Noun
A bitter purgative principle in aloes.
Source: Webster's dictionaryBoth the translucent inner pulp and the resinous yellow aloin from wounding the aloe plant are used externally for skin discomforts. Source: Internet
Unprocessed aloe that contains aloin is generally used as a laxative, whereas processed juice does not usually contain significant aloin. citation Some species, particularly Aloe vera, are used in alternative medicine and first aid. Source: Internet