Potentiating effects on pilocarpine-induced saliva secretion, by extracts and N-containing sugars derived from mulberry leaves, in streptozocin-diabetic mice.

The effects of hot water extracts and six compounds of N-containing sugars, 1-deoxynojirimycin (DNJ), N-methyl-DNJ (N-Me-DNJ), 2-O-alpha-D-galactopyranosyl-DNJ (GAL-DNJ), fagomine, 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), and 1,2 alpha,3 beta,4 alpha-tetrahydroxynortropane (calystegin B2), derived from mulberry leaves (Morus alba L.), were investigated on pilocarpine-induced saliva secretion in streptozocin (STZ)-induced diabetic mice. The extracts (100 and 200 mg/kg, i.p.) significantly potentiated the pilocarpine-induced salivary flow but not the protein content. The component compounds (37.5-300 mumol/kg) potentiated the saliva secretion, and the potency order was DAB > fagomine > GAL-DNJ. Only fagomine significantly increased the protein content in the saliva. The potentiation of pilocarpine-induced salivary flow was correlated with anti-hyperglycemic effects by the extract and GAL-DNJ from mulberry leaves in the same dose ranges.