求翻译：自下而上的模式是首先从药材或整体复方分离到有效组分或单体成分，再反过来通过研究有效组分或单体成分的组合回复到一个有效的复方。是什么意思？

Bottom up model was first isolated from medicinal herbs or compound as a whole to active components or individual components, then, in turn, through the study of active components or individual components combined back into one effective compound.