Other than spelling "aeiou up", there are no anagrams.
The smaller words that can be made are :
a, ape, pa, pi, pea, pie, poi, and up.
Those letters spell natural.
The letters in "these letters" can spell the phrase "ether settles." The letters can spell shorter words such as trestles, sheerest, shelters, and treeless.
Those letters will spell dollar.
The letters spell 'broccoli'.
Those letters spell delicate.
Those letters spell psycho.
Those letters will spell carnivore.
Those letters will spell artichoke.
The letters can spell the anagram "annotation."
Those letters will spell turnip.
Those letters will spell democratic.
The letters spell weary.