Effect of differently processed coffee on the gastric potential difference and intragastric pH in healthy volunteers.
Ehrlich A. Basse H. Henkel-Ernst J. Hey B. Menthe J. Lucker PW.
Medical Department Phase I, Institut fur Klinische Pharmakologie Bobenheim, Grunstadt, Germany.
The gastric irritation potential of orally administered coffee (150 ml) was investigated in four healthy volunteers by continuous measurement of gastric potential difference (GPD) and intragastric pH. Furthermore, serum gastrin concentrations were measured up to 45 min after administration of the coffee. One of the coffees, untreated, had to be compared with a pretreated coffee. The evaluation of the target parameters Reiz-Index, AUB, Pdmax and ttot revealed a significant difference between untreated coffee and specially treated coffee: the improved coffee processing produced significantly less mucosal irritation. Regarding the intragastric pH, no significant differences between the treatments were observed and no stimulation of gastric acid secretion following coffee was measurable. No consistent effect on serum gastrin concentration was seen: two of the four subjects had a steep increase in serum gastrin following administration with a clear difference between the differently processed coffees, whereas the other two subjects showed no change in serum gastrin. The results of this pilot study confirm the findings of former experiments on the reliability of continuous transmural GPD measurement when investigating the mucosal irritation potential of barrier breakers.
The antistress effect of majonoside-R2, a major saponin component of Vietnamese ginseng: neuronal mechanisms of action.
Huong NT. Matsumoto K. Watanabe H.
Department of Pharmacology, Research Institute for Wakan-Yaku (Oriental Medicines), Toyama Medical and Pharmaceutical University, Japan.
Majonoside-R2 (MR2), an ocotillol-type saponin, is a dominant saponin component of Vietnamese ginseng. We have investigated the effect of MR2 on behavioral and pathophysiological changes caused by psychological stress such as the communication box paradigm-induced psychological stress (CBP stress), conditioned fear stress and social isolation stress in laboratory animals, and elucidated the possible neuronal mechanisms underlying the action of this compound. MR2 attenuated CBP stress- and conditioned fear stress-induced antinociception, had a protective effect against CBP stress-induced gastric lesions, and restored the hypnotic activity of pentobarbital decreased by CBP stress or social isolation stress to the level of the unstressed controls. Accumulating evidence strongly suggests the involvement of the central opioid, GABAA receptor and corticotropin-releasing factor mechanisms in the effect of MR2. Here we review the antistress effect of Vietnamese ginseng, especially focusing on the effect of MR2 on psychosomatic disorders caused by psychological stress.