Macroalgae are a natural source of clinically relevant molecules such as polyunsaturated and monounsaturated fatty acids. The Antarctic environment, due to its cold climate, leads to high production of these bioactive molecules. Adenocystis utricularis, Curdiea racovitzae, and Georgiella confluens from three distinct islands in the Antarctic Peninsula were collected and analyzed for their fatty acid content by gas chromatography flame ionization detection. Results revealed that the algal extracts consisted of 22 fatty acids, of which 9 were saturated, 4 were monounsaturated, and 9 were polyunsaturated (PUFA). In addition, fucosterol was identified within the lipidic extracts. The cytotoxic activity of these fatty acids was evaluated in human breast cancer cell lines MCF-7 and MDA-MB-231. The most notable result was the effect of PUFA on the growth inhibition of cancer cells ranging from 61.04 to 69.78% in comparison to control cells. Significant cytotoxic activity of fatty acids from A. utricularis was observed at 48 h, resulting in an inhibition of growth of more than 50% for breast cancer cells at a concentration of 100 μg/mL. A cell viability assay showed that the fatty acids from A. utricularis significantly reduced cell viability (68.7% in MCF-7 and 89% in MDA-MB-231 after 72 h of exposure). At the same time, DAPI staining demonstrated chromatin condensation, and apoptotic bodies formed in cells that were cultured with fatty acids from A. utricularis. These data indicate that fatty acids from Antarctic macroalgae have the potential to reduce the proliferation of and induce apoptosis in breast cancer cells.

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Our results indicate that A. satureioides infusion possesses low toxicological potential and an effective antioxidant activity. These findings confirm the traditional use of this plant in the folk medicine.

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Campomanesia xanthocarpa is known in Brazil as Guabiroba and is popularly used for various diseases, such as inflammatory, renal, and digestive diseases and dyslipidemia. The aim of the study was to analyze the chemical composition and investigate the effects of aqueous extract of C. xanthocarpa on the blood pressure of normotensive rats, analyzing the possible action mechanism using experimental and in silico procedures. The extract was evaluated for total phenolic compounds and total flavonoid content. The chemical components were determined by HPLC analyses. Systolic and diastolic blood pressure and heart rate were measured with extract and drugs administration. The leaves of C. xanthocarpa presented the relevant content of phenolics and flavonoids, and we suggested the presence of chlorogenic acid, gallic acid, quercetin, and theobromine. The acute administration of aqueous extract of C. xanthocarpa has a dose-dependent hypotensive effect in normotensive rats, suggesting that the action mechanism may be mediated through the renin-angiotensin system by AT1 receptor blockade and sympathetic autonomic response. Docking studies showed models that indicated an interaction between chlorogenic acid and quercetin with the AT1 receptor (AT1R) active site. The findings of these docking studies suggest the potential of C. xanthocarpa constituents for use as preventive agents for blood pressure.