Scrophulariae Radix: An Overview of Its Biological Activities and Nutraceutical and Pharmaceutical Applications

Scrophulariae Radix (SR) has an important role as a medicinal plant, the roots of which are recorded used to cure fever, swelling, constipation, pharyngitis, laryngitis, neuritis, sore throat, rheumatism, and arthritis in Asia for more than two thousand years. In this paper, the studies published on Scrophularia buergeriana (SB) and Scrophularia ningpoensis (SN) in the latest 20 years were reviewed, and the biological activities of SB and SN were evaluated based on in vitro and in vivo studies. SB presented anti-inflammatory activities, immune-enhancing effects, bone disorder prevention activity, neuroprotective effect, anti-amnesic effect, and anti-allergic effect; SN showed a neuroprotective effect, anti-apoptotic effect, anti-amnesic effect, and anti-depressant effect; and SR exhibited an immune-enhancing effect and cardioprotective effects through in vitro and in vivo experiments. SB and SN are both known to exert neuroprotective and anti-amensice effects. This review investigated their applicability in the nutraceutical, functional foods, and pharmaceutical industries. Further studies, such as toxicological studies and clinical trials, on the efficacy and safety of SR, including SB and SN, need to be conducted.