Identification of Apocarotenoids as Chemical Markers of In Vitro Anti-Inflammatory Activity for Spirulina Supplements.

Identification of chemical markers in food additives and dietary supplements is crucial for quantitative assessment and standardization of their quality and efficacy. Arthrospira platensis, formerly Spirulina platensis and known colloquially as spirulina, has been widely investigated for its various biological effects, including anti-inflammation, antihypertension, antioxidant, and antiatherosclerosis. In this study, we utilized an approach involving a combination of bioassay-guided fractionation, synthesis, mass spectral molecular networking, principal component analysis (PCA), and correlation analysis to identify measurable chemical markers in spirulina products that can be used to evaluate the efficacy of commercial products in downregulating the expression level of the proinflammatory cytokines, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor α (TNFα). Consequently, we found that the apocarotenoids 3-hydroxy-β-ionone (1) and apo-13-zeaxanthinones (2a/2b) significantly repressed expression of IL-1β (9.5 ± 1.5 and 28.7 ± 0.6%, respectively) and IL-6 (10.1 ± 0.7 and 6.1 ± 0.4%, respectively) at 10 μg/mL (p < 0.05) using RAW 264.7 mouse macrophages. Notably, this is the first report of the isolation of these apocarotenoids from spirulina and their in vitro anti-inflammatory properties. Finally, we propose the use of our approach as a convenient way to establish markers in other dietary supplements.