Siam weed, scientifically known as Chromolaena odorata and belonging to the Asteraceae family, is a fast-growing plant with prolific seed production. Although it is a traditional medicinal plant, it has become an agricultural weed in Africa and Asia, posing a threat to biodiversity and causing environmental damage. Despite this, C. odorata is highly regarded as a medicinal herb in tropical Africa, with anticancer effects on breast, liver, and colorectal cancer. However, it is important to regulate the intake of the plant extract as it can have a hepatotoxic effect on liver cells at higher doses. Further research needs to be conducted on the plant extract, and proper orientation and knowledge of its oral daily administration are necessary. This review summarizes current scientific investigations using ethanolic and methanolic aqueous extracts of C. odorata leaves on various cancer cells, to uncover its potential as an anticancer agent. The investigations were sourced from online databases like Google Scholar, PubMed, and other online-based journals.

Breast cancer (BC) ranks among the most prevalent cancers diagnosed in women. Its treatment necessitates precision tailored to the cancer's genetic makeup for enhanced efficacy. Research has been directed towards natural compounds for their anti-BC properties, aiming to augment existing treatment modalities. Chromolaena tacotana (Klatt) R.M. King and H. Rob, commonly referred to as Ch. tacotana, is a notable source of bioactive hydroxy-methylated flavonoids. However, the specific anti-BC mechanisms of these flavonoids, particularly those present in the plant's inflorescences, remain partly undefined. This study focuses on assessing a chalcone derivative extracted from Ch. tacotana inflorescences for its potential to concurrently activate regulated autophagy and intrinsic apoptosis in Luminal A and triple-negative BC cells. We determined the chemical composition of the chalcone using ultraviolet (UV) and nuclear magnetic resonance (NMR) spectroscopy. Its selective cytotoxicity against BC cell lines was assessed using the MTT assay. Flow cytometry and western blot analysis were employed to examine the modulation of proteins governing autophagy and the intrinsic apoptosis pathway. Additionally, in silico simulations were conducted to predict interactions between the chalcone and various anti-apoptotic proteins, including the mTOR protein. The chalcone was identified as 2',4-dihydroxy-4',6'-dimethoxy-chalcone (DDC), also known as Flavokavain C (FKC). This compound demonstrated selective inhibition of BC cell proliferation and triggered autophagy and intrinsic apoptosis. It induced cell cycle arrest in the G0/G1 phase and altered mitochondrial outer membrane potential (∆ψm). The study observed the activation of autophagic LC3-II and mitochondrial pro-apoptotic proteins in both BC cell lines. The regulation of Bcl-XL and Bcl-2 proteins varied according to BC subtype, yet they showed promising molecular interactions with DDC. Among the examined pro-survival proteins, mTOR and Mcl-1 exhibited the most favorable binding energies and were downregulated in MCF-7 and MDA-MB-231 cell lines. Further research is needed to fully understand the molecular dynamics involved in the activation and interaction of autophagy and apoptosis pathways in cancer cells in response to potential anticancer agents like the hydroxy-methylated flavonoids from Ch. tacotana.