT) and flavonoid (FV) fractions using differentiated pre-osteoblast (MC3T3-E1) as a control, and then determined concentrations, evaluated the migratory potential, production of reactive oxygen species from the cells (ROS) and assays to verify the activity of matrix metalloproteinases (MMP) -2 and -9 in the period of 48h. The results in UMR-106 showed that CE 80 g/mL, ELT 160 g/mL and FV 64 g/mL reduced cell viability (p <0.05). The FV fraction 64 g/mL inhibited cell migration, decreased the production of ROS and had an effect in reducing the activity of MMP-2 with significant differences when compared to the control and showed a tendency in reducing the activity of MMP-9. From the results obtained, the CE and mainly FV showed antioxidant activity and cytotoxic effect on the tested cell line. (AU)

• FAPESP's process: 17/26261-6 - Evaluation of Myrcia bella in murine osteosarcoma cells: effect of the crude extract and fractions of ellagitannins and flavonoids
• Grantee: Vanessa Svizzero Fakhoury
• Support Opportunities: Scholarships in Brazil - Master