Cytotoxic action of the leaves of Uvaria chamae P.Beauv. and Dicliptera paniculata (Forssk.) I.Darbysh. from Nigeria mediated through intrinsic apoptotic pathway induction in four cancer cell lines

Abstract

BackgroundOver the years, the morbidity and mortality due to cancer have continued to increase worldwide. Plants are well utilized in Nigeria ethno-medicine for cancer treatment. However, scientific evidence, particularly at the molecular level, has been lacking, and biodiversity loss is a threat. Aim of the studyThe cytotoxic activity of the leaves of six plants used in Nigeria ethno-medicine was investigated and the molecular pathway of cytotoxic action of two active extracts on four cancer cell lines (A549, RD, MCF-7, and HeLa) was also assessed. Materials and methodsCytotoxic activities of the plant extracts were assessed on breast (MCF-7), lung (A549), cervical (HeLa), adenocarcinoma and rhabdomyosarcoma (RD) cells using MTT cell viability assay in a time-dependent manner. The sandwich ELISA method was used to assess the protein expressions (Bcl-2, BAX, and executioner caspase 3) involved in the apoptotic pathway in cancer cells after treatment with cytotoxic extracts. UHPLC-MS/MS approach was used to analyze the possible bioactive phytochemicals of the cytotoxic plant extract. ResultsUvaria chamae and Dicliptera paniculata extracts displayed good cytotoxicity across all cell lines in a time- and concentration-dependent manner (CC50 <30 µg/mL). Increased pro-apoptotic BAX and lowered expression of anti-apoptotic Bcl-2 show the cytotoxic action of the two extracts followed the intrinsic apoptotic pathway compared to untreated cells. The increased expression of executioner caspase 3 indicated that the intrinsic apoptotic pathway was caspase-dependent. ConclusionThe anticancer potential of U. chamae and D. paniculata in this study validates the use of these plants in Nigerian ethno-medicine, highlighting apoptosis as a molecular pathway of their cytotoxicity.