  Knowledge graphs (KGs) are gaining prominence in Healthcare AI, especially in
drug discovery and pharmaceutical research as they provide a structured way to
integrate diverse information sources, enhancing AI system interpretability.
This interpretability is crucial in healthcare, where trust and transparency
matter, and eXplainable AI (XAI) supports decision making for healthcare
professionals. This overview summarizes recent literature on the impact of KGs
in healthcare and their role in developing explainable AI models. We cover KG
workflow, including construction, relationship extraction, reasoning, and their
applications in areas like Drug-Drug Interactions (DDI), Drug Target
Interactions (DTI), Drug Development (DD), Adverse Drug Reactions (ADR), and
bioinformatics. We emphasize the importance of making KGs more interpretable
through knowledge-infused learning in healthcare. Finally, we highlight
research challenges and provide insights for future directions.
