**4. Conclusions**

Until recently, Ech A was rarely used for the treatment of brain ischemic stroke. Our findings indicate that Ech A as a novel therapeutic source from the ocean has considerable efficacy for cerebral ischemic injury. We demonstrate that Ech A restores the damaged brain area and strengthens the behavioral deterioration by supporting the expression of cell viability-related factors after brain ischemic stroke. Taken together, the results of this study propose a new application as a potential therapeutic agent for this marine drug.

**Author Contributions:** R.K. and D.H. conducted the experiments, tests, and data analyses. N.P.M. and S.A.F. provided echinochrome A. H.K.K., J.H., V.A.S., and W.C. summarized the work and wrote the manuscript.

**Funding:** This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Korea government (MSIT) (2018R1A2B6003158) and the Bio and Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science and ICT (NRF-2017M3A9G7072568), and the Ministry of Science and Higher Education of the Russian Federation (RFMEFI61317X0076).

**Acknowledgments:** This study was supported by a grant from the National Research Foundation of Korea (NRF). The study was carried out using the equipment of the Collective Facilities Center (The Far Eastern Center for Structural Molecular Research (NMR/MS) PIBOC FEB RAS).

**Conflicts of Interest:** The authors declare no conflict of interest.
