Evaluation of systemic effects of ginger fractions on salivation in rats

Various herbal drugs and treatment modalities claim to stimulate salivary flow. Since the effect of ginger on increasing salivation and cholinergic activity has been shown in previous studies, we decided to evaluate the systemic effects of ginger extracts on salivation. The extracts of ginger fractions (Petroleum ether, Diethyl ether, Dichloromethane, Chloroform, Ethyl acetate, Methanol, Watery) and Total methanolic extract of ginger were prepared. In this experimental investigation ten groups of rats for seven types of ginger fractions, total ginger extract and negative and positive control groups were studied (n=7 for each group). Saliva volumes were measured gravimetrically after intraperitoneal (I.p.)injection of extracts during four continuous seven minute intervals. Systemic injection of ginger extract and each of the seven fractions did not result in an increase in saliva secretion. After injection of six extracts (Petroleum ether, Dichloromethane, Chloroform, Ethylacetate, Methanol, Watery) a significant decrease in the saliva secretion occurred (P<0.05). A decrease in salivation may be explained by dual activity of ginger (cholinergic and calcium antagonist). Use of different doses of ginger extracts (especially aqueous extract) or other preparations of ginger may be helpful for future studies on the effects of ginger on salivation.