The authors of this manuscript verify that:

• the work is original and that they accept the responsibility of the integrity of the presented work.
• the manuscript has not been and will not be submitted to any other journal.
• the manuscript or any of its part has not been previously published.
• the manuscript or any of its part will not be published in any other journal if accepted for publication in "Frontiers in Bioscience"
• all the authors have read, edited and agree with the contents of the manuscript.
• the consents of the persons who have been acknowledged were obtained.
• the clinical investigations have been performed in accordance with the guidelines proposed in the Declaration of Helsinki and that the appropriate approval for the conduct of the experiments has been obtained from internal review board of their university or organization.
• the animal experiments were conducted in accord with the highest standards of humane animal care and that the appropriate approval for the conduct of the experiments has been obtained from their organization or the university committee dealing with this issue.
• The consent of the publishers for the use of any previously published material or images have been obtained.