Holly is not really a home remedy tree, but could be useful under the direction of a qualified herbalist. Never consume the berries for any reason though!

As with all natural remedies consumption of Willow
should be guided by a qualified herbalist or physician.
This information here is for information purposes only,
and certainly not for prescription.

best use ...  

though Holly leaf home remedies are published it is not wise to try them, but a skilled herbalist could guide you with its use for relieving digestive, heart and lung congestion ... but never attempt to consume the berries.

qualities of Holly are said to be ...

astringent - reduces fluid loss, constricts tissues, such as stop bleeding
diuretic - increases urination, useful when clearing toxins
expectorant - mucous breakdown and flow
febrifuge - lowers body temperature

toxicity? ...  as all plants have a nourishing level and toxic level

Berries should not be used in any preparations as they can be upsetting to adults and dangerous for children. For a lot of people the seeds in the berries are quite toxic and could even be fatal.

Leaves, twigs, bark and root should be consumed very carefully with guidance by a qualified herbalist

to read about the crafting potential of Holly, please click here