It is known as Spanish Needle. The butanol fraction of B. pilosa inhibits the differentiation of naive helper T (ThO) cells into Thl cells but enhances their transition into type II helper T (Th2) cells, thus can prevent diabetes pausibly via suppressing the differentiation of ThO cells into Thl cells and promoting that of ThO cells into Th2 cells, thus preventing autoimmune diabetes in non-obese diabetic mice.