The Herb is the only healing item found in Resident Evil: The Darkside Chronicles.
— Inventory description
The herb can be used on the AI partner if needed by pausing the game and going into the "status" menu, there it will also show how many herbs are available. Additionally, the amount of health recovered is based on the current difficulty, with the herb only healing a small chunk of health on Very Hard difficulty.
There is a title in the game related to using 50 herbs called "Vegetarian".