Grape leaves and kedushat shevi'it
Question
What is the status of grape leaves? They are sometimes cooked or pickled.
Answer
As you noted, grape leaves are edible and often cooked or pickled. They are actually quite nutritious and are rich in iron and zinc.
Grape leaves are traditionally used in many cuisines as wraps for rice and meat. They are steamed, cooked, and often pickled. Since they are edible for humans, the laws of kedushat shevi'it apply to them.
(However, some are lenient and think there is no KS in the leaves).
If prepared with rice or meat, the other foods will also have kedushat shevi'it. It is extremely important to check the leaves for infestation (against sunlight), since there are tunneling insects that often infest the leaves.
Note that the laws of orlah do not apply to grape leaves, so even if you have a grape vine that is in its orlah years, you may use the leaves (and, as mentioned above, they do have kedushat shevi'it).