**5. Conclusions**

In conclusion, RDE enhances cell activity by directly scavenging ROS and strengthening the cellular antioxidant system, as well as by repairing tight junction proteins and inducing their expression.

**Author Contributions:** Conceptualization, C.Y. and R.Y.; Data analysis, R.Y., S.L., Q.H., H.Z. and Q.J.; Financial funding, C.Y.; Methodology, F.L., S.L., J.W. and R.Y.; Supervision, C.Y. and K.O; Writing, R.Y., C.Y. and K.O.

**Funding:** This project was funded by the Natural Sciences and Engineering Research Council (NSERC) Engage gran<sup>t</sup> (C. Yang, EGP 523472-2018) and the University of Manitoba Start-Up Grant (C. Yang, 46561). Runqiang Yang was a Visiting Scholar at the Department of Animal Science in the University of Manitoba and supported by the Chinese Scholarship Council (CSC).

**Acknowledgments:** The authors are grateful to Red Dog Enterprises Ltd. for providing red-osier dogwood extracts.

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