Sambucus nigra L. cell cultures produce main species-specific phytochemicals with anti-inflammatory properties and in vitro ACE2 binding inhibition to SARS-CoV2

Sambucus nigra fruit and flower extracts exhibit anti-viral and anti-inflammatory properties however, the potential of S. nigra in vitro cell suspension cultures to produce biologically active compounds remains unexplored. This study describes the establishment of S. nigra cell suspension cultures and their phytochemical content and biological activity. S. nigra cell cultures contain major compounds characteristic for whole-plant S. nigra tissues albeit at uncharacteristic ratios. Elicitation with methyl jasmonate, visual selection of pigmented cells, and optimization of culture parameters resulted in cell suspensions with high contents of anthocyanins, organic acids, and phenolic compounds. Enzyme-linked immunosorbent assay (ELISA) and fluorometric assay-based assessment of biological activity of developed cultures demonstrated inhibitory capacity against cyclooxygenase enzyme COX2 activity and against the binding of SARS-CoV2 receptor-binding domain (RBD) to angiotensin-converting enzyme 2 (ACE2) in vitro suggesting that S. nigra cell suspensions exhibit anti-inflammatory and viral entry blocking potential. Differences in phytochemical content and biological activity of S. nigra cell suspensions subjected to different optimization approaches indicate potential for optimization towards desired biotechnological products with anti-inflammatory properties and inhibitory capacity against viral binding.