Cytotoxicity, Apoptosis Induction, Oxidative Stress, and Cell Cycle Arrest of Clerodendrum chinense Flower Extract Nanoparticles in HeLa Cells

Abstract

Clerodendrum chinense is a plant containing numerous secondary active metabolites. This study aimed to evaluate the antioxidant and anti-cancer activities of C. chinense flower ethanolic extract and identify the bioactive compounds. High-performance liquid chromatography was used to identify and quantify the bioactive compounds of the extract. The antioxidant activity of the extract was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging assays and the Ferric Reducing Antioxidant Power Assay (FRAP). The cytotoxicity of C. chinense flower ethanolic extract against A549, MCF-7 and HeLa cells was determined using the sulforhodamine B (SRB) assay. Nanoparticles (NPs) of C. chinense flower extract were fabricated using a solvent displacement method. Then the anti-cancer activities of the extract and NPs were confirmed by cytotoxicity, cell apoptotic induction, reactive oxygen species (ROS) formation, colony formation and cell cycle assays against HeLa cervical cancer cells. C. chinense flower extract and NPs showed significant free radical scavenging activities and ferric-reducing power. As shown by Pearson’s correlation coefficients, the total phenolic and total flavonoid contents of C. chinense flower extract and NPs significantly correlated with antioxidant activity. C. chinense flower extract demonstrated antiproliferative activity against A549, MCF-7 and HeLa cancer cells after treatment for 24, 48 and 72 h. The growth inhibition of HeLa cells mediated by C. chinense flower extract and NPs appears to be associated with apoptosis, ROS formation and cell cycle arrest. Thus, this study provided evidence of the anticervical cancer potentials of C. chinense flower ethanolic extract and NPs. Keywords: Natural products, Nanoparticles, Pharmaceutical, Phenolic compounds, Plant extract, Clerodendrum chinense