Wild Betel leaf is very popular in Vietnam, Thailand and Asia. In Vietnamese cousin, we use this leaf to make the delicious dish: Grilled Beef wrapping by this leaf. 
We also can cook this leaf with pork and green banana fruits, turmeric and shrimp paste, this is a traditional food provided a lot of nutritions and vitamins. 
People use betel leaf as herbs too. You can search AI , Google or read on  this site : 
https://pmc.ncbi.nlm.nih.gov/articles/PMC3892533/