From Plant Propagation to Anticancer Activity: Phytochemical and Biological Evaluation of Water Extracts of Salvia aethiopis L. Flowers, Leaves and Stems

Salvia aethiopis L. is a medicinal and aromatic species of growing scientific interest due to its biological potential. The study aimed to develop an efficient in vitro micropropagation protocol and to evaluate the antioxidant and anticancer activity of aqueous extracts derived from the three different aerial plant parts—flowers, leaves and stems—of the in vitro-cultivated plants and compare them with those of the wild-growing plants. Optimal parameters for the micropropagation of the species were established, yielding 80% field survival and flowering in the second year. The highest total polyphenol and flavonoid content and antioxidant activity were recorded in the flower extract from wild plants—14,681 ± 211 mg GAE/100 g, 2317 ± 77 mg RE/100 g and 4563 ± 280 µmol TE/g, respectively. HPLC analysis confirmed the presence of key bioactive compounds, including rosmarinic acid, caffeic acid, and apigenin. The anticancer potential of the different extracts was assessed against human cervical, mammary and colorectal cell lines. The extracts exhibited significant antiproliferative activity, with HT-29 colorectal carcinoma cells being the most sensitive. Flower extracts of wild plants showed the strongest cytotoxic effects with IC50 values at 72 h being lower than 100 μg/mL for all cancer cell lines. Fluorescence microscopy and flow cytometry analyses indicated that the observed extract-induced anticancer effects were associated with mitochondrial dysfunction, cell cycle alterations, modulation of autophagy, and induction of apoptotic and necrotic cancer cell death. These findings highlight the potential of extracts of S. aethiopis for anticancer therapy.