SharePoint website unexpected high load on the back-end content database

Yesterday at midnight we noticed high load on the content database of one of the SharePoint public websites, the following stored procedures were running between 10:30 PM to 1:30 AM.

The procedures are under the “WSS_Content_YXZ” database in millions of transactions.

proc_GetListMetaDataAndEventReceivers

proc_EnumLists

proc_GetTpWebMetaDataAndListMetaData

requests came from the web servers along with other high DB I/O statements.

Any idea if the mentioned stored procedures is used by any SharePoint services?