High-pressure extraction of marigold (Calendula officinalis); Evaluation of chemical composition, pharmacological and antitumor potential

Abstract

The isolation of bioactive compounds from plants has gained significant attention due to their potential in developing novel health-promoting products. Among these, marigold (Calendula officinalis) is recognized for its antioxidant, hepatoprotective, and wound-healing properties. This study examined five marigold plant parts–petals (MP), calyxes (MC), calyxes with petals (MCP), stems (MS), and stems with calyxes and petals (MSCP)–extracted using supercritical carbon dioxide (scCO₂), an advanced technique that avoids toxic solvents and reduces extraction time compared to conventional methods. GC–MS analysis of the scCO₂ extracts revealed that sesquiterpenes were the predominant constituents, including δ-cadinene (19.13–26.96 %), γ-cadinene (9.62–12.92 %), t-muurolol (2.08–10.07 %), α-cadinol (1.42–5.81 %), and ledene (1.24–8.87 %). In addition, monoterpenes such as thymol (1.85–2.87 %), camphor (1.77–2.07 %), β-thujone (0.93–1.13 %), and carvacrol (0.58–1.25 %), as well as the alkane nonadecane (0.50–23.17 %), were also identified. The in vitro antitumor potential of MP, MC, and MS plant parts was evaluated in H4IIE hepatoma cells. Cell viability, morphological analysis, and colony formation assays demonstrated cytotoxic activity, with marigold calyxes showing the most pronounced effect. In addition, hepatoprotective properties were confirmed, further supporting the therapeutic relevance of marigold extracts. These findings suggest that sc-CO₂ extracts of marigold hold promise as potential antitumor agents. However, further preclinical and clinical studies are required to assess their safety, efficacy, and applicability in human therapy.