Exploring the Cytotoxic and Antiproliferative Properties of Kalanchoe pinnata Leaf Extracts on Human Breast Cancer (MCF-7) Cells: An Investigation of Phytochemicals and In Vitro Cytotoxicity

G. Karkuzhali

Abstract: Kalanchoe pinnata (Lam.) Pers. (generally called the 'air plant' or 'life plant') is a succulent herb documented for use in traditional medicine systems owing to its extensive pharmacological properties. This study assessed the phytochemical components and cytotoxic effects of aqueous and ethanolic leaf extracts of the plant against the human breast adenocarcinoma cell line MCF-7. Fresh leaves were macerated separately in 95% ethanol and distilled water for 48 h, then filtered to establish the extraction yield and loss on drying. Qualitative phytochemical screening was carried out for carbohydrates, glycosides, flavonoids, alkaloids, saponins, triterpenes, phytosterols, tannins, phenolic compounds, and proteins/amino acids. Cytotoxicity was assessed using the MTT assay over a concentration range of 20-100 µg/mL after 24 h of treatment, and cell morphology was examined through acridine orange-ethidium bromide staining. The ethanolic extract showed greater recovery (3.4%) than the aqueous extract (1.2%), along with a broader range of secondary metabolites. Both extracts decreased MCF-7 viability in a concentration-dependent fashion, yet the ethanolic extract was markedly more potent (IC₅₀ = 38.18 µg/mL vs. 73.45 µg/mL). AO-EB staining supported these findings, revealing progressive morphological alterations as extract concentrations increased. The current study therefore offers evidence supporting the traditional use of K. pinnata and points to the potential phytoconstituents in its ethanolic leaf extract that could account for its anti-proliferative action against MCF-7 breast cancer cells, justifying further mechanistic and in vivo research.

Keywords: Kalanchoe pinnata; phytochemical screening; MTT assay; MCF-7 breast cancer cell; AO-EB staining and cytotoxicity