Abstract
Background: Cancer continues to be one of the foremost causes of global mortality, with an estimated 20 million new cases and 9.7 million cancer-related mortalities recorded in 2022. Among the various forms of cancer, cervical cancer ranks as one of the most prevalent malignancies affecting women. Persistent infection with high-risk human papillomavirus (HPV) strains is widely recognised as the primary cause of cervical cancer. Conventional treatments for cervical cancer, such as surgery, radiotherapy, and chemotherapy, often result in severe side effects and reduced quality of life due to their invasive nature and toxicity to normal cells. At the same time, preventive strategies such as HPV vaccination also present adverse effects in some individuals. As a result, there is a need for the development of alternative therapies that are both cost-effective with reduced toxicity. Medicinal plants, long regarded as valuable sources of therapeutic compounds, have demonstrated considerable potential in cancer research. In this study, the anticancer potential of Salvia clevelandii crude extracts against cervical cancer cells is explored, as this plant is traditionally recognised for its medicinal properties and rich phytochemical profile. Furthermore, the crude extracts’ phytochemical composition was investigated through advanced metabolomics approaches.
Objectives: The objective of this study was to evaluate the apoptotic effects of S. clevelandii crude extracts on ME-180 cancer cells. Furthermore, the study aimed to identify the phytochemical constituents of the plant extracts using liquid chromatography-mass spectrometry (LC-MS)-based metabolomics.
Methods: A sequential solvent extraction method was used to acquire four crude extracts of S. clevelandii using solvents of increasing polarity: hexane, dichloromethane (DCM), ethyl acetate (EtOAc), and methanol (MeOH). The cytotoxic effects of each extract were evaluated against ME-180 cancer cells and non-cancer HEK293 cells using the Alamar Blue viability assay. Morphological changes indicative of apoptosis were assessed through light microscopy and Hoechst nuclear staining. To further examine the phytochemical composition, untargeted metabolomics analysis was conducted using a Waters Acquity UHPLC system coupled with a SYNAPT G1 high-definition Q-TOF mass spectrometer. The obtained LC-MS data were processed and converted into mzML format, and thereafter, analysed through MS-DIAL. Compound annotation was explored using the Global Natural Products Social Molecular Networking (GNPS) web platform. Following that, statistical analysis was performed using principal Component Analysis (PCA), Venn diagram and heatmap cluster analysis to represent the qualitative distribution and overlap of metabolites across the solvent extracts, as well as compound distribution visualisation. For deeper insights into the distribution of the compounds across each extract, some of the clusters were closely analysed and supplemented by the bar graphs.
Results and Discussion: The findings indicated that IC50 values for the crude extracts ranged from 162.23 μg/mL to 269.69 μg/mL. Among the four extracts, MeOH and EtOAc exhibited more distinct ...