Phytochemical and pharmacological profile of Origanum sipyleum extracts: exploring novel sources for potential pharmaceutical, food, and cosmetic applications

Origanum sipyleum L., an endemic plant of Western Anatolia has been used as a medicinal tea, food additive, and for the production of essential oil. In this study, the biological potential of three extracts (ethyl acetate, methanol, and aqueous) of O. sipyleum was assessed based on antioxidant activity against key enzymes of clinical relvance. The chemical profile of the plant was assessed using spectrophotometric and LC-MS techniques. Additionally, we explored potential antioxidant and anti-inflammatory effects duced by the extracts in an experimental model of ulcerative colitis induced by LPS challenging. LC-MS analysis revealed that the extracts contained different classes of phenolics, such as rosmarinic acid, phlorizin and gallic acid. We found that the aqueous extract was the most effective antioxidant, displaying the highest DPPH and ABTS scavenging, FRAP, CUPRAC, molybdenum(VI) reducing, and metal chelating effect. The aqueous extract howed the strongest acetylcholinesterase (AChE) inhibition; the methanol extract showed the highest α-glucosidase inhibition, while the ethyl acetate extract was the most effective on butyrylcholinesterase (BChE), tyrosinase, and α-amylase. The total flavonoid content was highest in the aqueous and ethyl acetate extract, respectively. Finally, we found that all extracts were effective in reducing LPS-induced activity of pro-oxidant and pro-inflammatory biomarkers including nitrites, LDH, PGE2 and 5-HT, in rat colon, with the best activity showed by ethyl acetate extract. Our results indicated that the three solvent extracts varied in their chemical and biological profiles, but overall, O. sipyleum showed promising therapeutic properties, nonetheless, need to be further validated in in vivo models.