is exerted through the stimulation of epithelial no generation see tamaoki et al zizyphi fructus a constituent of antiasthmatic herbal medicine stimulates airway epithelial ciliary motility through nitric oxide generation may june 22 3 255 66 exp lung res 1996 the present inventors have found that the combination of zizyphi fructus and ginseng or its purified derivative ginsenoside or rg1 as described above plus l arginine work synergistically to stimulate the release of no in the corpus cavernosum to promote smooth muscle relaxation each of the three constituents has an individual tendency to enhance the release of no in the corpus cavernosum during sexual stimulation the inventors have found that the synergy stems from a catalyst effect as illustrated in the flow diagram of fig2 the zizyphi fructus and ginseng speed up the conversion of l arginine to no thus the combination of zizyphi fructus ginseng or its purified derivative ginsenoside or rg1 as described above plus l arginine when administered in proper concentration stimulate sufficient release of no in the corpus cavernosum to allow the inflow of blood and alleviate erectile dysfunction while any of the three constituents taken alone would be insufficient to produce the desired result in combination they work synergistically to produce significant no as seen in the flow diagram of fig2 the additional no is converted by guanylate cyclase resulting in increased levels of cyclic guanosine monophosphate cgmp in the corpus cavernosum the cgmp in turn produces smooth muscle relaxation and improves arterial blood flow which results in an improved trapping of blood in the corpus cavernosum the same mechanism should improve female sexual conditions as well see park et al supra it should be understood that the proper relative concentrations of the three constituents may vary depending on the physical characteristics of each person.