Unveiling the protective role of Sisymbrium officinale (L.) Scop. in brain cells: a phytochemical and biological evaluation

Sisymbrium officinale (L.) Scop. (syn. Erysimum officinale L., hedge mustard; Fam. Brassicaceae), is a traditional medicinal plant used for [ADS1.1]respiratory system’s disorders and vocal cord ailments, hence its “singers’ plant” name [1]. Scientific evidence also revealed its myorelaxant, antimicrobial, antimutagenic, antinflammatory and antioxidant activities [1,2]. Sulphur compounds (mainly glucoputranjivin and isopropyl isothiocyanate) and phenolics are its major phytochemicals; they have been reported to possess promising chemopreventive, cytoprotective and neuroprotective properties [1,3]. Based on this evidence, here an aqueous dry extract from the aerial parts of S. officinale (EPO S.r.l.; standardized to contain 0.50% w/w glucosinolates) has been assessed for the potential cytoprotective properties in human cell models towards the oxidative damage induced by tert-butyl hydroperoxide (tBOOH) and amyloid beta peptide (Aβ). The extract was preliminarily evaluated for its phytochemical composition by spectrophotometric and chromatographic analysis. Moreover, nontoxic concentrations were selected by MTT assay for the evaluation of cytoprotection, assessed as capability of the extracts to increase the cell viability impaired by tBOOH and Aβ protein, and to affect the intracellular levels of reactive oxygen species [4,5]. Moreover, the extract was assayed for its radical scavenging and reducing activity, and for the ability to inhibit key enzymes (monoaminoxidase A, acetylcholinesterase, tyrosinase) in the central nervous system (CNS) [4]. Under our experimental conditions, we found that the extract contained both glucosinolates and phenolic compounds, as well as alcohols, sugars, fatty acids and carboxylic acids. The extract significantly counteracted the oxidative damage induced by Aβ protein in SHSY-5Y cells, while slightly restoring the cell viability impaired by tBOOH. Interesting radical scavenging effects against the free radical DPPH and superoxide anion were highlighted too, with a moderate inhibition of the monoaminoxidase enzyme. Further studies are needed to clarify the bioactivities of S. officinale through improved extracts and experimental models, to confirm its protective power in vivo and to discover the contribution of phenolic compounds and glucosinolates in the phytocomplex. References 1. Di Sotto et al. Journal of Ethnopharmacology 2010, 127, 731–736. 2. Di Sotto et al. Phytotherapy research 2016, 30, 829–834. 3. Borgonovo et al. Molecules 2019, 24(24). 4. Cásedas et al. Food and Chemical Toxicology 2018, 118, 572–580. 5. Di Giacomo et al., Pharmaceuticals 15, 987, 2022.