Sideritis scardica Extracts Demonstrate Neuroprotective Activity against Aβ25-35 Toxicity

Alzheimer's disease (AD) is the most prevalent neurodegenerative condition, primarily affecting seniors. Despite the significant time and money spent over the past few decades, no therapy has been developed yet. In recent years, the research has focused on ameliorating the cytotoxic amyloid beta (A beta) peptide aggregates and the increased elevated oxidative stress, two interconnected main AD hallmarks. Medicinal plants constitute a large pool for identifying bioactive compounds or mixtures with a therapeutic effect. Sideritis scardica (SS) has been previously characterized as neuroprotective toward AD. We investigated this ability of SS by generating eight distinct solvent fractions, which were chemically characterized and assessed for their antioxidant and neuroprotective potential. The majority of the fractions were rich in phenolics and flavonoids, and all except one showed significant antioxidant activity. Additionally, four SS extracts partly rescued the viability in A beta(25-35)-treated SH-SY5Y human neuroblastoma cells, with the initial aqueous extract being the most potent and demonstrating similar activity in retinoic-acid-differentiated cells as well. These extracts were rich in neuroprotective substances, such as apigenin, myricetin-3-galactoside, and ellagic acid. Our findings indicate that specific SS mixtures can benefit the pharmaceutical industry to develop herbal drugs and functional food products that may alleviate AD.

Automated summary

Alzheimer's disease (AD) is a prevalent neurodegenerative condition in aging populations with no effective therapy available. Recent research has focused on reducing the toxic amyloid beta aggregates and oxidative stress, which are closely associated with AD. Medicinal plants, such as Sideritis scardica (SS), have shown neuroprotective effects against AD. We investigated the antioxidant and neuroprotective potential of eight solvent fractions derived from SS and found that most fractions were rich in phenolics and flavonoids, with significant antioxidant activity. Four SS extracts were able to partially restore cell viability in A beta(25-35)-treated neuroblastoma cells, indicating their neuroprotective properties. These extracts contained neuroprotective substances like apigenin, myricetin-3-galactoside, and ellagic acid. The findings suggest that specific SS mixtures have potential for the development of herbal drugs and functional food products to alleviate AD symptoms.