Red Clover and the Importance of Extraction Processes—Ways in Which Extraction Techniques and Parameters Affect Trifolium pratense L. Extracts’ Phytochemical Profile and Biological Activities

The purpose of this study was to gain an insight into the manner in which several extraction processes (both classical as well as innovative) affected bioactive compound yield, and subsequently to assess several of their biological activities. Red clover extracts were obtained using maceration, Soxhlet extraction, turbo-extraction, ultrasound-assisted extraction, and a combination of the last two. The resulting extracts were analyzed for total phenolic and flavonoid content. The extracts presenting the best results were subjected to a phytochemical assessment by way of HPLC-MS analysis. After a final sorting based on the phytochemical profiles of the extracts, the samples were assessed for their antimicrobial activity, anti-inflammatory activity, and oxidative stress reduction potential, using animal inflammation models. The Soxhlet extraction yielded the most satisfactory results both qualitatively and quantitatively. The ultrasound-assisted extraction offered comparable yields. The extracts showed a high potential against gram-negative bacteria and induced a modest antioxidant effect on the experimental inflammation model in Wistar rats.