Characterization of the Sideritis scardica Extract SidTea plus ™ and Its Effect on Physiological Profile, Metabolic Health and Redox Biomarkers in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study

This study aimed to characterize a Sideritis scardica extract (SidTea+(TM)) and investigate its effect on the physiological profile, metabolic health and redox status in healthy individuals. The chemical profile and antioxidant potential of the SidTea+(TM) extract were evaluated by UPLC-HRMS analysis and in vitro cell-free methods. Twenty-eight healthy adults participated in this randomized, double-blind, placebo-controlled study. Participants consumed 1500 mg/day of SidTea+(TM) or a placebo for 4 weeks. At baseline and post-supplementation, participants were assessed for their anthropometric and physiological profile and provided a resting blood sample. SidTea+(TM) decreased (p < 0.05) systolic blood pressure (-10.8 mmHg), mean arterial pressure (-4.5 mmHg), resting heart rate (-3.1 bpm) and handgrip strength of the non-dominant limb (-0.8 kg) whereas the placebo decreased (p < 0.05) handgrip strength of the dominant (-5.8 kg) and non-dominant (-3.2 kg) limb. SidTea+(TM) also resulted in an increase (p < 0.05) in estimated VO(2)max (+1.1 mL/kg/min) and a reduction (p < 0.05) in gamma-GT and SGPT enzymatic activity in serum (-3.7 and -3.3 U/L, respectively). Finally, SidTea+(TM) increased (p < 0.001) total antioxidant capacity and decreased (p < 0.05) lipid peroxidation levels in plasma. These results indicate that SidTea+(TM) is a potent and safe to use antioxidant that can elicit positive changes in indices of blood pressure, cardiorespiratory capacity, liver metabolism, and redox status in healthy adults over a 4-week supplementation period.