Rosemary Tea Consumption Alters Peripheral Anxiety and Depression Biomarkers: A Pilot Study in Limited Healthy Volunteers

Abstract

Background: Rosmarinus officinalis L.is traditionally used as an infusion in the treatment of several diseases and in particular against neuropsychiatric disorders, such as anxiety and depression. It was established that rosemary extracts show an antidepressant effect on animal models. However, to the best of our knowledge, there is no scientific data that highlights the therapeutic effects of rosemary intake on human mental health.

Aim: This study investigated whether rosemary tea consumption affects the plasma levels of anxiety and depression biomarkers in healthy volunteers.

Methods: Twenty-two healthy volunteers aged between 20 and 50 years old consumed rosemary tea prepared from 5 g of dried rosemary in 100 mL boiled water once a day for 10 days. Plasma concentrations of Brain-Derived Neurotrophic Factor (BDNF), Interleukine-6 (IL-6), Interleukine-4 (IL-4), Tumor Necrosis Factor- alpha (TNF-α), Interferon-gamma (IFNϒ), and cortisol were measured by enzyme-linked immunosorbent assay using commercial ELISA kits (R&D systems) before rosemary consumption and at the end of the experiment.

Results: Rosemary tea consumption significantly increased the concentration of BDNF([BDNF]D0 = 22363.86 ± 12987.66 pg/mL, [BDNF]D10 = 41803.64 ± 28109.19, p = 0.006) and TNF-α([TNF-α] D0 = 39.49 ± 14.44 pg/mL, [TNF-α] D10 = 56.24 ± 39.01, p = 0.016). However, a slight variation that was statistically non-significant in INFϒ, cortisol, IL-4, IL-6 levels and in the ratio IL-4/INFϒ was observed (p > 0.05).

Conclusion: Our findings highlight the promising anxiolytic and/or antidepressant effects of rosemary tea consumption in healthy volunteers since it increases the level of the most reliable depression biomarker BDNF. However, more powerful studies with larger sample size, carefully-chosen target population and, an extended intervention period are required.

Keywords:

• Rosemary tea
• BDNF
• anxiety
• depression
• cytokine
• cortisol

Acknowledgments

The authors acknowledge financial support from the Tunisian Ministry of Higher Education and Scientific Research, and from both the Japanese International Cooperation Agency (JICA) and Japan Science and Technology agency (JST) (Project: Science and Technology Research Partnership for Sustainable Development: SATREPS II).

Disclosure statement

The authors state no conflicts of interest.

Contribution of authors

Conceptualization, M.A. and S.S.; Methodology, M.A., S.S., M.N. and M.B.F; Investigation, M.A., I.B.S.; Writing – Original Draft, M.A; Writing – Review & Editing, M.A., F.F., S.S., H.I. and A.M.; Visualization: M.A. and F.F.; Resources, S.S. and H.I; Supervision, S.S; Project Administration, S.S.; Funding Acquisition, S.S. and H.I.