Antioxidant properties and bioactivity of three marine microalgae on human cancer cell lines

Marine microalgae offer significant potential as sustainably cultivable microorganisms for the biorefining of a diverse array of functional metabolites. In this study, three species of marine microalgae, Tetraselmis chuii Butcher CCAP 66/21B (Chlorophyte), Phaeodactylum tricornutum Bohlin CCAP 1052/1 (Diatom) and Amphidinium carterae Hulburt CCAP 1102/8 (Dinoflagellate), were batch cultivated and their biomass retrieved for analysis in terms of pigment and fatty acid composition as well as bioactivity potential. Sequential solvent maceration of the biomass returned extracts was used to determine antioxidant capacity and assess their growth inhibition potential against A549 (a human lung carcinoma) and MCF-7 (a breast carcinoma) cell lines. The extracts of A. carterae showed higher antioxidant capacity (≤ 33.5 μmol Trolox Equivalent mg Recovered Dried Material‒1) compared to the other extracts. No major cytotoxic activity nor production of reactive oxygen species was observed using the extracts of T. chuii and P. tricornutum. However, the methanolic extraction of A. carterae inhibited the growth of both A549 and MCF-7 cells (< 4%) at 25, 50 and 100 µg ml−1 concentrations, as determined using the MTS assay and AO/PI cell staining. Microalgal metabolites have the potential for practical applications in a variety of industrial sectors. The absence of toxicity and substantial antioxidant potential of extracts of T. chuii and P. tricornutum confirm their suitability for incorporation into animal feeds or human nutrition supplements. A. carterae also appears to be a promising source of bioactives that can be further valorized via multi-compound biorefinery pipelines. Microalgal extracts show high antioxidant potential. Tetraselmis chuii and Phaeodactylum tricornutum extracts display non-cytotoxicity in cancer cells. Amphidinium carterae extracts inhibit cancer cell growth, offering biorefining potential. Microalgal extracts show high antioxidant potential. Tetraselmis chuii and Phaeodactylum tricornutum extracts display non-cytotoxicity in cancer cells. Amphidinium carterae extracts inhibit cancer cell growth, offering biorefining potential.海洋微藻（Marine microalgae）作为可规模化可持续培养的微生物，在多类功能性代谢物的生物炼制（biorefining）中具有极高应用潜力。本研究选取3种海洋微藻：四鞭藻（Tetraselmis chuii Butcher CCAP 66/21B，绿藻门）、三角褐指藻（Phaeodactylum tricornutum Bohlin CCAP 1052/1，硅藻门）以及卡特前沟藻（Amphidinium carterae Hulburt CCAP 1102/8，甲藻门），通过分批培养方式获取其生物质，随后针对其色素、脂肪酸组成及生物活性潜力开展分析。采用连续溶剂浸渍法对生物质进行处理以获得提取物，用以测定抗氧化能力，并评估其对A549人肺癌细胞（A549）与MCF-7人乳腺癌细胞（MCF-7）的生长抑制活性。结果显示，卡特前沟藻提取物的抗氧化能力≤33.5 μmol Trolox当量（Trolox Equivalent）·mg⁻¹回收干物质，优于其余两种微藻提取物。四鞭藻与三角褐指藻的提取物未表现出显著细胞毒性，亦未诱导活性氧（reactive oxygen species）生成。而在25、50及100 μg·mL⁻¹浓度下，卡特前沟藻的甲醇提取物可显著抑制A549与MCF-7细胞的生长（抑制率<4%），该结果通过MTS实验（MTS assay）与AO/PI细胞染色法（AO/PI cell staining）得以验证。微藻提取物在诸多工业领域具备实际应用价值：四鞭藻与三角褐指藻提取物无毒性且抗氧化能力优异，证实其可用于动物饲料或人体营养补充剂的开发；卡特前沟藻则是极具前景的生物活性物质来源，可通过多组分生物炼制工艺管线实现进一步增值利用。 微藻提取物具备优异的抗氧化潜力。 四鞭藻与三角褐指藻提取物对癌细胞无细胞毒性。 卡特前沟藻提取物可抑制癌细胞生长，具备生物炼制应用潜力。 微藻提取物具备优异的抗氧化潜力。 四鞭藻与三角褐指藻提取物对癌细胞无细胞毒性。 卡特前沟藻提取物可抑制癌细胞生长，具备生物炼制应用潜力。