Avaliação do efeito antitumoral de extratos de plantas no carcinoma de células escamosas oral: revisão de escopo e estudo In vitro

Abstract

Introduction: Despite advances in understanding the tumoral biology of oral squamous cell carcinoma (OSCC), therapeutic approaches remain aggressive, reducing the quality of life and life expectancy. In this context, research has investigated the antitumor effect of natural drugs derived from plant extracts, where recent studies show that the plant species Acnistus arborescens, found in abundance in the Brazilian Northeast, has pharmacological potential in some cancers, such as leukemia and colon. Objective: This study sought to carry out a scoping review of the different extracts used in OSCC cell lines, in addition to investigating the possible antitumor effects of Acnistus arborescens extract grown in OSCC cell culture (SCC-4), to identify its possible cytotoxic and antitumor actions in this cell lineage and in normal keratinocytes (HaCaT). Methods: In Chapter 1, a scoping review was conducted according to the PRISMA checklist. The search was conducted in LILACS, PubMed, Embase, Livivo, Scopus and Web of Science databases, without date or language restrictions. In Chapter 2, we analyze the selective cytotoxicity of different extracts. For the acetone extract of cultured Acnistus arborescens, the proliferation, invasion, cell migration, and genotoxic damage were investigated. Results: The scoping review identified that the studies had different designs, mainly evaluating cellular events related to apoptosis and the cell cycle, and with the following limitations: many studies did not show IC50 or selectivity index; many studies used a small number of cell lines; and a considerable proportion of the articles presented data referring only to the cytotoxicity assay. In the in vitro study, the cytotoxicity of the different extracts were determined in SCC-4 and HaCaT by MTT test, showing better selectivity index (SI) for the acetone extract of cultivated Acnistus arborescens (IC50 for 72h = 2.7 μg/mL; R2 = 0.99; SI = 1.06). This extract also reduced cell invasion (p=0.0001), reduced cell proliferation (p<0.0001), and induced DNA damage (p=0.0173). Conclusion: In chapter 1, some studies presented different designs, where many did not present IC50 or selectivity index; many studies used a reduced number of cell lines and a considerable proportion of the articles presented data referring only to the cytotoxicity assay. In chapter 2, it was shown that the acetone extract of cultivated Acnistus arborescens showed greater cytotoxicity for the tumor cell line when compared to the normal cell line, showing genotoxic damage, reduced invasion, and inhibition of cell proliferation.