Lantana camara is an important medicinal plant that contains many active compounds, including pentacyclic triterpenoids, with numerous biological activities. The present study was conducted to evaluate the anti-oxidant, anti-tumour, and cell cycle arrest properties of chemical compounds extracted from L. camara leaves. Four compounds were identified after subjecting the plant methanolic extract to LC-MS/MS analysis: lantadene A, lantadene B, icterogenin, and lantadene C. Potential antioxidant activity was examined using 2, 2-diphenyl-1-picrylhydrazyl and compared with vitamin C as a control. Lantadene A and B were confirmed to possess the highest scavenging activity, while icterogenin and lantadene C exhibited a lesser antioxidant effect. All extracted compounds exerted a dose-dependent reduction in MCF-7 cell viability; however, lantadene B showed the highest anti-cancer activity, with an IC50 of 112.2 μg mL-1, and was therefore used in subsequent experiments. The results also confirmed the significant release of caspase 9 in a dose-dependent pattern following treatment of MCF-7 cells with a range of lantadene B concentrations. Lantadene B was found to induce MCF-7 cell cycle arrest in G1, blocking the G1/S transition with a maximum significant (p ≤ 0.01) cell count of 80.35% at 25 µg mL-1. No significant changes were observed in S phase, but a decrease in the MCF-7 population was exhibited in G2/M phase.
Keywords: Cell cycle; Lantadene; Lantana camara; MCF-7; Plant antioxidants.